NASA Astrophysics Data System (ADS)
Zhao, Yijia; Zhang, Yichen; Xu, Bingjie; Yu, Song; Guo, Hong
2018-04-01
The method of improving the performance of continuous-variable quantum key distribution protocols by postselection has been recently proposed and verified. In continuous-variable measurement-device-independent quantum key distribution (CV-MDI QKD) protocols, the measurement results are obtained from untrusted third party Charlie. There is still not an effective method of improving CV-MDI QKD by the postselection with untrusted measurement. We propose a method to improve the performance of coherent-state CV-MDI QKD protocol by virtual photon subtraction via non-Gaussian postselection. The non-Gaussian postselection of transmitted data is equivalent to an ideal photon subtraction on the two-mode squeezed vacuum state, which is favorable to enhance the performance of CV-MDI QKD. In CV-MDI QKD protocol with non-Gaussian postselection, two users select their own data independently. We demonstrate that the optimal performance of the renovated CV-MDI QKD protocol is obtained with the transmitted data only selected by Alice. By setting appropriate parameters of the virtual photon subtraction, the secret key rate and tolerable excess noise are both improved at long transmission distance. The method provides an effective optimization scheme for the application of CV-MDI QKD protocols.
Secure quantum key distribution using continuous variables of single photons.
Zhang, Lijian; Silberhorn, Christine; Walmsley, Ian A
2008-03-21
We analyze the distribution of secure keys using quantum cryptography based on the continuous variable degree of freedom of entangled photon pairs. We derive the information capacity of a scheme based on the spatial entanglement of photons from a realistic source, and show that the standard measures of security known for quadrature-based continuous variable quantum cryptography (CV-QKD) are inadequate. A specific simple eavesdropping attack is analyzed to illuminate how secret information may be distilled well beyond the bounds of the usual CV-QKD measures.
NASA Astrophysics Data System (ADS)
Opanchuk, B.; Arnaud, L.; Reid, M. D.
2014-06-01
We demonstrate the principle of one-sided device-independent continuous-variable (CV) quantum information. In situations of no trust, we show by enactment how the use of standard CV entanglement criteria can mislead Charlie into thinking that Alice and Bob share entanglement, when the data are actually generated classically using a local-hidden-variable theory based on the Wigner function. We distinguish between criteria that demonstrate CV entanglement, and criteria that demonstrate the CV Einstein-Podolsky-Rosen (EPR) steering paradox. We show that the latter, but not the former, are necessarily one-sided device-independent entanglement witnesses, and can be used by Charlie to signify genuine EPR entanglement, if he trusts only Alice. A monogamy result for the EPR steering paradox confirms the security of the shared amplitude values in that case.
Continuous-variable measurement-device-independent quantum key distribution with photon subtraction
NASA Astrophysics Data System (ADS)
Ma, Hong-Xin; Huang, Peng; Bai, Dong-Yun; Wang, Shi-Yu; Bao, Wan-Su; Zeng, Gui-Hua
2018-04-01
It has been found that non-Gaussian operations can be applied to increase and distill entanglement between Gaussian entangled states. We show the successful use of the non-Gaussian operation, in particular, photon subtraction operation, on the continuous-variable measurement-device-independent quantum key distribution (CV-MDI-QKD) protocol. The proposed method can be implemented based on existing technologies. Security analysis shows that the photon subtraction operation can remarkably increase the maximal transmission distance of the CV-MDI-QKD protocol, which precisely make up for the shortcoming of the original CV-MDI-QKD protocol, and one-photon subtraction operation has the best performance. Moreover, the proposed protocol provides a feasible method for the experimental implementation of the CV-MDI-QKD protocol.
High performance reconciliation for continuous-variable quantum key distribution with LDPC code
NASA Astrophysics Data System (ADS)
Lin, Dakai; Huang, Duan; Huang, Peng; Peng, Jinye; Zeng, Guihua
2015-03-01
Reconciliation is a significant procedure in a continuous-variable quantum key distribution (CV-QKD) system. It is employed to extract secure secret key from the resulted string through quantum channel between two users. However, the efficiency and the speed of previous reconciliation algorithms are low. These problems limit the secure communication distance and the secure key rate of CV-QKD systems. In this paper, we proposed a high-speed reconciliation algorithm through employing a well-structured decoding scheme based on low density parity-check (LDPC) code. The complexity of the proposed algorithm is reduced obviously. By using a graphics processing unit (GPU) device, our method may reach a reconciliation speed of 25 Mb/s for a CV-QKD system, which is currently the highest level and paves the way to high-speed CV-QKD.
Field demonstration of a continuous-variable quantum key distribution network.
Huang, Duan; Huang, Peng; Li, Huasheng; Wang, Tao; Zhou, Yingming; Zeng, Guihua
2016-08-01
We report on what we believe is the first field implementation of a continuous-variable quantum key distribution (CV-QKD) network with point-to-point configuration. Four QKD nodes are deployed on standard communication infrastructures connected with commercial telecom optical fiber. Reliable key exchange is achieved in the wavelength-division-multiplexing CV-QKD network. The impact of a complex and volatile field environment on the excess noise is investigated, since excess noise controlling and reduction is arguably the major issue pertaining to distance and the secure key rate. We confirm the applicability and verify the maturity of the CV-QKD network in a metropolitan area, thus paving the way for a next-generation global secure communication network.
Anonymous voting for multi-dimensional CV quantum system
NASA Astrophysics Data System (ADS)
Rong-Hua, Shi; Yi, Xiao; Jin-Jing, Shi; Ying, Guo; Moon-Ho, Lee
2016-06-01
We investigate the design of anonymous voting protocols, CV-based binary-valued ballot and CV-based multi-valued ballot with continuous variables (CV) in a multi-dimensional quantum cryptosystem to ensure the security of voting procedure and data privacy. The quantum entangled states are employed in the continuous variable quantum system to carry the voting information and assist information transmission, which takes the advantage of the GHZ-like states in terms of improving the utilization of quantum states by decreasing the number of required quantum states. It provides a potential approach to achieve the efficient quantum anonymous voting with high transmission security, especially in large-scale votes. Project supported by the National Natural Science Foundation of China (Grant Nos. 61272495, 61379153, and 61401519), the Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20130162110012), and the MEST-NRF of Korea (Grant No. 2012-002521).
Finite-size analysis of continuous-variable measurement-device-independent quantum key distribution
NASA Astrophysics Data System (ADS)
Zhang, Xueying; Zhang, Yichen; Zhao, Yijia; Wang, Xiangyu; Yu, Song; Guo, Hong
2017-10-01
We study the impact of the finite-size effect on the continuous-variable measurement-device-independent quantum key distribution (CV-MDI QKD) protocol, mainly considering the finite-size effect on the parameter estimation procedure. The central-limit theorem and maximum likelihood estimation theorem are used to estimate the parameters. We also analyze the relationship between the number of exchanged signals and the optimal modulation variance in the protocol. It is proved that when Charlie's position is close to Bob, the CV-MDI QKD protocol has the farthest transmission distance in the finite-size scenario. Finally, we discuss the impact of finite-size effects related to the practical detection in the CV-MDI QKD protocol. The overall results indicate that the finite-size effect has a great influence on the secret-key rate of the CV-MDI QKD protocol and should not be ignored.
Teleportation-based continuous variable quantum cryptography
NASA Astrophysics Data System (ADS)
Luiz, F. S.; Rigolin, Gustavo
2017-03-01
We present a continuous variable (CV) quantum key distribution (QKD) scheme based on the CV quantum teleportation of coherent states that yields a raw secret key made up of discrete variables for both Alice and Bob. This protocol preserves the efficient detection schemes of current CV technology (no single-photon detection techniques) and, at the same time, has efficient error correction and privacy amplification schemes due to the binary modulation of the key. We show that for a certain type of incoherent attack, it is secure for almost any value of the transmittance of the optical line used by Alice to share entangled two-mode squeezed states with Bob (no 3 dB or 50% loss limitation characteristic of beam splitting attacks). The present CVQKD protocol works deterministically (no postselection needed) with efficient direct reconciliation techniques (no reverse reconciliation) in order to generate a secure key and beyond the 50% loss case at the incoherent attack level.
Unconditional optimality of Gaussian attacks against continuous-variable quantum key distribution.
García-Patrón, Raúl; Cerf, Nicolas J
2006-11-10
A fully general approach to the security analysis of continuous-variable quantum key distribution (CV-QKD) is presented. Provided that the quantum channel is estimated via the covariance matrix of the quadratures, Gaussian attacks are shown to be optimal against all collective eavesdropping strategies. The proof is made strikingly simple by combining a physical model of measurement, an entanglement-based description of CV-QKD, and a recent powerful result on the extremality of Gaussian states [M. M. Wolf, Phys. Rev. Lett. 96, 080502 (2006)10.1103/PhysRevLett.96.080502].
NASA Astrophysics Data System (ADS)
Qi, Bing; Lougovski, Pavel; Pooser, Raphael; Grice, Warren; Bobrek, Miljko
2015-10-01
Continuous-variable quantum key distribution (CV-QKD) protocols based on coherent detection have been studied extensively in both theory and experiment. In all the existing implementations of CV-QKD, both the quantum signal and the local oscillator (LO) are generated from the same laser and propagate through the insecure quantum channel. This arrangement may open security loopholes and limit the potential applications of CV-QKD. In this paper, we propose and demonstrate a pilot-aided feedforward data recovery scheme that enables reliable coherent detection using a "locally" generated LO. Using two independent commercial laser sources and a spool of 25-km optical fiber, we construct a coherent communication system. The variance of the phase noise introduced by the proposed scheme is measured to be 0.04 (rad2 ), which is small enough to enable secure key distribution. This technology also opens the door for other quantum communication protocols, such as the recently proposed measurement-device-independent CV-QKD, where independent light sources are employed by different users.
Terada, Tasuku; Loehr, Sarah; Guigard, Emmanuel; McCargar, Linda J; Bell, Gordon J; Senior, Peter; Boulé, Normand G
2014-08-01
This study determined the test-retest reliability of a continuous glucose monitoring system (CGMS) (iPro™2; Medtronic, Northridge, CA) under standardized conditions in individuals with type 2 diabetes (T2D). Fourteen individuals with T2D spent two nonconsecutive days in a calorimetry unit. On both days, meals, medication, and exercise were standardized. Glucose concentrations were measured continuously by CGMS, from which daily mean glucose concentration (GLU(mean)), time spent in hyperglycemia (t(>10.0 mmol/L)), and meal, exercise, and nocturnal mean glucose concentrations, as well as glycemic variability (SD(w), percentage coefficient of variation [%cv(w)], mean amplitude of glycemic excursions [MAGEc, MAGE(ave), and MAGE(abs.gos)], and continuous overlapping net glycemic action [CONGA(n)]) were estimated. Absolute and relative reliabilities were investigated using coefficient of variation (CV) and intraclass correlation, respectively. Relative reliability ranged from 0.77 to 0.95 (P<0.05) for GLU(mean) and meal, exercise, and nocturnal glycemia with CV ranging from 3.9% to 11.7%. Despite significant relative reliability (R=0.93; P<0.01), t(>10.0 mmol/L) showed larger CV (54.7%). Among the different glycemic variability measures, a significant between-day difference was observed in MAGEc, MAGE(ave), CONGA6, and CONGA12. The remaining measures (i.e., SD(w), %cv(w), MAGE(abs.gos), and CONGA1-4) indicated no between-day differences and significant relative reliability. In individuals with T2D, CGMS-estimated glycemic profiles were characterized by high relative and absolute reliability for both daily and shorter-term measurements as represented by GLUmean and meal, exercise, and nocturnal glycemia. Among the different methods to calculate glycemic variability, our results showed SD(w), %cv(w), MAGE(abs.gos), and CONGAn with n ≤ 4 were reliable measures. These results suggest the usefulness of CGMS in clinical trials utilizing repeated measured.
High-speed continuous-variable quantum key distribution without sending a local oscillator.
Huang, Duan; Huang, Peng; Lin, Dakai; Wang, Chao; Zeng, Guihua
2015-08-15
We report a 100-MHz continuous-variable quantum key distribution (CV-QKD) experiment over a 25-km fiber channel without sending a local oscillator (LO). We use a "locally" generated LO and implement with a 1-GHz shot-noise-limited homodyne detector to achieve high-speed quantum measurement, and we propose a secure phase compensation scheme to maintain a low level of excess noise. These make high-bit-rate CV-QKD significantly simpler for larger transmission distances compared with previous schemes in which both LO and quantum signals are transmitted through the insecure quantum channel.
NASA Astrophysics Data System (ADS)
Guo, Ying; Zhao, Wei; Li, Fei; Huang, Duan; Liao, Qin; Xie, Cai-Lang
2017-08-01
The developing tendency of continuous-variable (CV) measurement-device-independent (MDI) quantum cryptography is to cope with the practical issue of implementing scalable quantum networks. Up to now, most theoretical and experimental researches on CV-MDI QKD are focused on two-party protocols. However, we suggest a CV-MDI multipartite quantum secret sharing (QSS) protocol use the EPR states coupled with optical amplifiers. More remarkable, QSS is the real application in multipartite CV-MDI QKD, in other words, is the concrete implementation method of multipartite CV-MDI QKD. It can implement a practical quantum network scheme, under which the legal participants create the secret correlations by using EPR states connecting to an untrusted relay via insecure links and applying the multi-entangled Greenberger-Horne-Zeilinger (GHZ) state analysis at relay station. Even if there is a possibility that the relay may be completely tampered, the legal participants are still able to extract a secret key from network communication. The numerical simulation indicates that the quantum network communication can be achieved in an asymmetric scenario, fulfilling the demands of a practical quantum network. Additionally, we illustrate that the use of optical amplifiers can compensate the partial inherent imperfections of detectors and increase the transmission distance of the CV-MDI quantum system.
NASA Astrophysics Data System (ADS)
Xie, Cailang; Guo, Ying; Liao, Qin; Zhao, Wei; Huang, Duan; Zhang, Ling; Zeng, Guihua
2018-03-01
How to narrow the gap of security between theory and practice has been a notoriously urgent problem in quantum cryptography. Here, we analyze and provide experimental evidence of the clock jitter effect on the practical continuous-variable quantum key distribution (CV-QKD) system. The clock jitter is a random noise which exists permanently in the clock synchronization in the practical CV-QKD system, it may compromise the system security because of its impact on data sampling and parameters estimation. In particular, the practical security of CV-QKD with different clock jitter against collective attack is analyzed theoretically based on different repetition frequencies, the numerical simulations indicate that the clock jitter has more impact on a high-speed scenario. Furthermore, a simplified experiment is designed to investigate the influence of the clock jitter.
RF-subcarrier-assisted four-state continuous-variable QKD based on coherent detection.
Qu, Zhen; Djordjevic, Ivan B; Neifeld, Mark A
2016-12-01
We theoretically investigate and experimentally demonstrate a RF-assisted four-state continuous-variable quantum key distribution (CV-QKD) system. Classical coherent detection is implemented with a simple digital phase noise cancelation scheme. In the proposed system, there is no need for frequency and phase locking between the quantum signals and the local oscillator laser. Moreover, in principle, there is no residual phase noise, and a mean excess noise of 0.0115 (in shot-noise units) can be acquired experimentally. In addition, the minimum transmittance of 0.45 is reached experimentally for secure transmission with commercial photodetectors, and the maximum secret key rate (SKR) of >12 Mbit/s can be obtained. The proposed RF-assisted CV-QKD system opens the door of incorporating microwave photonics into a CV-QKD system and improving the SKR significantly.
Channel-parameter estimation for satellite-to-submarine continuous-variable quantum key distribution
NASA Astrophysics Data System (ADS)
Guo, Ying; Xie, Cailang; Huang, Peng; Li, Jiawei; Zhang, Ling; Huang, Duan; Zeng, Guihua
2018-05-01
This paper deals with a channel-parameter estimation for continuous-variable quantum key distribution (CV-QKD) over a satellite-to-submarine link. In particular, we focus on the channel transmittances and the excess noise which are affected by atmospheric turbulence, surface roughness, zenith angle of the satellite, wind speed, submarine depth, etc. The estimation method is based on proposed algorithms and is applied to low-Earth orbits using the Monte Carlo approach. For light at 550 nm with a repetition frequency of 1 MHz, the effects of the estimated parameters on the performance of the CV-QKD system are assessed by a simulation by comparing the secret key bit rate in the daytime and at night. Our results show the feasibility of satellite-to-submarine CV-QKD, providing an unconditionally secure approach to achieve global networks for underwater communications.
Continuous operation of four-state continuous-variable quantum key distribution system
NASA Astrophysics Data System (ADS)
Matsubara, Takuto; Ono, Motoharu; Oguri, Yusuke; Ichikawa, Tsubasa; Hirano, Takuya; Kasai, Kenta; Matsumoto, Ryutaroh; Tsurumaru, Toyohiro
2016-10-01
We report on the development of continuous-variable quantum key distribution (CV-QKD) system that are based on discrete quadrature amplitude modulation (QAM) and homodyne detection of coherent states of light. We use a pulsed light source whose wavelength is 1550 nm and repetition rate is 10 MHz. The CV-QKD system can continuously generate secret key which is secure against entangling cloner attack. Key generation rate is 50 kbps when the quantum channel is a 10 km optical fiber. The CV-QKD system we have developed utilizes the four-state and post-selection protocol [T. Hirano, et al., Phys. Rev. A 68, 042331 (2003).]; Alice randomly sends one of four states {|+/-α⟩,|+/-𝑖α⟩}, and Bob randomly performs x- or p- measurement by homodyne detection. A commercially available balanced receiver is used to realize shot-noise-limited pulsed homodyne detection. GPU cards are used to accelerate the software-based post-processing. We use a non-binary LDPC code for error correction (reverse reconciliation) and the Toeplitz matrix multiplication for privacy amplification.
Implementation of bright six-partite entanglement by coupled intracavity sum frequency generation
NASA Astrophysics Data System (ADS)
Wang, Junfeng; Liu, Le; Liu, Yuzhu; Zhang, Yanan; Wu, Hongyan; Gong, Chengxuan; Zhang, Ruofan; Zhang, Houyuan; Fan, JingYu
2018-04-01
Bright six-partite continuous-variable (CV) entanglement generated by the coupled intracavity sum frequency generation is investigated. The entanglement characteristics of reflected pump fields and the output sum frequency fields are discussed theoretically in symmetric and asymmetric cases by applying van Loock and Furusawa criteria for multipartite CV entanglement. Such compact tunable multipartite CV entanglement, generated from an experimentally feasible coupled system, could be used in integrated quantum communication and networks.
NASA Astrophysics Data System (ADS)
Zhang, Hang; Mao, Yu; Huang, Duan; Li, Jiawei; Zhang, Ling; Guo, Ying
2018-05-01
We introduce a reliable scheme for continuous-variable quantum key distribution (CV-QKD) by using orthogonal frequency division multiplexing (OFDM). As a spectrally efficient multiplexing technique, OFDM allows a large number of closely spaced orthogonal subcarrier signals used to carry data on several parallel data streams or channels. We place emphasis on modulator impairments which would inevitably arise in the OFDM system and analyze how these impairments affect the OFDM-based CV-QKD system. Moreover, we also evaluate the security in the asymptotic limit and the Pirandola-Laurenza-Ottaviani-Banchi upper bound. Results indicate that although the emergence of imperfect modulation would bring about a slight decrease in the secret key bit rate of each subcarrier, the multiplexing technique combined with CV-QKD results in a desirable improvement on the total secret key bit rate which can raise the numerical value about an order of magnitude.
Self-referenced continuous-variable measurement-device-independent quantum key distribution
NASA Astrophysics Data System (ADS)
Wang, Yijun; Wang, Xudong; Li, Jiawei; Huang, Duan; Zhang, Ling; Guo, Ying
2018-05-01
We propose a scheme to remove the demand of transmitting a high-brightness local oscillator (LO) in continuous-variable measurement-device-independent quantum key distribution (CV-MDI QKD) protocol, which we call as the self-referenced (SR) CV-MDI QKD. We show that our scheme is immune to the side-channel attacks, such as the calibration attacks, the wavelength attacks and the LO fluctuation attacks, which are all exploiting the security loopholes introduced by transmitting the LO. Besides, the proposed scheme waives the necessity of complex multiplexer and demultiplexer, which can greatly simplify the QKD processes and improve the transmission efficiency. The numerical simulations under collective attacks show that all the improvements brought about by our scheme are only at the expense of slight transmission distance shortening. This scheme shows an available method to mend the security loopholes incurred by transmitting LO in CV-MDI QKD.
NASA Astrophysics Data System (ADS)
Lupo, Cosmo; Ottaviani, Carlo; Papanastasiou, Panagiotis; Pirandola, Stefano
2018-05-01
We present a rigorous security analysis of continuous-variable measurement-device-independent quantum key distribution (CV MDI QKD) in a finite-size scenario. The security proof is obtained in two steps: by first assessing the security against collective Gaussian attacks, and then extending to the most general class of coherent attacks via the Gaussian de Finetti reduction. Our result combines recent state-of-the-art security proofs for CV QKD with findings about min-entropy calculus and parameter estimation. In doing so, we improve the finite-size estimate of the secret key rate. Our conclusions confirm that CV MDI protocols allow for high rates on the metropolitan scale, and may achieve a nonzero secret key rate against the most general class of coherent attacks after 107-109 quantum signal transmissions, depending on loss and noise, and on the required level of security.
Experimental study on all-fiber-based unidimensional continuous-variable quantum key distribution
NASA Astrophysics Data System (ADS)
Wang, Xuyang; Liu, Wenyuan; Wang, Pu; Li, Yongmin
2017-06-01
We experimentally demonstrated an all-fiber-based unidimensional continuous-variable quantum key distribution (CV QKD) protocol and analyzed its security under collective attack in realistic conditions. A pulsed balanced homodyne detector, which could not be accessed by eavesdroppers, with phase-insensitive efficiency and electronic noise, was considered. Furthermore, a modulation method and an improved relative phase-locking technique with one amplitude modulator and one phase modulator were designed. The relative phase could be locked precisely with a standard deviation of 0.5° and a mean of almost zero. Secret key bit rates of 5.4 kbps and 700 bps were achieved for transmission fiber lengths of 30 and 50 km, respectively. The protocol, which simplified the CV QKD system and reduced the cost, displayed a performance comparable to that of a symmetrical counterpart under realistic conditions. It is expected that the developed protocol can facilitate the practical application of the CV QKD.
Qi, Bing; Lougovski, Pavel; Pooser, Raphael C.; ...
2015-10-21
Continuous-variable quantum key distribution (CV-QKD) protocols based on coherent detection have been studied extensively in both theory and experiment. In all the existing implementations of CV-QKD, both the quantum signal and the local oscillator (LO) are generated from the same laser and propagate through the insecure quantum channel. This arrangement may open security loopholes and limit the potential applications of CV-QKD. In our paper, we propose and demonstrate a pilot-aided feedforward data recovery scheme that enables reliable coherent detection using a “locally” generated LO. Using two independent commercial laser sources and a spool of 25-km optical fiber, we construct amore » coherent communication system. The variance of the phase noise introduced by the proposed scheme is measured to be 0.04 (rad 2), which is small enough to enable secure key distribution. This technology opens the door for other quantum communication protocols, such as the recently proposed measurement-device-independent CV-QKD, where independent light sources are employed by different users.« less
Optical hybrid quantum teleportation and its applications
NASA Astrophysics Data System (ADS)
Takeda, Shuntaro; Okada, Masanori; Furusawa, Akira
2017-08-01
Quantum teleportation, a transfer protocol of quantum states, is the essence of many sophisticated quantum information protocols. There have been two complementary approaches to optical quantum teleportation: discrete variables (DVs) and continuous variables (CVs). However, both approaches have pros and cons. Here we take a "hybrid" approach to overcome the current limitations: CV quantum teleportation of DVs. This approach enabled the first realization of deterministic quantum teleportation of photonic qubits without post-selection. We also applied the hybrid scheme to several experiments, including entanglement swapping between DVs and CVs, conditional CV teleportation of single photons, and CV teleportation of qutrits. We are now aiming at universal, scalable, and fault-tolerant quantum computing based on these hybrid technologies.
NASA Astrophysics Data System (ADS)
Li, Fei; Zhao, Wei; Guo, Ying
2018-01-01
Continuous-variable (CV) measurement-device-independent (MDI) quantum cryptography is now heading towards solving the practical problem of implementing scalable quantum networks. In this paper, we show that a solution can come from deploying an optical amplifier in the CV-MDI system, aiming to establish a high-rate quantum network. We suggest an improved CV-MDI protocol using the EPR states coupled with optical amplifiers. It can implement a practical quantum network scheme, where the legal participants create the secret correlations by using EPR states connecting to an untrusted relay via insecure links and applying the multi-entangled Greenberger-Horne-Zeilinger (GHZ) state analysis at relay station. Despite the possibility that the relay could be completely tampered with and imperfect links are subject to the powerful attacks, the legal participants are still able to extract a secret key from network communication. The numerical simulation indicates that the quantum network communication can be achieved in an asymmetric scenario, fulfilling the demands of a practical quantum network. Furthermore, we show that the use of optical amplifiers can compensate the inherent imperfections and improve the secret key rate of the CV-MDI system.
NASA Astrophysics Data System (ADS)
Qin, Hao; Kumar, Rupesh; Alleaume, Romain
2015-10-01
We report here a new side channel attack on a practical continuous-variable (CV) quantum key distribution (QKD) system. Inspired by blinding attack in discrete-variable QKD, we formalize an attack strategy by inserting an external light into a CV QKD system implemented Gaussian-modulated coherent state protocol and show that our attack can compromise its practical security. In this attack, we concern imperfections of a balanced homodyne detector used in CV QKD. According to our analysis, if one inserts an external light into Bob's signal port, due to the imperfect subtraction from the homodyne detector, the leakage of the external light contributes a displacement on the homodyne signal which causes detector electronics saturation. In consequence, Bob's quadrature measurement is not linear with the quadrature sent by Alice. By considering such vulnerability, a potential Eve can launch a full intercept-resend attack meanwhile she inserts an external light into Bob's signal port. By selecting proper properties of the external light, Eve actively controls the induced displacement value from the inserted light which results saturation of homodyne detection. In consequence, Eve can bias the excess noise due to the intercept-resend attack and the external light, such that Alice and Bob believe their excess noise estimation is below the null key threshold and they can still share a secret key. Our attack shows that the detector loopholes also exist in CV QKD, and it seems influence all the CV QKD systems using homodyne detection, since all the practical detectors have finite detection range.
Transceivers and receivers for quantum key distribution and methods pertaining thereto
DOE Office of Scientific and Technical Information (OSTI.GOV)
DeRose, Christopher; Sarovar, Mohan; Soh, Daniel B.S.
Various technologies for performing continuous-variable (CV) and discrete-variable (DV) quantum key distribution (QKD) with integrated electro-optical circuits are described herein. An integrated DV-QKD system uses Mach-Zehnder modulators to modulate a polarization of photons at a transmitter and select a photon polarization measurement basis at a receiver. An integrated CV-QKD system uses wavelength division multiplexing to send and receive amplitude-modulated and phase-modulated optical signals with a local oscillator signal while maintaining phase coherence between the modulated signals and the local oscillator signal.
NASA Astrophysics Data System (ADS)
Zhou, Jian; Guo, Ying
2017-02-01
A continuous-variable measurement-device-independent (CV-MDI) multipartite quantum communication protocol is designed to realize multipartite communication based on the GHZ state analysis using Gaussian coherent states. It can remove detector side attack as the multi-mode measurement is blindly done in a suitable Black Box. The entanglement-based CV-MDI multipartite communication scheme and the equivalent prepare-and-measurement scheme are proposed to analyze the security and guide experiment, respectively. The general eavesdropping and coherent attack are considered for the security analysis. Subsequently, all the attacks are ascribed to coherent attack against imperfect links. The asymptotic key rate of the asymmetric configuration is also derived with the numeric simulations illustrating the performance of the proposed protocol.
High-Rate Field Demonstration of Large-Alphabet Quantum Key Distribution
2017-05-22
QKD, 2015 MDI−QKD, 2016 CV/GMCS, 2016 BBM92, 2009 COW , 2015 This work Figure 4: Comparison of our P&M DO-QKD results to previously published QKD system...device-independent QKD (39). CV/GMCS: distance record for continuous-variable QKD (40). BBM92: secure throughput record for two-dimensional entanglement-based QKD (41). COW : distance record for QKD (20). 17
[Development and validation of quality standards for colonoscopy].
Sánchez Del Río, Antonio; Baudet, Juan Salvador; Naranjo Rodríguez, Antonio; Campo Fernández de Los Ríos, Rafael; Salces Franco, Inmaculada; Aparicio Tormo, Jose Ramón; Sánchez Muñoz, Diego; Llach, Joseph; Hervás Molina, Antonio; Parra-Blanco, Adolfo; Díaz Acosta, Juan Antonio
2010-01-30
Before starting programs for colorectal cancer screening it is necessary to evaluate the quality of colonoscopy. Our objectives were to develop a group of quality indicators of colonoscopy easily applicable and to determine the variability of their achievement. After reviewing the bibliography we prepared 21 potential indicators of quality that were submitted to a process of selection in which we measured their facial validity, content validity, reliability and viability of their measurement. We estimated the variability of their achievement by means of the coefficient of variability (CV) and the variability of the achievement of the standards by means of chi(2). Six indicators overcome the selection process: informed consent, medication administered, completed colonoscopy, complications, every polyp removed and recovered, and adenoma detection rate in patients older than 50 years. 1928 colonoscopies were included from eight endoscopy units. Every unit included the same number of colonoscopies selected by means of simple random sampling with substitution. There was an important variability in the achievement of some indicators and standards: medication administered (CV 43%, p<0.01), complications registered (CV 37%, p<0.01), every polyp removed and recovered (CV 12%, p<0.01) and adenoma detection rate in older than fifty years (CV 2%, p<0.01). We have validated six quality indicators for colonoscopy which are easily measurable. An important variability exists in the achievement of some indicators and standards. Our data highlight the importance of the development of continuous quality improvement programmes for colonoscopy before starting colorectal cancer screening. Copyright (c) 2009 Elsevier España, S.L. All rights reserved.
Continuous-Variable Instantaneous Quantum Computing is Hard to Sample.
Douce, T; Markham, D; Kashefi, E; Diamanti, E; Coudreau, T; Milman, P; van Loock, P; Ferrini, G
2017-02-17
Instantaneous quantum computing is a subuniversal quantum complexity class, whose circuits have proven to be hard to simulate classically in the discrete-variable realm. We extend this proof to the continuous-variable (CV) domain by using squeezed states and homodyne detection, and by exploring the properties of postselected circuits. In order to treat postselection in CVs, we consider finitely resolved homodyne detectors, corresponding to a realistic scheme based on discrete probability distributions of the measurement outcomes. The unavoidable errors stemming from the use of finitely squeezed states are suppressed through a qubit-into-oscillator Gottesman-Kitaev-Preskill encoding of quantum information, which was previously shown to enable fault-tolerant CV quantum computation. Finally, we show that, in order to render postselected computational classes in CVs meaningful, a logarithmic scaling of the squeezing parameter with the circuit size is necessary, translating into a polynomial scaling of the input energy.
Nimphius, Sophia; McGuigan, Michael R; Suchomel, Timothy J; Newton, Robert U
2016-06-01
This study assessed reliability of discrete ground reaction force (GRF) variables over multiple pitching trials, investigated the relationships between discrete GRF variables and pitch velocity (PV) and assessed the variability of the "force signature" or continuous force-time curve during the pitching motion of windmill softball pitchers. Intraclass correlation coefficient (ICC) for all discrete variables was high (0.86-0.99) while the coefficient of variance (CV) was low (1.4-5.2%). Two discrete variables were significantly correlated to PV; second vertical peak force (r(5)=0.81, p=0.03) and time between peak forces (r(5)=-0.79; p=0.03). High ICCs and low CVs support the reliability of discrete GRF and PV variables over multiple trials and significant correlations indicate there is a relationship between the ability to produce force and the timing of this force production with PV. The mean of all pitchers' curve-average standard deviation of their continuous force-time curves demonstrated low variability (CV=4.4%) indicating a repeatable and identifiable "force signature" pattern during this motion. As such, the continuous force-time curve in addition to discrete GRF variables should be examined in future research as a potential method to monitor or explain changes in pitching performance. Copyright © 2016 Elsevier B.V. All rights reserved.
Feng, Jinxia; Wan, Zhenju; Li, Yuanji; Zhang, Kuanshou
2017-09-01
The distribution of continuous variable (CV) Einstein-Podolsky-Rosen (EPR)-entangled beams at a telecommunication wavelength of 1550 nm over single-mode fibers is investigated. EPR-entangled beams with quantum entanglement of 8.3 dB are generated using a single nondegenerate optical parametric amplifier based on a type-II periodically poled KTiOPO 4 crystal. When one beam of the generated EPR-entangled beams is distributed over 20 km of single-mode fiber, 1.02 dB quantum entanglement can still be measured. The degradation of CV quantum entanglement in a noisy fiber channel is theoretically analyzed considering the effect of depolarized guided acoustic wave Brillouin scattering in optical fibers. The theoretical prediction is in good agreement with the experimental results.
Self-referenced continuous-variable quantum key distribution protocol
Soh, Daniel Beom Soo; Sarovar, Mohan; Brif, Constantin; ...
2015-10-21
We introduce a new continuous-variable quantum key distribution (CV-QKD) protocol, self-referenced CV-QKD, that eliminates the need for transmission of a high-power local oscillator between the communicating parties. In this protocol, each signal pulse is accompanied by a reference pulse (or a pair of twin reference pulses), used to align Alice’s and Bob’s measurement bases. The method of phase estimation and compensation based on the reference pulse measurement can be viewed as a quantum analog of intradyne detection used in classical coherent communication, which extracts the phase information from the modulated signal. We present a proof-of-principle, fiber-based experimental demonstration of themore » protocol and quantify the expected secret key rates by expressing them in terms of experimental parameters. Our analysis of the secret key rate fully takes into account the inherent uncertainty associated with the quantum nature of the reference pulse(s) and quantifies the limit at which the theoretical key rate approaches that of the respective conventional protocol that requires local oscillator transmission. The self-referenced protocol greatly simplifies the hardware required for CV-QKD, especially for potential integrated photonics implementations of transmitters and receivers, with minimum sacrifice of performance. Furthermore, it provides a pathway towards scalable integrated CV-QKD transceivers, a vital step towards large-scale QKD networks.« less
Self-referenced continuous-variable quantum key distribution protocol
DOE Office of Scientific and Technical Information (OSTI.GOV)
Soh, Daniel Beom Soo; Sarovar, Mohan; Brif, Constantin
We introduce a new continuous-variable quantum key distribution (CV-QKD) protocol, self-referenced CV-QKD, that eliminates the need for transmission of a high-power local oscillator between the communicating parties. In this protocol, each signal pulse is accompanied by a reference pulse (or a pair of twin reference pulses), used to align Alice’s and Bob’s measurement bases. The method of phase estimation and compensation based on the reference pulse measurement can be viewed as a quantum analog of intradyne detection used in classical coherent communication, which extracts the phase information from the modulated signal. We present a proof-of-principle, fiber-based experimental demonstration of themore » protocol and quantify the expected secret key rates by expressing them in terms of experimental parameters. Our analysis of the secret key rate fully takes into account the inherent uncertainty associated with the quantum nature of the reference pulse(s) and quantifies the limit at which the theoretical key rate approaches that of the respective conventional protocol that requires local oscillator transmission. The self-referenced protocol greatly simplifies the hardware required for CV-QKD, especially for potential integrated photonics implementations of transmitters and receivers, with minimum sacrifice of performance. Furthermore, it provides a pathway towards scalable integrated CV-QKD transceivers, a vital step towards large-scale QKD networks.« less
Self-Referenced Continuous-Variable Quantum Key Distribution Protocol
NASA Astrophysics Data System (ADS)
Soh, Daniel B. S.; Brif, Constantin; Coles, Patrick J.; Lütkenhaus, Norbert; Camacho, Ryan M.; Urayama, Junji; Sarovar, Mohan
2015-10-01
We introduce a new continuous-variable quantum key distribution (CV-QKD) protocol, self-referenced CV-QKD, that eliminates the need for transmission of a high-power local oscillator between the communicating parties. In this protocol, each signal pulse is accompanied by a reference pulse (or a pair of twin reference pulses), used to align Alice's and Bob's measurement bases. The method of phase estimation and compensation based on the reference pulse measurement can be viewed as a quantum analog of intradyne detection used in classical coherent communication, which extracts the phase information from the modulated signal. We present a proof-of-principle, fiber-based experimental demonstration of the protocol and quantify the expected secret key rates by expressing them in terms of experimental parameters. Our analysis of the secret key rate fully takes into account the inherent uncertainty associated with the quantum nature of the reference pulse(s) and quantifies the limit at which the theoretical key rate approaches that of the respective conventional protocol that requires local oscillator transmission. The self-referenced protocol greatly simplifies the hardware required for CV-QKD, especially for potential integrated photonics implementations of transmitters and receivers, with minimum sacrifice of performance. As such, it provides a pathway towards scalable integrated CV-QKD transceivers, a vital step towards large-scale QKD networks.
Continuous-variable quantum key distribution with Gaussian source noise
DOE Office of Scientific and Technical Information (OSTI.GOV)
Shen Yujie; Peng Xiang; Yang Jian
2011-05-15
Source noise affects the security of continuous-variable quantum key distribution (CV QKD) and is difficult to analyze. We propose a model to characterize Gaussian source noise through introducing a neutral party (Fred) who induces the noise with a general unitary transformation. Without knowing Fred's exact state, we derive the security bounds for both reverse and direct reconciliations and show that the bound for reverse reconciliation is tight.
Implementation of continuous-variable quantum key distribution with discrete modulation
NASA Astrophysics Data System (ADS)
Hirano, Takuya; Ichikawa, Tsubasa; Matsubara, Takuto; Ono, Motoharu; Oguri, Yusuke; Namiki, Ryo; Kasai, Kenta; Matsumoto, Ryutaroh; Tsurumaru, Toyohiro
2017-06-01
We have developed a continuous-variable quantum key distribution (CV-QKD) system that employs discrete quadrature-amplitude modulation and homodyne detection of coherent states of light. We experimentally demonstrated automated secure key generation with a rate of 50 kbps when a quantum channel is a 10 km optical fibre. The CV-QKD system utilises a four-state and post-selection protocol and generates a secure key against the entangling cloner attack. We used a pulsed light source of 1550 nm wavelength with a repetition rate of 10 MHz. A commercially available balanced receiver is used to realise shot-noise-limited pulsed homodyne detection. We used a non-binary LDPC code for error correction (reverse reconciliation) and the Toeplitz matrix multiplication for privacy amplification. A graphical processing unit card is used to accelerate the software-based post-processing.
NASA Astrophysics Data System (ADS)
Lu, Weizhao; Huang, Chunhui; Hou, Kun; Shi, Liting; Zhao, Huihui; Li, Zhengmei; Qiu, Jianfeng
2018-05-01
In continuous-variable quantum key distribution (CV-QKD), weak signal carrying information transmits from Alice to Bob; during this process it is easily influenced by unknown noise which reduces signal-to-noise ratio, and strongly impacts reliability and stability of the communication. Recurrent quantum neural network (RQNN) is an artificial neural network model which can perform stochastic filtering without any prior knowledge of the signal and noise. In this paper, a modified RQNN algorithm with expectation maximization algorithm is proposed to process the signal in CV-QKD, which follows the basic rule of quantum mechanics. After RQNN, noise power decreases about 15 dBm, coherent signal recognition rate of RQNN is 96%, quantum bit error rate (QBER) drops to 4%, which is 6.9% lower than original QBER, and channel capacity is notably enlarged.
NASA Astrophysics Data System (ADS)
Shinjo, Ami; Hashiyama, Naoyuki; Koshio, Akane; Eto, Yujiro; Hirano, Takuya
2016-10-01
The continuous-variable (CV) Einstein-Podolsky-Rosen (EPR) paradox and steering are demonstrated using a pulsed light source and waveguides. We shorten the duration of the local oscillator (LO) pulse by using parametric amplification to improve the temporal mode-matching between the entangled pulse and the LO pulse. After correcting for the amplifier noise, the product of the measured conditional variance of the quadrature-phase amplitudes is 0.74 < 1, which satisfies the EPR-Reid criterion.
NASA Astrophysics Data System (ADS)
Pradeep, Krishna; Poiroux, Thierry; Scheer, Patrick; Juge, André; Gouget, Gilles; Ghibaudo, Gérard
2018-07-01
This work details the analysis of wafer level global process variability in 28 nm FD-SOI using split C-V measurements. The proposed approach initially evaluates the native on wafer process variability using efficient extraction methods on split C-V measurements. The on-wafer threshold voltage (VT) variability is first studied and modeled using a simple analytical model. Then, a statistical model based on the Leti-UTSOI compact model is proposed to describe the total C-V variability in different bias conditions. This statistical model is finally used to study the contribution of each process parameter to the total C-V variability.
Characterizing Accuracy and Precision of Glucose Sensors and Meters
2014-01-01
There is need for a method to describe precision and accuracy of glucose measurement as a smooth continuous function of glucose level rather than as a step function for a few discrete ranges of glucose. We propose and illustrate a method to generate a “Glucose Precision Profile” showing absolute relative deviation (ARD) and /or %CV versus glucose level to better characterize measurement errors at any glucose level. We examine the relationship between glucose measured by test and comparator methods using linear regression. We examine bias by plotting deviation = (test – comparator method) versus glucose level. We compute the deviation, absolute deviation (AD), ARD, and standard deviation (SD) for each data pair. We utilize curve smoothing procedures to minimize the effects of random sampling variability to facilitate identification and display of the underlying relationships between ARD or %CV and glucose level. AD, ARD, SD, and %CV display smooth continuous relationships versus glucose level. Estimates of MARD and %CV are subject to relatively large errors in the hypoglycemic range due in part to a markedly nonlinear relationship with glucose level and in part to the limited number of observations in the hypoglycemic range. The curvilinear relationships of ARD and %CV versus glucose level are helpful when characterizing and comparing the precision and accuracy of glucose sensors and meters. PMID:25037194
Thyagarajan, Bharat; Howard, Annie Green; Durazo-Arvizu, Ramon; Eckfeldt, John H; Gellman, Marc D; Kim, Ryung S; Liu, Kiang; Mendez, Armando J; Penedo, Frank J; Talavera, Gregory A; Youngblood, Marston E; Zhao, Lihui; Sotres-Alvarez, Daniela
2016-12-01
Biomarker variability, which includes within-individual variability (CV I ), between-individual variability (CV G ) and methodological variability (CV P + A ) is an important determinant of our ability to detect biomarker-disease associations. Estimates of CV I and CV G may be population specific and little data exists on biomarker variability in diverse Hispanic populations. Hence, we evaluated all 3 components of biomarker variability in the Hispanic Community Health Study/Study of Latinos (HCHS/SOL) using repeat blood collections (n=58) and duplicate blood measurements (n=761-929 depending on the biomarker). We estimated the index of individuality (II) ((CV I +CV P + A )/CV G ) for 41 analytes and evaluated differences in the II across sexes and age groups. Biomarkers such as fasting glucose, triglycerides and ferritin had substantially higher inter-individual variability and lower II in HCHS/SOL as compared to the published literature. We also found significant sex-specific differences in the II for neutrophil count, platelet count, hemoglobin, % eosinophils and fasting glucose. The II for fasting insulin, post oral glucose tolerance test glucose and cystatin C was significantly higher among the 18-44y age group as compared to the 45+y age group. The implications of these findings for determining biomarker-disease associations in Hispanic populations need to be evaluated in future studies. Copyright © 2016 Elsevier B.V. All rights reserved.
NASA Astrophysics Data System (ADS)
Guo, Ying; Xie, Cailang; Liao, Qin; Zhao, Wei; Zeng, Guihua; Huang, Duan
2017-08-01
The survival of Gaussian quantum states in a turbulent atmospheric channel is of crucial importance in free-space continuous-variable (CV) quantum key distribution (QKD), in which the transmission coefficient will fluctuate in time, thus resulting in non-Gaussian quantum states. Different from quantum hacking of the imperfections of practical devices, here we propose a different type of attack by exploiting the security loopholes that occur in a real lossy channel. Under a turbulent atmospheric environment, the Gaussian states are inevitably afflicted by decoherence, which would cause a degradation of the transmitted entanglement. Therefore, an eavesdropper can perform an intercept-resend attack by applying an entanglement-distillation operation on the transmitted non-Gaussian mixed states, which allows the eavesdropper to bias the estimation of the parameters and renders the final keys shared between the legitimate parties insecure. Our proposal highlights the practical CV QKD vulnerabilities with free-space quantum channels, including the satellite-to-earth links, ground-to-ground links, and a link from moving objects to ground stations.
van Dijk, Peter R; Groenier, Klaas H; DeVries, J Hans; Gans, Reinold O B; Kleefstra, Nanno; Bilo, Henk J G; Logtenberg, Susan J J
2015-06-01
As continuous intraperitoneal insulin infusion (CIPII) results in a more physiologic action of insulin than subcutaneous (SC) insulin administration, we hypothesized that CIPII would result in less glycemic variability (GV) than SC insulin therapy among type 1 diabetes mellitus (T1DM) patients. Data from 5-day blind continuous glucose monitoring (CGM) measurements performed during a 26-week, prospective, observational case-control study were analyzed. The coefficient of variation (CV) was the primary measure of GV. In addition, the SD of the mean glucose level, mean of daily differences, and mean amplitude of glycemic excursions were calculated. In total, 176 patients (36% male; mean age, 49 [SD 13] years; median diabetes duration, 24 [interquartile range, 17, 35] years; glycated hemoglobin level, 63 [10] mmol/mmol), of which 37 used CIPII and 139 SC insulin therapy, were analyzed. CGM data were available for 169 patients at baseline (CIPII, n=35; SC, n=134) and for 164 patients at 26 weeks (CIPII, n=35; SC, n=129). After adjustment for baseline differences, the CV was 4.9% (95% confidence interval, 1.0, 8.8) lower with CIPII- compared with SC-treated patients, irrespective of the use of multiple daily injections or continuous SC insulin infusion. There were no differences in other indices of GV between groups. Despite higher blood glucose, the CV was slightly lower with CIPII compared with SC insulin therapy in T1DM patients, and other measures of GV were identical. Future studies are needed to confirm these findings and investigate whether this results in prevention of hypoglycemia and even perhaps (less) microvascular complications.
Syamsunder, Avupati Naga; Pal, Pravati; Pal, Gopal Krushna; Kamalanathan, Chandrakasan Sadishkumar; Parija, Subhash Chandra; Nanda, Nivedita; Sirisha, Allampalli
2017-02-01
Purpose/aim of the study: The present study investigated the link of hyperlipidemia, inflammation and oxidative stress (OS) to cardiovascular (CV) risks in subclinical hypothyroidism (SCH). We enrolled 81 subclinical hypothyroid patients and 80 healthy subjects as control. Their CV and autonomic functions were assessed by spectral analysis of heart rate variability (HRV), continuous blood pressure variability (BPV) measurement and conventional autonomic function testing. Thyroid profile, lipid profile, immunological, inflammatory and OS markers were estimated and correlated with the baro-reflex sensitivity (BRS), the marker of sympathovagal imbalance (SVI) & CV risk. Mean arterial pressure (MAP, P<0.0001), total peripheral resistance (TPR, P<0.0001), ratio of low-frequency to high-frequency power of HRV (LF-HF ratio) (P<0.0001) were significantly higher and BRS (P<0.0001) was significantly lower in SCH group than the control group. BRS significantly correlated with heart rate, MAP, LF-HF ratio, lipid risk factors, anti-thyroperoxidase antibody, thyroid-stimulating hormone, high-sensitive C-reactive protein (hsCRP), malondialdehyde (MDA) and SCH. It was concluded that SVI is associated with SCH. Though dyslipidemia, inflammation and OS contributed to decreased BRS, SCH per se contributed maximally to it. Decreased BRS could be a physiological basis of increased CV risks in patients with SCH.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Qi, Bing; Lougovski, Pavel; Pooser, Raphael C.
Continuous-variable quantum key distribution (CV-QKD) protocols based on coherent detection have been studied extensively in both theory and experiment. In all the existing implementations of CV-QKD, both the quantum signal and the local oscillator (LO) are generated from the same laser and propagate through the insecure quantum channel. This arrangement may open security loopholes and limit the potential applications of CV-QKD. In our paper, we propose and demonstrate a pilot-aided feedforward data recovery scheme that enables reliable coherent detection using a “locally” generated LO. Using two independent commercial laser sources and a spool of 25-km optical fiber, we construct amore » coherent communication system. The variance of the phase noise introduced by the proposed scheme is measured to be 0.04 (rad 2), which is small enough to enable secure key distribution. This technology opens the door for other quantum communication protocols, such as the recently proposed measurement-device-independent CV-QKD, where independent light sources are employed by different users.« less
Liakos, Charalampos I; Karpanou, Eva A; Markou, Maria I; Grassos, Charalampos A; Vyssoulis, Gregory P
2015-12-01
Intrarenal hemodynamics depend on blood pressure (BP), heart rate (HR), and smoking. Although BP levels have been associated with kidney function, the effect of HR levels, BP, and HR variability on renal function are less well clarified. This cross-sectional study sought to determine the association of 24-hour BP and HR variability with kidney function in hypertensive patients, stratified by smoking. The study comprised 9600 nondiabetic, never-treated hypertensive individuals without evident renal impairment examined from 1985 to 2014 (aged 53.3±13.4 years, 55.3% males). The 24-hour systolic BP (SBP) and HR variability were estimated via their coefficient of variation (CV =standard deviation×100/mean value) derived from ambulatory recording. The CV SBP-to-CV HR ratio (CV R) was used as a marker of the interplay between 24-hour SBP and HR variability. Renal function was estimated via 24-hour urine creatinine clearance (CrCl), estimated glomerular filtration rate (eGFR), albumin-to-creatinine ratio (ACR), and 24-hour urine α1 -microglobulin. After adjustment for age, sex, and smoking, CV SBP was found to be weakly correlated to eGFR (r=-0.017, P=.1) and somewhat more strongly to CrCl, ACR, and α1 -microglobulin (r=-0.032, 0.072, and 0.065; P=.002, <.001 and <.001, respectively). CV HR was much better related to renal function, with stronger adjusted correlations to CrCl, eGFR, ACR, and α1 -microglobulin (r=0.185, 0.134, -0.306, -0.247; all P<.001, respectively). CV R also showed equally good adjusted correlations (r=-0.175, -0.125, 0.336, 0.262; all P<.001, respectively). Most adjusted correlations for CV HR and CV R were even better in smokers (r=0.213, 0.158, -0.332, -0.272 and -0.183, -0.118, 0.351, 0.275, respectively; all P<.001). CV HR and CV R emerge as better related to kidney function than CV SBP, especially in smokers. The correlation of CV HR and CV SBP to renal function is inverse to each other. ACR and α1 -microglobulin are better related to variability indices than CrCl and eGFR. However, causal relations cannot be proved. © 2015 Wiley Periodicals, Inc.
NASA Astrophysics Data System (ADS)
Biederman, J. A.; Harpold, A. A.; Gochis, D. J.; Reed, D.; Brooks, P. D.
2010-12-01
Seasonal snowcover is a primary source of water to urban and agricultural regions in the western United States, where Mountain Pine Beetle (MPB) has caused rapid and extensive changes to vegetation in montane forests. Levels of MPB infestation in these seasonally snow-covered systems are unprecedented, and it is unknown how this will affect water yield, especially in changing climate conditions. To address this unknown we ask: How does snow accumulation and ablation vary across forest with differing levels of impact? Our study areas in the Rocky Mountains of CO and WY are similar in latitude, elevation and forest structure before infestation, but they vary in the intensity and timing of beetle infestation and tree mortality. We present a record for winter 2010 that includes continuous snow depth as well as stand-scale snow surveys at maximum accumulation. Additional measurements include snowfall, net radiation, temperature and wind speed as well as characterization of forest structure by leaf area index. In a stand uninfested by MPB, maximum snow depth was fairly uniform under canopy (mean = 86 cm, coefficient of variation = 0.021), while canopy gaps showed greater and more variable depth (mean = 117 cm, CV = 0.111). This is consistent with several studies demonstrating that snowfall into canopy gaps depends upon gap size, orientation, wind speed and storm size. In a stand impacted in 2007, snow depth under canopy was less uniform, and there were smaller differences in both mean depth and variability between canopy (mean = 93 cm, CV = 0.072) and gaps (mean = 97 cm, CV = 0.070), consistent with decreased canopy density. In a more recently infested (2009) stand with an intermediate level of MPB impact, mean snow depths were similar between canopy (96 cm, CV = 0.016) and gaps (95 cm, CV = 0.185) but gaps showed much greater variability, suggesting controls similar to those in effect in the uninfested stand. We further use these data to model snow accumulation and ablation as a function of vegetation, topography and fine-scale climate variability, with preliminary results presented at the meeting.
Winter, Randolph L; Saunders, Ashley B; Gordon, Sonya G; Buch, Jesse S; Miller, Matthew W
2017-04-01
To determine the biologic variability of N-terminal pro-brain natriuretic peptide (NTproBNP) in healthy dogs and dogs with various stages of myxomatous mitral valve disease (MMVD). Thirty-eight privately owned dogs: 28 with MMVD and 10 healthy controls. Prospective clinical study with comprehensive evaluation used to group dogs as healthy or into three stages of MMVD based on current guidelines. NTproBNP was measured hourly, daily, and weekly. For each group, analytical (CV A ), within-subject (CV I ), and between-subject (CV G ) coefficients of variability were calculated in addition to percent critical change value (CCV) and index of individuality (IoI). For healthy dogs, calculated NTproBNP values were: CV A = 4.2%; CV I = 25.2%; CV G = 49.3%; IoI = 0.52, and CCV = 70.8%. For dogs with MMVD, calculated NTproBNP values were: CV A = 6.2%; CV I = 20.0%; CV G = 61.3%; IoI = 0.34, and CCV = 58.2%. Biologic variability affects NTproBNP concentrations in healthy dogs and dogs with MMVD. Monitoring serial individual changes in NTproBNP may be clinically relevant in addition to using population-based reference ranges to determine changes in disease status. Copyright © 2016 Elsevier B.V. All rights reserved.
Schultz, Martin G; Otahal, Petr; Cleland, Verity J; Blizzard, Leigh; Marwick, Thomas H; Sharman, James E
2013-03-01
The prognostic relevance of a hypertensive response to exercise (HRE) is ill-defined in individuals undergoing exercise stress testing. The study described here was intended to provide a systematic review and meta-analysis of published literature to determine the value of exercise-related blood pressure (BP) (independent of office BP) for predicting cardiovascular (CV) events and mortality. Online databases were searched for published longitudinal studies reporting exercise-related BP and CV events and mortality rates. We identified for review 12 longitudinal studies with a total of 46,314 individuals without significant coronary artery disease, with total CV event and mortality rates recorded over a mean follow-up of 15.2±4.0 years. After adjustment for age, office BP, and CV risk factors, an HRE at moderate exercise intensity carried a 36% greater rate of CV events and mortality (95% CI, 1.02-1.83, P = 0.039) than that of subjects without an HRE. Additionally, each 10mm Hg increase in systolic BP during exercise at moderate intensity was accompanied by a 4% increase in CV events and mortality, independent of office BP, age, or CV risk factors (95% CI, 1.01-1.07, P = 0.02). Systolic BP at maximal workload was not significantly associated with the outcome of an increased rate of CV, whether analyzed as a categorical (HR=1.49, 95% CI, 0.90-2.46, P = 0.12) or a continuous (HR=1.01, 95% CI, 0.98-1.04, P = 0.53) variable. An HRE at moderate exercise intensity during exercise stress testing is an independent risk factor for CV events and mortality. This highlights the need to determine underlying pathophysiological mechanisms of exercise-induced hypertension.
García-Ramos, Amador; Haff, G Gregory; Padial, Paulino; Feriche, Belén
2018-03-01
This study aimed to examine the reliability of different power and velocity variables during the Smith machine bench press (BP) and bench press throw (BPT) exercises. Twenty-two healthy men conducted four testing sessions after a preliminary BP one-repetition maximum (1RM) test. In a counterbalanced order, participants performed two sessions of BP in one week and two sessions of BPT in another week. Mean propulsive power, peak power, mean propulsive velocity, and peak velocity at each tenth percentile (20-70% of 1RM) were recorded by a linear transducer. The within-participants coefficient of variation (CV) was higher for the load-power relationship compared to the load-velocity relationship in both the BP (5.3% vs. 4.1%; CV ratio = 1.29) and BPT (4.7% vs. 3.4%; CV ratio = 1.38). Mean propulsive variables showed lower reliability than peak variables in both the BP (5.4% vs. 4.0%, CV ratio = 1.35) and BPT (4.8% vs. 3.3%, CV ratio = 1.45). All variables were deemed reliable, with the peak velocity demonstrating the lowest within-participants CV. Based upon these findings, the peak velocity should be chosen for the accurate assessment of BP and BPT performance.
Ecological Validity and Reliability of the Rugby Sevens Simulation Protocol.
Furlan, Nicola; Waldron, Mark; Osborne, Mark; Gray, Adrian J
2016-09-01
To assess the ecological validity of the Rugby Sevens Simulation Protocol (R7SP) and to evaluate its interday reliability. Ten male participants (20 ± 2 y, 74 ± 11 kg) completed 2 trials of the R7SP, separated by 7 d. The R7SP comprised typical running and collision activities, based on data recorded during international rugby sevens match play. Heart rate (HR) was monitored continuously during the R7SP, and the participants' movements were recorded through a 20-Hz global positioning system unit. Blood lactate and rating of perceived exertion were collected before and immediately after the 1st and 2nd halves of the R7SP. The average activity profile was 117 ± 5 m/min, of which 27 ± 2 m/min was covered at high speed, with a calculated energetic demand of 1037 ± 581 J/kg, of which ~40% was expended at a rate above 19 W/kg. Mean HR was 88% ± 4% of maximal HR. Participants spent ~45% ± 27% of time above 90% of maximal HR (t >90% HRmax ). There were no significant differences between trials, except for lactate between the halves of the R7SP. The majority of the measured variables demonstrated a between-trials coefficient of variation (CV%) lower than 5%. Blood lactate measurements (14-20% CV) and t >90% HRmax (26% CV) were less reliable variables. In most cases, the calculated moderate worthwhile change was higher than the CV%. The R7SP replicates the activity profile and HR responses of rugby sevens match play. It is a reliable simulation protocol that can be used in a research environment to detect systematic worthwhile changes in selected performance variables.
Continuous Variable Cluster State Generation over the Optical Spatial Mode Comb
Pooser, Raphael C.; Jing, Jietai
2014-10-20
One way quantum computing uses single qubit projective measurements performed on a cluster state (a highly entangled state of multiple qubits) in order to enact quantum gates. The model is promising due to its potential scalability; the cluster state may be produced at the beginning of the computation and operated on over time. Continuous variables (CV) offer another potential benefit in the form of deterministic entanglement generation. This determinism can lead to robust cluster states and scalable quantum computation. Recent demonstrations of CV cluster states have made great strides on the path to scalability utilizing either time or frequency multiplexingmore » in optical parametric oscillators (OPO) both above and below threshold. The techniques relied on a combination of entangling operators and beam splitter transformations. Here we show that an analogous transformation exists for amplifiers with Gaussian inputs states operating on multiple spatial modes. By judicious selection of local oscillators (LOs), the spatial mode distribution is analogous to the optical frequency comb consisting of axial modes in an OPO cavity. We outline an experimental system that generates cluster states across the spatial frequency comb which can also scale the amount of quantum noise reduction to potentially larger than in other systems.« less
Variation in nutrients formulated and nutrients supplied on 5 California dairies.
Rossow, H A; Aly, S S
2013-01-01
Computer models used in ration formulation assume that nutrients supplied by a ration formulation are the same as the nutrients presented in front of the cow in the final ration. Deviations in nutrients due to feed management effects such as dry matter changes (i.e., rain), loading, mixing, and delivery errors are assumed to not affect delivery of nutrients to the cow and her resulting milk production. To estimate how feed management affects nutrients supplied to the cow and milk production, and determine if nutrients can serve as indexes of feed management practices, weekly total mixed ration samples were collected and analyzed for 4 pens (close-up cows, fresh cows, high-milk-producing, and low-milk-producing cows, if available) for 7 to 12 wk on 5 commercial California dairies. Differences among nutrient analyses from these samples and nutrients from the formulated rations were analyzed by PROC MIXED of SAS (SAS Institute Inc., Cary, NC). Milk fat and milk protein percentages did not vary as much [coefficient of variation (CV) = 18 to 33%] as milk yield (kg; CV = 16 to 47 %) across all dairies and pens. Variability in nutrients delivered were highest for macronutrient fat (CV = 22%), lignin (CV = 15%), and ash (CV = 11%) percentages and micronutrients Fe (mg/kg; CV = 48%), Na (%; CV = 42%), and Zn (mg/kg; CV = 38%) for the milking pens across all dairies. Partitioning of the variability in random effects of nutrients delivered and intraclass correlation coefficients showed that variability in lignin percentage of TMR had the highest correlation with variability in milk yield and milk fat percentage, followed by fat and crude protein percentages. But, variability in ash, fat, and lignin percentages of total mixed ration had the highest correlation with variability in milk protein percentage. Therefore, lignin, fat, and ash may be the best indices of feed management to include effects of variability in nutrients on variability in milk yield, milk fat, and milk protein percentages in ration formulation models. Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.
Cardiovascular risk in peritoneal dialysis - a Portuguese multicenter study.
Neves, Marta; Machado, Susana; Rodrigues, Luís; Borges, Andreia; Maia, Pedro; Campos, Mário
2014-01-01
Cardiovascular (CV) disease is the major cause of mortality in patients undergoing renal replacement therapy. The primary aim of the study was to evaluate the CV risk profile and prevalence of CV disease in patients on peritoneal dialysis (PD) in Portugal. The secondary goal was to establish parameters most associated with CV disease. Retrospective, multicenter study of the prevalent adult population on PD. Six hundred patients were included (56.7% male; mean age 53.5 ± 15.3 years), on PD for 25.6 ± 21.9 months. Patients were divided into two groups: group 1 (n=166) with CV disease and group 2 (n=434) without CV disease. Comparisons were made regarding traditional CV risk factors and those associated with uremia and PD itself, and a multivariate analysis was performed to determine variables independently associated with CV disease. At the end of the study, the prevalence of CV disease was 28%. At univariate analysis, group 1 presented a higher frequency of males (p<.01), older patients (p<.01), diabetics (p<.01), occurrence of left ventricular hypertrophy (LVH) (p<.01), mean C-reactive protein (CRP) (p=.04), lower mean parathormone level (p=.014), lower serum phosphorus (p=.02), lower daily urine output (p=.04), lower weekly Kt/V (p=.008), increased use of icodextrin and hypertonic glucose-based PD solutions (p<.001 and p=.006, respectively) and more were under continuous ambulatory PD (CAPD) (p=.014) and had a high peritoneal transport status (p=.02). Multivariate analysis provided a significant discriminatory influence pertaining to age >50 years, CRP>0.6 mg/dl, male gender, diabetes, LVH, CAPD and anuria, when comparing group 1 and group 2. Risk factors most related to the development of CV disease in PD in Portugal are age >50 years, CRP>0.6 mg/dL, male gender, diabetes, LVH, CAPD and anuria.
2016-12-02
Quantum Computing , University of Waterloo, Waterloo ON, N2L 3G1, Canada (Dated: December 1, 2016) Continuous variable (CV) quantum key distribution (QKD...Networking with QUantum operationally-Secure Technology for Maritime Deployment (CONQUEST) Contract Period of Performance: 2 September 2016 – 1 September...this letter or have any other questions. Sincerely, Raytheon BBN Technologies Kathryn Carson Program Manager Quantum Information Processing
Quantum cryptography with an ideal local relay
NASA Astrophysics Data System (ADS)
Spedalieri, Gaetana; Ottaviani, Carlo; Braunstein, Samuel L.; Gehring, Tobias; Jacobsen, Christian S.; Andersen, Ulrik L.; Pirandola, Stefano
2015-10-01
We consider two remote parties connected to a relay by two quantum channels. To generate a secret key, they transmit coherent states to the relay, where the states are subject to a continuous-variable (CV) Bell detection. We study the ideal case where Alice's channel is lossless, i.e., the relay is locally in her lab and the Bell detection is perfomed with unit efficiency. This configuration allows us to explore the optimal performances achievable by CV measurement-device-independent quantum key distribution. This corresponds to the limit of a trusted local relay, where the detection loss can be re-scaled. Our theoretical analysis is confirmed by an experimental simulation where 10-4 secret bits per use can potentially be distributed at 170km assuming ideal reconciliation.
Chiu, Hsien-Tsai; Li, Tsai-Chung; Li, Chia-Ing; Liu, Chiu-Shong; Lin, Wen-Yuan; Lin, Cheng-Chieh
2017-01-01
This study aims to examine the association between visit-to-visit glucose variability, which was measured by coefficient of variation (CV) of fasting plasma glucose (FPG) and hemoglobin A1c (HbA1c), and risk of chronic obstructive pulmonary disease (COPD) in a large number of patients with type 2 diabetes with an average follow-up of 7.58 years. We conducted a retrospective cohort study on 27,257 patients with type 2 diabetes who participated in the National Diabetes Case Management Program in Taiwan. Visit-to-visit variability in HbA1c and FPG at baseline and the incidence of COPD were analyzed using a modified Cox proportional hazards model considering competing risks. A total of 2,346 incident cases of COPD. Patients were grouped into tertiles of FPG-CV and HbA1c-CV. The incidence rates in the first, second, and third tertiles were 9.87, 11.06, and 13.19, respectively, for FPG-CV and 10.2, 11.81, and 12.07, for HbA1c-CV per 1000 person-years. After adjusting for age, gender, diabetes duration, treatment type, smoking, hypertension, hyperlipidemia, baseline FPG and HbA1c levels, and complications, both FPG-CV and HbA1c-CV were independently associated with COPD. The hazard ratios of COPD for the third terile compared with the first tertile of FPG-CV were 1.26 (95% confidence interval [CI]: 1.13-1.40). Moreover, the hazard ratios of COPD for the third and second tertiles compared with the first tertile of HbA1c-CV were 1.13 (1.02-1.25) and 1.13 (1.02-1.26), respectively. Patients with FPG-CV higher than 34.6% or HbA1c-CV higher than 8.4% exhibited an increased risk of COPD. This finding confirmed the linear relationship of FPG-CV and HbA1c-CV to COPD. Visit-to-visit variability in FPG and HbA1c levels are strong predictors of COPD in patients with type 2 diabetes. Future studies should focus on lung dysfunction in diabetes, and adequate glucose control strategy in regular clinical practices must be established for COPD prevention.
Effect of source tampering in the security of quantum cryptography
NASA Astrophysics Data System (ADS)
Sun, Shi-Hai; Xu, Feihu; Jiang, Mu-Sheng; Ma, Xiang-Chun; Lo, Hoi-Kwong; Liang, Lin-Mei
2015-08-01
The security of source has become an increasingly important issue in quantum cryptography. Based on the framework of measurement-device-independent quantum key distribution (MDI-QKD), the source becomes the only region exploitable by a potential eavesdropper (Eve). Phase randomization is a cornerstone assumption in most discrete-variable (DV) quantum communication protocols (e.g., QKD, quantum coin tossing, weak-coherent-state blind quantum computing, and so on), and the violation of such an assumption is thus fatal to the security of those protocols. In this paper, we show a simple quantum hacking strategy, with commercial and homemade pulsed lasers, by Eve that allows her to actively tamper with the source and violate such an assumption, without leaving a trace afterwards. Furthermore, our attack may also be valid for continuous-variable (CV) QKD, which is another main class of QKD protocol, since, excepting the phase random assumption, other parameters (e.g., intensity) could also be changed, which directly determine the security of CV-QKD.
Knee extension torque variability after exercise in ACL reconstructed knees.
Goetschius, John; Kuenze, Christopher M; Hart, Joseph M
2015-08-01
The purpose of this study was to compare knee extension torque variability in patients with ACL reconstructed knees before and after exercise. Thirty two patients with an ACL reconstructed knee (ACL-R group) and 32 healthy controls (control group) completed measures of maximal isometric knee extension torque (90° flexion) at baseline and following a 30-min exercise protocol (post-exercise). Exercise included 30-min of repeated cycles of inclined treadmill walking and hopping tasks. Dependent variables were the coefficient of variation (CV) and raw-change in CV (ΔCV): CV = (torque standard deviation/torque mean x 100), ΔCV = (post-exercise - baseline). There was a group-by-time interaction (p = 0.03) on CV. The ACL-R group demonstrated greater CV than the control group at baseline (ACL-R = 1.07 ± 0.55, control = 0.79 ± 0.42, p = 0.03) and post-exercise (ACL-R = 1.60 ± 0.91, control = 0.94 ± 0.41, p = 0.001). ΔCV was greater (p = 0.03) in the ACL-R group (0.52 ± 0.82) than control group (0.15 ± 0.46). CV significantly increased from baseline to post-exercise (p = 0.001) in the ACL-R group, while the control group did not (p = 0.06). The ACL-R group demonstrated greater knee extension torque variability than the control group. Exercise increased torque variability more in the ACL-R group than control group. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.
Reliability and variability of day-to-day vault training measures in artistic gymnastics.
Bradshaw, Elizabeth; Hume, Patria; Calton, Mark; Aisbett, Brad
2010-06-01
Inter-day training reliability and variability in artistic gymnastics vaulting was determined using a customised infra-red timing gate and contact mat timing system. Thirteen Australian high performance gymnasts (eight males and five females) aged 11-23 years were assessed during two consecutive days of normal training. Each gymnast completed a number of vault repetitions per daily session. Inter-day variability of vault run-up velocities (at -18 to -12 m, -12 to -6 m, -6 to -2 m, and -2 to 0 m from the nearest edge of the beat board), and board contact, pre-flight, and table contact times were determined using mixed modelling statistics to account for random (within-subject variability) and fixed effects (gender, number of subjects, number of trials). The difference in the mean (Mdiff) and Cohen's effect sizes for reliability assessment and intra-class correlation coefficients, and the coefficient of variation percentage (CV%) were calculated for variability assessment. Approach velocity (-18 to -2m, CV = 2.4-7.8%) and board contact time (CV = 3.5%) were less variable measures when accounting for day-to-day performance differences, than pre-flight time (CV = 17.7%) and table contact time (CV = 20.5%). While pre-flight and table contact times are relevant training measures, approach velocity and board contact time are more reliable when quantifying vaulting performance.
Variability of gait, bilateral coordination, and asymmetry in women with fibromyalgia.
Heredia-Jimenez, J; Orantes-Gonzalez, E; Soto-Hermoso, V M
2016-03-01
To analyze how fibromyalgia affected the variability, asymmetry, and bilateral coordination of gait walking at comfortable and fast speeds. 65 fibromyalgia (FM) patients and 50 healthy women were analyzed. Gait analysis was performed using an instrumented walkway (GAITRite system). Average walking speed, coefficient of variation (CV) of stride length, swing time, and step width data were obtained and bilateral coordination and gait asymmetry were analyzed. FM patients presented significantly lower speeds than the healthy group. FM patients obtained significantly higher values of CV_StrideLength (p=0.04; p<0.001), CV_SwingTime (p<0.001; p<0.001), CV_StepWidth (p=0.004; p<0.001), phase coordination index (p=0.01; p=0.03), and p_CV (p<0.001; p=0.001) than the control group, walking at comfortable or fast speeds. Gait asymmetry only showed significant differences in the fast condition. FM patients walked more slowly and presented a greater variability of gait and worse bilateral coordination than healthy subjects. Gait asymmetry only showed differences in the fast condition. The variability and the bilateral coordination were particularly affected by FM in women. Therefore, variability and bilateral coordination of gait could be analyzed to complement the gait evaluation of FM patients. Copyright © 2016 Elsevier B.V. All rights reserved.
NASA Astrophysics Data System (ADS)
Swami, D.; Parthasarathy, D.; Dave, P.
2016-12-01
Climate variability (CV) has adverse impact on crop production and inadequate research carried out to assess the impact of CV on crop production has aggravated the ability of farmers to adapt (Jones et al., 2000). A better understanding of CV is required to reduce the vulnerability of farmers towards existing and future CV. Further, a wide variation in policies related to climate change exists at global level and considering the state/nation as a single unit for policy formulations may lead to under-representation of regional problems. Hence, the present work chooses to focus on CVassessment at the regional/district level of Maharashtra state in India. Here, interannual variability of wet and dry spells from year 1951-2013, are used as a measure of CV. Statistical declining trend of wet spells for (12/34) districts was observed across all the districts of Maharashtra. Districts showing highest change in wet spell pre and post 1976/77 are Beed, Latur and Osmanabad belong to Central Maharashtra Plateau zone and Western Maharashtra scarcity zone. Dry spells for (8/34) districts were found to statistically increase across all the districts of Maharashtra. Washim, Yavatmal of Vidarbha zone; and Latur, Parbhani of Amravati division belonging to Central Maharashtra Plateau zone and Central Vidarbha zone are found to reflect the large variation in their behavior pre and post 1976/77. Findings reveal that districts from the same agro-climate zones respond differently to CV, indicating significant spatial heterogeneity within the region. Trend in monsoon variability was found to be prominent after 1976/77, suggesting an enhanced role of climate change on climate variability after 1977. It necessitates separate policy formulation related to CV and agriculture for each district to bring out the solution for regional issues (socio-political, farmers, agriculturalists, economical) more clearly. Further we have attempted to link agriculture vulnerability and crop sensitivity to CV. Results signify spatial and temporal variability of different agro-ecological and climate parameters; suitable adaptation measures to famers and policy makers need to address this change. The findings can be utilized by farmers and policy makers while formulating agricultural policies and adaptation measures related to climate change.
Li, Tsai-Chung; Yang, Chun-Pai; Tseng, Shih-Ting; Li, Chia-Ing; Liu, Chiu-Shong; Lin, Wen-Yuan; Hwang, Kai-Lin; Yang, Sing-Yu; Chiang, Jen-Huai; Lin, Cheng-Chieh
2017-09-01
The relationship between glycemic variability and the incidence of Alzheimer disease (AD) in patients with type 2 diabetes mellitus (T2DM) is unclear. The aim of this study was to examine visit-to-visit variations in fasting plasma glucose (FPG) and glycated hemoglobin (HbA 1c ) represented by the coefficient of variation (CV) and to determine whether they were independently associated with AD, irrespective of HbA 1c and other traditional risk factors in such patients. Patients with T2DM enrolled in the National Diabetes Care Management Program, age ≥60 years, and without diagnosis of AD ( n = 16,706) were included in the study. Potential risk factors were analyzed using extended Cox proportional hazards regression models for competing risk of mortality on AD incidence. During a median follow-up of 8.88 years, 831 incident cases of AD were identified, with a crude incidence rate of 3.5/1,000 person-years. After adjustment for sociodemographic factors, lifestyle behaviors, diabetes-related variables, FPG and HbA 1c , drug-related variables, and comorbidities, both FPG CV and HbA 1c CV were found to be significant predictors of AD, with corresponding hazard ratios of 1.27 (95% CI 1.06-1.52) for the third tertile in FPG CV and 1.32 (95% CI 1.11-1.58) for the third tertile in HbA 1c CV. FPG CV and HbA 1c CV are independently associated with AD. The associations between glycemic variability and AD demonstrated in this study suggest a linked pathophysiological mechanism, which is worthy of further investigation. Further research is required to confirm our results and to evaluate whether FPG CV and HbA 1c CV can be valuable therapeutic targets for patients with T2DM at risk. © 2017 by the American Diabetes Association.
The use of designed experiments in the process development of continuous propellant mixing
NASA Technical Reports Server (NTRS)
Campbell, J. A.; Clemons, K. T.; Wong, M. K.
1993-01-01
A continuous mix pilot plant was constructed at Aerojet Propulsion Division in Sacramento, California to develop a robust propellant mixing process for the full scale plant that was to be built at the NASA Advanced Solid Rocket Motor facility Yellow Creek, Mississippi. The plant was used to conduct dozens of subsystem and full system mixing tests for evaluation of equipment, processing methods, and control schemes for later use at the production plant. As a culmination to this work, a series of designed experiments were conducted using an eight run Taguchi analysis with four factors at two levels each to determine the primary effect of processing parameters on propellant ballistic and mechanical properties. The factors examined in these runs included the propellant production rate (454 (1000) and 622 kg/hr (1371 Ib/hr)), the product temperature out of the mixer (49 (120) and 63 deg C (145 deg F)), mixer screw speed (75 and 90 rpm), and the deaerator excess capacity (20 and 80 percent). Measured response variables included the uncured and cured density, Crawford Bomb liquid strand burning rates, and selected mechanical properties. The experiment revealed that several of the response variables displayed significant changes from run-to-run with the product temperature being the single most important factor. After concluding this experiment, a twenty-six hour confirmation run was conducted to verify the conclusions reached in the designed experiment. The extended run produced over 12,250 kgs (27,000 lbs) of propellant meeting all of the pre-run targeted properties including density (1.803 g/cc (0.065 lb/in(exp 3)) with a 0.12 percent coefficient of variation (CV) at 25 deg C (77 deg F)), liquid strand burn rate (0.889 cm/s (0.350 in/s) with a 0.69 percent CV at 4210 KPa (610 psig), 15.6 deg C (60 deg F)), nominal maximum stress (828 KPa (120 psig) with a 2.84 percent CV, S&E at 25 deg C (77 deg F), 5.08 cm/min (2 in/min)), strain at nominal maximum (47.4 percent with a 3.96 percent CV), and initial tangent modulus (5349 KPa (775 psig) with a 7.26 percent CV).
Hamer, Mark; Steptoe, Andrew; Endrighi, Romano
2016-01-01
Abstract Cardiovascular (CV) responses to mental stress are prospectively associated with poor CV outcomes. The association between CV responses to mental stress and reaction times (RTs) in aging individuals may be important but warrants further investigation. The present study assessed RTs to examine associations with CV responses to mental stress in healthy, older individuals using robust regression techniques. Participants were 262 men and women (mean age = 63.3 ± 5.5 years) from the Whitehall II cohort who completed a RT task (Stroop) and underwent acute mental stress (mirror tracing) to elicit CV responses. Blood pressure, heart rate, and heart rate variability were measured at baseline, during acute stress, and through a 75‐min recovery. RT measures were generated from an ex‐Gaussian distribution that yielded three predictors: mu‐RT, sigma‐RT, and tau‐RT, the mean, standard deviation, and mean of the exponential component of the normal distribution, respectively. Decreased intraindividual RT variability was marginally associated with greater systolic (B = −.009, SE = .005, p = .09) and diastolic (B = −.004, SE = .002, p = .08) blood pressure reactivity. Decreased intraindividual RT variability was associated with impaired systolic blood pressure recovery (B = −.007, SE = .003, p = .03) and impaired vagal tone (B = −.0047, SE = .0024, p = .045). Study findings offer tentative support for an association between RTs and CV responses. Despite small effect sizes and associations not consistent across predictors, these data may point to a link between intrinsic neuronal plasticity and CV responses. PMID:26894967
NASA Astrophysics Data System (ADS)
Iijima, Katsuya; Kameyama, Yumi; Akishita, Masahiro; Ouchi, Yasuyoshi; Yanagimoto, Shintaro; Imai, Yasushi; Yahagi, Naoki; Lopez, Guillaume; Shuzo, Masaki; Yamada, Ichiro
An increase in short-term blood pressure (BP) variability is a characteristic feature in the elderly. It makes the management of hemodynamics more difficult, because it is frequently seen disturbed baro-reflex function and increased arterial stiffness, leading to isolated systolic hypertension. Large BP variability aggravates hypertensive target organ damage and is an independent risk factor for the cardiovascular (CV) events in elderly hypertensive patients. Therefore, appropriate control in BP is indispensable to manage lifestyle-related diseases and to prevent subsequent CV events. In addition, accumulating recent reports show that excessive BP variability is also associated with a decline in cognitive function and fall in the elderly. In the clinical settings, we usually evaluate their health condition, mainly with single point BP measurement using cuff inflation. However, unfortunately we are not able to find the close changes in BP by the traditional way. Here, we can show our advantageous approach of continuous BP monitoring using newly developing device `wearable BP sensing' without a cuff stress in the elderly. The new device could reflect systolic BP and its detailed changes, in consistent with cuff-based BP measurement. Our new challenge suggests new possibility of its clinical application with high accuracy.
Antisperm contraceptive vaccines: where we are and where we are going?
Naz, Rajesh K
2011-07-01
This is a review of current status and future perspectives on the development of antisperm contraceptive vaccines (CV) and immunocontraceptives. The development of antisperm CV is an exciting proposition. There is a strong rationale and recent data indicating that this proposition can translate into reality. The search for novel sperm-specific antigens/genes, that can be used for CV, continues using various recent developing technologies. Various approaches of proteomics, genomics, reproductive biology, mucosal immunity and vaccinology and several novel technologies such as gene knockout technology, phage display technology, antibody engineering, differential display technique, subtractive hybridization, and hybridoma technology are being used to delineate sperm-specific antigens and construct CV. Various sperm antigens/genes have been delineated, cloned, and sequenced from various laboratories. Vaccination with these sperm antigens (recombinant/synthetic peptide/DNA) causes a reversible contraceptive effect in females and males of various animal species, by inducing a systemic and local antisperm antibody response. The efficacy is enhanced by combination vaccination, including peptides based on various sperm antigens. Several human novel scFv antibodies with unique complementarity-determining regions (CDRs), that react with specific well-defined fertility-related sperm antigens, have been synthesized. These human infertility-related antibodies may find application in the development of novel immunocontraceptives. Besides finding the novel sperm antigens, the present and future focus is on enhancing the immunogenicity, bioefficacy, and on obliterating the inter-individual variability of the immune response, and proceeding for primate and human clinical trials. Multi-epitope vaccines combining sperm proteins involved in various steps of fertilization cascade have been found to enhance the immunogenicity and bioefficacy of the contraceptive effect. The in vitro synthesis of infertility-related human scFv antibodies may provide unique once-a-month immunocontraceptives, the first of its kind, for human use. The multi-epitope CV and preformed engineered human antibodies of defined specificity may obliterate the concern related to inter-individual variability of the immune response. © 2011 John Wiley & Sons A/S.
Zhang, Dan; Jia, Huan; Li, Weiming; Hou, Yingchun; Lu, Shaoying; He, Shuixiang
2016-01-01
CD44, especially the isoforms with variable exons (CD44v), is a promising biomarker for the detection of cancer. To develop a CD44v-specific probe, we screened a 7-mer phage peptide library against the CD44v3-v10 protein using an improved subtractive method. The consensus sequences with the highest frequency (designated CV-1) emerged after four rounds of panning. The binding affinity and specificity of the CV-1 phage and the synthesized peptide for the region of CD44 encoded by the variable exons were confirmed using enzyme-linked immunosorbent assay and competitive inhibition assays. Furthermore, the binding of the CV-1 probe to gastric cancer cells and tissues was validated using immunofluorescence and immunohistochemistry assays. CV-1 sensitively and specifically bound to CD44v on cancer cells and tissues. Thus, CV-1 has the potential to serve as a promising probe for cancer molecular imaging and target therapy. © 2015 Society for Laboratory Automation and Screening.
Wawrzyniak, Andrew J; Hamer, Mark; Steptoe, Andrew; Endrighi, Romano
2016-05-01
Cardiovascular (CV) responses to mental stress are prospectively associated with poor CV outcomes. The association between CV responses to mental stress and reaction times (RTs) in aging individuals may be important but warrants further investigation. The present study assessed RTs to examine associations with CV responses to mental stress in healthy, older individuals using robust regression techniques. Participants were 262 men and women (mean age = 63.3 ± 5.5 years) from the Whitehall II cohort who completed a RT task (Stroop) and underwent acute mental stress (mirror tracing) to elicit CV responses. Blood pressure, heart rate, and heart rate variability were measured at baseline, during acute stress, and through a 75-min recovery. RT measures were generated from an ex-Gaussian distribution that yielded three predictors: mu-RT, sigma-RT, and tau-RT, the mean, standard deviation, and mean of the exponential component of the normal distribution, respectively. Decreased intraindividual RT variability was marginally associated with greater systolic (B = -.009, SE = .005, p = .09) and diastolic (B = -.004, SE = .002, p = .08) blood pressure reactivity. Decreased intraindividual RT variability was associated with impaired systolic blood pressure recovery (B = -.007, SE = .003, p = .03) and impaired vagal tone (B = -.0047, SE = .0024, p = .045). Study findings offer tentative support for an association between RTs and CV responses. Despite small effect sizes and associations not consistent across predictors, these data may point to a link between intrinsic neuronal plasticity and CV responses. © 2016 The Authors. Psychophysiology published by Wiley Periodicals, Inc. on behalf of Society for Psychophysiological Research.
Diaz, K M; Veerabhadrappa, P; Kashem, M A; Thakkar, S R; Feairheller, D L; Sturgeon, K M; Ling, C; Williamson, S T; Kretzschmar, J; Lee, H; Grimm, H; Babbitt, D M; Vin, C; Fan, X; Crabbe, D L; Brown, M D
2013-11-01
The purpose of this study was to investigate the association of visit-to-visit and 24-h blood pressure (BP) variability with markers of endothelial injury and vascular function. We recruited 72 African Americans who were non-diabetic, non-smoking and free of cardiovascular (CV) and renal disease. Office BP was measured at three visits and 24-h ambulatory BP monitoring was conducted to measure visit-to-visit and 24-h BP variability, respectively. The 5-min time-course of brachial artery flow-mediated dilation and nitroglycerin-mediated dilation were assessed as measures of endothelial and smooth muscle function. Fasted blood samples were analyzed for circulating endothelial microparticles (EMPs). Significantly lower CD31+CD42- EMPs were found in participants with high visit-to-visit systolic blood pressure (SBP) variability or high 24-h diastolic blood pressure (DBP) variability. Participants with high visit-to-visit DBP variability had significantly lower flow-mediated dilation and higher nitroglycerin-mediated dilation at multiple time-points. When analyzed as continuous variables, 24-h mean arterial pressure variability was inversely associated with CD62+ EMPs; visit-to-visit DBP variability was inversely associated with flow-mediated dilation normalized by smooth muscle function and was positively associated with nitroglycerin-mediated dilation; and 24-h DBP variability was positively associated with nitroglycerin-mediated dilation. All associations were independent of age, gender, body mass index and mean BP. In conclusion, in this cohort of African Americans visit-to-visit and 24-h BP variability were associated with measures of endothelial injury, endothelial function and smooth muscle function. These results suggest that BP variability may influence the pathogenesis of CV disease, in part, through influences on vascular health.
The match-to-match variation of match-running in elite female soccer.
Trewin, Joshua; Meylan, César; Varley, Matthew C; Cronin, John
2018-02-01
The purpose of this study was to examine the match-to-match variation of match-running in elite female soccer players utilising GPS, using full-match and rolling period analyses. Longitudinal study. Elite female soccer players (n=45) from the same national team were observed during 55 international fixtures across 5 years (2012-2016). Data was analysed using a custom built MS Excel spreadsheet as full-matches and using a rolling 5-min analysis period, for all players who played 90-min matches (files=172). Variation was examined using co-efficient of variation and 90% confidence limits, calculated following log transformation. Total distance per minute exhibited the smallest variation when both the full-match and peak 5-min running periods were examined (CV=6.8-7.2%). Sprint-efforts were the most variable during a full-match (CV=53%), whilst high-speed running per minute exhibited the greatest variation in the post-peak 5-min period (CV=143%). Peak running periods were observed as slightly more variable than full-match analyses, with the post-peak period very-highly variable. Variability of accelerations (CV=17%) and Player Load (CV=14%) was lower than that of high-speed actions. Positional differences were also present, with centre backs exhibiting the greatest variation in high-speed movements (CV=41-65%). Practitioners and researchers should account for within player variability when examining match performances. Identification of peak running periods should be used to assist worst case scenarios. Whilst micro-sensor technology should be further examined as to its viable use within match-analyses. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.
Buscemi, Silvio; Cosentino, Loretta; Rosafio, Giuseppe; Morgana, Manuela; Mattina, Alessandro; Sprini, Delia; Verga, Salvatore; Rini, Giovam Battista
2013-06-01
The role of glycemic index of the diet in glucose control and cardiovascular prevention is still not clear. The aim of this study was to determine the effects of hypocaloric diets with different glycemic indexes and glycemic loads on endothelial function and glycemic variability in nondiabetic participants at increased cardiovascular risk. Forty nondiabetic obese participants were randomly assigned to a three-month treatment with either a low glycemic index (LGI; n=19) or high glycemic index (HGI; n=21) hypocaloric diet with similar macronutrient and fiber content. Endothelial function was measured as flow-mediated dilatation (FMD) of the brachial artery before and after dieting. In addition, 48-h continuous subcutaneous glucose monitoring was done before and after dieting in a subgroup of 24 participants. The amount of weight loss after dieting was similar in both groups. The glycemic index of the diet significantly influenced the FMD (P<0.005). In particular, the change of FMD was 2.3±2.6% following the LGI diet, and -0.9±3.6% after the HGI diet (P<0.005). The mean 48-h glycemia decreased significantly after dietary treatment (P<0.05), but no significant effect of the glycemic index of the diet on results was observed. The glycemic index of the diet significantly influenced the 48-h glycemic variability measured as coefficient of variability (CV%; P<0.001). The CV% decreased after the LGI diet (from 23.5 to 20.0%) and increased after the HGI diet (from 23.6 to 26.6%). The change in percentage of FMD was inversely correlated with the change in the 48-h glycemic CV% (r=-0.45; P<0.05). Endothelial function and glycemic variability ameliorate in association with the adherence to an LGI hypocaloric diet in nondiabetic obese persons. ISRCTN56834511. Copyright © 2012 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.
Hafer, Jocelyn F; Boyer, Katherine A
2017-01-01
Coordination variability (CV) quantifies the variety of movement patterns an individual uses during a task and may provide a measure of the flexibility of that individual's motor system. While there is growing popularity of segment CV as a marker of motor system health or adaptability, it is not known how many strides of data are needed to reliably calculate CV. This study aimed to determine the number of strides needed to reliably calculate CV in treadmill walking and running, and to compare CV between walking and running in a healthy population. Ten healthy young adults walked and ran at preferred speeds on a treadmill and a modified vector coding technique was used to calculate CV for the following segment couples: pelvis frontal plane vs. thigh frontal plane, thigh sagittal plane vs. shank sagittal plane, thigh sagittal plane vs. shank transverse plane, and shank transverse plane vs. rearfoot frontal plane. CV for each coupling of interest was calculated for 2-15 strides for each participant and gait type. Mean CV was calculated across the entire gait cycle and, separately, for 4 phases of the gait cycle. For running and walking 8 and 10 strides, respectively, were sufficient to obtain a reliable CV estimate. CV was significantly different between walking and running for the thigh vs. shank couple comparisons. These results suggest that 10 strides of treadmill data are needed to reliably calculate CV for walking and running. Additionally, the differences in CV between walking and running suggest that the role of knee (i.e., inter-thigh- shank) control may differ between these forms of locomotion. Copyright © 2016 Elsevier B.V. All rights reserved.
Variability of Metabolic Power Data in Elite Soccer Players During Pre-Season Matches
Hoppe, Matthias Wilhelm; Baumgart, Christian; Slomka, Mirko; Polglaze, Ted; Freiwald, Jürgen
2017-01-01
Abstract This study aimed to determine the within-subject variability of GPS-derived metabolic power data in elite soccer players across several pre-season matches and compare the variability of high metabolic power, velocity, acceleration and deceleration running. Additionally, differences in metabolic power data among playing positions and relationships with various physical abilities were also investigated. Metabolic power data from 12 outfield starting players competing in the German Bundesliga were collected during five pre-season matches using GPS-technology (10 Hz). The players were also tested for speed, agility, power and intermittent endurance. Variability of global metabolic power data such as energy expenditure (CV = 2.2-7.0%) was lower than that for high-intensity including time ≥20 W·kg-1 (CV = 14.0-26.2%). Variability of high metabolic power (≥20 W·kg-1; CV = 14.1 ± 3.5%) was comparable to that of high velocity (≥15.5 km·h-1; CV = 17.0 ± 6.2%), acceleration (≥3 m·s-2; CV = 11.1 ± 5.1%) and deceleration running (≤-3 m·s-2; CV = 11.9 ± 4.5%) (p > 0.05, ES < 0.2). Defenders had a largely higher overall energy expenditure than midfielders and attackers (p < 0.01, ES > 0.6). Overall energy expenditure and cost were largely to very largely correlated with 5 m speed and 22 m agility sprint time and counter movement jump height (r = -0.70-0.69, p < 0.05). The detected variability indicates that global GPS-derived metabolic power data in elite soccer players from a single preseason match should be preferably used for practical applications. Contrary, high-intensity indicators should be interpreted cautiously and repeated match observations are recommended to establish meaningful high-intensity profiles of the players. Differences among playing positions and relationships with explosive physical abilities indicate that metabolic power analyses can provide new insights into the mechanics and energetics of soccer. PMID:28828094
Variability of Metabolic Power Data in Elite Soccer Players During Pre-Season Matches.
Hoppe, Matthias Wilhelm; Baumgart, Christian; Slomka, Mirko; Polglaze, Ted; Freiwald, Jürgen
2017-09-01
This study aimed to determine the within-subject variability of GPS-derived metabolic power data in elite soccer players across several pre-season matches and compare the variability of high metabolic power, velocity, acceleration and deceleration running. Additionally, differences in metabolic power data among playing positions and relationships with various physical abilities were also investigated. Metabolic power data from 12 outfield starting players competing in the German Bundesliga were collected during five pre-season matches using GPS-technology (10 Hz). The players were also tested for speed, agility, power and intermittent endurance. Variability of global metabolic power data such as energy expenditure (CV = 2.2-7.0%) was lower than that for high-intensity including time ≥20 W·kg -1 (CV = 14.0-26.2%). Variability of high metabolic power (≥20 W·kg -1 ; CV = 14.1 ± 3.5%) was comparable to that of high velocity (≥15.5 km·h -1 ; CV = 17.0 ± 6.2%), acceleration (≥3 m·s -2 ; CV = 11.1 ± 5.1%) and deceleration running (≤-3 m·s -2 ; CV = 11.9 ± 4.5%) (p > 0.05, ES < 0.2). Defenders had a largely higher overall energy expenditure than midfielders and attackers (p < 0.01, ES > 0.6). Overall energy expenditure and cost were largely to very largely correlated with 5 m speed and 22 m agility sprint time and counter movement jump height (r = -0.70-0.69, p < 0.05). The detected variability indicates that global GPS-derived metabolic power data in elite soccer players from a single preseason match should be preferably used for practical applications. Contrary, high-intensity indicators should be interpreted cautiously and repeated match observations are recommended to establish meaningful high-intensity profiles of the players. Differences among playing positions and relationships with explosive physical abilities indicate that metabolic power analyses can provide new insights into the mechanics and energetics of soccer.
Induced Mutations for Improving Production on Bread and Durum Wheat
NASA Astrophysics Data System (ADS)
Stamo, Ilirjana; Ylli, Ariana; Dodbiba, Andon
2007-04-01
Wheat is a very important crop and has been bred for food and its improvement is continuous from cross-breeding. Radiation and chemically induced mutations have provided variability in selection for novel varieties. Four bread and one durum wheat cultivars were exposed to gamma rays, Cs 137 with doses 10, 15 and 20 krad (2000 seeds of each dose and cultivars). We have isolated mutant plants with height reduced and on cv Progress spike without chaff.
Induced Mutations for Improving Production on Bread and Durum Wheat
DOE Office of Scientific and Technical Information (OSTI.GOV)
Stamo, Ilirjana; Ylli, Ariana; Dodbiba, Andon
Wheat is a very important crop and has been bred for food and its improvement is continuous from cross-breeding. Radiation and chemically induced mutations have provided variability in selection for novel varieties. Four bread and one durum wheat cultivars were exposed to gamma rays, Cs 137 with doses 10, 15 and 20 krad (2000 seeds of each dose and cultivars). We have isolated mutant plants with height reduced and on cv Progress spike without chaff.
Liu, Jiakai; Tan, Chin Hon; Badrick, Tony; Loh, Tze Ping
2018-02-01
An increase in analytical imprecision (expressed as CV a ) can introduce additional variability (i.e. noise) to the patient results, which poses a challenge to the optimal management of patients. Relatively little work has been done to address the need for continuous monitoring of analytical imprecision. Through numerical simulations, we describe the use of moving standard deviation (movSD) and a recently described moving sum of outlier (movSO) patient results as means for detecting increased analytical imprecision, and compare their performances against internal quality control (QC) and the average of normal (AoN) approaches. The power of detecting an increase in CV a is suboptimal under routine internal QC procedures. The AoN technique almost always had the highest average number of patient results affected before error detection (ANPed), indicating that it had generally the worst capability for detecting an increased CV a . On the other hand, the movSD and movSO approaches were able to detect an increased CV a at significantly lower ANPed, particularly for measurands that displayed a relatively small ratio of biological variation to CV a. CONCLUSION: The movSD and movSO approaches are effective in detecting an increase in CV a for high-risk measurands with small biological variation. Their performance is relatively poor when the biological variation is large. However, the clinical risks of an increase in analytical imprecision is attenuated for these measurands as an increased analytical imprecision will only add marginally to the total variation and less likely to impact on the clinical care. Copyright © 2017 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.
NASA Astrophysics Data System (ADS)
Erić, Suzana; Logar, Mihovil; Milovanović, Dragan; Babič, Danilo; Adnađević, Borivoj
2009-02-01
The study discusses the application of the Ti-in-biotite geothermometer of Henry et al. (2005) to the example of biotites from non-graphitic peraluminous micaschists of Central Serbia. Three petrographically different micaschists were distinguished on the basis of the following mineral assemblages: CV1 (St-Grt-Bt-Ms-Pg-Pl-Qtz), CV2 (Grt-St-Ky-Bt-Ms-Pl-Qtz) and RH (Grt-St-Bt-Ms-Pl-Qtz). Applying different geothermobarometers it was estimated that the studied micaschists were metamorphosed at average temperatures and pressures of 530 °C and 520 MPa (CV1incl), 580 °C and 670 MPa (CV1), 630 °C and 700 MPa (CV2) and 550 °C, 680 MPa (RH). The average temperatures obtained by the Ti-in-biotite method revealed uniform values for CV1 and CV2 micaschists and these values are very similar to the temperatures obtained by other methods. In contrast, the application of Ti-in-biotite geothermometer for RH micaschist yields the temperature difference of 85-110 °C. The variability of temperature is interpreted as a result of a positive correlation of Ti contents and XMg values in RH biotite, which is in disagreement with the principles of the Ti-in-biotite method. The positive Ti-XMg correlation is a result of the compositional variability shown by RH biotites from different samples, which can possibly be related to compositional inhomogeneities of the pelitic protolith. On the other hand, the Ti-in-biotite geothermometer for CV2 biotite gave very uniform temperatures despite variable Ti contents (Ti = 0.260, sd = 0.018 apfu). This is explained as result of the low sensitivity of Ti-in-biotite geothermometer for high Ti concentrations (> 0.25 apfu).
Diaz, Keith M; Veerabhadrappa, Praveen; Kashem, Mohammed A; Feairheller, Deborah L; Sturgeon, Kathleen M; Williamson, Sheara T; Crabbe, Deborah L; Brown, Michael D
2012-01-01
Visit-to-visit clinic blood pressure variability (BPV) and 24-h BPV have both been identified as independent risk factors for cardiovascular (CV) morbidity and mortality; however, the mechanisms contributing to the increased CV risk as yet are unclear. The purpose of this study was to assess the relationship between BPV and endothelial function in a cohort of putatively healthy African Americans. A total of 36 African Americans who were sedentary, non-diabetic, non-smoking, free of CV and renal disease and not on antihypertensive medication followed an American Heart Association low fat, low salt diet for 6 weeks. Upon completion of the 6-week dietary stabilization period, participants underwent 24-h ambulatory BP monitoring and had their office blood pressure (BP) measured on 3 separate days. Right brachial artery diameter was assessed at rest, during reactive hyperemia (flow-mediated vasodilation: FMD), and after nitroglycerin administration (nitroglycerin-mediated vasodilation: NMD). Participants classified as having decreased endothelial function according to either %FMD or the FMD/NMD ratio had significantly higher 24-h BPV and a trend for higher visit-to-visit BPV when compared with participants with normal endothelial function. Continuous variable analyses revealed a significant positive association between NMD and 24-h diastolic BPV (DBPV). Visit-to-visit systolic BPV (SBPV), 24-h SBPV and 24-h DBPV were all negatively associated with the FMD/NMD ratio. All relationships remained significant after adjustment for age, body mass index and mean BP levels. These results may suggest that BPV is increased in African Americans with decreased endothelial function and is associated with the vascular smooth muscle response to nitric oxide.
Valcke, Mathieu; Haddad, Sami
2015-01-01
The objective of this study was to compare the magnitude of interindividual variability in internal dose for inhalation exposure to single versus multiple chemicals. Physiologically based pharmacokinetic models for adults (AD), neonates (NEO), toddlers (TODD), and pregnant women (PW) were used to simulate inhalation exposure to "low" (RfC-like) or "high" (AEGL-like) air concentrations of benzene (Bz) or dichloromethane (DCM), along with various levels of toluene alone or toluene with ethylbenzene and xylene. Monte Carlo simulations were performed and distributions of relevant internal dose metrics of either Bz or DCM were computed. Area under the blood concentration of parent compound versus time curve (AUC)-based variability in AD, TODD, and PW rose for Bz when concomitant "low" exposure to mixtures of increasing complexities occurred (coefficient of variation (CV) = 16-24%, vs. 12-15% for Bz alone), but remained unchanged considering DCM. Conversely, AUC-based CV in NEO fell (15 to 5% for Bz; 12 to 6% for DCM). Comparable trends were observed considering production of metabolites (AMET), except for NEO's CYP2E1-mediated metabolites of Bz, where an increased CV was observed (20 to 71%). For "high" exposure scenarios, Cmax-based variability of Bz and DCM remained unchanged in AD and PW, but decreased in NEO (CV= 11-16% to 2-6%) and TODD (CV= 12-13% to 7-9%). Conversely, AMET-based variability for both substrates rose in every subpopulation. This study analyzed for the first time the impact of multiple exposures on interindividual variability in toxicokinetics. Evidence indicates that this impact depends upon chemical concentrations and biochemical properties, as well as the subpopulation and internal dose metrics considered.
Rayar, Michel; Tron, Camille; Jézéquel, Caroline; Beaurepaire, Jean Marie; Petitcollin, Antoine; Houssel-Debry, Pauline; Camus, Christophe; Verdier, Marie Clémence; Dehlawi, Ammar; Lakéhal, Mohamed; Desfourneaux, Véronique; Meunier, Bernard; Sulpice, Laurent; Bellissant, Eric; Boudjema, Karim; Lemaitre, Florian
2018-03-01
Tacrolimus (TAC) is the cornerstone of immunosuppressive regimen in liver transplantation (LT). Its pharmacokinetics is characterized by a high interpatient and intrapatient variability (IPV) leading to an unpredictable dose-response relationship. The aim of our study was to evaluate the impact of TAC IPV (IPV) on graft and patient outcomes after LT. We retrospectively analyzed 812 LT recipients treated with TAC. The IPV of TAC concentrations was estimated by calculating the coefficient of variation (CV) of whole blood trough concentrations. Patients were categorized in 2 groups: low IPV (CV < 40%) and high IPV (CV ≥ 40%). There were significantly more neurologic complications (31.2% vs 16.6%, P < 0.001), cardiovascular complications (19.7% vs 9.7%, P < 0.001), and acute renal failure requiring dialysis (8.5% vs 2.2%, P < 0.001) in the high CV group than in the low CV group. Moreover, graft survival was significantly poorer in the high CV group (hazard ratio, 1.42; 95% confidence interval, 1.04-1.95; P = 0.03). A pretransplantation elevated Model for End-Stage Liver Disease score (P < 0.001) and Child-Pugh grade (P < 0.001) were identified as risk factors for presenting a high CV. A high CV of TAC concentrations was found to be predictive of TAC-related toxicity and poorer survival.
Walsh, Michael; Manns, Braden J; Klarenbach, Scott; Tonelli, Marcello; Hemmelgarn, Brenda; Culleton, Bruce
2010-04-01
Hyperphosphatemia is common among patients receiving dialysis and is associated with increased mortality. Nocturnal hemodialysis (NHD) is a long, slow dialytic modality that may improve hyperphosphatemia and disorders of mineral metabolism. We performed a randomized-controlled trial of NHD compared with conventional hemodialysis (CvHD); in this paper, we report detailed results of mineral metabolism outcomes. Prevalent patients were randomized to receive NHD 5 to 6 nights per week for 6to 10 hours per night or to continue CvHD thrice weekly for 6 months. Oral phosphate binders and vitamin D analogs were adjusted to maintain phosphate, calcium and parathyroid hormone (PTH) levels within recommended targets. Compared with CvHD patients, patients in the NHD group had a significant decrease in serum phosphate over the course of the study (0.49 mmol/L, 95% confidence interval 0.24-0.74; P=0.002) despite a significant reduction in the use of phosphate binders. Sixty-one percent of patients in the NHD group compared with 20% in the CvHD group had a decline in intact PTH (P=0.003). Nocturnal hemodialysis lowers serum phosphate, calcium-phosphate product and requirement for phosphate binders. The effects of NHD on PTH are variable. The impact of these changes on long-term cardiovascular and bone-related outcomes requires further investigation.
Ferguson, Gail M; Nguyen, Jacqueline; Iturbide, Maria I
2017-01-01
Cultural variability (CV) is introduced as an overlooked dimension of cultural identity development pertaining to emphasizing and de-emphasizing the influence of a single cultural identity (i.e., cultural influence [CI]) on daily interactions and behaviors. The Cultural IDentity Influence Measure (CIDIM) is introduced as a novel measure of CI and CV, and hypothesis-driven validation is conducted in two samples along with exploration of associations between CV and well-being. A multicultural sample of 242 emerging adults participated in a daily diary study (Mage = 19.95 years, SDage = 1.40) by completing up to eight daily online surveys containing the CIDIM, criterion measures (ethnic identity, other group orientation, ethnic identity salience and daily variability in salience, social desirability), and measures of personal and interpersonal well-being. A second validation sample (n = 245) completed a 1-time survey with the CIDIM and a subset of criterion measures. Results using both samples show evidence of CI and CV and demonstrate the validity, reliability, and domain-sensitivity of the CIDIM. Further, CV made unique and positive contributions to predicting interaction quality after accounting for ethnic salience and variability in ethnic salience. An analytic approach utilizing standard deviations produced near-identical results to multilevel modeling and is recommended for parsimony. Ethnic minority and majority individuals make daily adjustments to play up and play down the influence of cultural identity on their social interactions and behaviors, and these adjustments predict interpersonal well-being. Cultural influence and cultural variability contribute to our emerging understanding of cultural identity as dynamic and agentic. (PsycINFO Database Record (c) 2017 APA, all rights reserved).
Discrete and continuous variables for measurement-device-independent quantum cryptography
DOE Office of Scientific and Technical Information (OSTI.GOV)
Xu, Feihu; Curty, Marcos; Qi, Bing
In a recent Article in Nature Photonics, Pirandola et al.1 claim that the achievable secret key rates of discrete-variable (DV) measurementdevice- independent (MDI) quantum key distribution (QKD) (refs 2,3) are “typically very low, unsuitable for the demands of a metropolitan network” and introduce a continuous-variable (CV) MDI QKD protocol capable of providing key rates which, they claim, are “three orders of magnitude higher” than those of DV MDI QKD. We believe, however, that the claims regarding low key rates of DV MDI QKD made by Pirandola et al.1 are too pessimistic. Here in this paper, we show that the secretmore » key rate of DV MDI QKD with commercially available high-efficiency single-photon detectors (SPDs) (for example, see http://www.photonspot.com/detectors and http://www.singlequantum.com) and good system alignment is typically rather high and thus highly suitable for not only long-distance communication but also metropolitan networks.« less
Discrete and continuous variables for measurement-device-independent quantum cryptography
Xu, Feihu; Curty, Marcos; Qi, Bing; ...
2015-11-16
In a recent Article in Nature Photonics, Pirandola et al.1 claim that the achievable secret key rates of discrete-variable (DV) measurementdevice- independent (MDI) quantum key distribution (QKD) (refs 2,3) are “typically very low, unsuitable for the demands of a metropolitan network” and introduce a continuous-variable (CV) MDI QKD protocol capable of providing key rates which, they claim, are “three orders of magnitude higher” than those of DV MDI QKD. We believe, however, that the claims regarding low key rates of DV MDI QKD made by Pirandola et al.1 are too pessimistic. Here in this paper, we show that the secretmore » key rate of DV MDI QKD with commercially available high-efficiency single-photon detectors (SPDs) (for example, see http://www.photonspot.com/detectors and http://www.singlequantum.com) and good system alignment is typically rather high and thus highly suitable for not only long-distance communication but also metropolitan networks.« less
Nibali, Maria L; Tombleson, Tom; Brady, Philip H; Wagner, Phillip
2015-10-01
Understanding typical variation of vertical jump (VJ) performance and confounding sources of its typical variability (i.e., familiarization and competitive level) is pertinent in the routine monitoring of athletes. We evaluated the presence of systematic error (learning effect) and nonuniformity of error (heteroscedasticity) across VJ performances of athletes that differ in competitive level and quantified the reliability of VJ kinetic and kinematic variables relative to the smallest worthwhile change (SWC). One hundred thirteen high school athletes, 30 college athletes, and 35 professional athletes completed repeat VJ trials. Average eccentric rate of force development (RFD), average concentric (CON) force, CON impulse, and jump height measurements were obtained from vertical ground reaction force (VGRF) data. Systematic error was assessed by evaluating changes in the mean of repeat trials. Heteroscedasticity was evaluated by plotting the difference score (trial 2 - trial 1) against the mean of the trials. Variability of jump variables was calculated as the typical error (TE) and coefficient of variation (%CV). No substantial systematic error (effect size range: -0.07 to 0.11) or heteroscedasticity was present for any of the VJ variables. Vertical jump can be performed without the need for familiarization trials, and the variability can be conveyed as either the raw TE or the %CV. Assessment of VGRF variables is an effective and reliable means of assessing VJ performance. Average CON force and CON impulse are highly reliable (%CV: 2.7% ×/÷ 1.10), although jump height was the only variable to display a %CV ≤SWC. Eccentric RFD is highly variable yet should not be discounted from VJ assessments on this factor alone because it may be sensitive to changes in response to training or fatigue that exceed the TE.
Park, So Young; Kim, Sun Young; Lee, Hye Mi; Hur, Kyu Yeon; Kim, Jae Hyeon; Lee, Moon-Kyu
2017-01-01
Background Despite the established benefits of diabetes camps for the continuing education of children with type 1 diabetes mellitus, little is known about the long-term metabolic benefits of diabetes camps for middle-aged and elderly people with type 2 diabetes mellitus (T2DM), especially in terms of glycosylated hemoglobin (HbA1c) variability. Methods The 1-year mean and variability of HbA1c before and after the diabetes camp was compared between the participants of the diabetes camp (n=57; median age 65 years [range, 50 to 86 years]; median diabetes duration 14 years [range, 1 to 48 years]). Additional case-control analysis compared the metabolic outcomes of the participants of the diabetes camp and their propensity score-matched controls who underwent conventional diabetes education (n=93). Results The levels of HbA1c during the first year after the diabetes camp were comparable to those of the matched controls (P=0.341). In an analysis of all participants of the diabetes camp, the 1-year mean±standard deviation (SD) of HbA1c decreased (P=0.010 and P=0.041) after the diabetes camp, whereas the adjusted SD and coefficient of variance (CV) of HbA1c did not decrease. The adjusted SD and CV significantly decreased after the diabetes camp in participants whose 1-year mean HbA1c was ≥6.5% before the diabetes camp (n=40) and those with a duration of diabetes less than 15 years (n=32). Conclusion The 1-year mean and SD of HbA1c decreased after the diabetes camp, with significant reduction in the adjusted SD and CV in those with higher baseline HbA1c and a shorter duration of diabetes. PMID:28447438
Psychosocial determinants of premature cardiovascular mortality differences within Hungary.
Kopp, Maria; Skrabski, Arpád; Szántó, Zsuzsa; Siegrist, Johannes
2006-09-01
The life expectancy gap between Central-Eastern European (CEE) countries, including Hungary, and Western Europe (WE) is mainly attributable to excess cardiovascular (CV) mortality in midlife. This study explores the contribution of socioeconomic, work related, psychosocial, and behavioural variables to explaining variations of middle aged male and female CV mortality across 150 sub-regions in Hungary. Cross sectional, ecological analyses. 150 sub-regions of Hungary. 12 643 people were interviewed in Hungarostudy 2002 survey, representing the Hungarian population according to sex, age, and sub-regions. Independent variables were income, education, control in work, job insecurity, weekend working hours, social support, depression, hostility, anomie, smoking, body mass index, and alcohol misuse. Gender specific standardised premature (45-64 years) total CV, ischaemic heart disease, and cerebrovascular mortality rates in 150 sub-regions of Hungary. Low education and income were the most important determinants of mid-aged CV mortality differences across sub-regions. High weekend workload, low social support at work, and low control at work account for a large part of variation in male premature CV mortality rates, whereas job insecurity, high weekend workload, and low control at work contribute most noticeably to variations in premature CV mortality rates among women. Low social support from friends, depression, anomie, hostility, alcohol misuse and cigarette smoking can also explain a considerable part of variations of premature CV mortality differences. Variations in middle aged CV mortality rates in a rapidly changing society in CEE are largely accounted for by distinct unfavourable working and other psychosocial stress conditions.
Variability in Wechsler Adult Intelligence Scale-IV subtest performance across age.
Wisdom, Nick M; Mignogna, Joseph; Collins, Robert L
2012-06-01
Normal Wechsler Adult Intelligence Scale (WAIS)-IV performance relative to average normative scores alone can be an oversimplification as this fails to recognize disparate subtest heterogeneity that occurs with increasing age. The purpose of the present study is to characterize the patterns of raw score change and associated variability on WAIS-IV subtests across age groupings. Raw WAIS-IV subtest means and standard deviations for each age group were tabulated from the WAIS-IV normative manual along with the coefficient of variation (CV), a measure of score dispersion calculated by dividing the standard deviation by the mean and multiplying by 100. The CV further informs the magnitude of variability represented by each standard deviation. Raw mean scores predictably decreased across age groups. Increased variability was noted in Perceptual Reasoning and Processing Speed Index subtests, as Block Design, Matrix Reasoning, Picture Completion, Symbol Search, and Coding had CV percentage increases ranging from 56% to 98%. In contrast, Working Memory and Verbal Comprehension subtests were more homogeneous with Digit Span, Comprehension, Information, and Similarities percentage of the mean increases ranging from 32% to 43%. Little change in the CV was noted on Cancellation, Arithmetic, Letter/Number Sequencing, Figure Weights, Visual Puzzles, and Vocabulary subtests (<14%). A thorough understanding of age-related subtest variability will help to identify test limitations as well as further our understanding of cognitive domains which remain relatively steady versus those which steadily decline.
Young, William R; Shreve, Lauren; Quinn, Emma Jane; Craig, Cathy; Bronte-Stewart, Helen
2016-07-01
Gait disturbances are a common feature of Parkinson's disease, one of the most severe being freezing of gait. Sensory cueing is a common method used to facilitate stepping in people with Parkinson's. Recent work has shown that, compared to walking to a metronome, Parkinson's patients without freezing of gait (nFOG) showed reduced gait variability when imitating recorded sounds of footsteps made on gravel. However, it is not known if these benefits are realised through the continuity of the acoustic information or the action-relevance. Furthermore, no study has examined if these benefits extend to PD with freezing of gait. We prepared four different auditory cues (varying in action-relevance and acoustic continuity) and asked 19 Parkinson's patients (10 nFOG, 9 with freezing of gait (FOG)) to step in place to each cue. Results showed a superiority of action-relevant cues (regardless of cue-continuity) for inducing reductions in Step coefficient of variation (CV). Acoustic continuity was associated with a significant reduction in Swing CV. Neither cue-continuity nor action-relevance was independently sufficient to increase the time spent stepping before freezing. However, combining both attributes in the same cue did yield significant improvements. This study demonstrates the potential of using action-sounds as sensory cues for Parkinson's patients with freezing of gait. We suggest that the improvements shown might be considered audio-motor 'priming' (i.e., listening to the sounds of footsteps will engage sensorimotor circuitry relevant to the production of that same action, thus effectively bypassing the defective basal ganglia). Copyright © 2016. Published by Elsevier Ltd.
A fiber-based quasi-continuous-wave quantum key distribution system
Shen, Yong; Chen, Yan; Zou, Hongxin; Yuan, Jianmin
2014-01-01
We report a fiber-based quasi-continuous-wave (CW) quantum key distribution (QKD) system with continuous variables (CV). This system employs coherent light pulses and time multiplexing to maximally reduce cross talk in the fiber. No-switching detection scheme is adopted to optimize the repetition rate. Information is encoded on the sideband of the pulsed coherent light to fully exploit the continuous wave nature of laser field. With this configuration, high secret key rate can be achieved. For the 50 MHz detected bandwidth in our experiment, when the multidimensional reconciliation protocol is applied, a secret key rate of 187 kb/s can be achieved over 50 km of optical fiber against collective attacks, which have been shown to be asymptotically optimal. Moreover, recently studied loopholes have been fixed in our system. PMID:24691409
Variability of breathing during wakefulness while using CPAP predicts adherence.
Fujita, Yukio; Yamauchi, Motoo; Uyama, Hiroki; Kumamoto, Makiko; Koyama, Noriko; Yoshikawa, Masanori; Strohl, Kingman P; Kimura, Hiroshi
2017-02-01
The standard therapy for obstructive sleep apnoea (OSA) is continuous positive airway pressure (CPAP) therapy. However, long-term adherence remains at ~50% despite improvements in behavioural and educational interventions. Based on prior work, we explored whether regularity of breathing during wakefulness might be a physiologic predictor of CPAP adherence. Of the 117 consecutive patients who were diagnosed with OSA and prescribed CPAP, 79 CPAP naïve patients were enrolled in this prospective study. During CPAP initiation, respiratory signals were collected using respiratory inductance plethysmography while wearing CPAP during wakefulness in a seated position. Breathing regularity was assessed by the coefficient of variation (CV) for breath-by-breath estimated tidal volume (V T ) and total duration of respiratory cycle (Ttot). In a derivation group (n = 36), we determined the cut-off CV value which predicted poor CPAP adherence at the first month of therapy, and verified the validity of this predetermined cut-off value in the remaining participants (validation group; n = 43). In the derivation group, the CV for estimated V T was significantly higher in patients with poor adherence than with good adherence (median (interquartile range): 44.2 (33.4-57.4) vs 26.0 (20.4-33.2), P < 0.001). The CV cut-off value for estimated V T for poor CPAP adherence was 34.0, according to a receiver-operating characteristic (ROC) curve. In the validation group, the CV value for estimated V T >34.0 confirmed to be predicting poor CPAP adherence (sensitivity, 0.78; specificity, 0.83). At the initiation of therapy, breathing regularity during wakefulness while wearing CPAP is an objective predictor of short-term CPAP adherence. © 2016 Asian Pacific Society of Respirology.
Choe, Leila H; Lee, Kelvin H
2003-10-01
We investigate one approach to assess the quantitative variability in two-dimensional gel electrophoresis (2-DE) separations based on gel-to-gel variability, sample preparation variability, sample load differences, and the effect of automation on image analysis. We observe that 95% of spots present in three out of four replicate gels exhibit less than a 0.52 coefficient of variation (CV) in fluorescent stain intensity (% volume) for a single sample run on multiple gels. When four parallel sample preparations are performed, this value increases to 0.57. We do not observe any significant change in quantitative value for an increase or decrease in sample load of 30% when using appropriate image analysis variables. Increasing use of automation, while necessary in modern 2-DE experiments, does change the observed level of quantitative and qualitative variability among replicate gels. The number of spots that change qualitatively for a single sample run in parallel varies from a CV = 0.03 for fully manual analysis to CV = 0.20 for a fully automated analysis. We present a systematic method by which a single laboratory can measure gel-to-gel variability using only three gel runs.
Winter, Randolph L; Saunders, Ashley B; Gordon, Sonya G; Miller, Matthew W; Fosgate, Geoffrey T; Suchodolski, Jan S; Steiner, Jörg M
2017-06-01
Biologic variability (BV) is one aspect of interpreting changes in biomarker concentrations known to be clinically important in people with cardiac disease, but it has not been adequately addressed in dogs so far. The purpose of the study was to determine BV of cardiac troponin I (cTnI) in healthy dogs and dogs with 3 stages of myxomatous mitral valve disease (MMVD). Healthy dogs and dogs with 3 stages of MMVD were prospectively assigned to groups based on comprehensive clinical evaluation using current guidelines. Concentrations of cTnI were measured hourly, daily, and weekly using standard and high-sensitivity immunoassays. Within- (CV I ) and between-subject (CV G ) coefficients of variability, percent reference change value (RCV), and index of individuality (IoI) were calculated. All 10 healthy dogs and 76/112 (68%) of samples from 28 MMVD dogs had cTnI concentrations below the limit of detection (LOD) using a standard sensitivity immunoassay. Only 49/160 (31%) of healthy dog samples and no MMVD samples had cTnI below the high-sensitivity immunoassay LOD. Data analysis for the high-sensitivity immunoassay revealed CV I of 48.1%, CV G of 60.1%, RCV of 134.0%, and IoI of 0.804 in healthy dogs. In MMVD dogs, CV I was 39.6%, CV G was 80.7%, RCV was 110%, and IoI was 0.494. Of all MMVD dogs, those with Stage B2 had the lowest RCV of 91%. Biologic variability affects cTnI concentrations in healthy dogs and dogs with MMVD. Consideration of BV may be clinically relevant when monitoring individual changes in cTnI values, using high-sensitivity immunoassays. © 2017 American Society for Veterinary Clinical Pathology.
2018-01-01
This study tested the hypothesis that object-based attention modulates the discrimination of level increments in stop-consonant noise bursts. With consonant-vowel-consonant (CvC) words consisting of an ≈80-dB vowel (v), a pre-vocalic (Cv) and a post-vocalic (vC) stop-consonant noise burst (≈60-dB SPL), we measured discrimination thresholds (LDTs) for level increments (ΔL) in the noise bursts presented either in CvC context or in isolation. In the 2-interval 2-alternative forced-choice task, each observation interval presented a CvC word (e.g., /pæk/ /pæk/), and normal-hearing participants had to discern ΔL in the Cv or vC burst. Based on the linguistic word labels, the auditory events of each trial were perceived as two auditory objects (Cv-v-vC and Cv-v-vC) that group together the bursts and vowels, hindering selective attention to ΔL. To discern ΔL in Cv or vC, the events must be reorganized into three auditory objects: the to-be-attended pre-vocalic (Cv–Cv) or post-vocalic burst pair (vC–vC), and the to-be-ignored vowel pair (v–v). Our results suggest that instead of being automatic this reorganization requires training, in spite of using familiar CvC words. Relative to bursts in isolation, bursts in context always produced inferior ΔL discrimination accuracy (a context effect), which depended strongly on the acoustic separation between the bursts and the vowel, being much keener for the object apart from (post-vocalic) than for the object adjoining (pre-vocalic) the vowel (a temporal-position effect). Variability in CvC dimensions that did not alter the noise-burst perceptual grouping had minor effects on discrimination accuracy. In addition to being robust and persistent, these effects are relatively general, evincing in forced-choice tasks with one or two observation intervals, with or without variability in the temporal position of ΔL, and with either fixed or roving CvC standards. The results lend support to the hypothesis. PMID:29364931
Nishihara, E; Shimmen, T; Sonobe, S
2007-01-01
The contractile vacuole (CV) cycle of Amoeba proteus has been studied by phase contrast and electron microscopy. However, the understanding of membrane dynamics in this cycle is still poor. In this study, we used live imaging by fluorescence microscopy to obtain new insights. We succeeded in staining the CV with a styryl dye, FM 4-64 (N-(3-triethylammoniumpropyl)-4-(6-(4-(diethylamino)phenyl)hexatrienyl)pyridinium dibromide), and obtained the following results. (1) The CV membrane was directly stained with the dye in the external medium when the CV pore opened upon contraction. This indicates that transfer of plasma membrane to the CV does not occur. (2) The membrane dynamics during the CV cycle were elucidated. In particular, the fluorescent CV membrane was maintained as an aggregate just after contraction and the vacuole re-formed from the aggregate. Staining was maintained during continued contraction cycles. We conclude that the CV membrane is maintained during the CV cycle.
Nakazato, Yuichi; Kurane, Riichi; Hirose, Satoru; Watanabe, Akihisa; Shimoyama, Hiromi
2017-01-01
Several epidemiological studies have demonstrated associations between variability in a number of biological parameters and adverse outcomes. As the variability may reflect impaired homeostatic regulation, we assessed albumin variability over time in chronic hemodialysis (HD) patients. Data from 1346 subjects who received chronic HD treatment from May 2001 to February 2015 were analyzed according to three phases of HD treatment: post-HD initiation, during maintenance HD treatment, and before death. The serum albumin values were grouped according to the time interval from HD initiation or death, and the yearly trends for both the albumin levels and the intra-individual albumin variability (quantified by the residual coefficient of variation: Alb-rCV) were examined. The HD initiation and death-associated changes were also analyzed using generalized additive mixed models. Furthermore, the long-term trend throughout the maintenance treatment period was evaluated separately using linear regression models. Albumin levels and variability showed distinctive changes during each of the 3 periods. After HD initiation, albumin variability decreased and reached a nadir within a year. During the subsequent maintenance treatment period (interquartile range = 5.2-11.0 years), the log Alb-rCV showed a significant upward trend (mean slope: 0.011 ± 0.035 /year), and its overall mean was -1.49 ± 0.08 (equivalent to an Alb-rCV of 3.22%). During the 1-2 years before death, this upward trend clearly accelerated, and the mean log Alb-rCV in the last year of life was -1.36 ± 0.17. The albumin levels and variability were negatively correlated with each other and exhibited exactly opposite movements throughout the course of chronic HD treatment. Different from the albumin levels, albumin variability was not dependent on chronological age but was independently associated with an individual's aging and death process. The observed upward trend in albumin variability seems to be consistent with a presumed aging-related decline in homeostatic capacity.
Annotated Bibliography of Armed Services Vocational Aptitude Battery (ASVAB) Validity Studies
1990-02-01
research to study reading skills of applicants for military service. Understanding the nature of literacy and the relationships of literacy to aptitude...NORMS (see POPULATION, NORMS) NORMING AF68001 AF75001 AF76006 AS80002 AS84002 CV84002 CV85002 CV80001 MC86005 NV84002 NUMERICAL SKILLS (see LITERACY ...characteristic of interest. Ability, as a construct, should derive its meaning from a conceptual framework, the pattern of relationships among variables
Koga, Masafumi; Murai, Jun; Morita, Shinya; Saito, Hiroshi; Kasayama, Soji
2013-01-01
It has been suggested that plasma glucose (PG) levels per se and long-term variations in PG levels are associated with diabetic vascular complications. Glycated albumin (GA) reflects shorter-term glycemic control, as well as postprandial PG levels, as compared to HbA1c. In this study, we hypothesized that GA more strongly reflects long-term variations in PG levels than HbA1c, and compared the variability of HbA1c and that of GA in patients with type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM). This study included 8 T1DM patients and 48 T2DM patients. Over a 1-year period, HbA1c and GA were measured every month and the mean values and coefficients of variation (CV) for each patient were calculated. In both T1DM and T2DM patients, the CV of GA was significantly higher than the CV of HbA1c. Both the CV of HbA1c and the CV of GA were significantly higher in the T1DM patients than in the T2DM patients. The annual variability in GA was greater than that in HbA1c. In addition, the annual variability in HbA1c and that in GA in the T1DM patients were greater than in the T2DM patients. Our findings suggest that GA more accurately reflects long-term variations in PG levels than HbA1c. Copyright © 2013 Elsevier Inc. All rights reserved.
NASA Astrophysics Data System (ADS)
Rosero-Vlasova, O.; Borini Alves, D.; Vlassova, L.; Perez-Cabello, F.; Montorio Lloveria, R.
2017-10-01
Deforestation in Amazon basin due, among other factors, to frequent wildfires demands continuous post-fire monitoring of soil and vegetation. Thus, the study posed two objectives: (1) evaluate the capacity of Visible - Near InfraRed - ShortWave InfraRed (VIS-NIR-SWIR) spectroscopy to estimate soil organic matter (SOM) in fire-affected soils, and (2) assess the feasibility of SOM mapping from satellite images. For this purpose, 30 soil samples (surface layer) were collected in 2016 in areas of grass and riparian vegetation of Campos Amazonicos National Park, Brazil, repeatedly affected by wildfires. Standard laboratory procedures were applied to determine SOM. Reflectance spectra of soils were obtained in controlled laboratory conditions using Fieldspec4 spectroradiometer (spectral range 350nm- 2500nm). Measured spectra were resampled to simulate reflectances for Landsat-8, Sentinel-2 and EnMap spectral bands, used as predictors in SOM models developed using Partial Least Squares regression and step-down variable selection algorithm (PLSR-SD). The best fit was achieved with models based on reflectances simulated for EnMap bands (R2=0.93; R2cv=0.82 and NMSE=0.07; NMSEcv=0.19). The model uses only 8 out of 244 predictors (bands) chosen by the step-down variable selection algorithm. The least reliable estimates (R2=0.55 and R2cv=0.40 and NMSE=0.43; NMSEcv=0.60) resulted from Landsat model, while Sentinel-2 model showed R2=0.68 and R2cv=0.63; NMSE=0.31 and NMSEcv=0.38. The results confirm high potential of VIS-NIR-SWIR spectroscopy for SOM estimation. Application of step-down produces sparser and better-fit models. Finally, SOM can be estimated with an acceptable accuracy (NMSE 0.35) from EnMap and Sentinel-2 data enabling mapping and analysis of impacts of repeated wildfires on soils in the study area.
Rawlins, S C; Chen, A; Rawlins, J M; Chadee, D D; Legall, G
2007-03-01
To determine the level of understanding of the issues of climate change (CC)/variability (CV) and public health by populations of St Kitts and Nevis (SKN) and Trinidad and Tobago (T&T) and to find whether respondents would be willing to incorporate these values into strategies for dengue fever (DF) prevention. Using a cluster sampling system, representative samples of the communities of SKN (227) and T&T (650) were surveyed for responses to a questionnaire document with questions on the impact of climate variability on health, the physical environment, respondents' willingness to utilize climate issues to predict and adapt to climate variability for DF prevention. Data were analyzed by Epi Info. Sixty-two per cent SKN and 55% T&T of respondents showed some understanding of the concept of climate change (CC) and distinguished this from climate variability (CV). With regard to causes of CC, 48% SKN and 50% T&T attributed CC to all of green houses gases, holes in the ozone layer burning of vegetation and vehicular exhaust gases. However some 39.3% SKN and 31% (T&T) did not answer this question. In response to ranking issues of life affected by CC/CV in both countries, respondents ranked them: health > water resources > agriculture > biodiversity > coastal degradation. The major health issues identified for SKN and T&T respondents were: food-borne diseases > water-borne diseases > heat stresses; vector-borne diseases were only ranked 4th and 5th for SKN and T&T respondents respectively. There was in both countries a significant proportion of respondents (p < 0.001) who reported wet season-related increase of DF cases as a CC/CV link. Respondents identified use of environmental sanitation (ES) at appropriate times as a method of choice of using CC/CV to prevent DF outbreaks. More than 82% in both countries saw the use of the CC/CV information for DF prevention by prediction and control as strategic but only 50-51% were inclined to become personally involved. Currently, only 50% SKN and 45% T&T respondents claimed current involvement in DF vector surveillance and control in the last two days. Despite the fact that knowledge and attitudes did not always coincide with practices of using ES for DF prevention, in both countries, even with CC/CV tools of prediction being available, it seems that respondents could be persuaded to use such strategies. There is a need for demonstration of the efficacy of CC/CV information and promotion of its usefulness for community involvement in DF and possibly other disease prevention.
Fully moderated T-statistic for small sample size gene expression arrays.
Yu, Lianbo; Gulati, Parul; Fernandez, Soledad; Pennell, Michael; Kirschner, Lawrence; Jarjoura, David
2011-09-15
Gene expression microarray experiments with few replications lead to great variability in estimates of gene variances. Several Bayesian methods have been developed to reduce this variability and to increase power. Thus far, moderated t methods assumed a constant coefficient of variation (CV) for the gene variances. We provide evidence against this assumption, and extend the method by allowing the CV to vary with gene expression. Our CV varying method, which we refer to as the fully moderated t-statistic, was compared to three other methods (ordinary t, and two moderated t predecessors). A simulation study and a familiar spike-in data set were used to assess the performance of the testing methods. The results showed that our CV varying method had higher power than the other three methods, identified a greater number of true positives in spike-in data, fit simulated data under varying assumptions very well, and in a real data set better identified higher expressing genes that were consistent with functional pathways associated with the experiments.
Zumárraga, Mercedes; González-Torres, Miguel A; Arrue, Aurora; Dávila, Ricardo; Dávila, Wendy; Inchausti, Lucía; Pérez-Cabeza, Lucía; Fernández-Rivas, Aránzazu; Bustamante, Sonia; Basterreche, Nieves; Guimón, José
2011-08-01
In the present study we have measured, on a monthly basis, the concentration of plasma homovanillic acid (pHVA) in schizophrenic patients during 13 months of their pharmacological treatment. The average pHVA values of each patient were within the range of 7.30-17.70 ng/ml and the coefficients of variation for each patient (CV %) were within the range of 13-33%. Half of the patients that showed higher pHVA CV% values also showed higher scores on the Brief Psychiatric Rating Scale at the beginning of the study, and improved more after 6 months, when compared to the remaining 50% with lower CV% values. There was no significant relationship between the scores of the Wisconsin Card Sort Test and the concentration or the CV% of the pHVA of each patient. A greater variability in the pHVA may be associated with a greater plasticity of the dopaminergic system and a better clinical response.
Reid, Colleen E; Jerrett, Michael; Petersen, Maya L; Pfister, Gabriele G; Morefield, Philip E; Tager, Ira B; Raffuse, Sean M; Balmes, John R
2015-03-17
Estimating population exposure to particulate matter during wildfires can be difficult because of insufficient monitoring data to capture the spatiotemporal variability of smoke plumes. Chemical transport models (CTMs) and satellite retrievals provide spatiotemporal data that may be useful in predicting PM2.5 during wildfires. We estimated PM2.5 concentrations during the 2008 northern California wildfires using 10-fold cross-validation (CV) to select an optimal prediction model from a set of 11 statistical algorithms and 29 predictor variables. The variables included CTM output, three measures of satellite aerosol optical depth, distance to the nearest fires, meteorological data, and land use, traffic, spatial location, and temporal characteristics. The generalized boosting model (GBM) with 29 predictor variables had the lowest CV root mean squared error and a CV-R2 of 0.803. The most important predictor variable was the Geostationary Operational Environmental Satellite Aerosol/Smoke Product (GASP) Aerosol Optical Depth (AOD), followed by the CTM output and distance to the nearest fire cluster. Parsimonious models with various combinations of fewer variables also predicted PM2.5 well. Using machine learning algorithms to combine spatiotemporal data from satellites and CTMs can reliably predict PM2.5 concentrations during a major wildfire event.
Zhang, Y; Zhang, X; Liu, L; Zanchetti, A
2015-06-01
Many antihypertensive outcome trials have shown that visit-to-visit blood pressure variability is correlated closely with clinical outcomes in hypertensive patients. The objective of the study was to investigate the relationship between visit-to-visit blood pressure variability (BPV) and the major cardiovascular outcomes in the Chinese hypertensive patients. Felodipine Event Reduction (FEVER) study was a double-blind, randomized trial on 9711 Chinese hypertensive patients, in whom cardiovascular outcomes were significantly reduced by more intense therapy achieving a mean of 138 mmHg SBP compared with less-intense therapy achieving a mean of 142 mmHg. Visit-to-visit BPV during the follow-up period [defined as standard deviation (SD), coefficient of variation (CV), and average real variability(ARV)] was derived from casual cuff BP measures after six months follow-up until the end of the study. Hazard ratios (HRs), for the incidence of CVD associated with SD, CV, and ARV of SBP and DBP were calculated using Cox proportional hazard models. Overall predictive power [area under receiver operating characteristic (AUC ROC) curve] of the level of blood pressure, blood pressure variability and other baseline characteristics was calculated. In FEVER study, visit-to-visit variability in SBP were significant predictors of subsequent stroke [eg, hazard ratios [HR] for ARV, SD and CV was 1.071 (95% CI: 1.025-1.118), 1.373 (95% CI: 1.159-1.626) and 0.572 (95% CI: 0.451-0,726)]. Visit-to-visit variability in DBP were also showed similar trend [eg, HR for ARV, SD and CV was 1.066 (95% CI: 0.992-1.145), 1.931 (95% CI: 1.435-2.598) and 0.558 (95% CI: 0.438-0,710)]. However, using the analysis of AUC ROC analysis, the risk importance sequence of the stroke events in this cohort was level of SBP, age, level of DBP ARV, SD, sex, CV and treatment. Visit-to-visit blood pressure variability has some effects on the cardiovascular outcomes in the Chinese hypertensive patents in the cohort in FEVER Study. However, blood pressure per se is even more important for the development of stroke in this group of patients.
Hecker, Suzanne; Abrahamson, N.A.; Wooddell, Kathryn
2013-01-01
To investigate the nature of earthquake‐magnitude distributions on faults, we compare the interevent variability of surface displacement at a point on a fault from a composite global data set of paleoseismic observations with the variability expected from two prevailing magnitude–frequency distributions: the truncated‐exponential model and the characteristic‐earthquake model. We use forward modeling to predict the coefficient of variation (CV) for the alternative earthquake distributions, incorporating factors that would effect observations of displacement at a site. The characteristic‐earthquake model (with a characteristic‐magnitude range of ±0.25) produces CV values consistent with the data (CV∼0.5) only if the variability for a given earthquake magnitude is small. This condition implies that rupture patterns on a fault are stable, in keeping with the concept behind the model. This constraint also bears upon fault‐rupture hazard analysis, which, for lack of point‐specific information, has used global scaling relations to infer variability in average displacement for a given‐size earthquake. Exponential distributions of earthquakes (from M 5 to the maximum magnitude) give rise to CV values that are significantly larger than the empirical constraint. A version of the model truncated at M 7, however, yields values consistent with a larger CV (∼0.6) determined for small‐displacement sites. Although this result allows for a difference in the magnitude distribution of smaller surface‐rupturing earthquakes, it may reflect, in part, less stability in the displacement profile of smaller ruptures and/or the tails of larger ruptures.
Psychobiological Factors Affecting Cortisol Variability in Human-Dog Dyads
Schöberl, Iris; Wedl, Manuela; Beetz, Andrea; Kotrschal, Kurt
2017-01-01
Stress responses within dyads are modulated by interactions such as mutual emotional support and conflict. We investigated dyadic psychobiological factors influencing intra-individual cortisol variability in response to different challenging situations by testing 132 owners and their dogs in a laboratory setting. Salivary cortisol was measured and questionnaires were used to assess owner and dog personality as well as owners' social attitudes towards the dog and towards other humans. We calculated the individual coefficient of variance of cortisol (iCV = sd/mean*100) over the different test situations as a parameter representing individual variability of cortisol concentration. We hypothesized that high cortisol variability indicates efficient and adaptive coping and a balanced individual and dyadic social performance. Female owners of male dogs had lower iCV than all other owner gender-dog sex combinations (F = 14.194, p<0.001), whereas owner Agreeableness (NEO-FFI) scaled positively with owner iCV (F = 4.981, p = 0.028). Dogs of owners high in Neuroticism (NEO-FFI) and of owners who were insecure-ambivalently attached to their dogs (FERT), had low iCV (F = 4.290, p = 0.041 and F = 5.948, p = 0.016), as had dogs of owners with human-directed separation anxiety (RSQ) or dogs of owners with a strong desire of independence (RSQ) (F = 7.661, p = 0.007 and F = 9.192, p = 0.003). We suggest that both owner and dog social characteristics influence dyadic cortisol variability, with the human partner being more influential than the dog. Our results support systemic approaches (i.e. considering the social context) in science and in counselling. PMID:28178272
Qu, Zhen; Djordjevic, Ivan B
2017-04-03
A high-speed four-state continuous-variable quantum key distribution (CV-QKD) system, enabled by wavelength-division multiplexing, polarization multiplexing, and orbital angular momentum (OAM) multiplexing, is studied in the presence of atmospheric turbulence. The atmospheric turbulence channel is emulated by two spatial light modulators (SLMs) on which two randomly generated azimuthal phase patterns yielding Andrews' spectrum are recorded. The phase noise is mitigated by the phase noise cancellation (PNC) stage, and channel transmittance can be monitored directly by the D.C. level in our PNC stage. After the system calibration, a total SKR of >1.68 Gbit/s can be reached in the ideal system, featured with lossless channel and free of excess noise. In our experiment, based on commercial photodetectors, the minimum transmittances of 0.21 and 0.29 are required for OAM states of 2 (or -2) and 6 (or -6), respectively, to guarantee the secure transmission, while a total SKR of 120 Mbit/s can be obtained in case of mean transmittances.
Wang, N.; Augspurger, T.; Barnhart, M.C.; Bidwell, Joseph R.; Cope, W.G.; Dwyer, F.J.; Geis, S.; Greer, I.E.; Ingersoll, C.G.; Kane, C.M.; May, T.W.; Neves, R.J.; Newton, T.J.; Roberts, A.D.; Whites, D.W.
2007-01-01
The present study evaluated the performance and variability in acute toxicity tests with glochidia and newly transformed juvenile mussels using the standard methods outlined in American Society for Testing and Materials (ASTM). Multiple 48-h toxicity tests with glochidia and 96-h tests with juvenile mussels were conducted within a single laboratory and among five laboratories. All tests met the test acceptability requirements (e.g., ???90% control survival). Intralaboratory tests were conducted over two consecutive mussel-spawning seasons with mucket (Actinonaias ligamentina) or fatmucket (Lampsilis siliquoidea) using copper, ammonia, or chlorine as a toxicant. For the glochidia of both species, the variability of intralaboratory median effective concentrations (EC50s) for the three toxicants, expressed as the coefficient of variation (CV), ranged from 14 to 27% in 24-h exposures and from 13 to 36% in 48-h exposures. The intralaboratory CV of copper EC50s for juvenile fatmucket was 24% in 48-h exposures and 13% in 96-h exposures. Interlaboratory tests were conducted with fatmucket glochidia and juveniles by five laboratories using copper as a toxicant. The interlaboratory CV of copper EC50s for glochidia was 13% in 24-h exposures and 24% in 48-h exposures, and the interlaboratory CV for juveniles was 22% in 48-h exposures and 42% in 96-h exposures. The high completion success and the overall low variability in test results indicate that the test methods have acceptable precision and can be performed routinely. ?? 2007 SETAC.
Factors in Variability of Serial Gabapentin Concentrations in Elderly Patients with Epilepsy.
Conway, Jeannine M; Eberly, Lynn E; Collins, Joseph F; Macias, Flavia M; Ramsay, R Eugene; Leppik, Ilo E; Birnbaum, Angela K
2017-10-01
To characterize and quantify the variability of serial gabapentin concentrations in elderly patients with epilepsy. This study included 83 patients (age ≥ 60 yrs) from an 18-center randomized double-blind double-dummy parallel study from the Veterans Affairs Cooperative 428 Study. All patients were taking 1500 mg/day gabapentin. Within-person coefficient of variation (CV) in gabapentin concentrations, measured weekly to bimonthly for up to 52 weeks, then quarterly, was computed. Impact of patient characteristics on gabapentin concentrations (linear mixed model) and CV (linear regression) were estimated. A total of 482 gabapentin concentration measurements were available for analysis. Gabapentin concentrations and intrapatient CVs ranged from 0.5 to 22.6 μg/ml (mean 7.9 μg/ml, standard deviation [SD] 4.1 μg/ml) and 2% to 79% (mean 27.9%, SD 15.3%), respectively, across all visits. Intrapatient CV was higher by 7.3% for those with a body mass index of ≥ 30 kg/m 2 (coefficient = 7.3, p=0.04). CVs were on average 0.5% higher for each 1-unit higher CV in creatinine clearance (coefficient = 0.5, p=0.03) and 1.2% higher for each 1-hour longer mean time after dose (coefficient = 1.2, p=0.04). Substantial intrapatient variability in serial gabapentin concentration was noted in elderly patients with epilepsy. Creatinine clearance, time of sampling relative to dose, and obesity were found to be positively associated with variability. © 2017 Pharmacotherapy Publications, Inc.
Ouyang, Pamela; Wenger, Nanette K; Taylor, Doris; Rich-Edwards, Janet W; Steiner, Meir; Shaw, Leslee J; Berga, Sarah L; Miller, Virginia M; Merz, Noel Bairey
2016-01-01
In 2001, the Institute of Medicine's (IOM) report, "Exploring the Biological Contributions to Human Health: Does Sex Matter?" advocated for better understanding of the differences in human diseases between the sexes, with translation of these differences into clinical practice. Sex differences are well documented in the prevalence of cardiovascular (CV) risk factors, the clinical manifestation and incidence of cardiovascular disease (CVD), and the impact of risk factors on outcomes. There are also physiologic and psychosocial factors unique to women that may affect CVD risk, such as issues related to reproduction. The Society for Women's Health Research (SWHR) CV Network compiled an inventory of sex-specific strategies and methods for the study of women and CV health and disease across the lifespan. References for methods and strategy details are provided to gather and evaluate this information. Some items comprise robust measures; others are in development. To address female-specific CV health and disease in population, physiology, and clinical trial research, data should be collected on reproductive history, psychosocial variables, and other factors that disproportionately affect CVD in women. Variables related to reproductive health include the following: age of menarche, menstrual cycle regularity, hormone levels, oral contraceptive use, pregnancy history/complications, polycystic ovary syndrome (PCOS) components, menopause age, and use and type of menopausal hormone therapy. Other factors that differentially affect women's CV risk include diabetes mellitus, autoimmune inflammatory disease, and autonomic vasomotor control. Sex differences in aging as well as psychosocial variables such as depression and stress should also be considered. Women are frequently not included/enrolled in mixed-sex CVD studies; when they are included, information on these variables is generally not collected. These omissions limit the ability to determine the role of sex-specific contributors to CV health and disease. Lack of sex-specific knowledge contributes to the CVD health disparities that women face. The purpose of this review is to encourage investigators to consider ways to increase the usefulness of physiological and psychosocial data obtained from clinical populations, in an effort to improve the understanding of sex differences in clinical CVD research and health-care delivery for women and men.
Variability of quadriceps femoris motor neuron discharge and muscle force in human aging.
Welsh, Seth J; Dinenno, Devin V; Tracy, Brian L
2007-05-01
The purpose was to determine the contribution of visual feedback and the effect of aging on the variability of knee extensor (KE) muscle force and motor unit (MU) discharge. Single MUs were recorded during two types of isometric trials, (1) visual feedback provided (VIS) and then removed (NOVIS) during the trial (34 MUs from young, 32 from elderly), and (2) only NOVIS (66 MUs from young, 77 from elderly) during the trial. Recruitment threshold (RT) ranged from 0-37% MVC. Standard deviation (SD) and coefficient of variation (CV) of muscle force and MU interspike interval (ISI) was measured during steady contractions at target forces ranging from 0.3 to 54% MVC. Force drift (<0.5 Hz) was removed before analysis. VIS/NOVIS trials: the decrease in the CV of ISI from VIS to NOVIS was greater for MUs from elderly (12.5 +/- 4.1 to 9.94 +/- 2.6%) than young (10.6 +/- 3.3 to 10.3 +/- 2.8%, age group x vision interaction, P = 0.006). The change in CV of force from VIS to NOVIS was significantly greater for elderly (1.45 to 1.05%) than young (1.42 to 1.41%). NOVIS only trials: for all MUs, the average RT (6.6 +/- 7.7 % MVC), target force above RT (1.20 +/- 2.7% MVC), SD of ISI (0.012 +/- 0.005 s), and CV of ISI (11.1 +/- 3.3%) were similar for young and elderly MUs. The CV of force was similar between age groups for trials between 0 and 3% MVC (1.74 +/- 0.74%) and was greater for young subjects from 3 to 10% MVC (1.47 +/- 0.5 vs. 1.21 +/- 0.4%) and >10% MVC (1.44 +/- 0.6 vs. 1.01 +/- 0.3%). The CV of ISI was similar between age groups for MUs in 0-3, 3-10, and >10% bins of RT. Thus, the contribution of visuomotor correction to the variability of motor unit discharge and force is greater for elderly adults. The presence of visual feedback appears to be necessary to find greater discharge variability in motor units from the knee extensors of elderly adults.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Coates, J; Jeyaseelan, K; Ybarra, N
2014-06-15
Purpose: It has been realized that inter-patient radiation sensitivity variability is a multifactorial process involving dosimetric, clinical, and genetic factors. Therefore, we explore a new framework to integrate physical, clinical, and biological data denoted as radiogenomic modeling. In demonstrating the feasibility of this work, we investigate the association of genetic variants (copy number variations [CNVs] and single nucleotide polymorphisms [SNPs]) with radiation induced rectal bleeding (RB) and erectile dysfunction (ED) while taking into account dosimetric and clinical variables in prostate cancer patients treated with curative irradiation. Methods: A cohort of 62 prostate cancer patients who underwent hypofractionated radiotherapy (66 Gymore » in 22 fractions) was retrospectively genotyped for CNV and SNP rs25489 in the xrcc1 DNA repair gene. Dosevolume metrics were extracted from treatment plans of 54 patients who had complete dosimetric profiles. Treatment outcomes were considered to be a Result of functional mapping of radiogenomic input variables according to a logit transformation. Model orders were estimated using resampling by leave-one out cross-validation (LOO-CV). Radiogenomic model performance was evaluated using area under the ROC curve (AUC) and LOO-CV. For continuous univariate dosimetric and clinical variables, Spearmans rank coefficients were calculated and p-values reported accordingly. In the case of binary variables, Chi-squared statistics and contingency table calculations were used. Results: Ten patients were found to have three copies of xrcc1 CNV (RB: χ2=14.6 [p<0.001] and ED: χ2=4.88[p=0.0272]) and twelve had heterozygous rs25489 SNP (RB: χ2=0.278[p=0.599] and ED: χ2=0.112[p=0.732]). LOO-CV identified penile bulb D60 as the only significant QUANTEC predictor (rs=0.312 [p=0.0145]) for ED. Radiogenomic modeling yielded statistically significant, cross-validated NTCP models for RB (rs=0.243[p=0.0443], AUC=0.665) and ED (rs=0.276[p=0.0217], AUC=0.754). Conclusion: The radiogenomic modeling approach presented herein has been shown to identify NTCP models which have increased predictive power. Furthermore, CNVs appears to be useful genetic variants when added to dosimetric NTCP models. This work was partially supported by CIHR grant MOP-114910.« less
Panaite, Vanessa; Salomon, Kristen; Jin, Alvin; Rottenberg, Jonathan
2015-01-01
Objective Exaggerated cardiovascular (CV) reactivity to laboratory challenge has been shown to predict future CV morbidity and mortality. CV recovery, has been less studied, and has yielded inconsistent findings, possibly due to presence of moderators. Reviews on the relationship between CV recovery and CV outcomes have been limited to cross-sectional studies and have not considered methodological factors. We performed a comprehensive meta-analytic review of the prospective literature investigating CV recovery to physical and psychological challenge and adverse cardiovascular outcomes. Methods We searched PsycINFO and PubMed for prospective studies investigating the relationship between CV recovery and adverse CV outcomes. Studies were coded for variables of interest and for effect sizes (ES). We conducted a random effects weighted meta-analysis. Moderators were examined with ANOVA-analog and meta-regression analyses. Results Thirty seven studies met inclusion criteria (N=125386). Impaired recovery from challenge predicted adverse cardiovascular outcomes (summary effect, r = .17, p < .001). Physical challenge was associated with larger predictive effects than psychological challenge. Moderator analyses revealed that recovery measured at 1 minute post-exercise, passive recovery, use of mortality as an outcome measure, and older sample age were associated with larger effects. Conclusions Poor recovery from laboratory challenges predicts adverse CV outcomes, with recovery from exercise serving as a particularly strong predictor of CV outcomes. The overall ES for recovery and CV outcomes is similar to that observed for CV reactivity and suggests that the study of recovery may have incremental value for understanding adverse CV outcomes. PMID:25829236
NASA Astrophysics Data System (ADS)
Derkach, Ivan D.; Peuntinger, Christian; Ruppert, László; Heim, Bettina; Gunthner, Kevin; Usenko, Vladyslav C.; Elser, Dominique; Marquardt, Christoph; Filip, Radim; Leuchs, Gerd
2016-10-01
Continuous-variable quantum key distribution is a practical application of quantum information theory that is aimed at generation of secret cryptographic key between two remote trusted parties and that uses multi-photon quantum states as carriers of key bits. Remote parties share the secret key via a quantum channel, that presumably is under control of of an eavesdropper, and which properties must be taken into account in the security analysis. Well-studied fiber-optical quantum channels commonly possess stable transmittance and low noise levels, while free-space channels represent a simpler, less demanding and more flexible alternative, but suffer from atmospheric effects such as turbulence that in particular causes a non-uniform transmittance distribution referred to as fading. Nonetheless free-space channels, providing an unobstructed line-of-sight, are more apt for short, mid-range and potentially long-range (using satellites) communication and will play an important role in the future development and implementation of QKD networks. It was previously theoretically shown that coherent-state CV QKD should be in principle possible to implement over a free-space fading channel, but strong transmittance fluctuations result in the significant modulation-dependent channel excess noise. In this regime the post-selection of highly transmitting sub-channels may be needed, which can even restore the security of the protocol in the strongly turbulent channels. We now report the first proof-of-principle experimental test of coherent state CV QKD protocol using different levels Gaussian modulation over a mid-range (1.6-kilometer long) free-space atmospheric quantum channel. The transmittance of the link was characterized using intensity measurements for the reference but channel estimation using the modulated coherent states was also studied. We consider security against Gaussian collective attacks, that were shown to be optimal against CV QKD protocols . We assumed a general entangling cloner collective attack (modeled using data obtained from the state measurement results on both trusted sides of the protocol), that allows to purify the noise added in the quantum channel . Our security analysis of coherent-state protocol also took into account the effect of imperfect channel estimation, limited post-processing efficiency and finite data ensemble size on the performance of the protocol. In this regime we observe the positive key rate even without the need of applying post-selection. We show the positive improvement of the key rate with increase of the modulation variance, still remaining low enough to tolerate the transmittance fluctuations. The obtained results show that coherent-state CV QKD protocol that uses real free-space atmospheric channel can withstand negative influence of transmittance fluctuations, limited post-processing efficiency, imperfect channel estimation and other finite-size effects, and be successfully implemented. Our result paves the way to the full-scale implementation of the CV QKD in real free-space channels at mid-range distances.
Lee, Cameron C
2015-11-01
Previous research using varying methods has shown that the day-to-day variability in cardiovascular (CV)-related mortality is correlated with a number of different meteorological variables, though these relationships can vary geographically. This research systematically examines the relationship between anomalous winter CV-related mortality and geographically and seasonally relative multivariate surface weather types derived from a recently developed gridded weather typing classification (GWTC) for cities in varying climate regions of the United States of America (USA). Results indicate that for all locations examined, during winter, a dry and cool (DC) weather type is significantly related to increased CV-related mortality, especially in the 2 weeks immediately after it occurs, with no apparent mortality displacement. Across the USA as a whole, the peak of this relationship is a 4.1% increase in CV-related mortality at a lag of 3 days. Spike days in CV-related mortality show similar trends, being over 50% more likely 2 to 4 days after the DC type occurs. A humid and warm (HW) weather type exhibited a significant and opposite relationship to that of DC. While these results for DC and HW were statistically significant at every location examined, the magnitudes were larger in the warmer locations. Among other weather types, Warm Front Passages (WFP) were also related to significant increases in CV-related mortality, especially 1 day after they occurred. Though this link was much more varied geographically than results found with DC or HW, it suggests that sequences of multiple DC days followed by WFP may result in increased CV-related mortality.
NASA Astrophysics Data System (ADS)
Lee, Cameron C.
2015-11-01
Previous research using varying methods has shown that the day-to-day variability in cardiovascular (CV)-related mortality is correlated with a number of different meteorological variables, though these relationships can vary geographically. This research systematically examines the relationship between anomalous winter CV-related mortality and geographically and seasonally relative multivariate surface weather types derived from a recently developed gridded weather typing classification (GWTC) for cities in varying climate regions of the United States of America (USA). Results indicate that for all locations examined, during winter, a dry and cool (DC) weather type is significantly related to increased CV-related mortality, especially in the 2 weeks immediately after it occurs, with no apparent mortality displacement. Across the USA as a whole, the peak of this relationship is a 4.1% increase in CV-related mortality at a lag of 3 days. Spike days in CV-related mortality show similar trends, being over 50% more likely 2 to 4 days after the DC type occurs. A humid and warm (HW) weather type exhibited a significant and opposite relationship to that of DC. While these results for DC and HW were statistically significant at every location examined, the magnitudes were larger in the warmer locations. Among other weather types, Warm Front Passages (WFP) were also related to significant increases in CV-related mortality, especially 1 day after they occurred. Though this link was much more varied geographically than results found with DC or HW, it suggests that sequences of multiple DC days followed by WFP may result in increased CV-related mortality.
Paľa, Andrej; Schneider, Max; Brand, Christine; Pedro, Maria Teresa; Özpeynirci, Yigit; Schmitz, Bernd; Wirtz, Christian Rainer; Kapapa, Thomas; König, Ralph; Braun, Michael
2018-05-26
Cerebral vasospasm (CV) and delayed cerebral ischemia (DCI) are major factors that limit good outcome in patients with spontaneous subarachnoid hemorrhage (SAH). Continuous therapy with intra-arterial calcium channel blockers has been introduced as a new step in the invasive treatment cascade of CV and DCI. Sedation is routinely necessary for this procedure. We report about the feasibility to apply this therapy in awake compliant patients without intubation and sedation. Out of 67 patients with invasive endovascular treatment of cerebral vasospasm due to spontaneous SAH, 5 patients underwent continuous superselective intracarotid nimodipine therapy without intubation and sedation. Complications, neurological improvement, and outcome at discharge were summarized. Very good outcome was achieved in all 5 patients. The Barthel scale was 100 and the modified Rankin scale 0-1 in all cases at discharge. We found no severe complications and excellent neurological monitoring was possible in all cases due to patients' alert status. Symptoms of DCI resolved within 24 h in all 5 cases. We could demonstrate the feasibility and safety of selective intracarotid arterial nimodipine treatment in awake, compliant patients with spontaneous SAH and symptomatic CV and DCI. Using this method, an excellent monitoring of neurological function as well as early detection of other complications is possible. It might be an important step in the risk reduction of invasive CV therapy to improve the outcome with CV and DCI after SAH in selected patients.
Filimberti, E; Degl'Innocenti, S; Borsotti, M; Quercioli, M; Piomboni, P; Natali, I; Fino, M G; Caglieresi, C; Criscuoli, L; Gandini, L; Biggeri, A; Maggi, M; Baldi, E
2013-05-01
We report the results of the first three trials of an external quality control (EQC) programme performed in 71 laboratories executing semen analysis in Tuscany Region (Italy). At the end of the second trial, participants were invited to attend a teaching course illustrating and inviting to adhere to procedures recommended by WHO (V edition). Results of the first three trials of the EQC documented a huge variability in the procedures and the results. The highest variability was found for morphology (CV above 80% for all the trials), followed by count (CV of about 60% for all the trials) and motility (CV below 30% for all the trials). When results of sperm count and morphology were divided according to the used method, mean CV values did not show significant differences. CV for morphology dropped significantly at the third trial for most methods, indicating the usefulness of the teaching course for morphology assessment. Conversely, no differences were observed after the course for motility and for most methods to evaluate count, although CV values were lower at the second and third trial for the laboratories using the Burker cytometer. When results were divided according to tertiles of activity, the lowest mean bias values (difference between each laboratory result and the median value of the results) for count and morphology were observed for laboratories in the third tertile (performing over 200 semen analysis/year). Of interest, mean bias values for concentration dropped significantly at the third trial for low activity laboratories. In conclusion, lack of agreement of results of semen analysis in Tuscany is mainly because of the activity and the experience of the laboratory. Our study points out the importance of participating in EQC programmes and periodical teaching courses as well as the use of WHO recommended standardized procedures to increase precision and to allow the use of WHO reference values. © 2013 American Society of Andrology and European Academy of Andrology.
Urbina, Elaine M; Khoury, Philip R; McCoy, Connie E; Dolan, Lawrence M; Daniels, Stephen R; Kimball, Thomas R
2013-04-01
Lipid levels are linked to early atherosclerosis. Risk stratification may be improved by using triglyceride to high-density lipoprotein cholesterol ratio (TG/HDL-C), which relates to arterial stiffness in adults. We tested whether TG/HDL-C was an independent predictor of arterial stiffness in youth. Subjects 10 to 26 years old (mean 18.9 years, 39% male, 56% non-Caucasian, n = 893) had laboratory, anthropometric, blood pressure, and arterial stiffness data collected (brachial distensibility, augmentation index, carotid-femoral pulse-wave velocity). Subjects were stratified into tertiles of TG/HDL-C (low, n = 227; mid, n = 288; high, n = 379). There was a progressive rise in cardiovascular (CV) risk factors and arterial stiffness across TG/HDL-C ratio. The high TG/HDL-C ratio group had the stiffest vessels (all P < .03 by analysis of variance). TG/HDL-C as a continuous variable was an independent determinant of brachial distensibility in CV risk factor adjusted model and for carotid-femoral pulse-wave velocity in obese subjects, with trend for higher augmentation index. TG/HDL-C, an estimate of small, dense low-density lipoprotein cholesterol, is an independent determinant of arterial stiffness in adolescents and young adults, especially in obese youth. These data suggest that use of TG/HDL-C may be helpful in identifying young adults requiring aggressive intervention to prevent atherosclerotic CV diseases.
Khoury, Philip R.; McCoy, Connie E.; Dolan, Lawrence M.; Daniels, Stephen R.; Kimball, Thomas R.
2013-01-01
BACKGROUND AND OBJECTIVE: Lipid levels are linked to early atherosclerosis. Risk stratification may be improved by using triglyceride to high-density lipoprotein cholesterol ratio (TG/HDL-C), which relates to arterial stiffness in adults. We tested whether TG/HDL-C was an independent predictor of arterial stiffness in youth. METHODS: Subjects 10 to 26 years old (mean 18.9 years, 39% male, 56% non-Caucasian, n = 893) had laboratory, anthropometric, blood pressure, and arterial stiffness data collected (brachial distensibility, augmentation index, carotid-femoral pulse-wave velocity). Subjects were stratified into tertiles of TG/HDL-C (low, n = 227; mid, n = 288; high, n = 379). RESULTS: There was a progressive rise in cardiovascular (CV) risk factors and arterial stiffness across TG/HDL-C ratio. The high TG/HDL-C ratio group had the stiffest vessels (all P < .03 by analysis of variance). TG/HDL-C as a continuous variable was an independent determinant of brachial distensibility in CV risk factor adjusted model and for carotid-femoral pulse-wave velocity in obese subjects, with trend for higher augmentation index. CONCLUSIONS: TG/HDL-C, an estimate of small, dense low-density lipoprotein cholesterol, is an independent determinant of arterial stiffness in adolescents and young adults, especially in obese youth. These data suggest that use of TG/HDL-C may be helpful in identifying young adults requiring aggressive intervention to prevent atherosclerotic CV diseases. PMID:23460684
Wang, Ruichun; Chen, Junping; Wu, Guorong
2015-01-01
Postoperative cognitive dysfunction (POCD) is a subtle impairment of cognitive abilities and can manifest on different neuropsychological features in the early postoperative period. It has been proved that the use of mechanical ventilation (MV) increased the development of delirium and POCD. However, the impact of variable and conventional lung protective mechanical ventilation on the incidence of POCD still remains unknown, which was the aim of this study. 162 patients scheduled to undergo elective gastrointestinal tumor resection via laparotomy in Ningbo No. 2 hospital with expected duration >2 h from June, 2013 to June, 2015 were enrolled in this study. Patients included were divided into two groups according to the scheme of lung protective MV, variable ventilation group (VV group, n=79) and conventional ventilation group (CV group, n=83) by randomization performed by random block randomization. The plasma levels of inflammatory cytokines, characteristics of the surgical procedure, incidence of delirium and POCD were collected and compared. Postoperative delirium was detected in 36 of 162 patients (22.2%) and 12 patients of these (16.5%) belonged to the VV group while 24 patients (28.9%) were in the CV group (P=0.036). POCD on the seventh postoperative day in CV group (26/83, 31.3%) was increased in comparison with the VV group (14/79, 17.7%) with significant statistical difference (P=0.045). The levels of inflammatory cytokines were all significantly higher in CV group than those in VV group on the 1st postoperative day (P<0.05). On 7th postoperative day, the levels of IL-6 and TNF-α in CV group remained much higher compared with VV group (P<0.05). Variable vs conventional lung protective MV decreased the incidence of postoperative delirium and POCD by reducing the systemic proinflammatory response.
Lindholm, Daniel; Lindbäck, Johan; Armstrong, Paul W; Budaj, Andrzej; Cannon, Christopher P; Granger, Christopher B; Hagström, Emil; Held, Claes; Koenig, Wolfgang; Östlund, Ollie; Stewart, Ralph A H; Soffer, Joseph; White, Harvey D; de Winter, Robbert J; Steg, Philippe Gabriel; Siegbahn, Agneta; Kleber, Marcus E; Dressel, Alexander; Grammer, Tanja B; März, Winfried; Wallentin, Lars
2017-08-15
Currently, there is no generally accepted model to predict outcomes in stable coronary heart disease (CHD). This study evaluated and compared the prognostic value of biomarkers and clinical variables to develop a biomarker-based prediction model in patients with stable CHD. In a prospective, randomized trial cohort of 13,164 patients with stable CHD, we analyzed several candidate biomarkers and clinical variables and used multivariable Cox regression to develop a clinical prediction model based on the most important markers. The primary outcome was cardiovascular (CV) death, but model performance was also explored for other key outcomes. It was internally bootstrap validated, and externally validated in 1,547 patients in another study. During a median follow-up of 3.7 years, there were 591 cases of CV death. The 3 most important biomarkers were N-terminal pro-B-type natriuretic peptide (NT-proBNP), high-sensitivity cardiac troponin T (hs-cTnT), and low-density lipoprotein cholesterol, where NT-proBNP and hs-cTnT had greater prognostic value than any other biomarker or clinical variable. The final prediction model included age (A), biomarkers (B) (NT-proBNP, hs-cTnT, and low-density lipoprotein cholesterol), and clinical variables (C) (smoking, diabetes mellitus, and peripheral arterial disease). This "ABC-CHD" model had high discriminatory ability for CV death (c-index 0.81 in derivation cohort, 0.78 in validation cohort), with adequate calibration in both cohorts. This model provided a robust tool for the prediction of CV death in patients with stable CHD. As it is based on a small number of readily available biomarkers and clinical factors, it can be widely employed to complement clinical assessment and guide management based on CV risk. (The Stabilization of Atherosclerotic Plaque by Initiation of Darapladib Therapy Trial [STABILITY]; NCT00799903). Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.
Permutation modulation for quantization and information reconciliation in CV-QKD systems
NASA Astrophysics Data System (ADS)
Daneshgaran, Fred; Mondin, Marina; Olia, Khashayar
2017-08-01
This paper is focused on the problem of Information Reconciliation (IR) for continuous variable Quantum Key Distribution (QKD). The main problem is quantization and assignment of labels to the samples of the Gaussian variables observed at Alice and Bob. Trouble is that most of the samples, assuming that the Gaussian variable is zero mean which is de-facto the case, tend to have small magnitudes and are easily disturbed by noise. Transmission over longer and longer distances increases the losses corresponding to a lower effective Signal to Noise Ratio (SNR) exasperating the problem. Here we propose to use Permutation Modulation (PM) as a means of quantization of Gaussian vectors at Alice and Bob over a d-dimensional space with d ≫ 1. The goal is to achieve the necessary coding efficiency to extend the achievable range of continuous variable QKD by quantizing over larger and larger dimensions. Fractional bit rate per sample is easily achieved using PM at very reasonable computational cost. Ordered statistics is used extensively throughout the development from generation of the seed vector in PM to analysis of error rates associated with the signs of the Gaussian samples at Alice and Bob as a function of the magnitude of the observed samples at Bob.
Quantum anonymous voting with unweighted continuous-variable graph states
NASA Astrophysics Data System (ADS)
Guo, Ying; Feng, Yanyan; Zeng, Guihua
2016-08-01
Motivated by the revealing topological structures of continuous-variable graph state (CVGS), we investigate the design of quantum voting scheme, which has serious advantages over the conventional ones in terms of efficiency and graphicness. Three phases are included, i.e., the preparing phase, the voting phase and the counting phase, together with three parties, i.e., the voters, the tallyman and the ballot agency. Two major voting operations are performed on the yielded CVGS in the voting process, namely the local rotation transformation and the displacement operation. The voting information is carried by the CVGS established before hand, whose persistent entanglement is deployed to keep the privacy of votes and the anonymity of legal voters. For practical applications, two CVGS-based quantum ballots, i.e., comparative ballot and anonymous survey, are specially designed, followed by the extended ballot schemes for the binary-valued and multi-valued ballots under some constraints for the voting design. Security is ensured by entanglement of the CVGS, the voting operations and the laws of quantum mechanics. The proposed schemes can be implemented using the standard off-the-shelf components when compared to discrete-variable quantum voting schemes attributing to the characteristics of the CV-based quantum cryptography.
Improving the Signal-To-Noise Ratio When Monitoring Countermovement Jump Performance.
Kennedy, Rodney A; Drake, David
2018-05-08
Kennedy, RA and Drake, D. Improving the signal-to-noise ratio when monitoring countermovement jump performance. J Strength Cond Res XX(X): 000-000, 2018-Countermovement jump (CMJ) performance has been routinely used to monitor neuromuscular status. However, the protocol used to establish the criterion score is not well documented. The purpose of this study was to examine how the protocol used would influence of the sensitivity of CMJ variables in rugby union players. Fifteen male (age: 19.7 ± 0.5 years) rugby union players performed 8 CMJs on 2 occasions, separated by 7 days. The between-session coefficient of variation (CV) was calculated using 2 techniques for treating multiple trials, the average, and the trial with the best jump height (JH), and then compared with the smallest worthwhile change (SWC). The signal-to-noise ratio was measured as the group mean change in a variable divided by the CV. Using the average value across multiple trials is superior to the best trial method, based on lower CVs for all variables. Only the average performance across 6 or more trials was classified as ideal (CV < 0.5 × SWC) for peak velocity (PV). In addition, the signal-to-noise ratio for peak concentric power (PCP), PV, and JH were classified as good, irrespective of the treatment method. Although increasing the number of trials can reduce the random error, it may be pragmatic to simply take the average from 2 to 3 trials, facilitating a CV < SWC for PV, PCP, and JH. Due to its simplicity, JH may be considered the principal variable to monitor neuromuscular fatigue.
2013-06-01
distribution is unlimited 12b. DISTRIBUTION CODE A 13. ABSTRACT (maximum 200 words) Some major defense acquisition programs (MDAPs) are cancelled...68 VI. PRACTICAL IMPLICATIONS FOR DEFENSE ACQUISITION .....................73 A . OVERVIEW...Contract Performance Report C /SCSC Cost/Schedule Control Systems Criteria CV Cost Variance CV % Cost Variance Percentage DAE Defense Acquisition
Cole, David A; Zelkowitz, Rachel L; Nick, Elizabeth; Martin, Nina C; Roeder, Kathryn M; Sinclair-McBride, Keneisha; Spinelli, Tawny
2016-10-01
Adolescents are among the most frequent users of social media websites, raising concern about the dangers of cyber bullying or cybervictimization (CV). A 12-month longitudinal study examined the unique, prospective relation of CV to the development of negative self-cognitions and depressive symptoms in a community sample of 827 children and young adolescents (ages 8-13; 55.1 % female) from the southeastern United States. Over and above conventional types of peer victimization, CV significantly predicted changes in self-referential negative cognitions, victimization-related cognitive reactions, and depressive symptoms, even after controlling for baseline levels of the dependent variables. Results also showed that CV was significantly less stable than other forms of victimization and tended to increase slightly with time. The study highlights the unique effects of CV and has implications for research and practice.
Troester, Jordan C; Jasmin, Jason G; Duffield, Rob
2018-06-01
The present study examined the inter-trial (within test) and inter-test (between test) reliability of single-leg balance and single-leg landing measures performed on a force plate in professional rugby union players using commercially available software (SpartaMARS, Menlo Park, USA). Twenty-four players undertook test - re-test measures on two occasions (7 days apart) on the first training day of two respective pre-season weeks following 48h rest and similar weekly training loads. Two 20s single-leg balance trials were performed on a force plate with eyes closed. Three single-leg landing trials were performed by jumping off two feet and landing on one foot in the middle of a force plate 1m from the starting position. Single-leg balance results demonstrated acceptable inter-trial reliability (ICC = 0.60-0.81, CV = 11-13%) for sway velocity, anterior-posterior sway velocity, and mediolateral sway velocity variables. Acceptable inter-test reliability (ICC = 0.61-0.89, CV = 7-13%) was evident for all variables except mediolateral sway velocity on the dominant leg (ICC = 0.41, CV = 15%). Single-leg landing results only demonstrated acceptable inter-trial reliability for force based measures of relative peak landing force and impulse (ICC = 0.54-0.72, CV = 9-15%). Inter-test results indicate improved reliability through the averaging of three trials with force based measures again demonstrating acceptable reliability (ICC = 0.58-0.71, CV = 7-14%). Of the variables investigated here, total sway velocity and relative landing impulse are the most reliable measures of single-leg balance and landing performance, respectively. These measures should be considered for monitoring potential changes in postural control in professional rugby union.
Diel rhythms in the volatile emission of apple and grape foliage
USDA-ARS?s Scientific Manuscript database
This study investigated the emission of volatile organic compounds (VOCs) from intact apple (Malus x domestica Borkh., cv. Golden Delicious) and grape (Vitis vinifera L., cv. Pinot Noir) foliage. Volatiles were monitored continuously for 48 hours by proton transfer reaction - time of flight - mass s...
An Hα-selected sample of cataclysmic variables - I. Observations of newly discovered systems
NASA Astrophysics Data System (ADS)
Pretorius, Magaretha L.; Knigge, Christian
2008-04-01
Strong selection effects are present in observational samples of cataclysmic variables (CVs), complicating comparisons to theoretical predictions. The selection criteria used to define most CV samples discriminate heavily against the discovery of short-period, intrinsically faint systems. The situation can be improved by selecting CVs for the presence of emission lines. For this reason, we have constructed a homogeneous sample of CVs selected on the basis of Hα emission. We present discovery observations of the 14 CVs and two additional CV candidates found in this search. The orbital periods of 11 of the new CVs were measured; all are above 3 h. There are two eclipsing systems in the sample, and one in which we observed a quasi-periodic modulation on a ~1000s time-scale. We also detect the secondary star in the spectrum of one system, and measure its spectral type. Several of the new CVs have the spectroscopic appearance of nova-like variables, and a few display what may be SW Sex star behaviour. In a companion paper, we discuss the implications of this new sample for CV evolution.
Kelsey, Katharine C.; Wickland, Kimberly P.; Striegl, Robert G.; Neff, Jason C.
2012-01-01
Carbon dynamics of high-latitude regions are an important and highly uncertain component of global carbon budgets, and efforts to constrain estimates of soil-atmosphere carbon exchange in these regions are contingent on accurate representations of spatial and temporal variability in carbon fluxes. This study explores spatial and temporal variability in soilatmosphere carbon dynamics at both fine and coarse spatial scales in a high-elevation, permafrost-dominated boreal black spruce forest. We evaluate the importance of landscape-level investigations of soil-atmosphere carbon dynamics by characterizing seasonal trends in soil-atmosphere carbon exchange, describing soil temperature-moisture-respiration relations, and quantifying temporal and spatial variability at two spatial scales: the plot scale (0–5 m) and the landscape scale (500–1000 m). Plot-scale spatial variability (average variation on a given measurement day) in soil CO2 efflux ranged from a coefficient of variation (CV) of 0.25 to 0.69, and plot-scale temporal variability (average variation of plots across measurement days) in efflux ranged from a CV of 0.19 to 0.36. Landscape-scale spatial and temporal variability in efflux was represented by a CV of 0.40 and 0.31, respectively, indicating that plot-scale spatial variability in soil respiration is as great as landscape-scale spatial variability at this site. While soil respiration was related to soil temperature at both the plot- and landscape scale, landscape-level descriptions of soil moisture were necessary to define soil respiration-moisture relations. Soil moisture variability was also integral to explaining temporal variability in soil respiration. Our results have important implications for research efforts in high-latitude regions where remote study sites make landscape-scale field campaigns challenging.
NASA Astrophysics Data System (ADS)
Belloni, Diogo; Zorotovic, Mónica; Schreiber, Matthias R.; Leigh, Nathan W. C.; Giersz, Mirek; Askar, Abbas
2017-06-01
In this third of a series of papers related to cataclysmic variables (CVs) and related objects, we analyse the population of CVs in a set of 12 globular cluster models evolved with the MOCCA Monte Carlo code, for two initial binary populations (IBPs), two choices of common-envelope phase (CEP) parameters, and three different models for the evolution of CVs and the treatment of angular momentum loss. When more realistic models and parameters are considered, we find that present-day cluster CV duty cycles are extremely low (≲0.1 per cent) that makes their detection during outbursts rather difficult. Additionally, the IBP plays a significant role in shaping the CV population properties, and models that follow the Kroupa IBP are less affected by enhanced angular momentum loss. We also predict from our simulations that CVs formed dynamically in the past few Gyr (massive CVs) correspond to bright CVs (as expected) and that faint CVs formed several Gyr ago (dynamically or not) represent the overwhelming majority. Regarding the CV formation rate, we rule out the notion that it is similar irrespective of the cluster properties. Finally, we discuss the differences in the present-day CV properties related to the IBPs, the initial cluster conditions, the CEP parameters, formation channels, the CV evolution models and the angular momentum loss treatments.
Monogamy inequalities for the Einstein-Podolsky-Rosen paradox and quantum steering
NASA Astrophysics Data System (ADS)
Reid, M. D.
2013-12-01
Monogamy inequalities for the way bipartite Einstein-Podolsky-Rosen (EPR) steering can be distributed among N systems are derived. One set of inequalities is based on witnesses with two measurement settings, and may be used to demonstrate correlation of outcomes between two parties, that cannot be shared with more parties. It is shown that the monogamy for steering is directional. Two parties cannot independently demonstrate steering of a third system, using the same two-setting steering witness, but it is possible for one party to steer two independent systems. This result explains the monogamy of two-setting Bell inequality violations and the sensitivity of the continuous variable (CV) EPR criterion to losses on the steering party. We generalize to m settings. A second type of monogamy relation gives the quantitative amount of sharing possible, when the number of parties is less than or equal to m, and takes a form similar to the Coffman-Kundu-Wootters relation for entanglement. The results enable characterization of the tripartite steering for CV Gaussian systems and qubit Greenberger-Horne-Zeilinger and W states.
NASA Astrophysics Data System (ADS)
Huang, Duan; Huang, Peng; Wang, Tao; Li, Huasheng; Zhou, Yingming; Zeng, Guihua
2016-09-01
We propose and experimentally demonstrate a continuous-variable quantum key distribution (CV-QKD) protocol using dual-phase-modulated coherent states. We show that the modulation scheme of our protocol works equivalently to that of the Gaussian-modulated coherent-states (GMCS) protocol, but shows better experimental feasibility in the plug-and-play configuration. Besides, it waives the necessity of propagation of a local oscillator (LO) between legitimate users and generates a real local LO for quantum measurement. Our protocol is proposed independent of the one-way GMCS QKD without sending a LO [Opt. Lett. 40, 3695 (2015), 10.1364/OL.40.003695; Phys. Rev. X 5, 041009 (2015), 10.1103/PhysRevX.5.041009; Phys. Rev. X 5, 041010 (2015), 10.1103/PhysRevX.5.041010]. In those recent works, the system stability will suffer the impact of polarization drifts induced by environmental perturbations, and two independent frequency-locked laser sources are necessary to achieve reliable coherent detection. In the proposed protocol, these previous problems can be resolved. We derive the security bounds for our protocol against collective attacks, and we also perform a proof-of-principle experiment to confirm the utility of our proposal in real-life applications. Such an efficient scheme provides a way of removing the security loopholes associated with the transmitting LO, which have been a notoriously hard problem in continuous-variable quantum communication.
Body fat mass and lean mass as predictors of survival in hemodialysis patients.
Kakiya, R; Shoji, T; Tsujimoto, Y; Tatsumi, N; Hatsuda, S; Shinohara, K; Kimoto, E; Tahara, H; Koyama, H; Emoto, M; Ishimura, E; Miki, T; Tabata, T; Nishizawa, Y
2006-08-01
A higher body mass index (BMI) is a predictor of better survival in hemodialysis patients, although the relative importance of body fat and lean mass has not been examined in the dialysis population. We performed an observational cohort study in 808 patients with end-stage renal disease on maintenance hemodialysis. At baseline, fat mass was measured by dual-energy X-ray absorptiometry and expressed as fat mass index (FMI; kg/m2). Lean mass index (LMI) was defined as BMI minus FMI. During the mean follow-up period of 53 months, 147 deaths, including 62 cardiovascular (CV) and 85 non-CV fatal events, were recorded. In univariate analysis, LMI was not significantly associated with CV or non-CV death, whereas a higher FMI was predictive of lower risk for non-CV death. Analyses with multivariate Cox models, which took other confounding variables as covariates, indicated the independent associations between a higher LMI and a lower risk of CV death, as well as between a higher FMI and a lower risk of non-CV death. These results indicate that increased fat mass and lean mass were both conditions associated with better outcomes in the dialysis population.
A flexible continuous-variable QKD system using off-the-shelf components
NASA Astrophysics Data System (ADS)
Comandar, Lucian C.; Brunner, Hans H.; Bettelli, Stefano; Fung, Fred; Karinou, Fotini; Hillerkuss, David; Mikroulis, Spiros; Wang, Dawei; Kuschnerov, Maxim; Xie, Changsong; Poppe, Andreas; Peev, Momtchil
2017-10-01
We present the development of a robust and versatile CV-QKD architecture based on commercially available optical and electronic components. The system uses a pilot tone for phase synchronization with a local oscillator, as well as local feedback loops to mitigate frequency and polarization drifts. Transmit and receive-side digital signal processing is performed fully in software, allowing for rapid protocol reconfiguration. The quantum link is complemented with a software stack for secure-key processing, key storage and encrypted communication. All these features allow for the system to be at the same time a prototype for a future commercial product and a research platform.
ERIC Educational Resources Information Center
Scarpa, Angela; Tanaka, Akiho; Haden, Sara Chiara
2008-01-01
In order to more fully understand how individual differences influence adaptation to violence, this study examined the moderating influence of resting heart rate (HR) and HR variability (HRV) between community violence (CV) exposure and child reactive/proactive aggression. Forty 7-13-year-old community children self-reported CV exposure (i.e.,…
Phytochrome-mediated synthesis of novel growth inhibitors, A-2α and β, and dwarfism in peas.
Noguchi, H; Hashimoto, T
1990-05-01
Variations in the content of A-2α and β, novel endogenous growth inhibitors, andcis,trans- andtrans, trans-xanthoxins were determined in 6- or 7-d-old, dark-grown seedlings of peas (Pisum sativum L. cvs. Progress No. 9, dwarf, and Alaska, tall) under various treatments with red light (R), and compared with R-induced growth inhibition. After transfer of the plants to continuous R the contents of the A-2s in cv. Progress increased after a 20-min lag, and reached plateaus after 12 h, whereas they remained almost unchanged in darkness. Both the rates of increase of the A-2s and the plateau levels were proportional to the logarithm of the irradiance applied. After a 10-min R pulse, the contents of both A-2α and β increased with the same rapidity to reach peaks after 6 h, and then gradually decreased to the initial levels after about 24 h. The effect of R was shown to be phytochrome-dependent, being nullified by far-red light. The level of neithercis,trans- nortrans,trans-xanthoxin showed such a close correlation with growth inhibition, although both xanthoxins increased as a result of phytochrome action. It is highly suggestive that the A-2s, rather than the xanthoxins, are responsible for phytochrome-dependent growth inhibition in cv. Progress. In cv. Alaska, in contrast, R-induced increase of the A-2s was rapid but slight, and could not explain the transient growth inhibition, which was found to be as large as that in cv. Progress shortly after the onset of R. The large content of the A-2s in cv. Progress in the steady state under continuous R, compared with that in cv. Alaska, may explain the dwarfism of cv. Progress.
2009-01-01
CD VVV ∪= with DV countable and nCV ℜ∈ ; XInit ⊆ is a set of initial states; CXVXf →×: is a vector field, assumed to be 4 globally...DV countable and nCV ℜ∈ ; XInit ⊆ is a set of initial states; CXVXf →×: is a vector field, assumed to be globally Lipschitz in CX and...8217 ; V is a finite collection of input variables. We assume ( )CD VVV ∪= with DV countable and nCV ℜ∈ ; XInit ⊆ is a set of initial states
Olsen, Mia B.; Wielandt, Daniel; Schiller, Martin; Van Kooten, Elishevah M.M.E.; Bizzarro, Martin
2016-01-01
We report on the petrology, magnesium isotopes and mass-independent 54Cr/52Cr compositions (μ54Cr) of 42 chondrules from CV (Vigarano and NWA 3118) and CR (NWA 6043, NWA 801 and LAP 02342) chondrites. All sampled chondrules are classified as type IA or type IAB, have low 27Al/24Mg ratios (0.04–0.27) and display little or no evidence for secondary alteration processes. The CV and CR chondrules show variable 25Mg/24Mg and 26Mg/24Mg values corresponding to a range of mass-dependent fractionation of ~500 ppm (parts per million) per atomic mass unit. This mass-dependent Mg isotope fractionation is interpreted as reflecting Mg isotope heterogeneity of the chondrule precursors and not the result of secondary alteration or volatility-controlled processes during chondrule formation. The CV and CR chondrule populations studied here are characterized by systematic deficits in the mass-independent component of 26Mg (μ26Mg*) relative to the solar value defined by CI chondrites, which we interpret as reflecting formation from precursor material with a reduced initial abundance of 26Al compared to the canonical 26Al/27Al of ~5 × 10−5. Model initial 26Al/27Al values of CV and CR chondrules vary from (1.5 ± 4.0) × 10−6 to (2.2 ± 0.4) × 10−5. The CV chondrules display significant μ54Cr variability, defining a range of compositions that is comparable to that observed for inner Solar System primitive and differentiated meteorites. In contrast, CR chondrites are characterized by a narrower range of μ54Cr values restricted to compositions typically observed for bulk carbonaceous chondrites. Collectively, these observations suggest that the CV chondrules formed from precursors that originated in various regions of the protoplanetary disk and were then transported to the accretion region of the CV parent asteroid whereas CR chondrule predominantly formed from precursor with carbonaceous chondrite-like μ54Cr signatures. The observed μ54Cr variability in chondrules from CV and CR chondrites suggest that the matrix and chondrules did not necessarily formed from the same reservoir. The coupled μ26Mg* and μ54Cr systematics of CR chondrules establishes that these objects formed from a thermally unprocessed and 26Al-poor source reservoir distinct from most inner Solar System asteroids and planetary bodies, possibly located beyond the orbits of the gas giants. In contrast, a large fraction of the CV chondrules plot on the inner Solar System correlation line, indicating that these objects predominantly formed from thermally-processed, 26Al-bearing precursor material akin to that of inner Solar System solids, asteroids and planets. PMID:27563152
NASA Astrophysics Data System (ADS)
Olsen, Mia B.; Wielandt, Daniel; Schiller, Martin; Van Kooten, Elishevah M. M. E.; Bizzarro, Martin
2016-10-01
We report on the petrology, magnesium isotopes and mass-independent 54Cr/52Cr compositions (μ54Cr) of 42 chondrules from CV (Vigarano and NWA 3118) and CR (NWA 6043, NWA 801 and LAP 02342) chondrites. All sampled chondrules are classified as type IA or type IAB, have low 27Al/24Mg ratios (0.04-0.27) and display little or no evidence for secondary alteration processes. The CV and CR chondrules show variable 25Mg/24Mg and 26Mg/24Mg values corresponding to a range of mass-dependent fractionation of ∼500 ppm (parts per million) per atomic mass unit. This mass-dependent Mg isotope fractionation is interpreted as reflecting Mg isotope heterogeneity of the chondrule precursors and not the result of secondary alteration or volatility-controlled processes during chondrule formation. The CV and CR chondrule populations studied here are characterized by systematic deficits in the mass-independent component of 26Mg (μ26Mg∗) relative to the solar value defined by CI chondrites, which we interpret as reflecting formation from precursor material with a reduced initial abundance of 26Al compared to the canonical 26Al/27Al of ∼5 × 10-5. Model initial 26Al/27Al values of CV and CR chondrules vary from (1.5 ± 4.0) × 10-6 to (2.2 ± 0.4) × 10-5. The CV chondrules display significant μ54Cr variability, defining a range of compositions that is comparable to that observed for inner Solar System primitive and differentiated meteorites. In contrast, CR chondrites are characterized by a narrower range of μ54Cr values restricted to compositions typically observed for bulk carbonaceous chondrites. Collectively, these observations suggest that the CV chondrules formed from precursors that originated in various regions of the protoplanetary disk and were then transported to the accretion region of the CV parent asteroid whereas CR chondrule predominantly formed from precursor with carbonaceous chondrite-like μ54Cr signatures. The observed μ54Cr variability in chondrules from CV and CR chondrites suggest that the matrix and chondrules did not necessarily formed from the same reservoir. The coupled μ26Mg∗ and μ54Cr systematics of CR chondrules establishes that these objects formed from a thermally unprocessed and 26Al-poor source reservoir distinct from most inner Solar System asteroids and planetary bodies, possibly located beyond the orbits of the gas giants. In contrast, a large fraction of the CV chondrules plot on the inner Solar System correlation line, indicating that these objects predominantly formed from thermally-processed, 26Al-bearing precursor material akin to that of inner Solar System solids, asteroids and planets.
2011-01-01
Background Hydroxyurea (HU) is the first approved pharmacological treatment of sickle cell anemia (SCA). The objectives of this study were to develop population pharmacokinetic(PK)-pharmacodynamic(PD) models for HU in order to characterize the exposure-efficacy relationships and their variability, compare two dosing regimens by simulations and develop some recommendations for monitoring the treatment. Methods The models were built using population modelling software NONMEM VII based on data from two clinical studies of SCA adult patients receiving 500-2000 mg of HU once daily. Fetal hemoglobin percentage (HbF%) and mean corpuscular volume (MCV) were used as biomarkers for response. A sequential modelling approach was applied. Models were evaluated using simulation-based techniques. Comparisons of two dosing regimens were performed by simulating 10000 patients in each arm during 12 months. Results The PK profiles were described by a bicompartmental model. The median (and interindividual coefficient of variation (CV)) of clearance was 11.6 L/h (30%), the central volume was 45.3 L (35%). PK steady-state was reached in about 35 days. For a given dosing regimen, HU exposure varied approximately fivefold among patients. The dynamics of HbF% and MCV were described by turnover models with inhibition of elimination of response. In the studied range of drug exposures, the effect of HU on HbF% was at its maximum (median Imax was 0.57, CV was 27%); the effect on MCV was close to its maximum, with median value of 0.14 and CV of 49%. Simulations showed that 95% of the steady-state levels of HbF% and MCV need 26 months and 3 months to be reached, respectively. The CV of the steady-state value of HbF% was about 7 times larger than that of MCV. Simulations with two different dosing regimens showed that continuous dosing led to a stronger HbF% increase in some patients. Conclusions The high variability of response to HU was related in part to pharmacokinetics and to pharmacodynamics. The steady-state value of MCV at month 3 is not predictive of the HbF% value at month 26. Hence, HbF% level may be a better biomarker for monitoring HU treatment. Continuous dosing might be more advantageous in terms of HbF% for patients who have a strong response to HU. Trial Registration The clinical studies whose data are analysed and reported in this work were not required to be registered in France at their time. Both studies were approved by local ethics committees (of Mondor Hospital and of Kremlin-Bicetre Hospital) and written informed consent was obtained from each patient. PMID:21619673
Solomon, Daniel H.; Kremer, Joel; Curtis, Jeffrey R; Hochberg, Marc C.; Reed, George; Tsao, Peter; Farkouh, Michael E.; Setoguchi, Soko; Greenberg, Jeffrey D.
2010-01-01
Background Cardiovascular (CV) disease has a major impact on patients with rheumatoid arthritis (RA), however, the relative contributions of traditional CV risk factors and markers of RA severity are unclear. We examined the relative importance of traditional CV risk factors and RA markers in predicting CV events. Methods A prospective longitudinal cohort study was conducted in the setting of the CORRONA registry in the United States. Baseline data from subjects with RA enrolled in the CORRONA registry were examined to determine predictors of CV outcomes, including myocardial infarction (MI), stroke or transient ischemic attack (TIA). Possible predictors were of two types: traditional CV risk factors and markers of RA severity. The discriminatory value of these variables was assessed by calculating the area under the receiver operating characteristic curve (c-statistic) in logistic regression. We then assessed the incidence rate for CV events among subjects with an increasing number of traditional CV risk factors and/or RA severity markers. Results The cohort consisted of 10,156 patients with RA followed for a median of 22 months. We observed 76 primary CV events during follow-up for a composite event rate of 3.98 (95% CI 3.08 – 4.88) per 1,000 patient-years. The c-statistic improved from 0.57 for models with only CV risk factors to 0.67 for models with CV risk factors plus age and gender. The c-statistic improved further to 0.71 when markers of RA severity were also added. The incidence rate for CV events was 0 (95% CI 0 – 5.98) for persons without any CV risk factors or markers of RA severity, while in the group with two or more CV risk factors and 3 or more markers of RA severity the incidence was 7.47 (95% CI 4.21–10.73) per 1,000 person-years. Conclusions Traditional CV risk factors and markers of RA severity both contribute to models predicting CV events. Increasing numbers of both types of factors are associated with greater risk. PMID:20444756
Dorajoo, Sreemanee Raaj; Ng, Joceline Shi Ling; Goh, Jessica Hui Fen; Lim, Su Chi; Yap, Chun Wei; Chan, Alexandre; Lee, Joyce Yu Chia
2017-06-01
To evaluate the association between HbA1c coefficient of variation (HbA1c-CV) and 3-year new-onset albuminuria risk. A retrospective cohort study involving 716 normoalbuminuric type 2 diabetes patients was conducted between 2010 and 2014. HbA1c-CV was used to categorize patients into low, moderate or high variability groups. Multivariate logistic models were constructed and validated. Integrated discrimination (IDI) and net reclassification (NRI) improvement indices were used to quantify the added predictive value of HbA1c-CV. The mean age of our cohort was 56.1±12.9years with a baseline HbA1c of 8.3±1.3%. Over 3-years of follow-up, 35.2% (n=252) developed albuminuria. An incremental risk of albuminuria was observed with moderate (6.68-13.43%) and high (above 13.44%) HbA1c-CV categories demonstrating adjusted odds ratios of 1.63 (1.12-2.38) and 3.80 (2.10-6.97) for 3-year new-onset albuminuria, respectively. Including HbA1c-CV for 3-year new-onset albuminuria prediction improved model discrimination (IDI: 0.023, NRI: 0.293, p<0.05). The final model had a C-statistic of 0.760±0.018 on validation. HbA1c-CV improves 3-year prediction of new-onset albuminuria. Together with mean HbA1c, baseline urine albumin-to-creatinine ratio and presence of hypertension, accurate 3-year new-onset albuminuria prediction may be possible. Copyright © 2017 Elsevier B.V. All rights reserved.
Reliability of sprint test indices in well-trained cyclists.
Coleman, D A; Wiles, J D; Nunn, M; Smith, M F
2005-06-01
The study aim was to assess reliability of repeated laboratory sprint tests in well-trained endurance cyclists. Eleven male cyclists (mean +/- standard deviation: 27 +/- 6 yr, 1.79 +/- 0.04 m, 70.1 +/- 3.3 kg) performed a maximal 30-second sprint test on four separate occasions using their own bicycle fitted with an SRM powermeter on a Kingcycle air-braked ergometer. Peak power output (W (peak)), mean power (W (mean)) and an index of fatigue (FI) were calculated. Three minutes post sprint, capillarised blood lactate measurements were taken and analysed. No significant differences (p > 0.05) were found between trials for W (peak), W (mean), FI and blood lactate concentration. Repeatability of W (peak), W (mean), and fatigue index improved across trials 2 and 3 when compared to trials 1 and 2. The highest CV for these variables was recorded between trials 3 and 4. The CV for W (peak) was 4.5 +/- 1.6 %, W (mean) 2.4 +/- 1.2 %, and FI 17.2 +/- 7.1 %. Intraclass reliability coefficients were 0.93 (95 % CI 0.84 - 0.98), 0.94 (95 % CI 0.86 - 0.98) and 0.89 (95 % CI 0.69 - 0.95) respectively. Blood lactate concentration ranged between 5.35 and 14.52 mmol.l(-1), with a mean CV of 12.1 +/- 4.2 %. The CV for trials 2 and 3 revealed the highest CV for blood lactate concentration (15.1 %). The lowest CV for this variable (10.2 %) was recorded between trials 3 and 4. The intraclass reliability coefficient for blood lactate concentration was 0.79 (95 % CI 0.58 - 0.93). The results of this study indicate that there is no improvement in the reliability of sprint test indices when assessing well-trained, experienced cyclists, riding on their own cycle equipment.
Masmiquel, L; Leiter, L A; Vidal, J; Bain, S; Petrie, J; Franek, E; Raz, I; Comlekci, A; Jacob, S; van Gaal, L; Baeres, F M M; Marso, S P; Eriksson, M
2016-02-10
Epidemiological data on obesity are needed, particularly in patients with type 2 diabetes mellitus (T2DM) and high cardiovascular (CV) risk. We used the baseline data of liraglutide effect and action in diabetes: evaluation of CV outcome results-A long term Evaluation (LEADER) (a clinical trial to assess the CV safety of liraglutide) to investigate: (i) prevalence of overweight and obesity; (ii) relationship of the major cardiometabolic risk factors with anthropometric measures of adiposity [body mass index (BMI) and waist circumference (WC)]; and (iii) cardiometabolic treatment intensity in relation to BMI and WC. LEADER enrolled two distinct populations of high-risk patients with T2DM in 32 countries: (1) aged ≥50 years with prior CV disease; (2) aged ≥60 years with one or more CV risk factors. Associations of metabolic variables, demographic variables and treatment intensity with anthropometric measurements (BMI and WC) were explored using regression models (ClinicalTrials.gov identifier: NCT01179048). Mean BMI was 32.5 ± 6.3 kg/m(2) and only 9.1 % had BMI <25 kg/m(2). The prevalence of healthy WC was also extremely low (6.4 % according to International Joint Interim Statement for the Harmonization of the Metabolic Syndrome criteria). Obesity was associated with being younger, female, previous smoker, Caucasian, American, with shorter diabetes duration, uncontrolled blood pressure (BP), antihypertensive agents, insulin plus oral antihyperglycaemic treatment, higher levels of triglycerides and lower levels of high-density lipoprotein cholesterol. Overweight and obesity are prevalent in high CV risk patients with T2DM. BMI and WC are related to the major cardiometabolic risk factors. Furthermore, treatment intensity, such as insulin, statins or oral antihypertensive drugs, is higher in those who are overweight or obese; while BP and lipid control in these patients are remarkably suboptimal. LEADER confers a unique opportunity to explore the longitudinal effect of weight on CV risk factors and hard endpoints.
Stenfors, Cecilia U D; Hanson, Linda M; Theorell, Töres; Osika, Walter S
2016-01-01
Objective: Executive cognitive functioning is essential in private and working life and is sensitive to stress and aging. Cardiovascular (CV) health factors are related to cognitive decline and dementia, but there is relatively few studies of the role of CV autonomic regulation, a key component in stress responses and risk factor for cardiovascular disease (CVD), and executive processes. An emerging pattern of results from previous studies suggest that different executive processes may be differentially associated with CV autonomic regulation. The aim was thus to study the associations between multiple measures of CV autonomic regulation and measures of different executive cognitive processes. Method: Participants were 119 healthy working adults (79% women), from the Swedish Longitudinal Occupational Survey of Health. Electrocardiogram was sampled for analysis of heart rate variability (HRV) measures, including the Standard Deviation of NN, here heart beats (SDNN), root of the mean squares of successive differences (RMSSD), high frequency (HF) power band from spectral analyses, and QT variability index (QTVI), a measure of myocardial repolarization patterns. Executive cognitive functioning was measured by seven neuropsychological tests. The relationships between CV autonomic regulation measures and executive cognitive measures were tested with bivariate and partial correlational analyses, controlling for demographic variables, and mental health symptoms. Results: Higher SDNN and RMSSD and lower QTVI were significantly associated with better performance on cognitive tests tapping inhibition, updating, shifting, and psychomotor speed. After adjustments for demographic factors however (age being the greatest confounder), only QTVI was clearly associated with these executive tests. No such associations were seen for working memory capacity . Conclusion: Poorer CV autonomic regulation in terms of lower SDNN and RMSSD and higher QTVI was associated with poorer executive cognitive functioning in terms of inhibition, shifting, updating, and speed in healthy working adults. Age could largely explain the associations between the executive measures and SDNN and RMSSD, while associations with QTVI remained. QTVI may be a useful measure of autonomic regulation and promising as an early indicator of risk among otherwise healthy adults, compared to traditional HRV measures, as associations between QTVI and executive functioning was not affected by age.
Stenfors, Cecilia U. D.; Hanson, Linda M.; Theorell, Töres; Osika, Walter S.
2016-01-01
Objective: Executive cognitive functioning is essential in private and working life and is sensitive to stress and aging. Cardiovascular (CV) health factors are related to cognitive decline and dementia, but there is relatively few studies of the role of CV autonomic regulation, a key component in stress responses and risk factor for cardiovascular disease (CVD), and executive processes. An emerging pattern of results from previous studies suggest that different executive processes may be differentially associated with CV autonomic regulation. The aim was thus to study the associations between multiple measures of CV autonomic regulation and measures of different executive cognitive processes. Method: Participants were 119 healthy working adults (79% women), from the Swedish Longitudinal Occupational Survey of Health. Electrocardiogram was sampled for analysis of heart rate variability (HRV) measures, including the Standard Deviation of NN, here heart beats (SDNN), root of the mean squares of successive differences (RMSSD), high frequency (HF) power band from spectral analyses, and QT variability index (QTVI), a measure of myocardial repolarization patterns. Executive cognitive functioning was measured by seven neuropsychological tests. The relationships between CV autonomic regulation measures and executive cognitive measures were tested with bivariate and partial correlational analyses, controlling for demographic variables, and mental health symptoms. Results: Higher SDNN and RMSSD and lower QTVI were significantly associated with better performance on cognitive tests tapping inhibition, updating, shifting, and psychomotor speed. After adjustments for demographic factors however (age being the greatest confounder), only QTVI was clearly associated with these executive tests. No such associations were seen for working memory capacity. Conclusion: Poorer CV autonomic regulation in terms of lower SDNN and RMSSD and higher QTVI was associated with poorer executive cognitive functioning in terms of inhibition, shifting, updating, and speed in healthy working adults. Age could largely explain the associations between the executive measures and SDNN and RMSSD, while associations with QTVI remained. QTVI may be a useful measure of autonomic regulation and promising as an early indicator of risk among otherwise healthy adults, compared to traditional HRV measures, as associations between QTVI and executive functioning was not affected by age. PMID:27761124
Lupoli, Roberta; Ambrosino, Pasquale; Tortora, Anna; Barba, Livia; Lupoli, Gelsy Arianna; Di Minno, Matteo Nicola Dario
2017-05-01
Several studies reported an increased cardiovascular (CV) risk in Cushing's syndrome (CS). We performed a meta-analysis on the impact of CS on major markers of atherosclerosis. Studies on intima-media thickness (IMT), carotid plaques prevalence, and flow-mediated dilation (FMD) in CS patients and controls were searched in the PubMed, Web of Science, Scopus, and EMBASE. Differences between cases and controls were expressed as mean difference (MD) with 95% confidence intervals (95%CI) for continuous variables, and as Odds Ratio (OR) with 95%CI for dichotomous variables. Fourteen studies (332 CS, 462 controls) were included. Compared with controls, CS patients showed higher IMT (MD: 0.20 mm; 95% CI: 0.12, 0.28; p < .001), increased prevalence of carotid plaques (OR: 8.85, 95%CI: 4.09, 19.14; p < .001), and lower FMD (MD: -2.65%; 95% CI: -3.65, -1.65; p < .001). Difference in IMT and in the prevalence of carotid plaques was confirmed also in patients with CS remission (MD: 0.24 mm; 95% CI: 0.07, 0.40; p = .005 and OR: 9.88, 95%CI: 2.69, 36.3; p < 0.001, respectively). Regression models showed that age, diabetes, obesity, ACTH-dependent CS, serum and urinary cortisol levels impacted on the observed difference in IMT. CS is significantly associated with markers of subclinical atherosclerosis and CV risk. These findings could help establish more specific CV prevention strategies in this clinical setting. Key messages A series of studies reported an increased cardiovascular risk in patients with Cushing's syndrome (CS). In the present meta-analysis we demonstrated that CS is associated with an increased intima-media thickness, higher prevalence of carotid plaques, and lower flow-mediated dilation as compared with controls. These data consistently suggest the need for a strict monitoring of early signs of subclinical atherosclerosis in CS patients.
Quality of Cardiac Care in Canada: Recommendations for Building a Sustainable Future.
Young, Courtney; Lambert, Laurie; Abel, James; O'Neill, Blair J
2018-06-01
Cardiovascular (CV) disease continues to present a significant disease and economic burden in Canada. To improve the quality of care and ensure sustainability of services, a national quality improvement initiative is required. The purpose of this analysis was to review the evidence for public reporting (PR) and external benchmarking (EB) to improve patient outcomes, and to recommend a strategy to improve CV care in Canada. To incorporate recent literature, the Canadian Cardiovascular Society (CCS) commissioned the Institute of Health Economics to provide a rapid update on the literature of PR and EB. The review showed that EB is more likely to promote positive effects, such as improved mortality, morbidity, and evidence-based clinical practice, and to limit negative effects, such as access restrictions or unintended provider behaviour associated with some forms of "top-down" PR. On the basis of these findings, this we recommend the following: (1) secure funding for the provincial collection of CV quality indicators and the creation of annual National CV Quality Reports; (2) enhance the culture of using CV quality indicator data for continuous quality improvement and opportunities for national or regional EB and sharing best practices; and (3) implement ongoing evaluation and revision of CCS clinical practice guidelines incorporating key quality indicators. This is already under way to a limited extent by the CCS with its Quality Project, but intentional, sustained support needs to be secured to enhance this ongoing effort and improve the quality of CV care for all Canadians. Copyright © 2018 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.
Sánchez Pérez, A; Honrubia López, F M; Larrosa Poves, J M; Polo Llorens, V; Melcon Sánchez-Frieras, B
2001-09-01
To develop a lens planimetry technique for the optic disc using AutoCAD. To determine variability magnitude of the optic disc morphological measurements. We employed AutoCAD R.14.0 Autodesk: image acquisition, contour delimitation by multiple lines fitting or ellipse adjustment, image sectorialization and measurements quantification (optic disc and excavation, vertical diameters, optic disc area, excavation area, neuroretinal sector area and Beta atrophy area). Intraimage or operator and interimage o total reproducibility was studied by coefficient of variability (CV) (n=10) in normal and myopic optic discs. This technique allows to obtain optic disc measurement in 5 to 10 minutes time. Total or interimage variability of measurements introduced by one observer presents CV range from 1.18-4.42. Operator or intraimage measurement presents CV range from 0.30-4.21. Optic disc contour delimitation by ellipse adjustment achieved better reproducibility results than multiple lines adjustment in all measurements. Computer assisted AutoCAD planimetry is an interactive method to analyse the optic disc, feasible to incorporate to clinical practice. Reproducibility results are comparable to other analyzers in quantification optic disc morphology. Ellipse adjustment improves results in optic disc contours delimitation.
NASA Astrophysics Data System (ADS)
Hashemian, Behrooz; Millán, Daniel; Arroyo, Marino
2013-12-01
Collective variables (CVs) are low-dimensional representations of the state of a complex system, which help us rationalize molecular conformations and sample free energy landscapes with molecular dynamics simulations. Given their importance, there is need for systematic methods that effectively identify CVs for complex systems. In recent years, nonlinear manifold learning has shown its ability to automatically characterize molecular collective behavior. Unfortunately, these methods fail to provide a differentiable function mapping high-dimensional configurations to their low-dimensional representation, as required in enhanced sampling methods. We introduce a methodology that, starting from an ensemble representative of molecular flexibility, builds smooth and nonlinear data-driven collective variables (SandCV) from the output of nonlinear manifold learning algorithms. We demonstrate the method with a standard benchmark molecule, alanine dipeptide, and show how it can be non-intrusively combined with off-the-shelf enhanced sampling methods, here the adaptive biasing force method. We illustrate how enhanced sampling simulations with SandCV can explore regions that were poorly sampled in the original molecular ensemble. We further explore the transferability of SandCV from a simpler system, alanine dipeptide in vacuum, to a more complex system, alanine dipeptide in explicit water.
Hashemian, Behrooz; Millán, Daniel; Arroyo, Marino
2013-12-07
Collective variables (CVs) are low-dimensional representations of the state of a complex system, which help us rationalize molecular conformations and sample free energy landscapes with molecular dynamics simulations. Given their importance, there is need for systematic methods that effectively identify CVs for complex systems. In recent years, nonlinear manifold learning has shown its ability to automatically characterize molecular collective behavior. Unfortunately, these methods fail to provide a differentiable function mapping high-dimensional configurations to their low-dimensional representation, as required in enhanced sampling methods. We introduce a methodology that, starting from an ensemble representative of molecular flexibility, builds smooth and nonlinear data-driven collective variables (SandCV) from the output of nonlinear manifold learning algorithms. We demonstrate the method with a standard benchmark molecule, alanine dipeptide, and show how it can be non-intrusively combined with off-the-shelf enhanced sampling methods, here the adaptive biasing force method. We illustrate how enhanced sampling simulations with SandCV can explore regions that were poorly sampled in the original molecular ensemble. We further explore the transferability of SandCV from a simpler system, alanine dipeptide in vacuum, to a more complex system, alanine dipeptide in explicit water.
Troester, Jordan C.; Jasmin, Jason G.; Duffield, Rob
2018-01-01
The present study examined the inter-trial (within test) and inter-test (between test) reliability of single-leg balance and single-leg landing measures performed on a force plate in professional rugby union players using commercially available software (SpartaMARS, Menlo Park, USA). Twenty-four players undertook test – re-test measures on two occasions (7 days apart) on the first training day of two respective pre-season weeks following 48h rest and similar weekly training loads. Two 20s single-leg balance trials were performed on a force plate with eyes closed. Three single-leg landing trials were performed by jumping off two feet and landing on one foot in the middle of a force plate 1m from the starting position. Single-leg balance results demonstrated acceptable inter-trial reliability (ICC = 0.60-0.81, CV = 11-13%) for sway velocity, anterior-posterior sway velocity, and mediolateral sway velocity variables. Acceptable inter-test reliability (ICC = 0.61-0.89, CV = 7-13%) was evident for all variables except mediolateral sway velocity on the dominant leg (ICC = 0.41, CV = 15%). Single-leg landing results only demonstrated acceptable inter-trial reliability for force based measures of relative peak landing force and impulse (ICC = 0.54-0.72, CV = 9-15%). Inter-test results indicate improved reliability through the averaging of three trials with force based measures again demonstrating acceptable reliability (ICC = 0.58-0.71, CV = 7-14%). Of the variables investigated here, total sway velocity and relative landing impulse are the most reliable measures of single-leg balance and landing performance, respectively. These measures should be considered for monitoring potential changes in postural control in professional rugby union. Key points Single-leg balance demonstrated acceptable inter-trial and inter-test reliability. Single-leg landing demonstrated good inter-trial and inter-test reliability for measures of relative peak landing force and relative impulse, but not time to stabilization. Of the variables investigated, sway velocity and relative landing impulse are the most reliable measures of single-leg balance and landing respectively, and should considered for monitoring changes in postural control. PMID:29769817
NASA Astrophysics Data System (ADS)
Goodrich, J. P.; Cayan, D. R.
2017-12-01
California's Central Valley (CV) relies heavily on diverted surface water and groundwater pumping to supply irrigated agriculture. However, understanding the spatiotemporal character of water availability in the CV is difficult because of the number of individual farms and local, state, and federal agencies involved in using and managing water. Here we use the Central Valley Hydrologic Model (CVHM), developed by the USGS, to understand the relationships between climatic variability, surface water inputs, and resulting groundwater use over the historical period 1970-2013. We analyzed monthly surface water diversion data from >500 CV locations. Principle components analyses were applied to drivers constructed from meteorological data, surface reservoir storage, ET, land use cover, and upstream inflows, to feed multiple regressions and identify factors most important in predicting surface water diversions. Two thirds of the diversion locations ( 80% of total diverted water) can be predicted to within 15%. Along with monthly inputs, representations of cumulative precipitation over the previous 3 to 36 months can explain an additional 10% of variance, depending on location, compared to results that excluded this information. Diversions in the southern CV are highly sensitive to inter-annual variability in precipitation (R2 = 0.8), whereby more surface water is used during wet years. Until recently, this was not the case in the northern and mid-CV, where diversions were relatively constant annually, suggesting relative insensitivity to drought. In contrast, this has important implications for drought response in southern regions (eg. Tulare Basin) where extended dry conditions can severely limit surface water supplies and lead to excess groundwater pumping, storage loss, and subsidence. In addition to fueling our understanding of spatiotemporal variability in diversions, our ability to predict these water balance components allows us to update CVHM predictions before surface water data are compiled. We can then develop groundwater pumping and storage predictions in real time, and make them available to water managers. In addition, we are working toward future projections by coupling the regional CVHM to downscaled GCM output to assess future scenarios of water availability in this critical region.
Seed size variability: from carob to carats
Turnbull, Lindsay A; Santamaria, Luis; Martorell, Toni; Rallo, Joan; Hector, Andy
2006-01-01
The seeds of various plants were used as weights because their mass reputedly varies so little. Carob (Ceratonia siliqua), which has given its name to the carat, is particularly famous in this regard. But are carob seeds unusually constant in weight and, if not, how did the myth arise? The variability of seeds sampled from a collection of carob trees (CV=23%) was close to the average of 63 species reviewed from the literature (CV=25%). However, in a perception experiment observers could discriminate differences in carob seed weight of around 5% by eye demonstrating the potential for humans to greatly reduce natural variation. Interestingly, the variability of pre-metrication carat weight standards is also around 5% suggesting that human rather than natural selection gave rise to the carob myth. PMID:17148413
Variability and predictability of performance times of elite cross-country skiers.
Spencer, Matt; Losnegard, Thomas; Hallén, Jostein; Hopkins, Will G
2014-01-01
Analyses of elite competitive performance provide useful information for research and practical applications. Here the authors analyze performance times of cross-country skiers at international competitions (World Cup, World Championship, and Olympics) in classical and free styles of women's and men's distance and sprint events, each with a total of 410-569 athletes competing in 1-44 races at 15-25 venues from seasons 2002 to 2011. A linear mixed model of race times for each event provided estimates of within-athlete race-to-race variability expressed as a coefficient of variation (CV) after adjustment for fixed or random effects of snow conditions, altitude, race length, and competition terrain. Within-athlete variability was similar for men and women over various events for all athletes (CV of 1.5-1.8%) and for the annual top-10 athletes (1.1-1.4%). Observed effects of snow conditions and altitude on mean time were substantial (~2%) but mostly unclear, owing to large effects of terrain (CV of 4-10% in top-10 analyses). Predictability of performance was extremely high for all athletes (intraclass correlations of .90-.96) but only trivial to poor for top-10 athletes (men .00-.03, women .03-.35). The race-to-race variability of top-ranked skiers is similar to that of other elite endurance athletes. Estimates of the smallest worthwhile performance enhancement (0.3× within-athlete variability) will help researchers and practitioners evaluate strategies affecting performance of elite skiers.
Sherwood, Andrew; Hill, LaBarron K; Blumenthal, James A; Adams, Kirkwood F; Paine, Nicola J; Koch, Gary G; O'Connor, Christopher M; Johnson, Kristy S; Hinderliter, Alan L
2017-09-01
Cardiovascular (CV) reactivity to psychological stress has been implicated in the development and exacerbation of cardiovascular disease (CVD). Although high CV reactivity traditionally is thought to convey greater risk of CVD, the relationship between reactivity and clinical outcomes is inconsistent and may depend on the patient population under investigation. The present study examined CV reactivity in patients with heart failure (HF) and its potential association with long-term clinical outcomes. One hundred ninety-nine outpatients diagnosed with HF, with ejection fraction ≤40%, underwent an evaluation of blood pressure (BP) and heart rate reactivity to a laboratory-based simulated public-speaking stressor. Cox proportional hazards regression models were used to examine the prospective association between BP and heart rate reactivity on a combined end point of death or CV hospitalization over a 5-year median follow-up period. Both systolic blood pressure (SBP) and diastolic blood pressure (DBP) reactivity, quantified as continuous variables, were inversely related to risk of death or CV hospitalization (Ps < .01) after controlling for established risk factors, including HF disease severity and etiology. In similar models, heart rate reactivity was unrelated to outcome (P = .12). In models with tertiles of reactivity, high SBP reactivity, compared with intermediate SBP reactivity, was associated with lower risk (hazard ratio [HR] = .498, 95% CI .335-.742, P =.001), whereas low SBP reactivity did not differ from intermediate reactivity. For DBP, high reactivity was marginally associated with lower risk compared with intermediate DBP reactivity (HR = .767, 95% CI .515-1.14, P =.193), whereas low DBP reactivity was associated with greater risk (HR = 1.49, 95% CI 1.027-2.155, P =.0359). No relationship of heart rate reactivity to outcome was identified. For HF patients with reduced ejection fraction, a robust increase in BP evoked by a laboratory-based psychological challenge was associated with lower risk for adverse CVD events and may be a novel and unique marker of left ventricular systolic reserve that is accompanied by a more favorable long-term prognosis. Copyright © 2017 Elsevier Inc. All rights reserved.
NASA Astrophysics Data System (ADS)
Sloat, L.; Gerber, J. S.; Samberg, L. H.; Smith, W. K.; West, P. C.; Herrero, M.; Brendan, P.; Cecile, G.; Katharina, W.; Smith, W. K.
2016-12-01
The need to feed an increasing number of people while maintaining biodiversity and ecosystem services is one of the key challenges currently facing humanity. Livestock systems are likely to be a crucial piece of this puzzle, as urbanization and changing diets in much of the world lead to increases in global meat consumption. This predicted increase in global demand for livestock products will challenge the ability of pastures and rangelands to maintain or increase their productivity. The majority of people that depend on animal production for food security do so through grazing and herding on natural rangelands, and these systems make a significant contribution to global production of meat and milk. The vegetation dynamics of natural forage are highly dependent on climate, and subject to disruption with changes in climate and climate variability. Precipitation heterogeneity has been linked to the ecosystem dynamics of grazing lands through impacts on livestock carrying capacity and grassland degradation potential. Additionally, changes in precipitation variability are linked to the increased incidence of extreme events (e.g. droughts, floods) that negatively impact food production and food security. Here, we use the inter-annual coefficient of variation (CV) of precipitation as a metric to assess climate risk on global pastures. Comparisons of global satellite measures of vegetation greenness to climate reveal that the CV of precipitation is negatively related to mean annual NDVI, such that areas with low year-to-year precipitation variability have the highest measures of vegetation greenness, and vice versa. Furthermore, areas with high CV of precipitation support lower livestock densities and produce less meat. A sliding window analysis of changes in CV of precipitation over the last century shows that, overall, precipitation variability is increasing in global pasture areas, although global maps reveal a patchwork of both positive and negative changes. We use this information to identify regions in which changes in the variability of precipitation may already be affecting the ability of grazing systems to support intensified livestock production, and assess the potential impacts of those changes on pasture productivity.
Hernández-Guerrero, César; Parra-Carriedo, Alicia; Ruiz-de-Santiago, Diana; Galicia-Castillo, Oscar; Buenrostro-Jáuregui, Mario; Díaz-Gutiérrez, Carmen
2018-01-01
Genetic polymorphisms of antioxidant enzymes CAT, GPX, and SOD are involved in the etiology of obesity and its principal comorbidities. The aim of the present study was to analyze the effect of aforementioned SNPs over the output of several variables in people with obesity after a nutritional intervention. The study included 92 Mexican women, which received a dietary intervention by 3 months. Participants were genotyped and stratified into two groups: (1) carriers; mutated homozygous plus heterozygous (CR) and (2) homozygous wild type (WT). A comparison between CR and WT was done in clinical (CV), biochemical (BV), and anthropometric variables (AV), at the beginning and at the end of the intervention. Participants ( n = 92) showed statistically significant differences ( p < 0.05) at the end of the nutritional intervention in several CV, BV, and AV. However, two kinds of responses were observed after genotyping participants: (A) CR and WT showed statistically significant differences ( p < 0.05) in several CV, BV, and AV for the SNPs 599C>T GPX1 (rs1050450), - 251A>G SOD1 (rs2070424), and - 262C>T CAT (rs1001179). (B) Only CR showed statistically changes ( p < 0.05) in several CV, BV, and AV for the SNPs - 21A>T CAT (rs7943316) and 47C>T SOD2 (rs4880). The dietary intervention effect was statistically significantly between the polymorphisms of 47C>T SOD2 and BMI, SBP, TBARS, total cholesterol, and C-LCL ( p < 0.05) and between the polymorphisms of - 21A>T CAT (rs7943316) and SBP, DBP, total cholesterol, and atherogenic index ( p < 0.05). People with obesity display different response in several CV, BV, and AV after a nutritional intervention, depending on the antioxidant genetic background of SOD and CAT enzymes.
Instrumentation and optimization of intra-cavity fiber laser gas absorption sensing system
NASA Astrophysics Data System (ADS)
Liu, Kun; Liu, Tiegen; Jiang, Junfeng; Liang, Xiao; Zhang, Yimo
2011-11-01
Detection of pollution, inflammable, explosive gases such as methane, acetylene, carbon monoxide and so on is very important for many areas, such as environmental, mining and petrochemical industry. Intra-cavity gas absorption sensing technique (ICGAST) based on Erbium-doped fiber ring laser (EDFRL) is one of novel methods for trace gas with higher precision. It has attracted considerable attention, and many research institutes focus on it. Instrumentation and optimization of ICGAST was reported in this paper. The system consists of five parts, which are variable gain module, intelligent frequency-selection module, gas cell, DAQ module and computer respectively. Variable gain module and intelligent frequency-selection module are combined to establish the intra-cavity of the ring laser. Gas cell is used as gas sensor. DAQ module is used to realize data acquisition synchronously. And gas demodulation is finished in the computer finally. The system was optimized by adjusting the sequence of the components. Take experimental simulation as an example, the absorptance of gas was increased five times after optimization, and the sensitivity enhancement factor can reach more than twenty. By using Fabry-Perot (F-P) etalon, the absorption wavelength of the detected gas can be obtained, with error less than 20 pm. The spectra of the detected gas can be swept continuously to obtain several absorption lines in one loop. The coefficient of variation (CV) was used to show the repeatability of gas concentration detection. And results of CV value can be less than 0.014.
The Stability of GPS Carrier-Phase Receivers
2010-11-01
Frequency Transfer ( TWSTFT ) method [2]. For both CP and TWSTFT , accuracy in time transfer is achieved through special calibration efforts that retain...View (CV) receivers and TWSTFT equipment. Many of these geodetic receivers operate continuously within the International GNSS Service (IGS), and...with TWSTFT , GPS CV, and GPS P3. If ionosphere-free measurements are used in combination with nominally compensated tropospheric corrections, a
McGill, Kevin C; Lateva, Zoia C
2011-09-01
The conduction velocity (CV) of a muscle fiber is affected by the fiber's discharge history going back ∼1 s. We investigated this dependence by measuring CV fluctuations during voluntary isometric contractions of the human brachioradialis muscle. We recorded electromyogram (EMG) signals simultaneously from multiple intramuscular electrodes, identified potentials belonging to the same motor unit using EMG decomposition, and estimated the CV of each discharge from the interpotential interval. In 12 of 14 subjects, CV increased by ∼10% during the first second after recruitment and then fluctuated by about ±2% in a way that mirrored the fluctuations in the instantaneous firing rate. The CV profile could be precisely described in terms of the discharge history by a simple mathematical model. In the other two subjects, and one subject retested after cooling the arm, the CV fluctuations were inversely correlated with instantaneous firing rate. In all subjects, CV was additionally affected by very short interdischarge intervals (<25 ms): it was increased in doublets at recruitment, but decreased in doublets during continuous firing and after short interdischarge intervals in doubly innervated fibers. CV also exhibited a slow trend of about -0.05%/s that did not depend on the immediate discharge history. We suggest that measurements of CV fluctuations during voluntary contractions, or during stimulation protocols that involve longer and more complex stimulation patterns than are currently being used, may provide a sensitive approach for estimating the dynamic characteristics of ion channels in the human muscle-fiber membrane.
History dependence of human muscle-fiber conduction velocity during voluntary isometric contractions
Lateva, Zoia C.
2011-01-01
The conduction velocity (CV) of a muscle fiber is affected by the fiber's discharge history going back ∼1 s. We investigated this dependence by measuring CV fluctuations during voluntary isometric contractions of the human brachioradialis muscle. We recorded electromyogram (EMG) signals simultaneously from multiple intramuscular electrodes, identified potentials belonging to the same motor unit using EMG decomposition, and estimated the CV of each discharge from the interpotential interval. In 12 of 14 subjects, CV increased by ∼10% during the first second after recruitment and then fluctuated by about ±2% in a way that mirrored the fluctuations in the instantaneous firing rate. The CV profile could be precisely described in terms of the discharge history by a simple mathematical model. In the other two subjects, and one subject retested after cooling the arm, the CV fluctuations were inversely correlated with instantaneous firing rate. In all subjects, CV was additionally affected by very short interdischarge intervals (<25 ms): it was increased in doublets at recruitment, but decreased in doublets during continuous firing and after short interdischarge intervals in doubly innervated fibers. CV also exhibited a slow trend of about −0.05%/s that did not depend on the immediate discharge history. We suggest that measurements of CV fluctuations during voluntary contractions, or during stimulation protocols that involve longer and more complex stimulation patterns than are currently being used, may provide a sensitive approach for estimating the dynamic characteristics of ion channels in the human muscle-fiber membrane. PMID:21565985
Quantum steering of Gaussian states via non-Gaussian measurements
NASA Astrophysics Data System (ADS)
Ji, Se-Wan; Lee, Jaehak; Park, Jiyong; Nha, Hyunchul
2016-07-01
Quantum steering—a strong correlation to be verified even when one party or its measuring device is fully untrusted—not only provides a profound insight into quantum physics but also offers a crucial basis for practical applications. For continuous-variable (CV) systems, Gaussian states among others have been extensively studied, however, mostly confined to Gaussian measurements. While the fulfilment of Gaussian criterion is sufficient to detect CV steering, whether it is also necessary for Gaussian states is a question of fundamental importance in many contexts. This critically questions the validity of characterizations established only under Gaussian measurements like the quantification of steering and the monogamy relations. Here, we introduce a formalism based on local uncertainty relations of non-Gaussian measurements, which is shown to manifest quantum steering of some Gaussian states that Gaussian criterion fails to detect. To this aim, we look into Gaussian states of practical relevance, i.e. two-mode squeezed states under a lossy and an amplifying Gaussian channel. Our finding significantly modifies the characteristics of Gaussian-state steering so far established such as monogamy relations and one-way steering under Gaussian measurements, thus opening a new direction for critical studies beyond Gaussian regime.
Photoinduced Bulk Polarization and Its Effects on Photovoltaic Actions in Perovskite Solar Cells.
Wu, Ting; Collins, Liam; Zhang, Jia; Lin, Pei-Ying; Ahmadi, Mahshid; Jesse, Stephen; Hu, Bin
2017-11-28
This article reports an experimental demonstration of photoinduced bulk polarization in hysteresis-free methylammonium (MA) lead-halide perovskite solar cells [ITO/PEDOT:PSS/perovskite/PCBM/PEI/Ag]. An anomalous capacitance-voltage (CV) signal is observed as a broad "shoulder" in the depletion region from -0.5 to +0.5 V under photoexcitation based on CV measurements where a dc bias is gradually scanned to continuously drift mobile ions in order to detect local polarization under a low alternating bias (50 mV, 5 kHz). Essentially, gradually scanning the dc bias and applying a low alternating bias can separately generate continuously drifting ions and a bulk CV signal from local polarization under photoexcitation. Particularly, when the device efficiency is improved from 12.41% to 18.19% upon chlorine incorporation, this anomalous CV signal can be enhanced by a factor of 3. This anomalous CV signal can be assigned as the signature of photoinduced bulk polarization by distinguishing from surface polarization associated with interfacial charge accumulation. Meanwhile, replacing easy-rotational MA + with difficult-rotational formamidinium (FA + ) cations largely minimizes such anomalous CV signal, suggesting that photoinduced bulk polarization relies on the orientational freedom of dipolar organic cations. Furthermore, a Kelvin probe force microscopy study shows that chlorine incorporation can suppress the density of charged defects and thus enhances photoinduced bulk polarization due to the reduced screening effect from charged defects. A bias-dependent photoluminescence study indicates that increasing bulk polarization can suppress carrier recombination by decreasing charge capture probability through the Coulombic screening effect. Clearly, our studies provide an insightful understanding of photoinduced bulk polarization and its effects on photovoltaic actions in perovskite solar cells.
NASA Astrophysics Data System (ADS)
Doury, Maxime; Dizeux, Alexandre; de Cesare, Alain; Lucidarme, Olivier; Pellot-Barakat, Claire; Bridal, S. Lori; Frouin, Frédérique
2017-02-01
Dynamic contrast-enhanced ultrasound has been proposed to monitor tumor therapy, as a complement to volume measurements. To assess the variability of perfusion parameters in ideal conditions, four consecutive test-retest studies were acquired in a mouse tumor model, using controlled injections. The impact of mathematical modeling on parameter variability was then investigated. Coefficients of variation (CV) of tissue blood volume (BV) and tissue blood flow (BF) based-parameters were estimated inside 32 sub-regions of the tumors, comparing the log-normal (LN) model with a one-compartment model fed by an arterial input function (AIF) and improved by the introduction of a time delay parameter. Relative perfusion parameters were also estimated by normalization of the LN parameters and normalization of the one-compartment parameters estimated with the AIF, using a reference tissue (RT) region. A direct estimation (rRTd) of relative parameters, based on the one-compartment model without using the AIF, was also obtained by using the kinetics inside the RT region. Results of test-retest studies show that absolute regional parameters have high CV, whatever the approach, with median values of about 30% for BV, and 40% for BF. The positive impact of normalization was established, showing a coherent estimation of relative parameters, with reduced CV (about 20% for BV and 30% for BF using the rRTd approach). These values were significantly lower (p < 0.05) than the CV of absolute parameters. The rRTd approach provided the smallest CV and should be preferred for estimating relative perfusion parameters.
NASA Technical Reports Server (NTRS)
Mason, E.; Orio, M.; Mukai, K.; Bianchini, A.; deMartino, D.; diMille, F.; Williams, R. E.
2013-01-01
We present new X-ray and optical spectra of the old nova CP Pup (nova Pup 1942) obtained with Chandra and the CTIO 4m telescope. The X-ray spectrum reveals a multi-temperature optically thin plasma reaching a maximum temperature of 36+19 keV 16 absorbed by local complex neutral material. The time resolved optical spectroscopy confirms the presence of the 1.47 hr period, with cycle-to-cycle amplitude changes, as well as of an additional long term modulation which is suggestive either of a longer pe- riod or of non-Keplerian velocities in the emission line regions. These new observational facts add further support to CP Pup as a magnetic cataclysmic variable (mCV). We compare the mCV and the non-mCV scenarios and while we cannot conclude whether CP Pup is a long period system, all observational evidences point at an intermediate polar (IP) type CV.
Gamma-ray emission from Cataclysmic variables. 1: The Compton EGRET survey
NASA Technical Reports Server (NTRS)
Schlegel, Eric M.; Barrett, Paul E.; De Jager, O. C.; Chanmugam, G.; Hunter, S.; Mattox, J.
1995-01-01
We report the results of the first gamma-ray survey of cataclysmic variables (CVs) using observations obtained with the Energetic Gamma Ray Experiment Telescope (EGRET) instrument on the Compton Observatory. We briefly describe the theoretical models that are applicable to gamma-ray emission from CVs. These models are particularly relevant to magnetic CVs containing asynchronously rotating white dwarfs. No magnetic CV was detected with an upper limit on the flux at 1 GeV of approximately 2 x 10(exp -8)/sq cm/sec, which corresponds to an upper limit on the gamma-ray luminosity of approximately 10(exp 31) ergs/sec, assuming a typical CV distance of 100 pc.
Gram's Stain Does Not Cross the Bacterial Cytoplasmic Membrane.
Wilhelm, Michael J; Sheffield, Joel B; Sharifian Gh, Mohammad; Wu, Yajing; Spahr, Christian; Gonella, Grazia; Xu, Bolei; Dai, Hai-Lung
2015-07-17
For well over a century, Hans Christian Gram's famous staining protocol has been the standard go-to diagnostic for characterizing unknown bacteria. Despite continuous and ubiquitous use, we now demonstrate that the current understanding of the molecular mechanism for this differential stain is largely incorrect. Using the fully complementary time-resolved methods: second-harmonic light-scattering and bright-field transmission microscopy, we present a real-time and membrane specific quantitative characterization of the bacterial uptake of crystal-violet (CV), the dye used in Gram's protocol. Our observations contradict the currently accepted mechanism which depicts that, for both Gram-negative and Gram-positive bacteria, CV readily traverses the peptidoglycan mesh (PM) and cytoplasmic membrane (CM) before equilibrating within the cytosol. We find that not only is CV unable to traverse the CM but, on the time-scale of the Gram-stain procedure, CV is kinetically trapped within the PM. Our results indicate that CV, rather than dyes which rapidly traverse the PM, is uniquely suited as the Gram stain.
Beretta-Piccoli, Matteo; D'Antona, Giuseppe; Zampella, Cristian; Barbero, Marco; Clijsen, Ron; Cescon, Corrado
2017-04-01
The aim of this study was to determine the test-retest reliability of muscle fiber conduction velocity (CV) and fractal dimension (FD) obtained from multichannel surface electromyographic (sEMG) recordings. Forty healthy recreationally active subjects (20 men and 20 women) performed two elbow flexions on two trials with a 1 week interval. The first was a 20% maximal voluntary contraction (MVC) of 120 s, and the second at 60% MVC held until exhaustion. sEMG signals were detected from the biceps brachii, using bi-dimensional arrays. Initial values and slope of CV and FD were used for the reliability analysis. The intraclass correlation coefficient (ICC) values for the isometric contraction at 20% MVC were (-0.09) and 0.67 for CV and FD respectively; whereas the ICC values at 60% MVC were 0.78 and 0.82 for CV and FD respectively. The Bland Altman plots for the two isometric contractions showed a mean difference close to zero, with no evident outliers between the repeated measurements: at 20% MVC 0.001 53 for FD and -0.0277 for CV, and at 60% MVC 0.006 66 for FD and 0.009 07 for CV. Overall, our findings suggest that during isometric fatiguing contractions, CV and FD slopes are reliable variables, with potential application in clinical populations.
Vitamin D and the cardiovascular system: an overview of the recent literature.
Messa, Piergiorgio; Curreri, Manuela; Regalia, Anna; Alfieri, Carlo Maria
2014-02-01
Since the discovery that the enzyme catalyzing the synthesis of the most active natural vitamin D metabolite(calcitriol) and the vitamin D-specific receptor (VDR)were expressed in a wide range of tissues and organs, not only involved in the mineral metabolism (MM), there has been increasing interest on the putative ‘non classical’ roles of vitamin D metabolites, particularly on their possible effects on the cardiovascular (CV) system. These hypothetical CV effects of vitamin D gained particular interesting the nephrology field, given the high prevalence of CV disease in patients affected by either acute or chronic kidney diseases. However, notwithstanding a huge amount of experimental data suggesting a possible protective role of vitamin D on the CV system, the conclusions of two recent meta-analyses from the Cochrane group and a recent statement from the Institute of Medicine, based on a complete revision of the available data, concluded that there is no clear evidence for a role of vitamin D other than that strictly associated with bone health. However, a continuous and increasing flow of new studies still continues to add information on this topic. In the present review, we have tried to critically address the data added on this topicin the last 2 years, considering separately the experimental,observational, and intervention studies that have appeared in PubMed in the last 2 years, discussing the data providing proof, pro or contra, the involvement of vitamin D in CV disease, both in the absence or presence of kidney function impairment.
Future Warming Increases Global Maize Yield Variability with Implications for Food Markets
NASA Astrophysics Data System (ADS)
Tigchelaar, M.; Battisti, D. S.; Naylor, R. L.; Ray, D. K.
2017-12-01
If current trends in population growth and dietary shifts continue, the world will need to produce about 70% more food by 2050, while earth's climate is rapidly changing. Rising temperatures in particular are projected to negatively impact agricultural production, as the world's staple crops perform poorly in extreme heat. Theoretical models suggest that as temperatures rise above plants' optimal temperature for performance, not only will mean yields decline rapidly, but the variability of yields will increase, even as interannual variations in climate remain unchanged. Here we use global datasets of maize production and climate variability combined with CMIP5 temperature projections to quantify how yield variability will change in major maize producing countries under 2°C and 4°C of global warming. Maize is the world's most produced crop, and is linked to other staple crops through substitution in consumption and production. We find that in warmer climates - absent any breeding gains in heat tolerance - the Coefficient of Variation (CV) of maize yields increases almost everywhere, to values much larger than present-day. This increase in CV is due both to an increase in the standard deviation of yields, and a decrease in mean yields. In locations where crop failures become the norm under high (4°C) warming (mostly in tropical, low-yield environments), the standard deviation of yields ultimately decreases. The probability that in any given year the most productive areas in the top three maize producing countries (United States, China, Brazil) have simultaneous production losses greater than 10% is virtually zero under present-day climate conditions, but increases to 12% under 2°C warming, and 89% under 4°C warming. This has major implications for global food markets and staple crop prices, affecting especially the 2.5 billion people that comprise the world's poor, who already spend the majority of their disposable income on food and are particularly vulnerable to agricultural price spikes.
Effects of electrofishing gear type on spatial and temporal variability in fish community sampling
Meador, M.R.; McIntyre, J.P.
2003-01-01
Fish community data collected from 24 major river basins between 1993 and 1998 as part of the U.S. Geological Survey's National Water-Quality Assessment Program were analyzed to assess multiple-reach (three consecutive reaches) and multiple-year (three consecutive years) variability in samples collected at a site. Variability was assessed using the coefficient of variation (CV; SD/mean) of species richness, the Jaccard index (JI), and the percent similarity index (PSI). Data were categorized by three electrofishing sample collection methods: backpack, towed barge, and boat. Overall, multiple-reach CV values were significantly lower than those for multiple years, whereas multiple-reach JI and PSI values were significantly greater than those for multiple years. Multiple-reach and multiple-year CV values did not vary significantly among electrofishing methods, although JI and PSI values were significantly greatest for backpack electrofishing across multiple reaches and multiple years. The absolute difference between mean species richness for multiple-reach samples and mean species richness for multiple-year samples was 0.8 species (9.5% of total species richness) for backpack samples, 1.7 species (10.1%) for towed-barge samples, and 4.5 species (24.4%) for boat-collected samples. Review of boat-collected fish samples indicated that representatives of four taxonomic families - Catostomidae, Centrarchidae, Cyprinidae, and Ictaluridae - were collected at all sites. Of these, catostomids exhibited greater interannual variability than centrarchids, cyprinids, or ictalurids. Caution should be exercised when combining boat-collected fish community data from different years because of relatively high interannual variability, which is primarily due to certain relatively mobile species. Such variability may obscure longer-term trends.
Rain, temperature, and child-adolescent height among Native Amazonians in Bolivia.
Godoy, R; Goodman, E; Reyes-Garcia, V; Eisenberg, D T A; Leonard, W R; Huanca, T; McDade, T W; Tanner, S; Jha, N
2008-01-01
Global climate change and recent studies on early-life origins of well-being suggest that climate events early in life might affect health later in life. The study tested hypotheses about the association between the level and variability of rain and temperature early in life on the height of children and adolescents in a foraging-farming society of native Amazonians in Bolivia (Tsimane'). Measurements were taken for 525 children aged 2-12 and 218 adolescents aged 13-23 in 13 villages in 2005. Log of standing height was regressed on mean annual level and mean intra-annual monthly coefficient of variation (CV) of rain and mean annual level of temperature during gestation, birth year, and ages 2-4. Controls include age, quinquennium and season of birth, parent's attributes, and dummy variables for surveyors and villages. Climate variables were only related with the height of boys age 2-12. The level and CV of rain during birth year and the CV of rain and level of temperature during ages 2-4 were associated with taller stature. There were no secular changes in temperature (1973-2005) or rain (1943-2005). The height of young females and males is well protected from climate events, but protection works less well for boys ages 2-12.
Gao, Lidong; Zou, Gang; Liao, Qiaohong; Zhou, Yonghong; Liu, Fengfeng; Dai, Bingbing; Liu, Jia; Chen, Zhiyong; Xing, Weijia; Yang, Le; Liang, Hong; Zhang, Yi; Chen, Zhenhua; Luo, Li; Li, Qing; Luo, Kaiwei; Wu, Peng; Mo, Xiaowei; Wang, Lili; Lan, Ke; Horby, Peter W; Cowling, Benjamin J; Simmonds, Peter; Altmeyer, Ralf; van Doorn, H Rogier; Yu, Hongjie
2018-04-24
Hand, foot, and mouth disease (HFMD) represents a substantial disease burden in the Western Pacific region. We investigated the spectrum of causative enteroviruses of HFMD, and evaluated different clinical samples' diagnostic yield for enteroviruses. We enrolled pediatric patients hospitalized for HFMD among six hospitals in Anhua County, Hunan Province, China between October 2013 and September 2016. Throat swabs and stool samples (or rectal swabs) were collected to detect the enterovirus serotypes by real time RT-PCR or nested PCR. Among the 2,836 patients only one developed severe illness. Seventeen serotypes were identified in 2,401 patients (85%), with the most frequently detected being CV-A16 (29%, 814), CV-A6 (28%, 784), EV-A71 (17%, 491), CV-A10 (4%, 114), and CV-A4 (2%, 53). Children were younger in CV-A6, CV-A10, and CV-A4 infections (median 12 months, IQR 12-24 months) than EV-A71 and CV-A16 infections (median 24 months, IQR 12-36 months, p<0.05). Annual peaks of HFMD hospitalization occurred during April-June. The predominant enterovirus serotype shifted between CV-A16 and CV-A6 during the three years. Stool had a higher diagnostic yield (89%) than rectal (79%) and throat swabs (74%). Detection rates reached 93% when testing stools followed by throat swabs if stools were negative, and 89% when testing rectal swabs followed by throat swabs if rectal swabs were negative. Our results provide a virological benchmark for future surveillance and diagnostics. Continuous comprehensive virological surveillance is essential, especially after implementation of the EV-A71 vaccine in China, to monitor serotype replacement and the impact of EV-A71 vaccine.
Disease Activity in Rheumatoid Arthritis and the Risk of Cardiovascular Events
Solomon, DH; Reed, G; Kremer, JM; Curtis, JR; Farkouh, ME; Harrold, LR; Hochberg, MC; Tsao, P; Greenberg, J
2015-01-01
Background Use of several immunomodulatory agents has been associated with reduced cardiovascular (CV) events in epidemiologic studies of rheumatoid arthritis (RA). However, it is unknown whether time-averaged disease activity in RA correlates with CV events. Methods We studied patients with RA followed in a longitudinal US-based registry. Time-averaged disease activity was assessed using the area under the curve of the Clinical Disease Activity Index, a validated measure of rheumatoid arthritis disease activity, assessed during follow-up. Age, gender, diabetes, hypertension, hyperlipidemia, body mass index, family history of myocardial infarction (MI), aspirin use, NSAID use presence of CV disease, and baseline immunomodulator use were assessed at baseline. Cox proportional hazards regression models were examined to determine the risk of a composite CV endpoint that included MI, stroke, and CV death. Results 24,989 subjects followed for a median of 2.7 years were included in these analyses. During follow-up, we observed 422 confirmed CV endpoints for an incidence rate of 9.08 (95% confidence interval, CI, 7.90 – 10.26) per 1,000 person-years. In models adjusting for variables noted above, a 10-point reduction in time-averaged Clinical Disease Activity Index was associated with a 26% reduction in CV risk (95% confidence interval 17-34%). These results were robust in subgroup analyses stratified by presence of CV disease, use of corticosteroids, use of non-steroidal anti-inflammatory drugs or selective COX-2 inhibitors, change in RA treatment, and also when restricted to events adjudicated as definite or probable. Conclusions Reduced time-averaged disease activity in RA is associated with fewer CV events. PMID:25776112
Revealing nonclassicality beyond Gaussian states via a single marginal distribution
Park, Jiyong; Lu, Yao; Lee, Jaehak; Shen, Yangchao; Zhang, Kuan; Zhang, Shuaining; Zubairy, Muhammad Suhail; Kim, Kihwan; Nha, Hyunchul
2017-01-01
A standard method to obtain information on a quantum state is to measure marginal distributions along many different axes in phase space, which forms a basis of quantum-state tomography. We theoretically propose and experimentally demonstrate a general framework to manifest nonclassicality by observing a single marginal distribution only, which provides a unique insight into nonclassicality and a practical applicability to various quantum systems. Our approach maps the 1D marginal distribution into a factorized 2D distribution by multiplying the measured distribution or the vacuum-state distribution along an orthogonal axis. The resulting fictitious Wigner function becomes unphysical only for a nonclassical state; thus the negativity of the corresponding density operator provides evidence of nonclassicality. Furthermore, the negativity measured this way yields a lower bound for entanglement potential—a measure of entanglement generated using a nonclassical state with a beam-splitter setting that is a prototypical model to produce continuous-variable (CV) entangled states. Our approach detects both Gaussian and non-Gaussian nonclassical states in a reliable and efficient manner. Remarkably, it works regardless of measurement axis for all non-Gaussian states in finite-dimensional Fock space of any size, also extending to infinite-dimensional states of experimental relevance for CV quantum informatics. We experimentally illustrate the power of our criterion for motional states of a trapped ion, confirming their nonclassicality in a measurement-axis–independent manner. We also address an extension of our approach combined with phase-shift operations, which leads to a stronger test of nonclassicality, that is, detection of genuine non-Gaussianity under a CV measurement. PMID:28077456
Revealing nonclassicality beyond Gaussian states via a single marginal distribution.
Park, Jiyong; Lu, Yao; Lee, Jaehak; Shen, Yangchao; Zhang, Kuan; Zhang, Shuaining; Zubairy, Muhammad Suhail; Kim, Kihwan; Nha, Hyunchul
2017-01-31
A standard method to obtain information on a quantum state is to measure marginal distributions along many different axes in phase space, which forms a basis of quantum-state tomography. We theoretically propose and experimentally demonstrate a general framework to manifest nonclassicality by observing a single marginal distribution only, which provides a unique insight into nonclassicality and a practical applicability to various quantum systems. Our approach maps the 1D marginal distribution into a factorized 2D distribution by multiplying the measured distribution or the vacuum-state distribution along an orthogonal axis. The resulting fictitious Wigner function becomes unphysical only for a nonclassical state; thus the negativity of the corresponding density operator provides evidence of nonclassicality. Furthermore, the negativity measured this way yields a lower bound for entanglement potential-a measure of entanglement generated using a nonclassical state with a beam-splitter setting that is a prototypical model to produce continuous-variable (CV) entangled states. Our approach detects both Gaussian and non-Gaussian nonclassical states in a reliable and efficient manner. Remarkably, it works regardless of measurement axis for all non-Gaussian states in finite-dimensional Fock space of any size, also extending to infinite-dimensional states of experimental relevance for CV quantum informatics. We experimentally illustrate the power of our criterion for motional states of a trapped ion, confirming their nonclassicality in a measurement-axis-independent manner. We also address an extension of our approach combined with phase-shift operations, which leads to a stronger test of nonclassicality, that is, detection of genuine non-Gaussianity under a CV measurement.
Effect of rhythmic auditory cueing on gait in people with Alzheimer disease.
Wittwer, Joanne E; Webster, Kate E; Hill, Keith
2013-04-01
To determine whether rhythmic music and metronome cues alter spatiotemporal gait measures and gait variability in people with Alzheimer disease (AD). A repeated-measures study requiring participants to walk under different cueing conditions. University movement laboratory. Of the people (N=46) who met study criteria (a diagnosis of probable AD and ability to walk 100m) at routine medical review, 30 (16 men; mean age ± SD, 80±6y; revised Addenbrooke's Cognitive Examination range, 26-79) volunteered to participate. Participants walked 4 times over an electronic walkway synchronizing to (1) rhythmic music and (2) a metronome set at individual mean baseline comfortable speed cadence. Gait spatiotemporal measures and gait variability (coefficient of variation [CV]). Data from individual walks under each condition were combined. A 1-way repeated-measures analysis of variance was used to compare uncued baseline, cued, and retest measures. Gait velocity decreased with both music and metronome cues compared with baseline (baseline, 110.5cm/s; music, 103.4cm/s; metronome, 105.4cm/s), primarily because of significant decreases in stride length (baseline, 120.9cm; music, 112.5cm; metronome, 114.8cm) with both cue types. This was coupled with increased stride length variability compared with baseline (baseline CV, 3.4%; music CV, 4.3%; metronome CV, 4.5%) with both cue types. These changes did not persist at (uncued) retest. Temporal variability was unchanged. Rhythmic auditory cueing at comfortable speed tempo produced deleterious effects on gait in a single session in this group with AD. The deterioration in spatial gait parameters may result from impaired executive function associated with AD. Further research should investigate whether these instantaneous cue effects are altered with more practice or with learning methods tailored to people with cognitive impairment. Copyright © 2013 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.
Seabirds as indicators of marine food supplies: Cairns revisited
Piatt, John F.; Harding, Ann M.A.; Shultz, Michael T.; Speckman, Suzann G.; van Pelt, Thomas I.; Drew, Gary S.; Kettle, Arthur B.
2007-01-01
In his seminal paper about using seabirds as indicators of marine food supplies, Cairns (1987, Biol Oceanogr 5:261–271) predicted that (1) parameters of seabird biology and behavior would vary in curvilinear fashion with changes in food supply, (2) the threshold of prey density over which birds responded would be different for each parameter, and (3) different seabird species would respond differently to variation in food availability depending on foraging behavior and ability to adjust time budgets. We tested these predictions using data collected at colonies of common murre Uria aalge and black-legged kittiwake Rissa tridactyla in Cook Inlet, Alaska. (1) Of 22 seabird responses fitted with linear and non-linear functions, 16 responses exhibited significant curvilinear shapes, and Akaike’s information criterion (AIC) analysis indicated that curvilinear functions provided the best-fitting model for 12 of those. (2) However, there were few differences among parameters in their threshold to prey density, presumably because most responses ultimately depend upon a single threshold for prey acquisition at sea. (3) There were similarities and some differences in how species responded to variability in prey density. Both murres and kittiwakes minimized variability (CV < 15%) in their own body condition and growth of chicks in the face of high annual variability (CV = 69%) in local prey density. Whereas kittiwake breeding success (CV = 63%, r2 = 0.89) reflected prey variability, murre breeding success did not (CV = 29%, r2< 0.00). It appears that murres were able to buffer breeding success by reallocating discretionary ‘loafing’ time to foraging effort in response (r2 = 0.64) to declining prey density. Kittiwakes had little or no discretionary time, so fledging success was a more direct function of local prey density. Implications of these results for using ‘seabirds as indicators’ are discussed.
Reliability of Wearable Inertial Measurement Units to Measure Physical Activity in Team Handball.
Luteberget, Live S; Holme, Benjamin R; Spencer, Matt
2018-04-01
To assess the reliability and sensitivity of commercially available inertial measurement units to measure physical activity in team handball. Twenty-two handball players were instrumented with 2 inertial measurement units (OptimEye S5; Catapult Sports, Melbourne, Australia) taped together. They participated in either a laboratory assessment (n = 10) consisting of 7 team handball-specific tasks or field assessment (n = 12) conducted in 12 training sessions. Variables, including PlayerLoad™ and inertial movement analysis (IMA) magnitude and counts, were extracted from the manufacturers' software. IMA counts were divided into intensity bands of low (1.5-2.5 m·s -1 ), medium (2.5-3.5 m·s -1 ), high (>3.5 m·s -1 ), medium/high (>2.5 m·s -1 ), and total (>1.5 m·s -1 ). Reliability between devices and sensitivity was established using coefficient of variation (CV) and smallest worthwhile difference (SWD). Laboratory assessment: IMA magnitude showed a good reliability (CV = 3.1%) in well-controlled tasks. CV increased (4.4-6.7%) in more-complex tasks. Field assessment: Total IMA counts (CV = 1.8% and SWD = 2.5%), PlayerLoad (CV = 0.9% and SWD = 2.1%), and their associated variables (CV = 0.4-1.7%) showed a good reliability, well below the SWD. However, the CV of IMA increased when categorized into intensity bands (2.9-5.6%). The reliability of IMA counts was good when data were displayed as total, high, or medium/high counts. A good reliability for PlayerLoad and associated variables was evident. The CV of the previously mentioned variables was well below the SWD, suggesting that OptimEye's inertial measurement unit and its software are sensitive for use in team handball.
Wang, Xiaoxue; Li, Xuyong
2017-01-01
Particle grain size is an important indicator for the variability in physical characteristics and pollutants composition of road-deposited sediments (RDS). Quantitative assessment of the grain-size variability in RDS amount, metal concentration, metal load and GSFLoad is essential to elimination of the uncertainty it causes in estimation of RDS emission load and formulation of control strategies. In this study, grain-size variability was explored and quantified using the coefficient of variation (Cv) of the particle size compositions, metal concentrations, metal loads, and GSFLoad values in RDS. Several trends in grain-size variability of RDS were identified: (i) the medium class (105–450 µm) variability in terms of particle size composition, metal loads, and GSFLoad values in RDS was smaller than the fine (<105 µm) and coarse (450–2000 µm) class; (ii) The grain-size variability in terms of metal concentrations increased as the particle size increased, while the metal concentrations decreased; (iii) When compared to the Lorenz coefficient (Lc), the Cv was similarly effective at describing the grain-size variability, whereas it is simpler to calculate because it did not require the data to be pre-processed. The results of this study will facilitate identification of the uncertainty in modelling RDS caused by grain-size class variability. PMID:28788078
Rasmussen, Thomas Bruun; Boniotti, Maria Beatrice; Papetti, Alice; Grasland, Béatrice; Frossard, Jean-Pierre; Dastjerdi, Akbar; Hulst, Marcel; Hanke, Dennis; Pohlmann, Anne; Blome, Sandra; van der Poel, Wim H. M.; Steinbach, Falko; Blanchard, Yannick; Lavazza, Antonio; Bøtner, Anette
2018-01-01
Porcine epidemic diarrhoea virus, strain CV777, was initially characterized in 1978 as the causative agent of a disease first identified in the UK in 1971. This coronavirus has been widely distributed among laboratories and has been passaged both within pigs and in cell culture. To determine the variability between different stocks of the PEDV strain CV777, sequencing of the full-length genome (ca. 28kb) has been performed in 6 different laboratories, using different protocols. Not surprisingly, each of the different full genome sequences were distinct from each other and from the reference sequence (Accession number AF353511) but they are >99% identical. Unique and shared differences between sequences were identified. The coding region for the surface-exposed spike protein showed the highest proportion of variability including both point mutations and small deletions. The predicted expression of the ORF3 gene product was more dramatically affected in three different variants of this virus through either loss of the initiation codon or gain of a premature termination codon. The genome of one isolate had a substantially rearranged 5´-terminal sequence. This rearrangement was validated through the analysis of sub-genomic mRNAs from infected cells. It is clearly important to know the features of the specific sample of CV777 being used for experimental studies. PMID:29494671
Durango-Usuga, Paula; Guzmán-Duque, Fernando; Mosteo, Rosa; Vazquez, Mario V; Peñuela, Gustavo; Torres-Palma, Ricardo A
2010-07-15
An experimental design methodology was applied to evaluate the decolourization of crystal violet (CV) dye by electrocoagulation using iron or aluminium electrodes. The effects and interactions of four parameters, initial pH (3-9), current density (6-28 A m(-2)), substrate concentration (50-200 mg L(-1)) and supporting electrolyte concentration (284-1420 mg L(-1) of Na(2)SO(4)), were optimized and evaluated. Although the results using iron anodes were better than for aluminium, the effects and interactions of the studied parameters were quite similar. With a confidence level of 95%, initial pH and supporting electrolyte concentration showed limited effects on the removal rate of CV, whereas current density, pollutant concentration and the interaction of both were significant. Reduced models taking into account significant variables and interactions between variables have shown good correlations with the experimental results. Under optimal conditions, almost complete removal of CV and chemical oxygen demand were obtained after electrocoagulation for 5 and 30 min, using iron and aluminium electrodes, respectively. These results indicate that electrocoagulation with iron anodes is a rapid, economical and effective alternative to the complete removal of CV in waters. Evolutions of pH and residual iron or aluminium concentrations in solution are also discussed. 2010 Elsevier B.V. All rights reserved.
Cook, Andrea M; Moritz, Andreas; Freeman, Kathleen P; Bauer, Natali
2016-09-01
Scarce information exists about quality requirements and objective evaluation of performance of large veterinary bench top hematology analyzers. The study was aimed at comparing the observed total error (TEobs ) derived from meta-analysis of published method validation data to the total allowable error (TEa ) for veterinary hematology variables in small animals based on experts' opinions. Ideally, TEobs should be < TEa . An online survey was sent to veterinary experts in clinical pathology and small animal internal medicine for providing the maximal allowable deviation from a given result for each variable. Percent of TEa = (allowable median deviation/clinical threshold) * 100%. Second, TEobs for 3 laser-based bench top hematology analyzers (ADVIA 2120; Sysmex XT2000iV, and CellDyn 3500) was calculated based on method validation studies published between 2005 and 2013 (n = 4). The percent TEobs = 2 * CV (%) + bias (%). The CV was derived from published studies except for the ADVIA 2120 (internal data), and bias was estimated from the regression equation. A total of 41 veterinary experts (19 diplomates, 8 residents, 10 postgraduate students, 4 anonymous specialists) responded. The proposed range of TEa was wide, but generally ≤ 20%. The TEobs was < TEa for all variables and analyzers except for canine and feline HGB (high bias, low CV) and platelet counts (high bias, high CV). Overall, veterinary bench top analyzers fulfilled experts' requirements except for HGB due to method-related bias, and platelet counts due to known preanalytic/analytic issues. © 2016 American Society for Veterinary Clinical Pathology.
Fritz, Ann‐Kristina; Amrein, Irmgard
2017-01-01
Although most nervous system diseases affect women and men differentially, most behavioral studies using mouse models do not include subjects of both sexes. Many researchers worry that data of female mice may be unreliable due to the estrous cycle. Here, we retrospectively evaluated sex effects on coefficient of variation (CV) in 5,311 mice which had performed the same place navigation protocol in the water‐maze and in 4,554 mice tested in the same open field arena. Confidence intervals for Cohen's d as measure of effect size were computed and tested for equivalence with 0.2 as equivalence margin. Despite the large sample size, only few behavioral parameters showed a significant sex effect on CV. Confidence intervals of effect size indicated that CV was either equivalent or showed a small sex difference at most, accounting for less than 2% of total group to group variation of CV. While female mice were potentially slightly more variable in water‐maze acquisition and in the open field, males tended to perform less reliably in the water‐maze probe trial. In addition to evaluating variability, we also directly compared mean performance of female and male mice and found them to be equivalent in both water‐maze place navigation and open field exploration. Our data confirm and extend other large scale studies in demonstrating that including female mice in experiments does not cause a relevant increase of data variability. Our results make a strong case for including mice of both sexes whenever open field or water‐maze are used in preclinical research. PMID:28654717
Fritz, Ann-Kristina; Amrein, Irmgard; Wolfer, David P
2017-09-01
Although most nervous system diseases affect women and men differentially, most behavioral studies using mouse models do not include subjects of both sexes. Many researchers worry that data of female mice may be unreliable due to the estrous cycle. Here, we retrospectively evaluated sex effects on coefficient of variation (CV) in 5,311 mice which had performed the same place navigation protocol in the water-maze and in 4,554 mice tested in the same open field arena. Confidence intervals for Cohen's d as measure of effect size were computed and tested for equivalence with 0.2 as equivalence margin. Despite the large sample size, only few behavioral parameters showed a significant sex effect on CV. Confidence intervals of effect size indicated that CV was either equivalent or showed a small sex difference at most, accounting for less than 2% of total group to group variation of CV. While female mice were potentially slightly more variable in water-maze acquisition and in the open field, males tended to perform less reliably in the water-maze probe trial. In addition to evaluating variability, we also directly compared mean performance of female and male mice and found them to be equivalent in both water-maze place navigation and open field exploration. Our data confirm and extend other large scale studies in demonstrating that including female mice in experiments does not cause a relevant increase of data variability. Our results make a strong case for including mice of both sexes whenever open field or water-maze are used in preclinical research. © 2017 The Authors. American Journal of Medical Genetics Part C Published by Wiley Periodicals, Inc.
Zhu, Mingping; Chen, Aiqing
2017-01-01
This study aimed to compare within-subject blood pressure (BP) variabilities from different measurement techniques. Cuff pressures from three repeated BP measurements were obtained from 30 normotensive and 30 hypertensive subjects. Automatic BPs were determined from the pulses with normalised peak amplitude larger than a threshold (0.5 for SBP, 0.7 for DBP, and 1.0 for MAP). They were also determined from cuff pressures associated with the above thresholds on a fitted curve polynomial curve of the oscillometric pulse peaks. Finally, the standard deviation (SD) of three repeats and its coefficient of variability (CV) were compared between the two automatic techniques. For the normotensive group, polynomial curve fitting significantly reduced SD of repeats from 3.6 to 2.5 mmHg for SBP and from 3.7 to 2.1 mmHg for MAP and reduced CV from 3.0% to 2.2% for SBP and from 4.3% to 2.4% for MAP (all P < 0.01). For the hypertensive group, SD of repeats decreased from 6.5 to 5.5 mmHg for SBP and from 6.7 to 4.2 mmHg for MAP, and CV decreased from 4.2% to 3.6% for SBP and from 5.8% to 3.8% for MAP (all P < 0.05). In conclusion, polynomial curve fitting of oscillometric pulses had the ability to reduce automatic BP measurement variability. PMID:28785580
Effects of inter- and intra-observer variability on echocardiographic measurements in awake cats.
Chetboul, V; Concordet, D; Pouchelon, J L; Athanassiadis, N; Muller, C; Benigni, L; Munari, A C; Lefebvre, H P
2003-08-01
The objective of this study was to determine intra- and inter-observer variability of echocardiographic measurements in awake cats. Four observers with different levels of experience in echocardiography performed 96 echocardiographic examinations in four cats on four different days over a 3-week period. The examinations were randomized and blinded. The maximum within-day and between-day CV values were 17.4 and 18.5% for inter-ventricular septal thickness in diastole, 18.7 and 22.6% for left ventricular free-wall thickness in diastole, 9.8 and 14.9% for left ventricular end-diastolic diameter, 20.8 and 15.2% for left ventricular end-systolic diameter, and 21.2 and 18.4% for left ventricular shortening fraction. The maximum within-day CV values were most often associated with the least competent observer (i.e. the graduate student) and, the minimum CV values with the most competent observer (i.e. the associate professor in cardiology). A significant interaction between cat and observer was also evidenced. Thus, the most competent observer could not be replaced by any of the other observers.
New Southern Cataclysmic Variables: Discoveries from MASTER-SAAO
NASA Astrophysics Data System (ADS)
Buckley, D. A. H.; Potter, S. B.; Kniazev, A.; Lipunov, V.; Gorbovskoy, E.; Tiurina, N.
2017-03-01
In this paper we report on new cataclysmic variables (CVs) discovered by the first local optical transient detection system established at the SAAO Sutherland station, namely MASTER-SAAO. The characteristics of the MASTER-SAAO system are described and the parameters of the survey compared to the Catalina Real Time Survey (CRTS). To date MASTER-SAAO has discovered over 200 (non-Solar System) optical transients with about 75% of these being likely new CVs, most being dwarf novae (DNe). Approximately 50% of the DNe have outburst amplitudes in excess of 4 magnitudes, with some extreme amplitude (> 7 mag), probable WZ Sge systems. The MASTER-SAAO detection limit of B = 19-20 is comparable to the ˜20 magnitude limit of the CRTS (depending on CV colour). Based on the CV detection statistics of CRTS, we believe that MASTER-SAAO is detecting essentially the same CV population as CRTS, for a detection outburst amplitude threshold >2.2 magnitudes. We also present results of the initial follow-up program on CVs discovered by MASTER, including dwarf novae, a bright new VY Scl system and a new eclipsing polar.
Bhatia, Smita; Landier, Wendy; Hageman, Lindsey; Chen, Yanjun; Kim, Heeyoung; Sun, Can-Lan; Kornegay, Nancy; Evans, William E; Angiolillo, Anne L; Bostrom, Bruce; Casillas, Jacqueline; Lew, Glen; Maloney, Kelly W; Mascarenhas, Leo; Ritchey, A. Kim; Termuhlen, Amanda M; Carroll, William L; Wong, F Lennie; Relling, Mary V
2015-01-01
Importance Variability in prescribed 6-mercaptopurine and lack of adherence to 6-mercaptopurine could result in intra-individual variability in systemic exposure to 6-mercaptopurine (measured as erythrocyte thioguanine nucleotide levels) in children with acute lymphoblastic leukemia. The impact of intra-individual variability in systemic exposure to 6-mercaptopurine on relapse risk is unknown. Objective To determine impact of high intra-individual variability in 6-mercaptopurine systemic exposure on relapse risk in children with acute lymphoblastic leukemia. Design Prospective longitudinal design; daily adherence monitoring, 6-mercaptopurine dose-intensity and erythrocyte thioguanine nucleotide levels (pmol/8*10^8 erythrocytes) measured for 6 consecutive months per patient; cohort followed for a median of 6.7 years from diagnosis. Setting Children’s Oncology Group study (COG-AALL03N1); 94 participating institutions; ambulatory care setting. Participants Participants included 742 children meeting the following eligibility criteria: diagnosis of acute lymphoblastic leukemia at ≤21 years; in first continuous remission at study entry; receiving self/parent/caregiver-administered oral 6-mercaptopurine during maintenance. Median age at diagnosis: 5 years; 68% were male; 43% with NCI-based high-risk disease. Main Outcome Measures Adherence measured electronically using Medication Event Monitoring System that recorded date/time of each 6-mercaptopurine bottle opening; adherence rate defined as ratio of days of 6-mercaptopurine bottle opened to days when 6-mercaptopurine prescribed. 6-mercaptopurine doses actually prescribed were divided by planned protocol doses (75mg/m2/day) to compute average monthly dose-intensity. Electronically-monitored adherence (68,716 person-days), 6-mercaptopurine dose-intensity (120,439 person-days) and monthly erythrocyte thioguanine nucleotide levels (n=3,944 measurements) contributed to the analysis. Using intra-individual coefficients of variation (CV %), patients were classified as having stable (CV % <85th percentile) vs. varying (CV % ≥85th percentile) indices. Results Adjusting for clinical prognosticators, patients with 6-mercaptopurine non-adherence (mean adherence rate <95%) were at a 2.7 fold increased risk of relapse (95% confidence interval [CI], 1.3 to 5.6, p=0.01). Among adherers, high intra-individual variability in thioguanine nucleotide levels contributes to increased relapse risk (HR=4.4, 95% CI, 1.2 to 15.7, p=0.02). Furthermore, adherers with varying thioguanine nucleotide levels had varying 6-mercaptopurine dose-intensity (OR=4.5, p=0.006) and 6-mercaptopurine drug interruptions (OR=10.2, p=0.003). Conclusions and Relevance These findings emphasize the need to maximize 6-mercaptopurine adherence and maintain steady thiopurine exposure to minimize relapse in children with acute lymphoblastic leukemia. PMID:26181173
Phenotypic Intratumoral Heterogeneity of Endometrial Carcinomas.
Silva, Cátia; Pires-Luís, Ana S; Rocha, Eduardo; Bartosch, Carla; Lopes, José M
2018-03-01
Intratumoral heterogeneity has been shown to play an important role in diagnostic accuracy, development of treatment resistance, and prognosis of cancer patients. Recent studies have proposed quantitative measurement of phenotypic intratumoral heterogeneity, but no study is yet available in endometrial carcinomas. In our study we evaluated the phenotypic intratumoral heterogeneity of a consecutive series of 10 endometrial carcinomas using measures of dispersion and diversity. Morphometric architectural (%tumor cells, %solid tumor, %differentiated tumor, and %lumens) and nuclear [volume-weighted mean nuclear volume ((Equation is included in full-text article.))] parameters, as well as estrogen receptor, progesterone receptor, p53, vimentin, and beta-catenin immunoexpression (H-score) were digitally analyzed in 20 microscopic fields per carcinoma. Quantitative measures of intratumoral heterogeneity included coefficient of variation (CV) and relative quadratic entropy (rQE). In each endometrial carcinoma there was slight variation of architecture from field to field, resulting in globally low levels of heterogeneity measures (mean CV %tumor cells: 0.10, %solid tumor: 0.73, %differentiated tumor: 0.19, %lumens: 0.61 and mean rQE %tumor cells: 18.5, %solid tumor: 20.3, %differentiated tumor: 25.6, %lumens: 21.8). Nuclear intratumoral heterogeneity was also globally low (mean (Equation is included in full-text article.)CV: 0.23 and rQE: 27.3), but significantly higher than the heterogeneity of architectural parameters within most carcinomas. In general, there was low to moderate variability of immunoexpression markers within each carcinoma, but estrogen receptor (mean CV: 0.56 and rQE: 46.2) and progesterone receptor (mean CV: 0.60 and rQE: 39.3) displayed the highest values of heterogeneity measures. Intratumoral heterogeneity of immunoexpression was significantly higher than that observed for morphometric parameters. In conclusion, our study indicates that endometrial carcinomas present a variable but predominantly low degree of phenotypic intratumoral heterogeneity.
Genotyping of enteroviruses isolated in Kenya from pediatric patients using partial VP1 region.
Opanda, Silvanos M; Wamunyokoli, Fred; Khamadi, Samoel; Coldren, Rodney; Bulimo, Wallace D
2016-01-01
Enteroviruses (EV) are responsible for a wide range of clinical diseases in humans. Though studied broadly in several regions of the world, the genetic diversity of human enteroviruses (HEV) circulating in the sub-Saharan Africa remains under-documented. In the current study, we molecularly typed 61 HEV strains isolated in Kenya between 2008 and 2011 targeting the 3'-end of the VP1 gene. Viral RNA was extracted from the archived isolates and part of the VP1 gene amplified by RT-PCR, followed by sequence analysis. Twenty-two different EV types were detected. Majority (72.0 %) of these belonged to Enterovirus B species followed by Enterovirus D (21.3 %) and Enterovirus A (6.5 %). The most frequently detected types were Enterovirus-D68 (EV-D68), followed by Coxsackievirus B2 (CV-B2), CV-B1, CV-B4 and CV-B3. Phylogenetic analyses of these viruses revealed that Kenyan CV-B1 isolates were segregated among sequences of global CV-B1 strains. Conversely, the Kenyan CV-B2, CV-B3, CV-B4 and EV-D68 strains generally grouped together with those detected from other countries. Notably, the Kenyan EV-D68 strains largely clustered with sequences of global strains obtained between 2008 and 2010 than those circulating in recent years. Overall, our results indicate that HEV strains belonging to Enterovirus D and Enterovirus B species pre-dominantly circulated and played a significant role in pediatric respiratory infection in Kenya, during the study period. The Kenyan CV-B1 strains were genetically divergent from those circulating in other countries. Phylogenetic clustering of Kenyan EV-D68 strains with sequences of global strains circulating between 2008 and 2010 than those obtained in recent years suggests a high genomic variability associated with the surface protein encoding VP1 gene in these enteroviruses.
Saeed, Asma; Sharif, Mehwish; Iqbal, Muhammad
2010-07-15
This study reports the sorption of crystal violet (CV) dye by grapefruit peel (GFP), which has application potential in the remediation of dye-contaminated wastewaters using a solid waste generated by the citrus fruit juice industry. Batch adsorption of CV was conducted to evaluate the effect of initial pH, contact time, temperature, initial dye concentration, GFP adsorbent dose, and removal of the adsorbate CV dye from aqueous solution to understand the mechanism of sorption involved. Sorption equilibrium reached rapidly with 96% CV removal in 60 min. Fit of the sorption experimental data was tested on the pseudo-first and pseudo-second-order kinetics mathematical equations, which was noted to follow the pseudo-second-order kinetics better, with coefficient of correlation > or = 0.992. The equilibrium process was well described by the Langmuir isotherm model, with maximum sorption capacity of 254.16 mg g(-1). The GFP was regenerated using 1 M NaOH, with up to 98.25% recovery of CV and could be reused as a dye sorbent in repeated cycles. GFP was also shown to be highly effective in removing CV from aqueous solution in continuous-flow fixed-bed column reactors. The study shows that GFP has the potential of application as an efficient sorbent for the removal of CV from aqueous solutions. 2010 Elsevier B.V. All rights reserved.
Berent, Robert; Auer, Johann; Franklin, Barry; Schmid, Peter; von Duvillard, Serge P
2011-09-01
Aspirin has been shown to decrease cardiovascular (CV) events by ∼25%. Despite aspirin therapy 10% to 20% of patients with arterial vascular disease develop atherothrombotic events. A meta-analysis of antiplatelet therapy showed a progressive decrease in clinical efficacy of aspirin after 2 years. Whether this is due to a decreased sensitivity to aspirin during long-term therapy remains unclear. A prospective randomized clinical trial with serial monitoring over 5 years was conducted in 100 patients with documented coronary heart disease. We investigated whether long-term treatment with aspirin 50 and 100 mg affects platelet response similarly. Occurrence of CV events was documented. Platelet sensitivity to aspirin, prostacyclin, and adenosine diphosphate-, collagen-, and epinephrine-induced platelet aggregation were evaluated over time. In addition, β-thromboglobulin and inflammatory markers were measured. Four patients were lost to follow-up and 10 patients died. Eleven patients developed nonfatal CV events. In the 2 groups platelet response to aspirin and the referenced variables remained unchanged over 5 years. In patients who developed CV events, the last monitoring interval revealed no difference in platelet response to aspirin. However, patients with nonfatal and fatal CV events showed increased inflammatory markers versus patients without CV events independent of aspirin 50 or 100 mg intake. In conclusion, our study revealed no difference in antiplatelet response to aspirin 50 versus 100 mg or CV events over 5 years in patients with coronary heart disease. Copyright © 2011 Elsevier Inc. All rights reserved.
CV-990 Landing Systems Research Aircraft (LSRA) during final Space Shuttle tire test
NASA Technical Reports Server (NTRS)
1995-01-01
A Convair 990 (CV-990) was used as a Landing Systems Research Aircraft (LSRA) at NASA's Dryden Flight Research Center, Edwards, California, to test space shuttle landing gear and braking systems as part of NASA's effort to upgrade and improve space shuttle capabilities. The first flight at Dryden of the CV-990 with shuttle test components occurred in April 1993, and tests continued into August 1995, when this photo shows a test of the shuttle tires. The purpose of this series of tests was to determine the performance parameters and failure limits of the tires. This particular landing was on the dry lakebed at Edwards, but other tests occurred on the main runway there. The CV-990, built in 1962 by the Convair Division of General Dynamics Corp., Ft. Worth, Texas, served as a research aircraft at Ames Research Center, Moffett Field, California, before it came to Dryden.
NASA Technical Reports Server (NTRS)
Miller, I.; Moore, R.
1990-01-01
Root caps of primary, secondary, and seminal roots of Z. mays cv. Kys secrete large amounts of mucilage and are in close contact with the root all along the root apex. These roots are strongly graviresponsive. Secondary and seminal roots of Z. mays cv. Ageotropic are also strongly graviresponsive. Similarly, their caps secrete mucilage and closely appress the root all along the root apex. However, primary roots of Z. mays cv. Ageotropic are non-responsive to gravity. Their caps secrete negligible amounts of mucilage and contact the root only at the extreme apex of the root along the calyptrogen. These roots become graviresponsive when their tips are coated with mucilage or mucilage-like materials. Peripheral cells of root caps of roots of Z. mays cv. Kys contain many dictyosomes associated with vesicles that migrate to and fuse with the plasmalemma. Root-cap cells of secondary and seminal (i.e. graviresponsive) roots of Z. mays cv. Ageotropic are similar to those of primary roots of Z. mays cv. Kys. However, root-cap cells of primary (i.e. non-graviresponsive) roots of Z. mays cv. Ageotropic have distended dictyosomal cisternae filled with an electron-dense, granular material. Large vesicles full of this material populate the cells and apparently do not fuse with the plasmalemma. Taken together, these results suggest that non-graviresponsiveness of primary roots of Z. mays cv. Ageotropic results from the lack of apoplastic continuity between the root and the periphery of the root cap. This is a result of negligible secretion of mucilage by cells along the edge of the root cap which, in turn, appears to be due to the malfunctioning of dictyosomes in these cells.
Chaplais, Elodie; Greene, David; Hood, Anita; Telfer, Scott; du Toit, Verona; Singh-Grewal, Davinder; Burns, Joshua; Rome, Keith; Schiferl, Daniel J; Hendry, Gordon J
2014-07-19
Peripheral quantitative computed tomography (pQCT) is an established technology that allows for the measurement of the material properties of bone. Alterations to bone architecture are associated with an increased risk of fracture. Further pQCT research is necessary to identify regions of interest that are prone to fracture risk in people with chronic diseases. The second metatarsal is a common site for the development of insufficiency fractures, and as such the aim of this study was to assess the reproducibility of a novel scanning protocol of the second metatarsal using pQCT. Eleven embalmed cadaveric leg specimens were scanned six times; three times with and without repositioning. Each foot was positioned on a custom-designed acrylic foot plate to permit unimpeded scans of the region of interest. Sixty-six scans were obtained at 15% (distal) and 50% (mid shaft) of the second metatarsal. Voxel size and scan speed were reduced to 0.40 mm and 25 mm.sec(-1). The reference line was positioned at the most distal portion of the 2(nd) metatarsal. Repeated measurements of six key variables related to bone properties were subject to reproducibility testing. Data were log transformed and reproducibility of scans were assessed using intraclass correlation coefficients (ICC) and coefficients of variation (CV%). Reproducibility of the measurements without repositioning were estimated as: trabecular area (ICC 0.95; CV% 2.4), trabecular density (ICC 0.98; CV% 3.0), Strength Strain Index (SSI) - distal (ICC 0.99; CV% 5.6), cortical area (ICC 1.0; CV% 1.5), cortical density (ICC 0.99; CV% 0.1), SSI - mid shaft (ICC 1.0; CV% 2.4). Reproducibility of the measurements after repositioning were estimated as: trabecular area (ICC 0.96; CV% 2.4), trabecular density (ICC 0.98; CV% 2.8), SSI - distal (ICC 1.0; CV% 3.5), cortical area (ICC 0.99; CV%2.4), cortical density (ICC 0.98; CV% 0.8), SSI - mid shaft (ICC 0.99; CV% 3.2). The scanning protocol generated excellent reproducibility for key bone properties measured at the distal and mid-shaft regions of the 2(nd) metatarsal. This protocol extends the capabilities of pQCT to evaluate bone quality in people who may be at an increased risk of metatarsal insufficiency fractures.
2014-01-01
Background Peripheral quantitative computed tomography (pQCT) is an established technology that allows for the measurement of the material properties of bone. Alterations to bone architecture are associated with an increased risk of fracture. Further pQCT research is necessary to identify regions of interest that are prone to fracture risk in people with chronic diseases. The second metatarsal is a common site for the development of insufficiency fractures, and as such the aim of this study was to assess the reproducibility of a novel scanning protocol of the second metatarsal using pQCT. Methods Eleven embalmed cadaveric leg specimens were scanned six times; three times with and without repositioning. Each foot was positioned on a custom-designed acrylic foot plate to permit unimpeded scans of the region of interest. Sixty-six scans were obtained at 15% (distal) and 50% (mid shaft) of the second metatarsal. Voxel size and scan speed were reduced to 0.40 mm and 25 mm.sec-1. The reference line was positioned at the most distal portion of the 2nd metatarsal. Repeated measurements of six key variables related to bone properties were subject to reproducibility testing. Data were log transformed and reproducibility of scans were assessed using intraclass correlation coefficients (ICC) and coefficients of variation (CV%). Results Reproducibility of the measurements without repositioning were estimated as: trabecular area (ICC 0.95; CV% 2.4), trabecular density (ICC 0.98; CV% 3.0), Strength Strain Index (SSI) - distal (ICC 0.99; CV% 5.6), cortical area (ICC 1.0; CV% 1.5), cortical density (ICC 0.99; CV% 0.1), SSI – mid shaft (ICC 1.0; CV% 2.4). Reproducibility of the measurements after repositioning were estimated as: trabecular area (ICC 0.96; CV% 2.4), trabecular density (ICC 0.98; CV% 2.8), SSI - distal (ICC 1.0; CV% 3.5), cortical area (ICC 0.99; CV%2.4), cortical density (ICC 0.98; CV% 0.8), SSI – mid shaft (ICC 0.99; CV% 3.2). Conclusions The scanning protocol generated excellent reproducibility for key bone properties measured at the distal and mid-shaft regions of the 2nd metatarsal. This protocol extends the capabilities of pQCT to evaluate bone quality in people who may be at an increased risk of metatarsal insufficiency fractures. PMID:25037451
Changes in Aggressiveness of the Ascochyta lentis Population in Southern Australia
Davidson, Jennifer; Smetham, Gabriel; Russ, Michelle H.; McMurray, Larn; Rodda, Matthew; Krysinska-Kaczmarek, Marzena; Ford, Rebecca
2016-01-01
Anecdotal evidence identified a change in the reaction of the resistant lentil cv Nipper to ascochyta blight in South Australia in 2010 and subsequent seasons, leading to infection. This study investigated field reactions of lentil cultivars against Ascochyta lentis and the pathogenic variability of the A. lentis population in southern Australia on commonly grown cultivars and on parental germplasm used in the Australian lentil breeding program. Disease data recorded in agronomic and plant breeder field trials from 2005 to 2014 in southern Australia confirmed the change in reaction on the foliage of the previously resistant cvs Nipper and Northfield. Cultivar responses to seed staining from A. lentis did not change. The change in foliar response was confirmed in a series of controlled environment experiments using single, conidium-derived, isolates of A. lentis collected over different years and inoculated onto differential host sets. Specific isolate/cultivar interactions produced a significant range of disease reactions from high to low aggressiveness with a greater percentage of isolates more aggressive on cvs Nipper, Northfield and PBA Flash than previously detected. Specific isolates were tested against Australian lentil cultivars and breeding lines in controlled conditions, again verifying the aggressiveness on cv Nipper. A small percentage of isolates collected prior to the commercial release of cv Nipper were also able to infect this cultivar indicating a natural variability of the A. lentis population which subsequently may have been selected in response to high cropping intensity of cv Nipper. Spore release studies from naturally infested lentil stubbles collected from commercial crops also resulted in a high percentage of infection on the previously resistant cvs Nipper and Northfield. Less than 10% of the lesions developed on the resistant differentials ILL7537 and cv Indianhead. Pathogenic variation within the seasonal populations was not affected by the cultivar from which the stubble was sourced, further indicating a natural variability in aggressiveness. The impact of dominant cultivars in cropping systems and loss of effective disease resistance is discussed. Future studies are needed to determine if levels of aggressiveness among A. lentis isolates are increasing against a range of elite cultivars. PMID:27065073
Assessing the role of Climate Variability in the recent evolution of coastlines in southern Italy
NASA Astrophysics Data System (ADS)
Di Paola, Gianluigi; Atkinson, David; Rosskopf, Carmen M.; Walker, Ian
2016-04-01
During the last century, Climatic Variability (CV) and change effects have generated a discernable impact on the world's coasts, most notably through changes in the frequency and/or magnitude of storm surges, flooding, coastal erosion and sea-level rise. This study explores CV signals and coastal responses along a 36 km stretch of coast in the Molise region of southern Italy on the Central Adriatic Sea. Two dominant signals of CV in the Mediterranean region of Europe are characterized by the North Atlantic Oscillation (NAO) and the East Atlantic-West Russia (EAWR) patterns. The NAO is the leading mode of CV in the North Atlantic region and periods with positive NAO index values are typically associated with above average wind speeds across the mid-latitudes of the Atlantic and western Europe, with anomalously northerly flows across the Mediterranean region and enhanced trade winds over the sub-tropical North Atlantic. Although NAO is one of the most prominent patterns in all seasons, its relative role in regulating the variability of the European climate during non-winter months is not as clear as for the winter season. In contrast, the EAWR exerts strong influence on precipitation in the Mediterranean region such that, during the negative phase of EAWR, wetter conditions prevail across central Europe and the Mediterranean region, with precipitation extremes often occurring during these periods. This study examines the effects of NAO and EAWR on coastline response in the Molise region, which has a microtidal regime (ordinary tidal excursions of 30-40 cm). GIS analysis of shoreline changes from historical aerial photography from 1954-2011 was performed and 20 years (1989-2008) of wave data were analysed from the nearby Ortona buoy to define trends and extreme event occurrence in the wave climate in the study area. Finally, statistical associations between NAO, EAWR, and other CV indices of possible influence (e.g. Arctic Oscillation, Scandinavia Pattern, or the East Atlantic pattern) and shoreline position changes were explored in order to identify linkages between CV forcing and coastal response in this region. The study demonstrates that the recent evolution of the Molise coastline is responding to changes in the wave climate and increases in the frequency and intensity of storm surges in recent years. Coastal response in the region is also strongly controlled by engineering interventions, such as backwater structures and groynes (almost the 75% of coastline is characterized by offshore defenses, above all around Biferno and Trigno mouths and Termoli harbor), and the interaction of the river systems that feed the coastline. This condition may mitigate some of the impacts of CV events that are observed elsewhere along intervening stretches of coast.
Variability in human cone topography assessed by adaptive optics scanning laser ophthalmoscopy
Zhang, Tianjiao; Godara, Pooja; Blanco, Ernesto R.; Griffin, Russell L; Wang, Xiaolin; Curcio, Christine A.; Zhang, Yuhua
2015-01-01
Purpose To assess between- and within-individual variability of macular cone topography in the eyes of young adults. Design Observational case series. Methods Cone photoreceptors in 40 eyes of 20 subjects aged 19–29 years with normal maculae were imaged using a research adaptive optics scanning laser ophthalmoscope. Refractive errors ranged from −3.0 D to 0.63 D and differed by <0.50 D in fellow eyes. Cone density was assessed on a two-dimensional sampling grid over the central 2.4 mm × 2.4 mm. Between-individual variability was evaluated by coefficient of variation (CV). Within-individual variability was quantified by maximum difference and root-mean-square (RMS). Cones were cumulated over increasing eccentricity. Results Peak densities of foveal cones are 168,162 ± 23,529 cones/mm2 (mean ± SD) (CV = 0.14). The number of cones within the cone-dominated foveola (0.8–0.9 mm diameter) is 38,311 ± 2,319 (CV = 0.06). The RMS cone density difference between fellow eyes is 6.78%, and the maximum difference is 23.6%. Mixed model statistical analysis found no difference in the association between eccentricity and cone density in the superior/nasal (p=0.8503), superior/temporal (p=0.1551), inferior/nasal (p=0.8609), and inferior/temporal (p=0.6662) quadrants of fellow eyes. Conclusions New instrumentation imaged the smallest foveal cones, thus allowing accurate assignment of foveal centers and assessment of variability in macular cone density in a large sample of eyes. Though cone densities vary significantly in the fovea, the total number of foveolar cones are very similar both between- and within-subjects. Thus, the total number of foveolar cones may be an important measure of cone degeneration and loss. PMID:25935100
Accuracy and precision of stream reach water surface slopes estimated in the field and from maps
Isaak, D.J.; Hubert, W.A.; Krueger, K.L.
1999-01-01
The accuracy and precision of five tools used to measure stream water surface slope (WSS) were evaluated. Water surface slopes estimated in the field with a clinometer or from topographic maps used in conjunction with a map wheel or geographic information system (GIS) were significantly higher than WSS estimated in the field with a surveying level (biases of 34, 41, and 53%, respectively). Accuracy of WSS estimates obtained with an Abney level did not differ from surveying level estimates, but conclusions regarding the accuracy of Abney levels and clinometers were weakened by intratool variability. The surveying level estimated WSS most precisely (coefficient of variation [CV] = 0.26%), followed by the GIS (CV = 1.87%), map wheel (CV = 6.18%), Abney level (CV = 13.68%), and clinometer (CV = 21.57%). Estimates of WSS measured in the field with an Abney level and estimated for the same reaches with a GIS used in conjunction with l:24,000-scale topographic maps were significantly correlated (r = 0.86), but there was a tendency for the GIS to overestimate WSS. Detailed accounts of the methods used to measure WSS and recommendations regarding the measurement of WSS are provided.
Bittencourt, Marcio S; Hulten, Edward A; Ghoshhajra, Brian; Abbara, Suhny; Murthy, Venkatesh L; Divakaran, Sanjay; Nasir, Khurram; Gowdak, Luis Henrique W; Riella, Leonardo V; Chiumiento, Marco; Hoffmann, Udo; Di Carli, Marcelo F; Blankstein, Ron
2015-07-01
It is unknown whether mild chronic kidney disease (CKD) is associated with adverse cardiovascular (CV) prognosis after accounting for coronary artery disease (CAD). Here we evaluated the interplay between CKD and CAD in predicting CV death or myocardial infarction (MI) and all-cause death. We included 1541 consecutive patients in the Partners registry (mean age 55 years, 43% female) over 18 years old with no known prior CAD who underwent coronary computed tomography angiography (CCTA). The results of CCTA were categorized as normal, nonobstructive (under half), or obstructive (half and over). Overall, 653 of the patients had no CAD, 583 had nonobstructive CAD, and 305 had obstructive CAD, while 1299 had eGFR over 60 ml/min per 1.73 m(2) and 242 had an eGFR under this value. The presence and severity of CAD was significantly associated with an increased rate of CV death or MI and all-cause death, even after adjustment for age, gender, symptoms, and risk factors. Similarly, reduced eGFR was significantly associated with CV death or MI and all-cause death after similar adjustment. The addition of reduced GFR to a model which included both clinical variables and CCTA findings resulted in significant improvement in the prediction of CV death or MI and all-cause death. Thus, among individuals referred for CCTA to evaluate CAD, renal dysfunction is associated with an increased rate of CV events, mainly driven by an increase in the rate of noncoronary CV events. In this group of patients, both eGFR and the presence and severity of CAD together improve the prediction of future CV events and death.
Mind the Gap when Data Mining the Ritter-Kolb Cataclysmic Variable Catalogue
NASA Astrophysics Data System (ADS)
Sparks, Warren M.; Sion, Edward M.
2017-01-01
The cataclysmic variable (CV) binary consists of a white dwarf primary and a low-mass secondary which overflows its Roche lobe. The Ritter-Kolb catalogue (2003, A&A, 404, 301) is a collection (~1000) of CV binaries and related objects. We have mined this catalogue for CVs with unevolved secondaries whose mass ratio (secondary/primary) is known (~130). A plot of the secondary mass verses the log of the orbital period exhibits the well-known period gap at 2-3 hrs. In addition, this plot shows that the secondary masses just above the period gap are collectively much larger than those just below. The average of the first ten secondary masses above the period is 180% larger than the average below the gap.The disrupted magnetic braking hypothesis (Howell, Nelson, and Rappaport 2001, ApJ, 550, 897 [HNR]) predicts that when the secondary becomes fully convective, the magnetic braking, which has driven the secondary out of thermal equilibrium, stops. In adjusting to thermal equilibrium the secondary shrinks below its Roche lobe and no longer loses mass. The binary system ceases to appear as a CV until gravitational radiation loss brings the secondary back in contact with its Roche lobe. This scenario is at odds with the apparent secondary mass loss across the period gap. Either the secondary continues to lose mass while crossing the period gap or the secondary masses are miscalculated!Magnetic braking causes the secondary to expand or inflate larger than its single star counterpart. Any orbital parameter calculation which assumes a radius-mass relationship based on single main-sequence stars will overestimate the mass of the secondary. We can approximate this mass overestimation from calculations by HNR which take into account the thermal heating from magnetic braking. Using this approximation as a first-order correction to the secondary mass, we replot the deflated secondary mass versus the binary period. The deflated masses immediately above and below the period gap are similar and do not indicate secondary mass loss across the gap. Thus, magnetic braking not only explains the period gap but the apparent secondary mass shift across it. Orbital parameters must be based upon actual secondary mass-radius observations.
Fukuda, David H; Smith, Abbie E; Kendall, Kristina L; Cramer, Joel T; Stout, Jeffrey R
2012-02-01
The purpose of this study was to evaluate the use of critical velocity (CV) and isoperformance curves as an alternative to the Army Physical Fitness Test (APFT) two-mile running test. Seventy-eight men and women (mean +/- SE; age: 22.1 +/- 0.34 years; VO2(MAX): 46.1 +/- 0.82 mL/kg/min) volunteered to participate in this study. A VO2(MAX) test and four treadmill running bouts to exhaustion at varying intensities were completed. The relationship between total distance and time-to-exhaustion was tracked for each exhaustive run to determine CV and anaerobic running capacity. A VO2(MAX) prediction equation (Coefficient of determination: 0.805; Standard error of the estimate: 3.2377 mL/kg/min) was developed using these variables. Isoperformance curves were constructed for men and women to correspond with two-mile run times from APFT standards. Individual CV and anaerobic running capacity values were plotted and compared to isoperformance curves for APFT 2-mile run scores. Fifty-four individuals were determined to receive passing scores from this assessment. Physiological profiles identified from this procedure can be used to assess specific aerobic or anaerobic training needs. With the use of time-to-exhaustion as opposed to a time-trial format used in the two-mile run test, pacing strategies may be limited. The combination of variables from the CV test and isoperformance curves provides an alternative to standardized time-trial testing.
Modeling and Simulation of Capacitance-Voltage Characteristics of a Nitride GaAs Schottky Diode
NASA Astrophysics Data System (ADS)
Ziane, Abderrezzaq; Amrani, Mohammed; Benamara, Zineb; Rabehi, Abdelaziz
2018-06-01
A nitride GaAs Schottky diode has been fabricated by the nitridation of GaAs substrates using a radio frequency discharge nitrogen plasma source with a layer thickness of approximately 0.7 nm of GaN. The capacitance-voltage (C-V) characteristics of the Au/GaN/GaAs structure were investigated at room temperature for different frequencies, ranging from 1 kHz to 1 MHz. The C-V measurements for the Au/GaN/GaAs Schottky diode were found to be strongly dependent on the bias voltage and the frequency. The capacitance curves depict an anomalous peak and a negative capacitance phenomenon, indicating the presence of continuous interface state density behavior. A numerical drift-diffusion model based on the Scharfetter-Gummel algorithm was elaborated to solve a system composed of the Poisson and continuities equations. In this model, we take into account the continuous interface state density, and we have considered exponential and Gaussian distributions of trap states in the band gap. The effects of the GaAs doping concentration and the trap state density are discussed. We deduce the shape and values of the trap states, then we validate the developed model by fitting the computed C-V curves with experimental measurements at low frequency.
Fernández-Nebro, Antonio; Rúa-Figueroa, Íñigo; López-Longo, Francisco J; Galindo-Izquierdo, María; Calvo-Alén, Jaime; Olivé-Marqués, Alejandro; Ordóñez-Cañizares, Carmen; Martín-Martínez, María A; Blanco, Ricardo; Melero-González, Rafael; Ibáñez-Rúan, Jesús; Bernal-Vidal, José Antonio; Tomero-Muriel, Eva; Uriarte-Isacelaya, Esther; Horcada-Rubio, Loreto; Freire-González, Mercedes; Narváez, Javier; Boteanu, Alina L; Santos-Soler, Gregorio; Andreu, José L; Pego-Reigosa, José M
2015-07-01
This article estimates the frequency of cardiovascular (CV) events that occurred after diagnosis in a large Spanish cohort of patients with systemic lupus erythematosus (SLE) and investigates the main risk factors for atherosclerosis. RELESSER is a nationwide multicenter, hospital-based registry of SLE patients. This is a cross-sectional study. Demographic and clinical variables, the presence of traditional risk factors, and CV events were collected. A CV event was defined as a myocardial infarction, angina, stroke, and/or peripheral artery disease. Multiple logistic regression analysis was performed to investigate the possible risk factors for atherosclerosis. From 2011 to 2012, 3658 SLE patients were enrolled. Of these, 374 (10.9%) patients suffered at least a CV event. In 269 (7.4%) patients, the CV events occurred after SLE diagnosis (86.2% women, median [interquartile range] age 54.9 years [43.2-66.1], and SLE duration of 212.0 months [120.8-289.0]). Strokes (5.7%) were the most frequent CV event, followed by ischemic heart disease (3.8%) and peripheral artery disease (2.2%). Multivariate analysis identified age (odds ratio [95% confidence interval], 1.03 [1.02-1.04]), hypertension (1.71 [1.20-2.44]), smoking (1.48 [1.06-2.07]), diabetes (2.2 [1.32-3.74]), dyslipidemia (2.18 [1.54-3.09]), neurolupus (2.42 [1.56-3.75]), valvulopathy (2.44 [1.34-4.26]), serositis (1.54 [1.09-2.18]), antiphospholipid antibodies (1.57 [1.13-2.17]), low complement (1.81 [1.12-2.93]), and azathioprine (1.47 [1.04-2.07]) as risk factors for CV events. We have confirmed that SLE patients suffer a high prevalence of premature CV disease. Both traditional and nontraditional risk factors contribute to this higher prevalence. Although it needs to be verified with future studies, our study also shows-for the first time-an association between diabetes and CV events in SLE patients.
Cardiovascular Events in Systemic Lupus Erythematosus
Fernández-Nebro, Antonio; Rúa-Figueroa, Íñigo; López-Longo, Francisco J.; Galindo-Izquierdo, María; Calvo-Alén, Jaime; Olivé-Marqués, Alejandro; Ordóñez-Cañizares, Carmen; Martín-Martínez, María A.; Blanco, Ricardo; Melero-González, Rafael; Ibáñez-Rúan, Jesús; Bernal-Vidal, José Antonio; Tomero-Muriel, Eva; Uriarte-Isacelaya, Esther; Horcada-Rubio, Loreto; Freire-González, Mercedes; Narváez, Javier; Boteanu, Alina L.; Santos-Soler, Gregorio; Andreu, José L.; Pego-Reigosa, José M.
2015-01-01
Abstract This article estimates the frequency of cardiovascular (CV) events that occurred after diagnosis in a large Spanish cohort of patients with systemic lupus erythematosus (SLE) and investigates the main risk factors for atherosclerosis. RELESSER is a nationwide multicenter, hospital-based registry of SLE patients. This is a cross-sectional study. Demographic and clinical variables, the presence of traditional risk factors, and CV events were collected. A CV event was defined as a myocardial infarction, angina, stroke, and/or peripheral artery disease. Multiple logistic regression analysis was performed to investigate the possible risk factors for atherosclerosis. From 2011 to 2012, 3658 SLE patients were enrolled. Of these, 374 (10.9%) patients suffered at least a CV event. In 269 (7.4%) patients, the CV events occurred after SLE diagnosis (86.2% women, median [interquartile range] age 54.9 years [43.2–66.1], and SLE duration of 212.0 months [120.8–289.0]). Strokes (5.7%) were the most frequent CV event, followed by ischemic heart disease (3.8%) and peripheral artery disease (2.2%). Multivariate analysis identified age (odds ratio [95% confidence interval], 1.03 [1.02–1.04]), hypertension (1.71 [1.20–2.44]), smoking (1.48 [1.06–2.07]), diabetes (2.2 [1.32–3.74]), dyslipidemia (2.18 [1.54–3.09]), neurolupus (2.42 [1.56–3.75]), valvulopathy (2.44 [1.34–4.26]), serositis (1.54 [1.09–2.18]), antiphospholipid antibodies (1.57 [1.13–2.17]), low complement (1.81 [1.12–2.93]), and azathioprine (1.47 [1.04–2.07]) as risk factors for CV events. We have confirmed that SLE patients suffer a high prevalence of premature CV disease. Both traditional and nontraditional risk factors contribute to this higher prevalence. Although it needs to be verified with future studies, our study also shows—for the first time—an association between diabetes and CV events in SLE patients. PMID:26200625
[Warm acupuncture for chronic atrophic gastritis with spleen-stomach deficiency cold].
Wang, Lijun; Li, Guangqi
2017-02-12
To observe the clinical effect of warm acupuncture at Zhongwan(CV 12) for chronic atrophic gastritis(CAG) with spleen-stomach deficiency cold by the comparison with conventional acupuncture. Sixty-two patients were randomly assigned into a warm acupuncture group and a conventional acupuncture group,31 cases in each one. The acupoints in the two groups were Zhongwan(CV 12),Zusanli(ST 36),Neiguan(PC 6),Gongsun(SP 4),Qihai(CV 6),Pishu(BL 20) and Weishu(BL 21). Warm acupuncture was intervened at Zhongwan(CV 12) in the warm acupuncture group. Twirling reinforcing was applied at Zhongwan(CV 12) in the conventional acupuncture group. All the treatment was given for 3 courses continuously,5 days as one course,once a day. TCM syndrome score and symptom rating scale were observed before and after treatment in the two groups,and the effects were compared. The total effective rate was 93.5%(29/31) in the warm acupuncture group,which was better than 87.0%(27/31) in the conventional acupuncture group( P <0.05). The TCM syndrome score and symptom rating score were improved in the two groups after treatment( P <0.01, P <0.05),with more apparent improvement in the warm acupuncture group( P <0.01, P <0.05). Warm acupuncture at Zhongwan(CV 12) can improve gastrointestinal discomfort,which is better than twirling reinforcing at Zhongwan(CV 12) for CAG with spleen-stomach deficiency cold.
von Cramon-Taubadel, Noreen; Schroeder, Lauren
2016-10-01
Estimation of the variance-covariance (V/CV) structure of fragmentary bioarchaeological populations requires the use of proxy extant V/CV parameters. However, it is currently unclear whether extant human populations exhibit equivalent V/CV structures. Random skewers (RS) and hierarchical analyses of common principal components (CPC) were applied to a modern human cranial dataset. Cranial V/CV similarity was assessed globally for samples of individual populations (jackknifed method) and for pairwise population sample contrasts. The results were examined in light of potential explanatory factors for covariance difference, such as geographic region, among-group distance, and sample size. RS analyses showed that population samples exhibited highly correlated multivariate responses to selection, and that differences in RS results were primarily a consequence of differences in sample size. The CPC method yielded mixed results, depending upon the statistical criterion used to evaluate the hierarchy. The hypothesis-testing (step-up) approach was deemed problematic due to sensitivity to low statistical power and elevated Type I errors. In contrast, the model-fitting (lowest AIC) approach suggested that V/CV matrices were proportional and/or shared a large number of CPCs. Pairwise population sample CPC results were correlated with cranial distance, suggesting that population history explains some of the variability in V/CV structure among groups. The results indicate that patterns of covariance in human craniometric samples are broadly similar but not identical. These findings have important implications for choosing extant covariance matrices to use as proxy V/CV parameters in evolutionary analyses of past populations. © 2016 Wiley Periodicals, Inc.
Ntineri, A; Kollias, A; Zeniodi, M; Moyssakis, I; Georgakopoulos, D; Servos, G; Vazeou, A; Stergiou, G S
2015-06-01
Some studies suggested that ambulatory blood pressure (ABP) variability may provide useful information beyond that of average ABP levels. This study investigated the relationship between central ABP variability and target-organ damage in young individuals in whom the central-peripheral blood pressure discrepancy might be considerable. Apparently healthy adolescents and young adults referred for elevated blood pressure and healthy volunteers (age 12-26 years) were subjected to: (i) 24-hour monitoring of central ABP using a noninvasive brachial cuff-based oscillometric device (Mobil-O-Graph 24 h PWA); (ii) 24-hour pulse wave velocity (PWV) monitoring (Mobil-O-Graph 24 h PWA); (iii) echocardiographic determination of left ventricular mass index (LVMI); (iv) measurement (ultrasonography) of the common carotid intima-media thickness (IMT). The standard deviation (SD) of ABP (24-hour weighted/awake/asleep), as well as the respective coefficients of variation (CV) were used for assessing variability. The study included 68 individuals (mean age 18.7 ± 4.7 years, 52 males, body mass index [BMI] 24.5 ± 4.7 kg/m, 24 volunteers, 15 with hypertension [24-hour peripheral ABP >=95th percentile for adolescents or >=130/80 mmHg for adults]). LVMI was correlated with 24-hour/awake/asleep central systolic ABP (r=0.50/0.49/0.40, all p < 0.01), as well as with 24-hour weighted/awake/asleep SD of central systolic ABP (r = 0.40/0.37/0.30, all p < 0.05), whereas no association was observed for the respective CV. IMT was correlated with 24-hour/awake/asleep central pulse pressure (PP) (r = 0.37/0.33/0.27, all p < 0.05), 24-hour weighted/awake/asleep SD of central PP (r = 0.43/0.40/0.36, all p < 0.01) and the respective CV (r = 0.28/0.26/0.25, all p < 0.05). Regarding 24-hour PWV, there was a significant association with 24-hour/awake/asleep central systolic ABP (r = 0.94/0.88/0.84, all p < 0.001) and 24-hour weighted/awake/asleep SD of central PP (r = 0.48/0.51/0.25, all p < 0.05), but not with the respective CV. In multivariate regression analyses (independent variables: age, gender, BMI, central ABP and SD/CV of ABP values), LVMI and 24-hour PWV were determined by BMI, age, and 24-hour central systolic ABP, and IMT by male gender and 24-hour weighted SD of central PP. In young individuals, 24-hour central ABP variability appears to be associated only with early carotid damage when accounting for ABP levels, whereas LVMI and PWV are mainly determined by average ABP levels.
The influence of phonological priming on variability in articulation
NASA Astrophysics Data System (ADS)
Babel, Molly E.; Munson, Benjamin
2004-05-01
Previous research [Sevald and Dell, Cognition 53, 91-127 (1994)] has found that reiterant sequences of CVC words are produced more quickly when the prime word and target word share VC sequences (i.e., sequences like sit sick) than when they are identical (sequences like sick sick). Even slower production rates are found when primes and targets share a CV sequence (sequences like kick sick). These data have been used to support a model of speech production in which lexical items and their constituent phonemes are activated sequentially. The current experiment investigated whether phonological priming also influences variability in the acoustic characteristics of words. Specifically, we examined whether greater variability in the acoustic characteristics of target words was noted in the CV-related prime context than in the identical-prime context, and whether less variability was noted in the VC-related context. Thirty adult subjects with typical speech, language, and hearing ability produced reiterant two-word sequences that varied in their phonological similarity. The duration, first, and second formant frequencies of the target-words' vowels were measured. Preliminary analyses indicate that phonological priming does not have a systematic effect on variability in these acoustic parameters.
Solevåg, Anne Lee; Schmölzer, Georg M; O'Reilly, Megan; Lu, Min; Lee, Tze-Fun; Hornberger, Lisa K; Nakstad, Britt; Cheung, Po-Yin
2016-09-01
Despite the minimal evidence, neonatal resuscitation guidelines recommend using 100% oxygen when chest compressions (CC) are needed. Uninterrupted CC in adult cardiopulmonary resuscitation (CPR) may improve CPR hemodynamics. We aimed to examine 21% oxygen (air) vs. 100% oxygen in 3:1 CC:ventilation (C:V) CPR or continuous CC with asynchronous ventilation (CCaV) in asphyxiated newborn piglets following cardiac arrest. Piglets (1-3 days old) were progressively asphyxiated until cardiac arrest and randomized to 4 experimental groups (n=8 each): air and 3:1 C:V CPR, 100% oxygen and 3:1 C:V CPR, air and CCaV, or 100% oxygen and CCaV. Time to return of spontaneous circulation (ROSC), mortality, and clinical and biochemical parameters were compared between groups. We used echocardiography to measure left ventricular (LV) stroke volume at baseline, at 30min and 4h after ROSC. Left common carotid artery blood pressure was measured continuously. Time to ROSC (heart rate ≥100min(-1)) ranged from 75 to 592s and mortality 50-75%, with no differences between groups. Resuscitation with air was associated with higher LV stroke volume after ROSC and less myocardial oxidative stress compared to 100% oxygen groups. CCaV was associated with lower mean arterial blood pressure after ROSC and higher myocardial lactate than those of 3:1 C:V CPR. In neonatal asphyxia-induced cardiac arrest, using air during CC may reduce myocardial oxidative stress and improve cardiac function compared to 100% oxygen. Although overall recovery may be similar, CCaV may impair tissue perfusion compared to 3:1 C:V CPR. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.
High variability in baseline urinary free cortisol values in patients with Cushing's disease.
Petersenn, S; Newell-Price, J; Findling, J W; Gu, F; Maldonado, M; Sen, K; Salgado, L R; Colao, A; Biller, B M K
2014-02-01
Twenty-four-hour urinary free cortisol (UFC) sampling is commonly used to evaluate Cushing's syndrome. Because there are few data on UFC variability in patients with active Cushing's disease, we analysed baseline UFC in a large patient cohort with moderate-to-severe Cushing's disease and assessed whether variability correlates with hypercortisolism severity. These data will help clinicians establish the minimum number of UFC samples required to obtain reliable data. Observational study (enrolment phase of Phase III study). Patients (n = 152) with persistent/recurrent or de novo Cushing's disease and mean UFC (mUFC) ≥1·5×ULN (normal: 30-145 nmol/24 h) were included. Mean UFC level was calculated from four 24-h urine samples collected over 2 weeks. Over 600 24-h UFC samples were analysed. The mUFC levels of samples 1 and 2 and samples 3 and 4 were 1000 nmol/24 h (SD 1872) and 940 nmol/24 h (SD 2148), respectively; intrapatient coefficient of variation (CV) was 38% for mUFC. The intrapatient CV using all four samples was 52% (95% CI: 48-56). The intrapatient CV was 51% (95% CI: 44-58) for samples 1 and 2, 49% (95% CI: 43-56) for samples 3 and 4 and 54% (95% CI: 49-59) for samples 1, 2 and 3. Variability in mUFC increased as UFC levels increased. There were no correlations between UFC and clinical features of hypercortisolism. There is intrapatient variability of approximately 50% in 24-h UFC measurements, which is relevant to targets set to estimate any treatment effect. Analysing more than two 24-h collection periods in individual patients does not result in a relevant decrease in variability. Interestingly, UFC levels did not correlate with hypercortisolism severity. © 2013 The Authors. Clinical Endocrinology published by John Wiley & Sons Ltd.
Job enlargement and mechanical exposure variability in cyclic assembly work.
Möller, Therése; Mathiassen, Svend Erik; Franzon, Helena; Kihlberg, Steve
2004-01-15
Cyclic assembly work is known to imply a high risk for musculoskeletal disorders. To have operators rotate between work tasks is believed to be one way of decreasing this risk, since it is expected to increase variation in mechanical and psychological exposures (physical and mental loads). This assumption was investigated by assessing mechanical exposure variability in three assembly tasks in an electronics assembly plant, each on a separate workstation, as well as in a 'job enlargement' scenario combining all three stations. Five experienced operators worked for 1 h on each station. Data on upper trapezius and forearm extensor muscle activity were obtained by means of electromyography (EMG), and working postures of the head and upper arms were assessed by inclinometry. The cycle-to-cycle variance of parameters representing the three exposure dimensions: level, frequency and duration was estimated using ANOVA algorithms for each workstation separately as well as for a balanced combination of all three. For a particular station, the variability of trapezius EMG activity levels relative to the mean was higher than for extensor EMG: between-cycles coefficients of variation (CV) about 0.15 and 0.10, respectively. A similar relationship between CV applied to the parameter describing frequency of EMG activity. Except for head inclination levels, the between-cycles CV was larger for posture parameters than for EMG. The between-cycles variance increased up to six fold in the job enlargement scenario, as compared to working at only one station. The difference in mean exposure between workstations was larger for trapezius EMG parameters than for forearm extensor EMG and postures, and hence the effect of job enlargement on exposure variability was more pronounced for the trapezius. For some stations, job enlargement even implied less cycle-to-cycle variability in forearm extensor EMG parameters than working at that station only. Whether the changes in exposure variability associated with job enlargement were sufficient to imply a decreased risk for musculoskeletal disorders is not known.
Cardiovascular reactivity in real life settings: Measurement, mechanisms and meaning
Zanstra, Ydwine Jieldouw; Johnston, Derek William
2011-01-01
Cardiovascular reactivity to stress is most commonly studied in the laboratory. Laboratory stressors may have limited ecological validity due to the many constraints, operating in controlled environments. This paper will focus on paradigms that involve the measurement of cardiovascular reactions to stress in real life using ambulatory monitors. Probably the most commonly used paradigm in this field is to measure the response to a specific real life stressor, such as sitting an exam or public speaking. A more general approach has been to derive a measure of CV variability testing the hypothesis that more reactive participants will have more variable heart rate or blood pressure. Alternatively, self-reports of the participants’ perceived stress, emotion or demands may be linked to simultaneously collected ambulatory measures of cardiovascular parameters. This paper examines the following four questions: (1) What is the form and what are the determinants of stress-induced CV reactivity in real life? (2) What are the psychophysiological processes underlying heart rate and blood pressure reactivity in real life? (3) Does CV reactivity determined in the laboratory predict CV reactivity in real life? (4) Are ambulatory cardiovascular measures predictive of cardiovascular disease? It is concluded that the hemodynamic processes that underlie the blood pressure response can reliably be measured in real life and the psychophysiological relationships seen in the laboratory have been obtained in real life as well. Studies examining the effects of specific real life stressors show that responses obtained in real life are often larger than those obtained in the laboratory. Subjective ratings of stress, emotion and cognitive determinants of real life stress (e.g. demand, reward and control) also relate to real life CV responses. Surprisingly, ambulatory studies on real life cardiovascular reactivity to stress as a predictor of cardiovascular disease are rare. Measuring the CV response to stress in real life may provide a better measure of the stress-related process that are hypothesized to cause disease than is possible in the laboratory. In addressing these questions, below we review the studies that we believe are representative of the field. Therefore, this review is not comprehensive. PMID:20561941
Low, Serena; Lim, Su C; Yeoh, Lee Y; Liu, Yan L; Liu, Jian J; Fun, Sharon; Su, Chang; Zhang, Xiao; Subramaniam, Tavintharan; Sum, Chee F
2017-10-01
In the present study, we examined the association between HbA1c variability and renal disease progression based on estimated glomerular filtration rate (eGFR) decline in patients with type 2 diabetes mellitus (T2DM) in Singapore. Glycemic burden and renal function were retrospectively assessed in 1628 patients in 2002-2014. Multivariable logistic regression was used to assess the relationships between HbA1c variability (expressed as HbA1c coefficient of variation [HbA1c-CV] in quartiles), HbA1c intrapersonal mean (HbA1c-IM), and eGFR decline, adjusted for baseline covariates. Among patients with relatively good glycemic control (i.e. HbA1c-IM below the median cohort value [8.0%]), HbA1c-CV Quartile 4 was associated with eGFR decline (odds ratio [OR] 1.88; 95% confidence interval [CI] 1.10-3.25). The OR for HbA1c-CV Quartile 4 was 2.20 (95% CI 1.24-3.89) after additional adjustment for HbA1c-IM. Where HbA1c-IM was above the median cohort value, HbA1c-CV Quartiles 3 and 4 were associated with eGFR decline, with ORs of 2.60 (95% CI 1.48-4.55) and 3.29 (95% CI 1.89-5.76) respectively. After further adjusting for HbA1c-IM, the ORs for Quartiles 3 and 4 were 2.69 (95% CI 1.53-4.74) and 3.51 (95% CI 1.98-6.21), respectively. Variability in HbA1c is strongly and independently associated with eGFR decline in patients with T2DM independent of mean HbA1c. The findings may highlight the importance of sustained stable glycemic control in management of diabetes mellitus. © 2016 Ruijin Hospital, Shanghai Jiaotong University School of Medicine and John Wiley & Sons Australia, Ltd.
A Systematic Process for Developing High Quality SaaS Cloud Services
NASA Astrophysics Data System (ADS)
La, Hyun Jung; Kim, Soo Dong
Software-as-a-Service (SaaS) is a type of cloud service which provides software functionality through Internet. Its benefits are well received in academia and industry. To fully utilize the benefits, there should be effective methodologies to support the development of SaaS services which provide high reusability and applicability. Conventional approaches such as object-oriented methods do not effectively support SaaS-specific engineering activities such as modeling common features, variability, and designing quality services. In this paper, we present a systematic process for developing high quality SaaS and highlight the essentiality of commonality and variability (C&V) modeling to maximize the reusability. We first define criteria for designing the process model and provide a theoretical foundation for SaaS; its meta-model and C&V model. We clarify the notion of commonality and variability in SaaS, and propose a SaaS development process which is accompanied with engineering instructions. Using the proposed process, SaaS services with high quality can be effectively developed.
Bentley-Lewis, Rhonda; Aguilar, David; Riddle, Matthew C; Claggett, Brian; Diaz, Rafael; Dickstein, Kenneth; Gerstein, Hertzel C; Johnston, Peter; Køber, Lars V; Lawson, Francesca; Lewis, Eldrin F; Maggioni, Aldo P; McMurray, John J V; Ping, Lin; Probstfield, Jeffrey L; Solomon, Scott D; Tardif, Jean-Claude; Wu, Yujun; Pfeffer, Marc A
2015-05-01
Cardiovascular (CV) disease is the leading cause of morbidity and mortality in patients with type 2 diabetes mellitus (T2DM). Furthermore, patients with T2DM and acute coronary syndrome (ACS) have a particularly high risk of CV events. The glucagon-like peptide 1 receptor agonist, lixisenatide, improves glycemia, but its effects on CV events have not been thoroughly evaluated. ELIXA (www.clinicaltrials.gov no. NCT01147250) is a randomized, double-blind, placebo-controlled, parallel-group, multicenter study of lixisenatide in patients with T2DM and a recent ACS event. The primary aim is to evaluate the effects of lixisenatide on CV morbidity and mortality in a population at high CV risk. The primary efficacy end point is a composite of time to CV death, nonfatal myocardial infarction, nonfatal stroke, or hospitalization for unstable angina. Data are systematically collected for safety outcomes, including hypoglycemia, pancreatitis, and malignancy. Enrollment began in July 2010 and ended in August 2013; 6,068 patients from 49 countries were randomized. Of these, 69% are men and 75% are white; at baseline, the mean ± SD age was 60.3 ± 9.7 years, body mass index was 30.2 ± 5.7 kg/m(2), and duration of T2DM was 9.3 ± 8.2 years. The qualifying ACS was a myocardial infarction in 83% and unstable angina in 17%. The study will continue until the positive adjudication of the protocol-specified number of primary CV events. ELIXA will be the first trial to report the safety and efficacy of a glucagon-like peptide 1 receptor agonist in people with T2DM and high CV event risk. Copyright © 2015. Published by Elsevier Inc.
Secure Computer Systems: Extensions to the Bell-La Padula Model
2009-01-01
countable and n CX ℜ∈ ; V is a finite collection of input variables. We assume ( )CD VVV ∪= with DV countable and nCV ℜ∈ ; XInit ⊆ is a set of...assume ( )CD VVV ∪= with DV countable and nCV ℜ∈ ; XInit ⊆ is a set of initial states; CXVXf →×: is a vector field, assumed to be globally...built under the Eclipse Swordfish project. As indicated on the project web site,”The goal of the Swordfish project is to provide an extensible SOA
Research on Customer Value Based on Extension Data Mining
NASA Astrophysics Data System (ADS)
Chun-Yan, Yang; Wei-Hua, Li
Extenics is a new discipline for dealing with contradiction problems with formulize model. Extension data mining (EDM) is a product combining Extenics with data mining. It explores to acquire the knowledge based on extension transformations, which is called extension knowledge (EK), taking advantage of extension methods and data mining technology. EK includes extensible classification knowledge, conductive knowledge and so on. Extension data mining technology (EDMT) is a new data mining technology that mining EK in databases or data warehouse. Customer value (CV) can weigh the essentiality of customer relationship for an enterprise according to an enterprise as a subject of tasting value and customers as objects of tasting value at the same time. CV varies continually. Mining the changing knowledge of CV in databases using EDMT, including quantitative change knowledge and qualitative change knowledge, can provide a foundation for that an enterprise decides the strategy of customer relationship management (CRM). It can also provide a new idea for studying CV.
Corporate Repair Philosophy and Measuring for Continuous Improvement at Philadelphia Naval Shipyard
1992-09-01
processes and products of Improvement Program (NIIP) vegan a series Wavy depot-level activities, of discussions which centered on the development of a...alteration project have been made at the and workforce. Prior to entering the shipyard. These changes and their effect planning stages fortheUSS...the in CKO at 80% is slightly less for CV-64 "rippling effects " of a DSR submittal when compared to CV-63 at its 80% point such as work stoppage
Silvestrini, Nicolas
2017-09-01
Numerous studies have assessed cardiovascular (CV) reactivity as a measure of effort mobilization during cognitive tasks. However, psychological and neural processes underlying effort-related CV reactivity are still relatively unclear. Previous research reliably found that CV reactivity during cognitive tasks is mainly determined by one region of the brain, the dorsal anterior cingulate cortex (dACC), and that this region is systematically engaged during cognitively demanding tasks. The present integrative approach builds on the research on cognitive control and its brain correlates that shows that dACC function can be related to conflict monitoring and integration of information related to task difficulty and success importance-two key variables in determining effort mobilization. In contrast, evidence also indicates that executive cognitive functioning is processed in more lateral regions of the prefrontal cortex. The resulting model suggests that, when automatic cognitive processes are insufficient to sustain behavior, the dACC determines the amount of required and justified effort according to task difficulty and success importance, which leads to proportional adjustments in CV reactivity and executive cognitive functioning. These propositions are discussed in relation to previous findings on effort-related CV reactivity and cognitive performance, new predictions for future studies, and relevance for other self-regulatory processes. Copyright © 2016 Elsevier B.V. All rights reserved.
The cross-validated AUC for MCP-logistic regression with high-dimensional data.
Jiang, Dingfeng; Huang, Jian; Zhang, Ying
2013-10-01
We propose a cross-validated area under the receiving operator characteristic (ROC) curve (CV-AUC) criterion for tuning parameter selection for penalized methods in sparse, high-dimensional logistic regression models. We use this criterion in combination with the minimax concave penalty (MCP) method for variable selection. The CV-AUC criterion is specifically designed for optimizing the classification performance for binary outcome data. To implement the proposed approach, we derive an efficient coordinate descent algorithm to compute the MCP-logistic regression solution surface. Simulation studies are conducted to evaluate the finite sample performance of the proposed method and its comparison with the existing methods including the Akaike information criterion (AIC), Bayesian information criterion (BIC) or Extended BIC (EBIC). The model selected based on the CV-AUC criterion tends to have a larger predictive AUC and smaller classification error than those with tuning parameters selected using the AIC, BIC or EBIC. We illustrate the application of the MCP-logistic regression with the CV-AUC criterion on three microarray datasets from the studies that attempt to identify genes related to cancers. Our simulation studies and data examples demonstrate that the CV-AUC is an attractive method for tuning parameter selection for penalized methods in high-dimensional logistic regression models.
Polymorphisms in TRPV1 and TAS2Rs associate with sensations from sampled ethanol
Allen, Alissa L.; McGeary, John E.; Hayes, John E.
2014-01-01
Background Genetic variation in chemosensory genes can explain variability in individual’s perception of and preference for many foods and beverages. To gain insight into variable preference and intake of alcoholic beverages, we explored individual variability in the responses to sampled ethanol. In humans, ethanol elicits sweet, bitter and burning sensations. Here, we explore the relationship between variation in ethanol sensations and polymorphisms in genes encoding bitter taste receptors (TAS2Rs) and a polymodal nociceptor (TRPV1). Methods Caucasian participants (n=93) were genotyped for 16 SNPs in TRPV1, 3 SNPs in TAS2R38 and 1 SNP in TAS2R13. Participants rated sampled ethanol on a generalized Labeled Magnitude Scale. Two stimuli were presented: a 16% ethanol whole mouth sip-and-spit solution with a single time-point rating of overall intensity, and a cotton swab saturated with 50% ethanol on the circumvallate papillae (CV) with repeated ratings made over 3 minutes. Area under the curve (AUC) was calculated for the time-intensity data. Results The ethanol whole mouth solution had overall intensity ratings near ‘very strong’. Burning/stinging had the highest mean AUC values, followed by bitterness and sweetness. Whole mouth intensity ratings were significantly associated with burning/stinging and bitterness AUC values on the CV. Three TRPV1 SNPs (rs224547, rs4780521, rs161364) were associated with ethanol sensations on the CV, with two (rs224547 and rs4780521) exhibiting strong linkage disequilibrium. Additionally, the TAS2R38 SNPs rs713598, rs1726866, and rs10246939 formed a haplotype, and were associated with bitterness on the CV. Lastly, overall intensity for whole mouth ethanol associated with the TAS2R13 SNP rs1015443. Conclusions These data suggest genetic variations in TRPV1 and TAS2Rs influence sensations from sampled ethanol and may potentially influence how individuals initially respond to alcoholic beverages. PMID:25257701
Population Pharmacokinetics of Atazanavir in Patients with Human Immunodeficiency Virus Infection▿
Colombo, Sara ; Buclin, Thierry; Cavassini, Matthias; Décosterd, Laurent A.; Telenti, Amalio; Biollaz, Jérôme; Csajka, Chantal
2006-01-01
Atazanavir (ATV) is a new azapeptide protease inhibitor recently approved and currently used at a fixed dose of either 300 mg once per day (q.d.) in combination with 100 mg ritonavir (RTV) or 400 mg q.d. without boosting. ATV is highly bound to plasma proteins and extensively metabolized by CYP3A4. Since ATV plasma levels are highly variable and seem to be correlated with both viral response and toxicity, dosage individualization based on plasma concentration monitoring might be indicated. This study aimed to assess the ATV pharmacokinetic profile in a target population of HIV patients, to characterize interpatient and intrapatient variability, and to identify covariates that might influence ATV disposition. A population analysis was performed with NONMEM with 574 plasma samples from a cohort of 214 randomly selected patients receiving ATV. A total of 346 randomly collected ATV plasma levels and 19 full concentration-time profiles at steady state were available. The pharmacokinetic parameter estimates were an oral clearance (CL) of 12.9 liters/h (coefficient of variation [CV], 26%), a volume of distribution of 88.3 liters (CV, 29%), an absorption rate constant of 0.405 h−1 (CV, 122%), and a lag time of 0.88 h. A relative bioavailability value was introduced to account for undercompliance due to infrequent follow-ups (0.81; CV, 45%). Among the covariates tested, only RTV significantly reduced CL by 46%, thereby increasing the ATV elimination half-life from 4.6 h to 8.8 h. The pharmacokinetic parameters of ATV were adequately described by a one-compartment population model. The concomitant use of RTV improved the pharmacokinetic profile. However, the remaining high interpatient variability suggests the possibility of an impact of unmeasured covariates, such as genetic traits or environmental influences. This population pharmacokinetic model, together with therapeutic drug monitoring and Bayesian dosage adaptation, can be helpful in the selection and adaptation of ATV doses. PMID:16940065
[Evaluation of pipetting systems. III. Micropipette precision in a routine task].
Salas, R; Loría, A; Rocha, C
1995-01-01
To establish a norm of the precision achievable with a micropipette in an IRMA assay under routine conditions. A micropipette (Gilson) adjusted to dispense 100 microL was used by a single analyst with experience in its use. In each assay, ten aliquots of radioactive antiprolactin were pipetted in clean tubes (PRE-batch tubes), followed by pipetting of the tubes being processed in the assay, and at the end, a second pipetting of 10 aliquots in clean tubes (POST-batch tubes). The study includes the data of 15 consecutive batches during a seven month period with an overall mean of 283 tubes per batch. The PRE- and POST-tubes were read in a gamma counter (Crystal plus). The mean, SD and CV for PRE, POST and global (PRE+POST) tubes were calculated for each batch. The global CV of the 15 batches ranged from 1.6 to 6.9%, mean of 3.1%. We found no evidence of increased imprecision due to fatigue of the analyst, but surprisingly, we observed that in nine of the 15 batches there was a significant difference in the means of the PRE-tubes vs the POST-tubes (t test) without differences in precision. Thus, part of the global variability is due to what we have called pseudoimprecision (i.e. an increase in CV due to differences in means). In addition, the POST-tubes had higher values in the first 7 batches but the opposite occurred in the last 8 batches (table 2). This shift in the sign of the PRE-POST differences suggests the presence of opposite factors operating in time, i.e. one or more factors increased the volume of pipetting after using the pipette more than 150 times (batches 1-7) whereas other/others decreased it (batches 8-15). 1. Our first approximation to a norm of micropipetting precision in batches of 200-300 tubes was a CV of 3.1%. 2. This norm was influenced by a problem of pseudoimprecision detected ex-post-facto. 3. Our findings justify continuation studies to detect the pseudoimprecision and evaluate its causes prospectively.
Botha-Brink, Jennifer
2014-01-01
Therocephalians were a speciose clade of nonmammalian therapsids whose ecological diversity and survivorship of the end-Permian mass extinction offer the potential to investigate the evolution of growth patterns across the clade and their underlying influences on post-extinction body size reductions, or ‘Lilliput effects’. We present a phylogenetic survey of limb bone histology and growth patterns in therocephalians from the Middle Permian through Middle Triassic of the Karoo Basin, South Africa. Histologic sections were prepared from 80 limb bones representing 11 genera of therocephalians. Histologic indicators of skeletal growth, including cortical vascularity (%CV) and mean primary osteon diameters (POD), were evaluated in a phylogenetic framework and assessed for correlations with other biologically significant variables (e.g., size and robusticity). Changes in %CV and POD correlated strongly with evolutionary changes in body size (i.e., smaller-bodied descendants tended to have lower %CV than their larger-bodied ancestors across the tree). Bone wall thickness tended to be high in early therocephalians and lower in the gracile-limbed baurioids, but showed no general correlation with cross-sectional area or degree of vascularity (and, thus, growth). Clade-level patterns, however, deviated from previously studied within-lineage patterns. For example, Moschorhinus, one of few therapsid genera to have survived the extinction boundary, demonstrated higher %CV in the Triassic than in the Permian despite its smaller size in the extinction aftermath. Results support a synergistic model of size reductions for Triassic therocephalians, influenced both by within-lineage heterochronic shifts in survivor taxa (as reported in Moschorhinus and the dicynodont Lystrosaurus) and phylogenetically inferred survival of small-bodied taxa that had evolved short growth durations (e.g., baurioids). These findings mirror the multi-causal Lilliput patterns described in marine faunas, but contrast with skeletochronologic studies that suggest slow, prolonged shell secretion over several years in marine benthos. Applications of phylogenetic comparative methods to new histologic data will continue to improve our understanding of the evolutionary dynamics of growth and body size shifts during mass extinctions and recoveries. PMID:24765566
Intraday and Interday Reliability of Ultra-Short-Term Heart Rate Variability in Rugby Union Players.
Nakamura, Fábio Y; Pereira, Lucas A; Esco, Michael R; Flatt, Andrew A; Moraes, José E; Cal Abad, Cesar C; Loturco, Irineu
2017-02-01
Nakamura, FY, Pereira, LA, Esco, MR, Flatt, AA, Moraes, JE, Cal Abad, CC, and Loturco, I. Intraday and interday reliability of ultra-short-term heart rate variability in rugby union players. J Strength Cond Res 31(2): 548-551, 2017-The aim of this study was to examine the intraday and interday reliability of ultra-short-term vagal-related heart rate variability (HRV) in elite rugby union players. Forty players from the Brazilian National Rugby Team volunteered to participate in this study. The natural log of the root mean square of successive RR interval differences (lnRMSSD) assessments were performed on 4 different days. The HRV was assessed twice (intraday reliability) on the first day and once per day on the following 3 days (interday reliability). The RR interval recordings were obtained from 2-minute recordings using a portable heart rate monitor. The relative reliability of intraday and interday lnRMSSD measures was analyzed using the intraclass correlation coefficient (ICC). The typical error of measurement (absolute reliability) of intraday and interday lnRMSSD assessments was analyzed using the coefficient of variation (CV). Both intraday (ICC = 0.96; CV = 3.99%) and interday (ICC = 0.90; CV = 7.65%) measures were highly reliable. The ultra-short-term lnRMSSD is a consistent measure for evaluating elite rugby union players, in both intraday and interday settings. This study provides further validity to using this shortened method in practical field conditions with highly trained team sports athletes.
Spectroscopic classification of X-ray sources in the Galactic Bulge Survey
NASA Astrophysics Data System (ADS)
Wevers, T.; Torres, M. A. P.; Jonker, P. G.; Nelemans, G.; Heinke, C.; Mata Sánchez, D.; Johnson, C. B.; Gazer, R.; Steeghs, D. T. H.; Maccarone, T. J.; Hynes, R. I.; Casares, J.; Udalski, A.; Wetuski, J.; Britt, C. T.; Kostrzewa-Rutkowska, Z.; Wyrzykowski, Ł.
2017-10-01
We present the classification of 26 optical counterparts to X-ray sources discovered in the Galactic Bulge Survey. We use (time-resolved) photometric and spectroscopic observations to classify the X-ray sources based on their multiwavelength properties. We find a variety of source classes, spanning different phases of stellar/binary evolution. We classify CX21 as a quiescent cataclysmic variable (CV) below the period gap, and CX118 as a high accretion rate (nova-like) CV. CXB12 displays excess UV emission, and could contain a compact object with a giant star companion, making it a candidate symbiotic binary or quiescent low-mass X-ray binary (although other scenarios cannot be ruled out). CXB34 is a magnetic CV (polar) that shows photometric evidence for a change in accretion state. The magnetic classification is based on the detection of X-ray pulsations with a period of 81 ± 2 min. CXB42 is identified as a young stellar object, namely a weak-lined T Tauri star exhibiting (to date unexplained) UX Ori-like photometric variability. The optical spectrum of CXB43 contains two (resolved) unidentified double-peaked emission lines. No known scenario, such as an active galactic nucleus or symbiotic binary, can easily explain its characteristics. We additionally classify 20 objects as likely active stars based on optical spectroscopy, their X-ray to optical flux ratios and photometric variability. In four cases we identify the sources as binary stars.
Exploratory Spectroscopy of Magnetic Cataclysmic Variables Candidates and Other Variable Objects
DOE Office of Scientific and Technical Information (OSTI.GOV)
Oliveira, A. S.; Palhares, M. S.; Rodrigues, C. V.
2017-04-01
The increasing number of synoptic surveys made by small robotic telescopes, such as the photometric Catalina Real-Time Transient Survey (CRTS), provides a unique opportunity to discover variable sources and improves the statistical samples of such classes of objects. Our goal is the discovery of magnetic Cataclysmic Variables (mCVs). These are rare objects that probe interesting accretion scenarios controlled by the white-dwarf magnetic field. In particular, improved statistics of mCVs would help to address open questions on their formation and evolution. We performed an optical spectroscopy survey to search for signatures of magnetic accretion in 45 variable objects selected mostly from themore » CRTS. In this sample, we found 32 CVs, 22 being mCV candidates, 13 of which were previously unreported as such. If the proposed classifications are confirmed, it would represent an increase of 4% in the number of known polars and 12% in the number of known IPs. A fraction of our initial sample was classified as extragalactic sources or other types of variable stars by the inspection of the identification spectra. Despite the inherent complexity in identifying a source as an mCV, variability-based selection, followed by spectroscopic snapshot observations, has proved to be an efficient strategy for their discoveries, being a relatively inexpensive approach in terms of telescope time.« less
Spieth, Peter M; Güldner, Andreas; Uhlig, Christopher; Bluth, Thomas; Kiss, Thomas; Schultz, Marcus J; Pelosi, Paolo; Koch, Thea; Gama de Abreu, Marcelo
2014-05-02
General anesthesia usually requires mechanical ventilation, which is traditionally accomplished with constant tidal volumes in volume- or pressure-controlled modes. Experimental studies suggest that the use of variable tidal volumes (variable ventilation) recruits lung tissue, improves pulmonary function and reduces systemic inflammatory response. However, it is currently not known whether patients undergoing open abdominal surgery might benefit from intraoperative variable ventilation. The PROtective VARiable ventilation trial ('PROVAR') is a single center, randomized controlled trial enrolling 50 patients who are planning for open abdominal surgery expected to last longer than 3 hours. PROVAR compares conventional (non-variable) lung protective ventilation (CV) with variable lung protective ventilation (VV) regarding pulmonary function and inflammatory response. The primary endpoint of the study is the forced vital capacity on the first postoperative day. Secondary endpoints include further lung function tests, plasma cytokine levels, spatial distribution of ventilation assessed by means of electrical impedance tomography and postoperative pulmonary complications. We hypothesize that VV improves lung function and reduces systemic inflammatory response compared to CV in patients receiving mechanical ventilation during general anesthesia for open abdominal surgery longer than 3 hours. PROVAR is the first randomized controlled trial aiming at intra- and postoperative effects of VV on lung function. This study may help to define the role of VV during general anesthesia requiring mechanical ventilation. Clinicaltrials.gov NCT01683578 (registered on September 3 3012).
Millet, C; Roustit, M; Blaise, S; Cracowski, J L
2011-09-01
We tested the linearity between skin blood flux recorded with laser speckle contrast imaging (LSCI) and laser Doppler imaging (LDI), comparing different ways of expressing data. A secondary objective was to test within-subject variability of baseline flux with the two techniques. We performed local heating at 36, 39, 42, and 44°C on the forearm of healthy volunteers, and measured cutaneous blood flux with LDI and LSCI. Biological zero (BZ) was obtained by occluding the brachial artery. We expressed data as raw arbitrary perfusion units (APUs) and as a percentage increase from baseline (%BL), with and without subtracting BZ. Inter-site variability was expressed as a within subject coefficient of variation (CV). Twelve participants were enrolled. Inter-site variability at baseline was lower with LSCI (CV=9.2%) than with LDI (CV=20.7%). We observed an excellent correlation between both techniques when data were expressed as raw APUs or APU-BZ (R=0.90; p<0.001). The correlation remained correct for %BL (R=0.77, p<0.001), but decreased for %BL-BZ (R=0.44, p=0.003). Bland-Altman plots revealed a major proportional bias between the two techniques. This study suggests that skin blood flux measured with LSCI is linearly related to the LDI signal over a wide range of perfusion. Subtracting BZ does not affect this linearity but introduces variability in baseline flux, thus decreasing the correlation when data are expressed as a function of baseline. Finally, systematic bias makes it impossible to assimilate arbitrary perfusion units provided by the two systems. Copyright © 2011 Elsevier Inc. All rights reserved.
Unequal cluster sizes in stepped-wedge cluster randomised trials: a systematic review
Morris, Tom; Gray, Laura
2017-01-01
Objectives To investigate the extent to which cluster sizes vary in stepped-wedge cluster randomised trials (SW-CRT) and whether any variability is accounted for during the sample size calculation and analysis of these trials. Setting Any, not limited to healthcare settings. Participants Any taking part in an SW-CRT published up to March 2016. Primary and secondary outcome measures The primary outcome is the variability in cluster sizes, measured by the coefficient of variation (CV) in cluster size. Secondary outcomes include the difference between the cluster sizes assumed during the sample size calculation and those observed during the trial, any reported variability in cluster sizes and whether the methods of sample size calculation and methods of analysis accounted for any variability in cluster sizes. Results Of the 101 included SW-CRTs, 48% mentioned that the included clusters were known to vary in size, yet only 13% of these accounted for this during the calculation of the sample size. However, 69% of the trials did use a method of analysis appropriate for when clusters vary in size. Full trial reports were available for 53 trials. The CV was calculated for 23 of these: the median CV was 0.41 (IQR: 0.22–0.52). Actual cluster sizes could be compared with those assumed during the sample size calculation for 14 (26%) of the trial reports; the cluster sizes were between 29% and 480% of that which had been assumed. Conclusions Cluster sizes often vary in SW-CRTs. Reporting of SW-CRTs also remains suboptimal. The effect of unequal cluster sizes on the statistical power of SW-CRTs needs further exploration and methods appropriate to studies with unequal cluster sizes need to be employed. PMID:29146637
Phibbs, Padraic J; Jones, Ben; Roe, Gregory; Read, Dale; Darrall-Jones, Joshua; Weakley, Jonathon; Rock, Andrew; Till, Kevin
2018-04-01
The aims of this study were to determine the variability of weekly match and training loads in adolescent rugby union players across a competitive season, and to investigate the effect of match frequency on load distribution across different activities. Internal match and training load data (i.e. session-rating of perceived exertion (sRPE)) were collected daily from 20 players from a regional academy across a 14-week season. Data were analysed using a mixed-effects linear model, and variability was reported as a coefficient of variation (CV). Differences between 0-, 1-, 2-, and 3-match weeks were assessed using Cohen's d effect sizes and magnitude-based inferences. Mean weekly total match and training sRPE load was 1425 ± 545 arbitrary units (AU), with a between-player CV of 10 ± 6% and within-player CV of 37 ± 3%. Mean week-to-week change in total sRPE load was 497 ± 423 AU (35%), and 40% of weekly observations were outside the suggested acute:chronic workload ratio 'safe zone'. Total weekly sRPE loads increased substantially with match frequency (1210 ± 571, 1511 ± 489, and 1692 ± 517 AU, for 0-, 1-, and 2-match weeks, respectively), except for 3-match weeks (1520 ± 442 AU). Weekly match and training loads were highly variable for adolescent rugby players during the competitive season, and match frequency has a substantial effect on the distribution of loads. Therefore, match and training loads should be coordinated, monitored, and managed on an individual basis to protect players from negative training consequences, and to promote long-term athlete development.
Wuehr, M; Schniepp, R; Pradhan, C; Ilmberger, J; Strupp, M; Brandt, T; Jahn, K
2013-01-01
Healthy persons exhibit relatively small temporal and spatial gait variability when walking unimpeded. In contrast, patients with a sensory deficit (e.g., polyneuropathy) show an increased gait variability that depends on speed and is associated with an increased fall risk. The purpose of this study was to investigate the role of vision in gait stabilization by determining the effects of withdrawing visual information (eyes closed) on gait variability at different locomotion speeds. Ten healthy subjects (32.2 ± 7.9 years, 5 women) walked on a treadmill for 5-min periods at their preferred walking speed and at 20, 40, 70, and 80 % of maximal walking speed during the conditions of walking with eyes open (EO) and with eyes closed (EC). The coefficient of variation (CV) and fractal dimension (α) of the fluctuations in stride time, stride length, and base width were computed and analyzed. Withdrawing visual information increased the base width CV for all walking velocities (p < 0.001). The effects of absent visual information on CV and α of stride time and stride length were most pronounced during slow locomotion (p < 0.001) and declined during fast walking speeds. The results indicate that visual feedback control is used to stabilize the medio-lateral (i.e., base width) gait parameters at all speed sections. In contrast, sensory feedback control in the fore-aft direction (i.e., stride time and stride length) depends on speed. Sensory feedback contributes most to fore-aft gait stabilization during slow locomotion, whereas passive biomechanical mechanisms and an automated central pattern generation appear to control fast locomotion.
Ota, Leo; Uchitomi, Hirotaka; Ogawa, Ken-ichiro; Orimo, Satoshi; Miyake, Yoshihiro
2014-01-01
Walking is generated by the interaction between neural rhythmic and physical activities. In fact, Parkinson's disease (PD), which is an example of disease, causes not only neural rhythm generation disorders but also physical disabilities. However, the relationship between neural rhythm generation disorders and physical disabilities has not been determined. The aim of this study was to identify the mechanism of gait rhythm generation. In former research, neural rhythm generation disorders in PD patients' walking were characterized by stride intervals, which are more variable and fluctuate randomly. The variability and fluctuation property were quantified using the coefficient of variation (CV) and scaling exponent α. Conversely, because walking is a dynamic process, postural reflex disorder (PRD) is considered the best way to estimate physical disabilities in walking. Therefore, we classified the severity of PRD using CV and α. Specifically, PD patients and healthy elderly were classified into three groups: no-PRD, mild-PRD, and obvious-PRD. We compared the contributions of CV and α to the accuracy of this classification. In this study, 45 PD patients and 17 healthy elderly people walked 200 m. The severity of PRD was determined using the modified Hoehn-Yahr scale (mH-Y). People with mH-Y scores of 2.5 and 3 had mild-PRD and obvious-PRD, respectively. As a result, CV differentiated no-PRD from PRD, indicating the correlation between CV and PRD. Considering that PRD is independent of neural rhythm generation, this result suggests the existence of feedback process from physical activities to neural rhythmic activities. Moreover, α differentiated obvious-PRD from mild-PRD. Considering α reflects the intensity of interaction between factors, this result suggests the change of the interaction. Therefore, the interaction between neural rhythmic and physical activities is thought to plays an important role for gait rhythm generation. These characteristics have potential to evaluate the symptoms of PD.
Reliability of bounce drop jump parameters within elite male rugby players.
Costley, Lisa; Wallace, Eric; Johnston, Michael; Kennedy, Rodney
2017-07-25
The aims of the study were to investigate the number of familiarisation sessions required to establish reliability of the bounce drop jump (BDJ) and subsequent reliability once familiarisation is achieved. Seventeen trained male athletes completed 4 BDJs in 4 separate testing sessions. Force-time data from a 20 cm BDJ was obtained using two force plates (ensuring ground contact < 250 ms). Subjects were instructed to 'jump for maximal height and minimal contact time' while the best and average of four jumps were compared. A series of performance variables were assessed in both eccentric and concentric phases including jump height, contact time, flight time, reactive strength index (RSI), peak power, rate of force development (RFD) and actual dropping height (ADH). Reliability was assessed using the intraclass correlation coefficient (ICC) and coefficient of variation (CV) while familiarisation was assessed using a repeated measures analysis of variance (ANOVA). The majority of DJ parameters exhibited excellent reliability with no systematic bias evident, while the average of 4 trials provided greater reliability. With the exception of vertical stiffness (CV: 12.0 %) and RFD (CV: 16.2 %) all variables demonstrated low within subject variation (CV range: 3.1 - 8.9 %). Relative reliability was very poor for ADH, with heights ranging from 14.87 - 29.85 cm. High levels of reliability can be obtained from the BDJ with the exception of vertical stiffness and RFD, however, extreme caution must be taken when comparing DJ results between individuals and squads due to large discrepancies between actual drop height and platform height.
Blendea, Dan; Mansour, Moussa; Shah, Ravi V; Chung, Jeffrey; Nandigam, Veena; Heist, E Kevin; Mela, Theofanie; Reddy, Vivek Y; Manzke, Robert; McPherson, Craig A; Ruskin, Jeremy N; Singh, Jagmeet P
2007-11-15
Standard coronary venous angiography (SCVA) provides a static, fixed projection of the coronary venous (CV) tree. High-speed rotational coronary venous angiography (RCVA) is a novel method of mapping CV anatomy using dynamic, multiangle visualization. The purpose of this study was to assess the value of RCVA during cardiac resynchronization therapy. Digitally acquired rotational CV angiograms from 49 patients (mean age 69 +/- 11 years) who underwent left ventricular lead implantation were analyzed. RCVA, which uses rapid isocentric rotation over a 110 degrees arc, acquiring 120 frames/angiogram, was compared with SCVA, defined as 2 static orthogonal views: right anterior oblique 45 degrees and left anterior oblique 45 degrees . RCVA demonstrated that the posterior vein-to-coronary sinus (CS) angle and the left marginal vein-to-CS angle were misclassified in 5 and 11 patients, respectively, using SCVA. RCVA identified a greater number of second-order tributaries with diameters >1.5 mm than SCVA. The CV branch selected for lead placement was initially identified in 100% of patients using RCVA but in only 74% of patients using SCVA. RCVA showed that the best angiographic view for visualizing the CS and its tributaries differed significantly among different areas of the CV tree and among patients. The area of the CV tree that showed less variability was the CS ostium, which had a fairly constant relation with the spine in shallow right anterior oblique and left anterior oblique projections. In conclusion, RCVA provided a more precise map of CV anatomy and the spatial relation of venous branches. It allowed the identification of fluoroscopic views that could facilitate cannulation of the CS. The final x-ray view displaying the appropriate CV branch for left ventricular lead implantation was often different from the conventional left anterior oblique and right anterior oblique views. RCVA identified the target branch for lead implantation more often than SCVA.
Groot, Anne; Bots, Michiel L; Rutten, Frans H; den Ruijter, Hester M; Numans, Mattijs E; Vaartjes, Ilonca
2015-01-01
Background GPs need accurate tools for cardiovascular (CV) risk assessment. Abnormalities in resting electrocardiograms (ECGs) relate to increased CV risk. Aim To determine whether measurement of ECG abnormalities on top of established risk estimation (SCORE) improves CV risk classification in a primary care population. Design and setting A cohort study of patients enlisted with academic general practices in the Netherlands (the Utrecht Health Project [UHP]). Method Incident CV events were extracted from the GP records. MEANS algorithm was used to assess ECG abnormalities. Cox proportional hazards modelling was applied to relate ECG abnormalities to CV events. For a prediction model only with SCORE variables, and a model with SCORE+ECG abnormalities, the discriminative value (area under the receiver operator curve [AUC]) and the net reclassification improvement (NRI) were estimated. Results A total of 2370 participants aged 38–74 years were included, all eligible for CV risk assessment. During a mean follow-up of 7.8 years, 172 CV events occurred. In 19% of the participants at least one ECG abnormality was found (Lausanne criteria). Presence of atrial fibrillation/flutter (AF) and myocardial infarction (MI) were significantly related to CV events. The AUC of the SCORE risk factors was 0.75 (95% CI = 0.71 to 0.79). Addition of MI or AF resulted in an AUC of 0.76 (95% CI = 0.72 to 0.79) and 0.75 (95% CI = 0.72 to 0.79), respectively. The NRI with the addition of ECG abnormalities was small (MI 1.0%; 95% CI = −3.2% to 6.9%; AF 0.5%; 95% CI = −3.5% to 3.3%). Conclusion Performing a resting ECG in a primary care population does not seem to improve risk classification when SCORE information — age, sex, smoking, systolic blood pressure, and total cholesterol/HDL ratio — is already available. PMID:25548311
Groot, Anne; Bots, Michiel L; Rutten, Frans H; den Ruijter, Hester M; Numans, Mattijs E; Vaartjes, Ilonca
2015-01-01
GPs need accurate tools for cardiovascular (CV) risk assessment. Abnormalities in resting electrocardiograms (ECGs) relate to increased CV risk. To determine whether measurement of ECG abnormalities on top of established risk estimation (SCORE) improves CV risk classification in a primary care population. A cohort study of patients enlisted with academic general practices in the Netherlands (the Utrecht Health Project [UHP]). Incident CV events were extracted from the GP records. MEANS algorithm was used to assess ECG abnormalities. Cox proportional hazards modelling was applied to relate ECG abnormalities to CV events. For a prediction model only with SCORE variables, and a model with SCORE+ECG abnormalities, the discriminative value (area under the receiver operator curve [AUC]) and the net reclassification improvement (NRI) were estimated. A total of 2370 participants aged 38-74 years were included, all eligible for CV risk assessment. During a mean follow-up of 7.8 years, 172 CV events occurred. In 19% of the participants at least one ECG abnormality was found (Lausanne criteria). Presence of atrial fibrillation/flutter (AF) and myocardial infarction (MI) were significantly related to CV events. The AUC of the SCORE risk factors was 0.75 (95% CI = 0.71 to 0.79). Addition of MI or AF resulted in an AUC of 0.76 (95% CI = 0.72 to 0.79) and 0.75 (95% CI = 0.72 to 0.79), respectively. The NRI with the addition of ECG abnormalities was small (MI 1.0%; 95% CI = -3.2% to 6.9%; AF 0.5%; 95% CI = -3.5% to 3.3%). Performing a resting ECG in a primary care population does not seem to improve risk classification when SCORE information - age, sex, smoking, systolic blood pressure, and total cholesterol/HDL ratio - is already available. © British Journal of General Practice 2015.
Battut, I Barrier; Kempfer, A; Lemasson, N; Chevrier, L; Camugli, S
2017-07-15
Spermatozoa from some stallions do not maintain an acceptable fertility after freezing and thawing. The selection of frozen ejaculates that would be suitable for insemination is mainly based on post-thaw motility, but the prediction of fertility remains limited. A recent study in our laboratory has enabled the determination of a new protocol for the evaluation of fresh stallion semen, combining microscopical observation, computer-assisted motility analysis and flow cytometry, and providing a high level of fertility prediction. The purpose of the present experiment was to perform similar investigations on frozen semen. A panel of tests evaluating a large number of compartments or functions of the spermatozoa was applied to a population of 42 stallions, 33 of which showing widely differing fertilities (17-67% pregnancy rate per cycle [PRC]). Variability was evaluated by calculating the coefficient of variation (CV=SD/mean) and the intra-class correlation or "repeatability" for each variable. For paired variables, mean within-stallion CV% was significantly lower than between-stallion CV%, which was significantly lower than total CV%. Within-ejaculate repeatability, determined by analysing 6 straws for each of 10 ejaculates, ranged from 0.60 to 0.97. Within-stallion repeatability, determined by analysing at least 5 ejaculates for each of 38 stallions, ranged from 0.12 to 0.95. Principal component regression using a combination of 25 variables, including motility, morphology, viability, oxidation level, acrosome integrity, DNA integrity and hypoosmotic resistance, accounted for 94.5% of the variability regarding fertility, and was used to calculate a prediction of the PRC with a mean standard deviation of 2.2. The difference between the observed PRC and the calculated value ranged from -3.4 to 4.2. The 90% confidence interval (90CI) for the prediction of the PRC for the stallions of unknown fertility ranged from 8 to 30 (mean = 17). The best-fit model using only motility variables, evaluated after 10 min at 36 °C and 2 h at 36 °C or room temperature, accounted for only 74.2% of the variability. The difference between the observed PRC and the calculated value ranged from -7.2 to 14. The 90CI for the prediction of the PRC for the stallions of unknown fertility ranged from 23 to 48 (mean = 33). In conclusion, this study demonstrated that an appropriate combination of computer-assisted motility analysis, microscopical observation and flow cytometry can provide a higher prediction of fertility than motility analysis alone. Copyright © 2017 Elsevier Inc. All rights reserved.
Symstad, Amy J.; Jonas, Jayne L.; Edited by Guntenspergen, Glenn R.
2014-01-01
Natural range of variation (NRV) may be used to establish decision thresholds or action assessment points when ecological thresholds are either unknown or do not exist for attributes of interest in a managed ecosystem. The process for estimating NRV involves identifying spatial and temporal scales that adequately capture the heterogeneity of the ecosystem; compiling data for the attributes of interest via study of historic records, analysis and interpretation of proxy records, modeling, space-for-time substitutions, or analysis of long-term monitoring data; and quantifying the NRV from those data. At least 19 National Park Service (NPS) units in North America’s Great Plains are monitoring plant species richness and evenness as indicators of vegetation integrity in native grasslands, but little information on natural, temporal variability of these indicators is available. In this case study, we use six long-term vegetation monitoring datasets to quantify the temporal variability of these attributes in reference conditions for a variety of Great Plains grassland types, and then illustrate the implications of using different NRVs based on these quantities for setting management decision thresholds. Temporal variability of richness (as measured by the coefficient of variation, CV) is fairly consistent across the wide variety of conditions occurring in Colorado shortgrass prairie to Minnesota tallgrass sand savanna (CV 0.20–0.45) and generally less than that of production at the same sites. Temporal variability of evenness spans a greater range of CV than richness, and it is greater than that of production in some sites but less in other sites. This natural temporal variability may mask undesirable changes in Great Plains grasslands vegetation. Consequently, we suggest that managers consider using a relatively narrow NRV (interquartile range of all richness or evenness values observed in reference conditions) for designating a surveillance threshold, at which greater attention to the situation would be paid, and a broader NRV for designating management thresholds, at which action would be instigated.
Exploring the SDSS Dataset with Linked Scatter Plots: I. EMP, CEMP, and CV Stars
NASA Technical Reports Server (NTRS)
Carbon, Duane F.; Henze, Christopher; Nelson, Bron C.
2017-01-01
We present the results of a search for EMP, CEMP, and cataclysmic variable stars using a new exploration tool based on linked scatter plots (LSPs). Our approach is especially designed to work with very large spectrum data sets such as the SDSS, LAMOST, RAVE, and Gaia data sets and can be applied to stellar, galaxy, and quasar spectra. As a demonstration, we conduct a search for EMP, CEMP, and cataclysmic variable stars in the SDSS DR10 data set. We first created a 3326-dimensional phase space containing nearly 2 billion measures of the strengths of over 1600 spectral features in 569,738 SDSS stars. These measures capture essentially all the stellar atomic and molecular species visible at the resolution of SDSS spectra. We show how LSPs can be used to quickly isolate and examine interesting portions of this phase space. To illustrate, we use LSPs coupled with cuts in selected portions of phase space to extract EMP stars, C-rich EMP stars, and CV stars. We present identifications for 59 previously unrecognized candidate EMP stars and 11 previously unrecognized candidate CEMP stars. We also call attention to 2 candidate He II emission CV stars found by the LSP approach that have not yet been discussed in the literature.
Within-Session Stability of Short-Term Heart Rate Variability Measurement
2016-01-01
Abstract The primary aim of this study was to assess the retest stability of the short-term heart rate variability (HRV) measurement performed within one session and without the use of any intervention. Additionally, a precise investigation of the possible impact of intrinsic biological variation on HRV reliability was also performed. First, a single test-retest HRV measurement was conducted with 20-30 min apart from one another. Second, the HRV measurement was repeated in ten non-interrupted consecutive intervals. The lowest typical error (CV = 21.1%) was found for the square root of the mean squared differences of successive RR intervals (rMSSD) and the highest for the low frequency power (PLF) (CV = 93.9%). The standardized changes in the mean were trivial to small. The correlation analysis revealed the highest level for ln rMSSD (ICC = 0.87), while ln PLF represented the worst case (ICC = 0.59). The reliability indices for ln rMSSD in 10 consecutive intervals improved (CV = 9.9%; trivial standardized changes in the mean; ICC = 0.96). In conclusion, major differences were found in the reliability level between the HRV indices. The rMSSD demonstrated the highest reliability level. No substantial influence of intrinsic biological variation on the HRV reliability was observed. PMID:28149345
High-Throughput RNA Interference Screening: Tricks of the Trade
Nebane, N. Miranda; Coric, Tatjana; Whig, Kanupriya; McKellip, Sara; Woods, LaKeisha; Sosa, Melinda; Sheppard, Russell; Rasmussen, Lynn; Bjornsti, Mary-Ann; White, E. Lucile
2016-01-01
The process of validating an assay for high-throughput screening (HTS) involves identifying sources of variability and developing procedures that minimize the variability at each step in the protocol. The goal is to produce a robust and reproducible assay with good metrics. In all good cell-based assays, this means coefficient of variation (CV) values of less than 10% and a signal window of fivefold or greater. HTS assays are usually evaluated using Z′ factor, which incorporates both standard deviation and signal window. A Z′ factor value of 0.5 or higher is acceptable for HTS. We used a standard HTS validation procedure in developing small interfering RNA (siRNA) screening technology at the HTS center at Southern Research. Initially, our assay performance was similar to published screens, with CV values greater than 10% and Z′ factor values of 0.51 ± 0.16 (average ± standard deviation). After optimizing the siRNA assay, we got CV values averaging 7.2% and a robust Z′ factor value of 0.78 ± 0.06 (average ± standard deviation). We present an overview of the problems encountered in developing this whole-genome siRNA screening program at Southern Research and how equipment optimization led to improved data quality. PMID:23616418
Exploring the SDSS Dataset with Linked Scatter Plots: I. EMP, CEMP, and CV Stars.
Carbon, Duane F; Henze, Christopher; Nelson, Bron C
2017-02-01
We present the results of a search for EMP, CEMP, and cataclysmic variable stars using a new exploration tool based on linked scatter plots (LSPs). Our approach is especially designed to work with very large spectrum data sets such as the SDSS, LAMOST, RAVE, and Gaia data sets and can be applied to stellar, galaxy, and quasar spectra. As a demonstration, we conduct a search for EMP, CEMP, and cataclysmic variable stars in the SDSS DR10 data set. We first created a 3326-dimensional phase space containing nearly 2 billion measures of the strengths of over 1600 spectral features in 569,738 SDSS stars. These measures capture essentially all the stellar atomic and molecular species visible at the resolution of SDSS spectra. We show how LSPs can be used to quickly isolate and examine interesting portions of this phase space. To illustrate, we use LSPs coupled with cuts in selected portions of phase space to extract EMP stars, C-rich EMP stars, and CV stars. We present identifications for 59 previously unrecognized candidate EMP stars and 11 previously unrecognized candidate CEMP stars. We also call attention to 2 candidate He II emission CV stars found by the LSP approach that have not yet been discussed in the literature.
Reliability of Leg and Vertical Stiffness During High Speed Treadmill Running.
Pappas, Panagiotis; Dallas, Giorgos; Paradisis, Giorgos
2017-04-01
In research, the accurate and reliable measurement of leg and vertical stiffness could contribute to valid interpretations. The current study aimed at determining the intraparticipant variability (ie, intraday and interday reliabilities) of leg and vertical stiffness, as well as related parameters, during high speed treadmill running, using the "sine-wave" method. Thirty-one males ran on a treadmill at 6.67 m∙s -1 , and the contact and flight times were measured. To determine the intraday reliability, three 10-s running bouts with 10-min recovery were performed. In addition, to examine the interday reliability, three 10-s running bouts on 3 separate days with 48-h interbout intervals were performed. The reliability statistics included repeated-measure analysis of variance, average intertrial correlations, intraclass correlation coefficients (ICCs), Cronbach's α reliability coefficient, and the coefficient of variation (CV%). Both intraday and interday reliabilities were high for leg and vertical stiffness (ICC > 0.939 and CV < 4.3%), as well as related variables (ICC > 0.934 and CV < 3.9%). It was thus inferred that the measurements of leg and vertical stiffness, as well as the related parameters obtained using the "sine-wave" method during treadmill running at 6.67 m∙s -1 , were highly reliable, both within and across days.
Exploring the SDSS Dataset with Linked Scatter Plots: I. EMP, CEMP, and CV Stars
Carbon, Duane F.; Henze, Christopher; Nelson, Bron C.
2017-01-01
We present the results of a search for EMP, CEMP, and cataclysmic variable stars using a new exploration tool based on linked scatter plots (LSPs). Our approach is especially designed to work with very large spectrum data sets such as the SDSS, LAMOST, RAVE, and Gaia data sets and can be applied to stellar, galaxy, and quasar spectra. As a demonstration, we conduct a search for EMP, CEMP, and cataclysmic variable stars in the SDSS DR10 data set. We first created a 3326-dimensional phase space containing nearly 2 billion measures of the strengths of over 1600 spectral features in 569,738 SDSS stars. These measures capture essentially all the stellar atomic and molecular species visible at the resolution of SDSS spectra. We show how LSPs can be used to quickly isolate and examine interesting portions of this phase space. To illustrate, we use LSPs coupled with cuts in selected portions of phase space to extract EMP stars, C-rich EMP stars, and CV stars. We present identifications for 59 previously unrecognized candidate EMP stars and 11 previously unrecognized candidate CEMP stars. We also call attention to 2 candidate He II emission CV stars found by the LSP approach that have not yet been discussed in the literature. PMID:28684884
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.
NASA Astrophysics Data System (ADS)
Tampubolon, Marojahan; Pamungkas, Laskar; Hsieh, Yao Ching; Chiu, Huang Jen
2018-04-01
This paper presents the implementation of Constant Voltage (CV) and Constant Current (CC) control for a wireless charger system. A battery charging system needs these control modes to ensure the safety of the battery and the effectiveness of the charging system. Here, the wireless charger system does not employ any post-regulator stage to control the output voltage and output current of the charger. But, it uses a variable frequency control incorporated with a conventional PI control. As a result, the size and the weight of the system are reduced. This paper discusses the brief review of the SS-WPT, control strategy and implementation of the CV and CC control. Experimental hardware with 2kW output power has been performed and tested. The results show that the proposed CV and CC control method works well with the system.
Maietti, Annalisa; Tedeschi, Paola; Stagno, Caterina; Bordiga, Matteo; Travaglia, Fabiano; Locatelli, Monica; Arlorio, Marco; Brandolini, Vincenzo
2012-06-01
Two morphologically different cultivars of Italian melons (Baggio and Giusto) were characterized considering samples harvested in different times, at the beginning (BPP) and at the end of the physiological plant production period (EPP). Proximate composition, protein, minerals, pH, phenolic content, antioxidant capacity, ascorbic acid, carotenoids, condensed tannins, and flavonoids were measured, showing a significant decrease in EPP samples (phenolics, antioxidant capacity, condensed tannins, and flavonoids); ascorbic acid decreased in Giusto cv, carotenoids in Baggio cv. Mineral content increased in either the cultivars (EPP samples). Year-to-year difference was significantly highlighted; the plant growing cycle significantly affected the chemotype. Despite these effects, the Principal Component Analysis (PCA) permitted the discrimination of Baggio from Giusto cv, and the discrimination of BPP from EPP samples as well. © 2012 Institute of Food Technologists®
NASA Astrophysics Data System (ADS)
Giorgino, Toni
2018-07-01
The proper choice of collective variables (CVs) is central to biased-sampling free energy reconstruction methods in molecular dynamics simulations. The PLUMED 2 library, for instance, provides several sophisticated CV choices, implemented in a C++ framework; however, developing new CVs is still time consuming due to the need to provide code for the analytical derivatives of all functions with respect to atomic coordinates. We present two solutions to this problem, namely (a) symbolic differentiation and code generation, and (b) automatic code differentiation, in both cases leveraging open-source libraries (SymPy and Stan Math, respectively). The two approaches are demonstrated and discussed in detail implementing a realistic example CV, the local radius of curvature of a polymer. Users may use the code as a template to streamline the implementation of their own CVs using high-level constructs and automatic gradient computation.
Economic Evaluation of Frequent Home Nocturnal Hemodialysis Based on a Randomized Controlled Trial
Tonelli, Marcello; Pauly, Robert; Walsh, Michael; Culleton, Bruce; So, Helen; Hemmelgarn, Brenda; Manns, Braden
2014-01-01
Provider and patient enthusiasm for frequent home nocturnal hemodialysis (FHNHD) has been renewed; however, the cost-effectiveness of this technique is unknown. We performed a cost-utility analysis of FHNHD compared with conventional hemodialysis (CvHD; 4 hours three times per week) from a health payer perspective over a lifetime horizon using patient information from the Alberta NHD randomized controlled trial. Costs, including training costs, were obtained using microcosting and administrative data (CAN$2012). We determined the incremental cost per quality-adjusted life year (QALY) gained. Robustness was assessed using scenario, sensitivity, and probabilistic sensitivity analyses. Compared with CvHD (61% in-center, 14% satellite, and 25% home dialysis), FHNHD led to incremental cost savings (−$6700) and an additional 0.38 QALYs. In sensitivity analyses, when the annual probability of technique failure with FHNHD increased from 7.6% (reference case) to ≥19%, FHNHD became unattractive (>$75,000/QALY). The cost/QALY gained became $13,000 if average training time for FHNHD increased from 3.7 to 6 weeks. In scenarios with alternate comparator modalities, FHNHD remained dominant compared with in-center CvHD; cost/QALYs gained were $18,500, $198,000, and $423,000 compared with satellite CvHD, home CvHD, and peritoneal dialysis, respectively. In summary, FHNHD is attractive compared with in-center CvHD in this cohort. However, the attractiveness of FHNHD varies by technique failure rate, training time, and dialysis modalities from which patients are drawn, and these variables should be considered when establishing FHNHD programs. PMID:24231665
Yandrapalli, Srikanth; Jolly, George; Horblitt, Adam; Sanaani, Abdallah; Aronow, Wilbert S
2017-11-01
Diabetes mellitus is a growing in exponential proportions. If the current growth trend continues, it may result in every third adult in the United States having diabetes mellitus by 2050, and every 10 th adult worldwide. Type 2 diabetes mellitus (T2DM) confers a 2- to 3-fold increased risk of cardiovascular (CV) events compared with non-diabetic patients, and CV mortality is responsible for around 80% mortality in this population. Patients with T2DM can have other features of insulin resistance-metabolic syndrome like hypertension, lipid abnormalities, and obesity which are all associated with increased CV disease and stroke risk even in the absence of T2DM. The management of a T2DM calls for employing a holistic risk factor control approach. Metformin is the first line therapy for T2DM and has been shown to have cardiovascular beneficial effects. Intense debate regarding the risk of myocardial infarction with rosiglitazone led to regulatory agencies necessitating cardiovascular outcome trials with upcoming anti-diabetic medications. Glucagon like peptide-1 agonists and sodium glucose co-transporter-2 inhibitors have shown promising CV safety and additional CV benefit in recent clinical trials. These drugs have favorable effects on traditional CV risk factors. The findings from these studies further support that fact that CV risk factor control plays an important role in reducing morbidity and mortality in T2DM patients. This review article will discuss briefly the cardiovascular safety and benefits of the oral medications which are currently being used for T2DM and will then discuss in detail about the newer medications being investigated for the treatment of T2DM.
8760-Based Method for Representing Variable Generation Capacity Value in Capacity Expansion Models
DOE Office of Scientific and Technical Information (OSTI.GOV)
Frew, Bethany A
Capacity expansion models (CEMs) are widely used to evaluate the least-cost portfolio of electricity generators, transmission, and storage needed to reliably serve load over many years or decades. CEMs can be computationally complex and are often forced to estimate key parameters using simplified methods to achieve acceptable solve times or for other reasons. In this paper, we discuss one of these parameters -- capacity value (CV). We first provide a high-level motivation for and overview of CV. We next describe existing modeling simplifications and an alternate approach for estimating CV that utilizes hourly '8760' data of load and VG resources.more » We then apply this 8760 method to an established CEM, the National Renewable Energy Laboratory's (NREL's) Regional Energy Deployment System (ReEDS) model (Eurek et al. 2016). While this alternative approach for CV is not itself novel, it contributes to the broader CEM community by (1) demonstrating how a simplified 8760 hourly method, which can be easily implemented in other power sector models when data is available, more accurately captures CV trends than a statistical method within the ReEDS CEM, and (2) providing a flexible modeling framework from which other 8760-based system elements (e.g., demand response, storage, and transmission) can be added to further capture important dynamic interactions, such as curtailment.« less
Scheepers, Daan; Röell, Charlotte; Ellemers, Naomi
2015-01-01
Possessing social power has psychological and biological benefits. For example, during task interactions, people high in power are more likely to display a benign cardiovascular (CV) response pattern indicative of "challenge" whereas people low in power are more likely to display a maladaptive CV pattern indicative of "threat" (Scheepers et al., 2012). Challenge is marked by high cardiac output (CO) and low total peripheral resistance (TPR), while threat is marked by low CO and high TPR (Blascovich and Mendes, 2010). In the current work we addressed a possible moderator of the power-threat/challenge relationship, namely the stability of power. We examined the influence of the stability of power (roles could or could not change) on CV responses during a dyadic task where one person was the "chief designer" (high power) and one person was the "assistant" (low power). During the task, different CV-measures were taken [CO, TPR, heart rate, pre-ejection period). Whereas participants in the unstable low power condition showed a stronger tendency toward challenge, participants in the unstable high power condition showed a stronger tendency toward threat. Moreover, participants in the stable low power condition showed CV signs of task disengagement. Results are discussed in terms of the importance of contextual variables in shaping the relationship between power and benign/maladaptive physiological responses.
Update of green tea interactions with cardiovascular drugs and putative mechanisms.
Werba, José Pablo; Misaka, Shingen; Giroli, Monica Gianna; Shimomura, Kenju; Amato, Manuela; Simonelli, Niccolò; Vigo, Lorenzo; Tremoli, Elena
2018-04-01
Many patients treated with cardiovascular (CV) drugs drink green tea (GT), either as a cultural tradition or persuaded of its putative beneficial effects for health. Yet, GT may affect the pharmacokinetics and pharmacodynamics of CV compounds. Novel GT-CV drug interactions were reported for rosuvastatin, sildenafil and tacrolimus. Putative mechanisms involve inhibitory effects of GT catechins at the intestinal level on influx transporters OATP1A2 or OATP2B1 for rosuvastatin, on CYP3A for sildenafil and on both CYP3A and the efflux transporter p-glycoprotein for tacrolimus. These interactions, which add to those previously described with simvastatin, nadolol and warfarin, might lead, in some cases, to reduced drug efficacy or risk of drug toxicity. Oddly, available data on GT interaction with CV compounds with a narrow therapeutic index, such as warfarin and tacrolimus, derive from single case reports. Conversely, GT interactions with simvastatin, rosuvastatin, nadolol and sildenafil were documented through pharmacokinetic studies. In these, the effect of GT or GT derivatives on drug exposure was mild to moderate, but a high inter-individual variability was observed. Further investigations, including studies on the effect of the dose and the time of GT intake are necessary to understand more in depth the clinical relevance of GT-CV drug interactions. Copyright © 2018. Published by Elsevier B.V.
Scheepers, Daan; Röell, Charlotte; Ellemers, Naomi
2015-01-01
Possessing social power has psychological and biological benefits. For example, during task interactions, people high in power are more likely to display a benign cardiovascular (CV) response pattern indicative of “challenge” whereas people low in power are more likely to display a maladaptive CV pattern indicative of “threat” (Scheepers et al., 2012). Challenge is marked by high cardiac output (CO) and low total peripheral resistance (TPR), while threat is marked by low CO and high TPR (Blascovich and Mendes, 2010). In the current work we addressed a possible moderator of the power-threat/challenge relationship, namely the stability of power. We examined the influence of the stability of power (roles could or could not change) on CV responses during a dyadic task where one person was the “chief designer” (high power) and one person was the “assistant” (low power). During the task, different CV-measures were taken [CO, TPR, heart rate, pre-ejection period). Whereas participants in the unstable low power condition showed a stronger tendency toward challenge, participants in the unstable high power condition showed a stronger tendency toward threat. Moreover, participants in the stable low power condition showed CV signs of task disengagement. Results are discussed in terms of the importance of contextual variables in shaping the relationship between power and benign/maladaptive physiological responses. PMID:26074860
Discovery of a New Classical Nova Shell Around a Nova-like Cataclysmic Variable
NASA Astrophysics Data System (ADS)
Guerrero, Martín A.; Sabin, Laurence; Tovmassian, Gagik; Santamaría, Edgar; Michel, Raul; Ramos-Larios, Gerardo; Alarie, Alexandre; Morisset, Christophe; Bermúdez Bustamante, Luis C.; González, Chantal P.; Wright, Nicholas J.
2018-04-01
The morphology and optical spectrum of IPHASX J210204.7+471015, a nebula classified as a possible planetary nebula are, however, strikingly similar to those of AT Cnc, a classical nova shell around a dwarf nova. To investigate its true nature, we have obtained high-resolution narrowband [O III] and [N II] images and deep optical spectra. The nebula shows an arc of [N II]-bright knots notably enriched in nitrogen, while an [O III]-bright bow shock is progressing throughout the ISM. Diagnostic line ratios indicate that shocks are associated with the arc and bow shock. The central star of this nebula has been identified by its photometric variability. Time-resolved photometric and spectroscopic data of this source reveal a period of 4.26 hr, which is attributed to a binary system. The optical spectrum is notably similar to that of RW Sex, a cataclysmic variable star (CV) of the UX UMa nova-like (NL) type. Based on these results, we propose that IPHASX J210204.7 + 471015 is a classical nova shell observed around a CV-NL system in quiescence.
Phenotypic Variations in the Foliar Chemical Profile of Persea americana Mill. cv. Hass.
García-Rodríguez, Yolanda Magdalena; Torres-Gurrola, Guadalupe; Meléndez-González, Claudio; Espinosa-García, Francisco J
2016-12-01
The Hass avocado tree Persea americana cv. Hass was derived from a single hybrid tree of P. americana var. drymifolia and P. americana var. guatemalensis, and it is propagated clonally by grafting. This cultivar is the most widely planted in the world but its profile of secondary metabolites has been studied rarely despite of its importance in plant protection. We illustrate the variability of the volatilome of mature leaves by describing the average chemical composition and the phenotypic variability found in 70 trees. Contrary to the uniformity expected in the Hass cultivar, high variability coefficients were found for most of the 36 detected foliar volatile compounds; furthermore we found six chemotypes grouping the foliar phenotypes of the sampled trees using hierarchical cluster analysis. About 48% of trees were grouped in one chemotype; five chemotypes grouped the remaining trees. The compounds that determined these chemotypes were: estragole, α-farnesene, β-caryophyllene, germacrene D, α-cubebene and eugenol. This striking variation in a cultivar propagated clonally is discussed in terms of somatic mutation. © 2016 Wiley-VHCA AG, Zurich, Switzerland.
Ricotta, C.; Reed, B.C.; Tieszen, L.T.
2003-01-01
Time integrated normalized difference vegetation index (??NDVI) derived from National Oceanic and Atmospheric Administration (NOAA) Advanced Very High Resolution Radiometer (AVHRR) multi-temporal imagery over a 10-year period (1989-1998) was used as a surrogate for primary production to investigate the impact of interannual climate variability on grassland performance for central and northern US Great Plains. First, the contribution of C3 and C4 species abundance to the major grassland ecosystems of the US Great Plains is described. Next, the relation between mean ??NDVI and the ??NDVI coefficient of variation (CV ??NDVI) used as a proxy for interranual climate variability is analysed. Results suggest that the differences in the long-term climate control over ecosystem performance approximately coincide with changes between C3- and C4-dominant grassland classes. Variation in remotely sensed net primary production over time is higher for the southern and western plains grasslands (primary C4 grasslands), whereas the C3-dominated classes in the northern and eastern portion of the US Great Plains, generally show lower CV ??NDVI values.
Subha, M; Pal, Pravati; Pal, G K; Habeebullah, S; Adithan, C; Sridhar, M G
Pregnancy-induced hypertension (PIH) has been reported as a cardiovascular (CV) risk. We assessed the sympathovagal imbalance (SVI) and the association of inflammation and oxidative stress (OS) with CV risks in PIH. A total of 125 pregnant women having a risk factor for PIH were followed till term and the incidence of PIH was observed. Retrospectively, they were divided into two groups: Group I (those who did not develop PIH, n = 82) and Group II (those who developed PIH, n = 43). Blood pressure variability (BPV) parameters including baroreflex sensitivity (BRS), spectral heart rate variability (HRV), autonomic function tests (AFTs), inflammatory markers (interleukin-6, TNF-α, interferon-γ), and OS markers were measured in both the groups. Alterations in parasympathetic and sympathetic components of AFTs were analyzed. Link of various parameters to BRS was assessed by correlation and multiple regression analysis. Parasympathetic components of AFTs were decreased from the early part of pregnancy and sympathetic components were increased toward the later part of pregnancy. Decreased BRS, the marker of CV risk, was more prominent in Group II subjects. Independent contribution of interleukin-6 (β = 0.276, P = 0.020), TNF-α (β = 0.408, P = 0.002), interferon-γ (β = 0.355, P = 0.008), and thiobarbituric-acid reactive substance (β = 0.287, P = 0.015) to BRS was found to be significant. It was concluded that sympathetic overactivity that develops more in the later part (third trimester) of pregnancy contributes to SVI and genesis of PIH. In PIH women, CV risks are present from the beginning of pregnancy that intensifies in the later part of pregnancy. Retrograde inflammation and oxidative stress contribute to the decreased BRS in PIH.
Maternal investment in reproduction and its consequences in leatherback turtles.
Wallace, Bryan P; Sotherland, Paul R; Tomillo, Pilar Santidrian; Reina, Richard D; Spotila, James R; Paladino, Frank V
2007-05-01
Maternal investment in reproduction by oviparous non-avian reptiles is usually limited to pre-ovipositional allocations to the number and size of eggs and clutches, thus making these species good subjects for testing hypotheses of reproductive optimality models. Because leatherback turtles (Dermochelys coriacea) stand out among oviparous amniotes by having the highest clutch frequency and producing the largest mass of eggs per reproductive season, we quantified maternal investment of 146 female leatherbacks over four nesting seasons (2001-2004) and found high inter- and intra-female variation in several reproductive characteristics. Estimated clutch frequency [coefficient of variation (CV) = 31%] and clutch size (CV = 26%) varied more among females than did egg mass (CV = 9%) and hatchling mass (CV = 7%). Moreover, clutch size had an approximately threefold higher effect on clutch mass than did egg mass. These results generally support predictions of reproductive optimality models in which species that lay several, large clutches per reproductive season should exhibit low variation in egg size and instead maximize egg number (clutch frequency and/or size). The number of hatchlings emerging per nest was positively correlated with clutch size, but fraction of eggs in a clutch yielding hatchlings (emergence success) was not correlated with clutch size and varied highly among females. In addition, seasonal fecundity and seasonal hatchling production increased with the frequency and the size of clutches (in order of effect size). Our results demonstrate that female leatherbacks exhibit high phenotypic variation in reproductive traits, possibly in response to environmental variability and/or resulting from genotypic variability within the population. Furthermore, high seasonal and lifetime fecundity of leatherbacks probably reflect compensation for high and unpredictable mortality during early life history stages in this species.
García-Ramos, Amador; Feriche, Belén; Pérez-Castilla, Alejandro; Padial, Paulino; Jaric, Slobodan
2017-07-01
This study aimed to explore the strength of the force-velocity (F-V) relationship of lower limb muscles and the reliability of its parameters (maximum force [F 0 ], slope [a], maximum velocity [V 0 ], and maximum power [P 0 ]). Twenty-three men were tested in two different jump types (squat and countermovement jump: SJ and CMJ), performed under two different loading conditions (free weight and Smith machine: Free and Smith) with 0, 17, 30, 45, 60, and 75 kg loads. The maximum and averaged values of F and V were obtained for the F-V relationship modelling. All F-V relationships were strong and linear independently whether observed from the averaged across the participants (r ≥ 0.98) or individual data (r = 0.94-0.98), while their parameters were generally highly reliable (F 0 [CV: 4.85%, ICC: 0.87], V 0 [CV: 6.10%, ICC: 0.82], a [CV: 10.5%, ICC: 0.81], and P 0 [CV: 3.5%, ICC: 0.93]). Both the strength of the F-V relationships and the reliability of their parameters were significantly higher for (1) the CMJ over the SJ, (2) the Free over the Smith loading type, and (3) the maximum over the averaged F and V variables. In conclusion, although the F-V relationships obtained from all the jumps tested were linear and generally highly reliable, the less appropriate choice for testing the F-V relationship could be through the averaged F and V data obtained from the SJ performed either in a Free weight or in a Smith machine. Insubstantial differences exist among the other combinations tested.
Blendea, Dan; Shah, Ravi V; Auricchio, Angelo; Nandigam, Veena; Orencole, Mary; Heist, E Kevin; Reddy, Vivek Y; McPherson, Craig A; Ruskin, Jeremy N; Singh, Jagmeet P
2007-09-01
Imaging the coronary venous (CV) tree to delineate the coronary sinus and its tributaries can facilitate electrophysiological procedures, such as cardiac resynchronization therapy (CRT) and catheter ablation. Venography also allows visualization of the left atrial (LA) veins, which may be a potential conduit for ablative or pacing strategies given their proximity to foci that can trigger atrial fibrillation. The aim of this study was to provide a detailed description of CV anatomy using rotational venography in patients undergoing CRT. Coronary sinus (CS) size and the presence, size, and angulation of its tributaries were determined from the analysis of rotational CV angiograms from 51 patients (age 68 +/- 11 years; n = 12 women) undergoing CRT. The CS, posterior veins, and lateral veins were identified in 100%, 76%, and 91% of patients. Lateral veins were less prevalent in patients with a history of lateral myocardial infarction than in patients without such a history (33% vs. 96%; P = .014). The diameters of the CS and its tributaries were fairly variable (7.3-18.9 mm for CS, 1.3-10.5 mm for CS tributaries). The CS was larger in men than in women and in cases of ischemic than in cases of nonischemic cardiomyopathy (all P <.05). The vein of Marshall, the most constant LA vein, was identified in 37 patients; its diameter is 1.7 +/- 0.5 mm, and its takeoff angle is 154 degrees +/- 15 degrees , making the vein potentially accessible for cannulation. Differences in CV anatomy that are related to either gender or coronary artery disease could have important practical implications during the left ventricular lead implantation. The anatomical features of the vein of Marshall make it a feasible potential conduit for epicardial LA pacing.
Kolls, Brad J; Lai, Amy H; Srinivas, Anang A; Reid, Robert R
2014-06-01
The purpose of this study was to determine the relative cost reductions within different staffing models for continuous video-electroencephalography (cvEEG) service by introducing a template system for 10/20 lead application. We compared six staffing models using decision tree modeling based on historical service line utilization data from the cvEEG service at our center. Templates were integrated into technologist-based service lines in six different ways. The six models studied were templates for all studies, templates for intensive care unit (ICU) studies, templates for on-call studies, templates for studies of ≤ 24-hour duration, technologists for on-call studies, and technologists for all studies. Cost was linearly related to the study volume for all models with the "templates for all" model incurring the lowest cost. The "technologists for all" model carried the greatest cost. Direct cost comparison shows that any introduction of templates results in cost savings, with the templates being used for patients located in the ICU being the second most cost efficient and the most practical of the combined models to implement. Cost difference between the highest and lowest cost models under the base case produced an annual estimated savings of $267,574. Implementation of the ICU template model at our institution under base case conditions would result in a $205,230 savings over our current "technologist for all" model. Any implementation of templates into a technologist-based cvEEG service line results in cost savings, with the most significant annual savings coming from using the templates for all studies, but the most practical implementation approach with the second highest cost reduction being the template used in the ICU. The lowered costs determined in this work suggest that a template-based cvEEG service could be supported at smaller centers with significantly reduced costs and could allow for broader use of cvEEG patient monitoring.
Monogamy relation in multipartite continuous-variable quantum teleportation
NASA Astrophysics Data System (ADS)
Lee, Jaehak; Ji, Se-Wan; Park, Jiyong; Nha, Hyunchul
2016-12-01
Quantum teleportation (QT) is a fundamentally remarkable communication protocol that also finds many important applications for quantum informatics. Given a quantum entangled resource, it is crucial to know to what extent one can accomplish the QT. This is usually assessed in terms of output fidelity, which can also be regarded as an operational measure of entanglement. In the case of multipartite communication when each communicator possesses a part of an N -partite entangled state, not all pairs of communicators can achieve a high fidelity due to the monogamy property of quantum entanglement. We here investigate how such a monogamy relation arises in multipartite continuous-variable (CV) teleportation, particularly when using a Gaussian entangled state. We show a strict monogamy relation, i.e., a sender cannot achieve a fidelity higher than optimal cloning limit with more than one receiver. While this seems rather natural owing to the no-cloning theorem, a strict monogamy relation still holds even if the sender is allowed to individually manipulate the reduced state in collaboration with each receiver to improve fidelity. The local operations are further extended to non-Gaussian operations such as photon subtraction and addition, and we demonstrate that the Gaussian cloning bound cannot be beaten by more than one pair of communicators. Furthermore, we investigate a quantitative form of monogamy relation in terms of teleportation capability, for which we show that a faithful monogamy inequality does not exist.
MacDonald, Thomas M.; Hawkey, Chris J.; Ford, Ian; McMurray, John J.V.; Scheiman, James M.; Hallas, Jesper; Findlay, Evelyn; Grobbee, Diederick E.; Hobbs, F.D. Richard; Ralston, Stuart H.; Reid, David M.; Walters, Matthew R.; Webster, John; Ruschitzka, Frank; Ritchie, Lewis D.; Perez-Gutthann, Susana; Connolly, Eugene; Greenlaw, Nicola; Wilson, Adam; Wei, Li; Mackenzie, Isla S.
2017-01-01
Background Selective cyclooxygenase-2 inhibitors and conventional non-selective non-steroidal anti-inflammatory drugs (nsNSAIDs) have been associated with adverse cardiovascular (CV) effects. We compared the CV safety of switching to celecoxib vs. continuing nsNSAID therapy in a European setting. Method Patients aged 60 years and over with osteoarthritis or rheumatoid arthritis, free from established CV disease and taking chronic prescribed nsNSAIDs, were randomized to switch to celecoxib or to continue their previous nsNSAID. The primary endpoint was hospitalization for non-fatal myocardial infarction or other biomarker positive acute coronary syndrome, non-fatal stroke or CV death analysed using a Cox model with a pre-specified non-inferiority limit of 1.4 for the hazard ratio (HR). Results In total, 7297 participants were randomized. During a median 3-year follow-up, fewer subjects than expected developed an on-treatment (OT) primary CV event and the rate was similar for celecoxib, 0.95 per 100 patient-years, and nsNSAIDs, 0.86 per 100 patient-years (HR = 1.12, 95% confidence interval, 0.81–1.55; P = 0.50). Comparable intention-to-treat (ITT) rates were 1.14 per 100 patient-years with celecoxib and 1.10 per 100 patient-years with nsNSAIDs (HR = 1.04; 95% confidence interval, 0.81–1.33; P = 0.75). Pre-specified non-inferiority was achieved in the ITT analysis. The upper bound of the 95% confidence limit for the absolute increase in OT risk associated with celecoxib treatment was two primary events per 1000 patient-years exposure. There were only 15 adjudicated secondary upper gastrointestinal complication endpoints (0.078/100 patient-years on celecoxib vs. 0.053 on nsNSAIDs OT, 0.078 vs. 0.053 ITT). More gastrointestinal serious adverse reactions and haematological adverse reactions were reported on nsNSAIDs than celecoxib, but more patients withdrew from celecoxib than nsNSAIDs (50.9% patients vs. 30.2%; P < 0.0001). Interpretation In subjects 60 years and over, free from CV disease and taking prescribed chronic nsNSAIDs, CV events were infrequent and similar on celecoxib and nsNSAIDs. There was no advantage of a strategy of switching prescribed nsNSAIDs to prescribed celecoxib. This study excluded an increased risk of the primary endpoint of more than two events per 1000 patient-years associated with switching to prescribed celecoxib. Clinical Trial Registration https://clinicaltrials.gov/show/NCT00447759; Unique identifier: NCT00447759. PMID:27705888
The light curve of CV Serpentis, the sometimes-eclipsing Wolf-Rayet star
NASA Technical Reports Server (NTRS)
Schild, R.; Liller, W.
1975-01-01
New photoelectric observations of the B-magnitude of CV Ser made in 1973 and 1974 show no clear evidence of an eclipse, but they establish night-to-night variability of several percent, a systematic brightness change of 0.035 mag during a portion of the single orbit observed in 1973, and irregular flaring in 1974. We made iris photometer measurements of Harvard patrol plates taken between 1905 June and 1953 July, and find no evidence of a very deep eclipse such as observed by Hjellming and Hiltner. We present several new light curves and discuss then in the light of the recent results of Cowley et al.
Colonic volvulus in the United States: trends, outcomes, and predictors of mortality.
Halabi, Wissam J; Jafari, Mehraneh D; Kang, Celeste Y; Nguyen, Vinh Q; Carmichael, Joseph C; Mills, Steven; Pigazzi, Alessio; Stamos, Michael J
2014-02-01
Colonic volvulus is a rare entity associated with high mortality rates. Most studies come from areas of high endemicity and are limited by small numbers. No studies have investigated trends, outcomes, and predictors of mortality at the national level. The Nationwide Inpatient Sample 2002-2010 was retrospectively reviewed for colonic volvulus cases admitted emergently. Patients' demographics, hospital factors, and outcomes of the different procedures were analyzed. The LASSO algorithm for logistic regression was used to build a predictive model for mortality in cases of sigmoid (SV) and cecal volvulus (CV) taking into account preoperative and operative variables. An estimated 3,351,152 cases of bowel obstruction were admitted in the United States over the study period. Colonic volvulus was found to be the cause in 63,749 cases (1.90%). The incidence of CV increased by 5.53% per year whereas the incidence of SV remained stable. SV was more common in elderly males (aged 70 years), African Americans, and patients with diabetes and neuropsychiatric disorders. In contrast, CV was more common in younger females. Nonsurgical decompression alone was used in 17% of cases. Among cases managed surgically, resective procedures were performed in 89% of cases, whereas operative detorsion with or without fixation procedures remained uncommon. Mortality rates were 9.44% for SV, 6.64% for CV, 17% for synchronous CV and SV, and 18% for transverse colon volvulus. The LASSO algorithm identified bowel gangrene and peritonitis, coagulopathy, age, the use of stoma, and chronic kidney disease as strong predictors of mortality. Colonic volvulus is a rare cause of bowel obstruction in the United States and is associated with high mortality rates. CV and SV affect different populations and the incidence of CV is on the rise. The presence of bowel gangrene and coagulopathy strongly predicts mortality, suggesting that prompt diagnosis and management are essential.
Kim, Youngju; Choi, Yoon-Jung; Oh, Seung-Won; Joh, Hee-Kyung; Kwon, Hyuktae; Um, Yoo-Jin; Ahn, Sang Hyun; Kim, Hyun Joo; Lee, Cheol Min
2016-05-01
Enquiry into smoking status and recommendations for smoking cessation is an essential preventive service. However, there are few studies comparing self-reported (SR) and cotinine-verified (CV) smoking statuses, using medical check-up data. The rates of discrepancy and under-reporting are unknown. We performed a cross-sectional study using health examination data from Healthcare System Gangnam Center, Seoul National University Hospital in 2013. We analyzed SR and CV smoking statuses and discrepancies between the two in relation to sociodemographic variables. We also attempted to ascertain the factors associated with a discrepant smoking status among current smokers. In the sample of 3,477 men, CV smoking rate was 11.1% higher than the SR rate. About 1 in 3 participants either omitted the smoking questionnaire or gave a false reply. The ratio of CV to SR smoking rates was 1.49 (95% confidence interval [CI], 1.38-1.61). After adjusting for confounding factors, older adults (≥60 years) showed an increased adjusted odds ratio (aOR) for discrepancy between SR and CV when compared to those in their twenties and thirties (aOR, 5.43; 95% CI, 2.69-10.96). Educational levels of high school graduation or lower (aOR, 2.33; 95% CI, 1.36-4.01), repeated health check-ups (aOR, 1.45; 95% CI, 1.03-2.06), and low cotinine levels of <500 ng/mL (aOR, 2.03; 95% CI, 1.33-3.09), were also associated with discordance between SR and CV smoking status. Omissions and false responses impede the accurate assessment of smoking status in health check-up participants. In order to improve accuracy, it is suggested that researcher pay attention to participants with greater discrepancy between SR and CV smoking status, and formulate interventions to improve response rates.
Polymorphisms in TRPV1 and TAS2Rs associate with sensations from sampled ethanol.
Allen, Alissa L; McGeary, John E; Hayes, John E
2014-10-01
Genetic variation in chemosensory genes can explain variability in individual's perception of and preference for many foods and beverages. To gain insight into variable preference and intake of alcoholic beverages, we explored individual variability in the responses to sampled ethanol (EtOH). In humans, EtOH elicits sweet, bitter, and burning sensations. Here, we explore the relationship between variation in EtOH sensations and polymorphisms in genes encoding bitter taste receptors (TAS2Rs) and a polymodal nociceptor (TRPV1). Caucasian participants (n = 93) were genotyped for 16 single nucleotide polymorphisms (SNPs) in TRPV1, 3 SNPs in TAS2R38, and 1 SNP in TAS2R13. Participants rated sampled EtOH on a generalized Labeled Magnitude Scale. Two stimuli were presented: a 16% EtOH whole-mouth sip-and-spit solution with a single time-point rating of overall intensity and a cotton swab saturated with 50% EtOH on the circumvallate papillae (CV) with ratings of multiple qualities over 3 minutes. Area-under-the-curve (AUC) was calculated for the time-intensity data. The EtOH whole-mouth solution had overall intensity ratings near "very strong." Burning/stinging had the highest mean AUC values, followed by bitterness and sweetness. Whole-mouth intensity ratings were significantly associated with burning/stinging and bitterness AUC values on the CV. Three TRPV1 SNPs (rs224547, rs4780521, rs161364) were associated with EtOH sensations on the CV, with 2 (rs224547 and rs4780521) exhibiting strong linkage disequilibrium. Additionally, the TAS2R38 SNPs rs713598, rs1726866, and rs10246939 formed a haplotype, and were associated with bitterness on the CV. Last, overall intensity for whole-mouth EtOH associated with the TAS2R13 SNP rs1015443. These data suggest genetic variation in TRPV1 and TAS2Rs influence sensations from sampled EtOH and may potentially influence how individuals initially respond to alcoholic beverages. Copyright © 2014 by the Research Society on Alcoholism.
Hansen, Michael J.; Schorfhaar, Richard G.; Peck, James W.; Selgeby, James H.; Taylor, William W.
1995-01-01
Self-sustaining populations of lake trout Salvelinus namaycush have returned to most areas in Lake Superior, but progress toward achieving historic commercial yields has been difficult to measure because of unrecorded losses to predation by sea lamprey Petromyzon marinus and to fisheries. Consequently, we developed restoration targets (catch per effort, CPE; geometric mean number per kilometer of 114-mm stretch-meaure gill net during 1929-1943, when historic yields were sustained) from linear relationships between CPE in commercial and assessment fisheries in Michigan. Target CPEs for lake trout restoration were higher and less variable than the modern CPEs in all areas. Modern CPEs generally increased during the 1970s and early 1980s but declined during the late 1980s and early 1990s. Modern CPEs were highest in western Michigan from the Keweenaw Peninsula to Marquette (71 to 81% of target CPEs), but coefficients of variation (CV,SD/mean) of mean CPEs were 1.4 to 2.4 times greater than target CVs. Around Munising, the modern CPE was lower (41% of the target CPE), whereas the CV was 1.9 times greater than the target CV. Around Grand Marais, the modern CPE was lowest among all areas (17% of the target CPE), but the CV was nearly the same (1.1 times the target CV). In Whitefish Bay, the modern CPE was only 28% of the target CPE and the CV was 9.0 times greater, though the modern period was based on only the years 1979-1982 and 1984-1985. Further progress in restoration in most areas can be achieved only if fishery managers adequately protect existing stocks of wild fish from sea lamprey predation and fishery exploitation.
Thiyagarajan, Ramkumar; Pal, Pravati; Pal, Gopal Krushna; Subramanian, Senthil Kumar; Bobby, Zachariah; Das, Ashok Kumar; Trakroo, Madanmohan
2013-07-01
Hypertension, one of the modifiable risk factors for cardiovascular disease (CVD), is known to be associated with increased oxidative stress and reduced cardiovagal modulation. Similar to hypertension, prehypertension is associated with increased risk of adverse cardiovascular (CV) events. We planned this study to find the association between prehypertension, cardiovagal modulation, oxidative stress, and associated CV risk factors. We recruited 178 subjects through hypertension screening camps conducted in Puducherry, India. Subjects were grouped into prehypertensive (n = 97) and normotensive (n = 81) groups. They were further subdivided, based on age, as young (20-39 years) and middle-aged (40-60 years) adults. We measured basal physiological parameters, heart rate variability, oxidative stress (thiobarbituric acid reactive substance and total antioxidant capacity (TAC)), and CV risk factors. We found significant increase in oxidative stress in prehypertensive subjects of both age groups but the cardiovagal modulation decreased significantly in young prehypertensive subjects when compared with normotensive subjects. Correlation of TAC with root mean square of the sum of successive R wave to R wave (RR) interval differences (RMSSD), a cardiovagal modulation parameter (r = 0. 437; P < 0.001), and mean arterial pressure (MAP) (r = -0.318; P < 0.001) was significant even after adjusting for CV risk factors. The correlation between MAP and RMSSD (r = 0.199; P = 0.009) was reduced after adjusting for CV risk factors. Prehypertension in young adults is associated with increased oxidative stress and altered cardiovagal modulation. The risk factors for CVDs in prehypertensive young adults were found to be equivalent to that of middle-aged adults who are in the twilight zone for developing CV dysfunctions.
Progressive disease in glioblastoma: Benefits and limitations of semi-automated volumetry
Alber, Georgina; Bette, Stefanie; Kaesmacher, Johannes; Boeckh-Behrens, Tobias; Gempt, Jens; Ringel, Florian; Specht, Hanno M.; Meyer, Bernhard; Zimmer, Claus
2017-01-01
Purpose Unambiguous evaluation of glioblastoma (GB) progression is crucial, both for clinical trials as well as day by day routine management of GB patients. 3D-volumetry in the follow-up of GB provides quantitative data on tumor extent and growth, and therefore has the potential to facilitate objective disease assessment. The present study investigated the utility of absolute changes in volume (delta) or regional, segmentation-based subtractions for detecting disease progression in longitudinal MRI follow-ups. Methods 165 high resolution 3-Tesla MRIs of 30 GB patients (23m, mean age 60.2y) were retrospectively included in this single center study. Contrast enhancement (CV) and tumor-related signal alterations in FLAIR images (FV) were semi-automatically segmented. Delta volume (dCV, dFV) and regional subtractions (sCV, sFV) were calculated. Disease progression was classified for every follow-up according to histopathologic results, decisions of the local multidisciplinary CNS tumor board and a consensus rating of the neuro-radiologic report. Results A generalized logistic mixed model for disease progression (yes / no) with dCV, dFV, sCV and sFV as input variables revealed that only dCV was significantly associated with prediction of disease progression (P = .005). Delta volume had a better accuracy than regional, segmentation-based subtractions (79% versus 72%) and a higher area under the curve by trend in ROC curves (.83 versus .75). Conclusion Absolute volume changes of the contrast enhancing tumor part were the most accurate volumetric determinant to detect progressive disease in assessment of GB and outweighed FLAIR changes as well as regional, segmentation-based image subtractions. This parameter might be useful in upcoming objective response criteria for glioblastoma. PMID:28245291
Bhatia, Smita; Landier, Wendy; Hageman, Lindsey; Chen, Yanjun; Kim, Heeyoung; Sun, Can-Lan; Kornegay, Nancy; Evans, William E; Angiolillo, Anne L; Bostrom, Bruce; Casillas, Jacqueline; Lew, Glen; Maloney, Kelly W; Mascarenhas, Leo; Ritchey, A Kim; Termuhlen, Amanda M; Carroll, William L; Wong, F Lennie; Relling, Mary V
2015-06-01
Variability in prescribed doses of 6-mercaptopurine (6MP) and lack of adherence to a 6MP treatment regimen could result in intra-individual variability in systemic exposure to 6MP (measured as erythrocyte thioguanine nucleotide [TGN] levels) in children with acute lymphoblastic leukemia (ALL). The effect on relapse risk of this variability is unknown. To determine the effect of high intra-individual variability of 6MP systemic exposure on relapse risk in children with ALL. We used a prospective longitudinal design (Children's Oncology Group study [COG-AALL03N1]) to monitor 6MP and disease relapse in 742 children with ALL in ambulatory care settings of 94 participating institutions from May 30, 2005, to September 9, 2011. All participants met the following eligibility criteria: (1) diagnosis of ALL at 21 years or younger; (2) first continuous remission in progress at the time of study entry; (3) receiving self-, parent-, or caregiver-administered oral 6MP during maintenance therapy; and (4) completion of at least 6 months of maintenance therapy at the time of study enrollment. The median patient age at diagnosis was 5 years; 68% were boys; and 43% had National Cancer Institute-based high-risk disease. Daily 6MP regimen adherence was measured over 68 716 person-days using an electronic system that recorded the date and time of each 6MP bottle opening; adherence rate was defined as the ratio of days that a 6MP bottle was opened to days thata 6MP bottle was prescribed. Average monthly 6MP dose intensity was measured over 120 439 person-days by dividing the number of 6MP doses actually prescribed by the number of planned protocol doses (75 mg/m2/d). Monthly erythrocyte TGN levels (pmol/8 × 108 erythrocytes) were measured over 6 consecutive months per patient (n = 3944 measurements). Using intra-individual coefficients of variation (CV%), patients were classified as having stable (CV% <85th percentile) vs varying (CV% ≥85th percentile) indices. Median follow-up time was 6.7 years from the time of diagnosis. Adjusting for clinical prognosticators, we found that patients with 6MP nonadherence (mean adherence rate <95%) were at a 2.7-fold increased risk of relapse (95% CI, 1.3-5.6; P = .01) compared with patients with a mean adherence rate of 95% or greater. Among adherers, high intra-individual variability in TGN levels contributed to increased relapse risk (hazard ratio, 4.4; 95% CI, 1.2-15.7; P = .02). Furthermore, adherers with varying TGN levels had varying 6MP dose intensity (odds ratio [OR], 4.5; 95% CI, 1.5-13.4; P = .01) and 6MP drug interruptions (OR, 10.2; 95% CI, 2.2-48.3; P = .003). These findings emphasize the need to maximize 6MP regimen adherence and maintain steady thiopurine exposure to minimize relapse in children with ALL.
Skoglund, Per H; Arpegård, Johannes; Ostergren, Jan; Svensson, Per
2014-03-01
Patients with peripheral arterial disease (PAD) are at high risk for cardiovascular (CV) events. We have previously shown that ambulatory pulse pressure (APP) predicts CV events in PAD patients. The biomarkers amino-terminal pro-B-type natriuretic peptide (NT-proBNP), high-sensitivity C-reactive protein (hs-CRP), and cystatin C are related to a worse outcome in patients with CV disease, but their predictive values have not been studied in relation to APP. Blood samples and 24-hour measurements of ambulatory blood pressure were examined in 98 men referred for PAD evaluation during 1998-2001. Patients were followed for a median of 71 months. The outcome variable was CV events defined as either CV mortality or any hospitalization for myocardial infarction, stroke, or coronary revascularization. The predictive values of log(NT-proBNP), log(hs-CRP), and log(cystatin C) alone and together with APP were assessed by multivariable Cox regression. Area under the curve (AUC) and net reclassification improvement (NRI) were calculated compared with a model containing other significant risk factors. During follow-up, 36 patients had at least 1 CV event. APP, log(NT-proBNP), and log(hs-CRP) all predicted CV events in univariable analysis, whereas log(cystatin C) did not. In multivariable analysis log(NT-proBNP) (hazard ratio (HR) = 1.62; 95% confidence interval (CI) = 1.05-2.51) and log(hs-CRP) (HR = 1.63; 95% CI = 1.19-2.24) predicted events independently of 24-hour PP. The combination of log(NT-proBNP), log(hs-CRP), and average day PP improved risk discrimination (AUC = 0.833 vs. 0.736; P < 0.05) and NRI (37%; P < 0.01) when added to other significant risk factors. NT-proBNP and hs-CRP predict CV events independently of APP and the combination of hs-CRP, NT-proBNP, and day PP improves risk discrimination in PAD patients.
Neuropeptide Y - an early biomarker for cerebral vasospasm after aneurysmal subarachnoid hemorrhage.
Schebesch, Karl-Michael; Brawanski, Alexander; Bele, Sylvia; Schödel, Petra; Herbst, Andreas; Bründl, Elisabeth; Kagerbauer, Simone Maria; Martin, Jan; Lohmeier, Anette; Stoerr, Eva-Maria; Proescholdt, Martin
2013-12-01
In the human brain, the potent vasoconstrictive neuropeptide Y (NPY) is abundantly expressed. Neuropeptide Y, which is stored in perivascular nerve fibers of the cerebral arteries, regulates the cerebral vascular diameter as well as cerebral blood flow. However, the role of NPY in the pathogenesis of cerebral vasospasm (CV) related to subarachnoid hemorrhage (SAH) is unclear. We prospectively analyzed and compared the release of endogenous NPY in the cerebrospinal fluid (CSF) of 66 patients with SAH to NPY release in a control group. Additionally, we correlated the levels of NPY with CV and consecutive ischemic stroke. Sixty-six consecutive patients (40 women, 26 men; mean age 53·1 years) with aneurysmal SAH were included. In the SAH group, CSF was drawn daily from day 1 to day 10 after the onset of SAH. The CSF of 29 patients undergoing spinal anesthesia for orthopedic surgery served as control samples. The NPY levels were determined in duplicate CSF samples by means of a competitive enzyme immunoassay (EIA). The levels of NPY in CSF were correlated with the development of CV over the 10-day period after the onset of SAH and to the occurrence of consecutive ischemic stroke. To evaluate CSF NPY levels as a predictive biomarker for vasospasm, we calculated the sensitivity and specificity as well as the positive and negative predictive values. The NPY levels were significantly higher in the SAH group than in the control group (p < 0·001). The treatment modality (clip versus coil) did not influence the level of NPY in CSF (p > 0·05). Patients with CV showed significantly higher NPY levels than patients without CV during the entire observation period. The NPY levels of the non-CV group dissipated over time, whereas the CV group showed continuously increasing values. The NPY levels from day 4 to 10 were significantly higher in patients with CV-related stroke than in non-stroke patients. Using 0·3 ng/ml as a cut-off value, NPY levels on day 3 predicted the occurrence of CV with a sensitivity and specificity of 82% and 72%, respectively. High NPY levels, starting on day 4, significantly correlated with poor Glasgow Outcome Score grading at the follow-up (p < 0·05). Our data indicate that NPY is involved in the pathogenesis of SAH-related CV and ischemia. Neuropeptide Y represents an early and reliable biomarker for the prediction of CV and consecutive stroke due to aneurysmal SAH.
NASA Astrophysics Data System (ADS)
Li, Yuhan; Ho, Wingkei; Lv, Kangle; Zhu, Bicheng; Lee, Shun Cheng
2018-02-01
g-C3N4 (gCN) with carbon vacancy has been extensively investigated and applied in (photo)catalysis. Engineering the carbon vacancy in gCN is of great importance, but it remains a challenging task. In this work, we report for the first time the fabrication of gCN with carbon vacancy (Cv-gCN) via thermal treatment of pristine gCN in CO2 atmosphere. The photocatalytic performance of Cv-gCN is evaluated on the basis of NO oxidization under visible light irradiation (λ > 400 nm) in a continual reactor. The successful formation of carbon vacancy in gCN is confirmed through electron paramagnetic resonance (EPR) and X-ray photoelectron spectroscopy (XPS). The photocatalytic oxidation removal rate of NO over Cv-gCN is 59.0%, which is two times higher than that over pristine gCN (24.2%). The results of the quenching experiment show that superoxide radicals (O2rad -) act as the main reactive oxygen species, which is responsible for the oxidation of NO. The enlarged BET surface areas and negatively shifted conduction band (CB) potential enhance the photocatalytic activity of Cv-gCN, which facilitates the efficient electron transfer from the CB of Cv-gCN to the surface adsorbed oxygen, resulting in the formation of O2rad - that can oxidize NO.
Global burden of CVD: focus on secondary prevention of cardiovascular disease.
Bansilal, Sameer; Castellano, José M; Fuster, Valentín
2015-12-01
Despite encouraging advances in prevention and treatment of atherothrombosis, cardiovascular disease (CVD) remains a major cause of deaths and disability worldwide and will continue to grow mainly due to the increase in incidence in low and middle income countries (LMIC). In Europe and the United States of America (USA), coronary heart disease (CHD) mortality rates have decreased since the mid-1990s due to improvements in acute care, however the prevalence of CHD is increasing largely in part due to the overall aging of the population, increased prevalence of cardiovascular (CV) risk factors, and improved survival of patients after a CV event. Data from clinical trials has consistently proven the efficacy of pharmacologic interventions with aspirin, statins, and blood pressure (BP)-lowering agents in reducing the risk of CV events and total mortality in the ever growing pool of patients in secondary prevention. However, large gaps between indicated therapy and prescribed medication can be observed worldwide, with very low rates of use of effective therapies in LMIC countries. Adherence to medication is very poor in chronic patients, especially those treated with multiple pharmacologic agents, and has been directly correlated to a greater incidence of recurrent CV events and increase in direct and indirect healthcare costs. In this article, we review the global burden of CV disease, status of secondary prevention therapy and major barriers for treatment adherence. Copyright © 2015 Elsevier B.V. All rights reserved.
Design and Construction of an Urban Runoff Research Facility
Wherley, Benjamin G.; White, Richard H.; McInnes, Kevin J.; Fontanier, Charles H.; Thomas, James C.; Aitkenhead-Peterson, Jacqueline A.; Kelly, Steven T.
2014-01-01
As the urban population increases, so does the area of irrigated urban landscape. Summer water use in urban areas can be 2-3x winter base line water use due to increased demand for landscape irrigation. Improper irrigation practices and large rainfall events can result in runoff from urban landscapes which has potential to carry nutrients and sediments into local streams and lakes where they may contribute to eutrophication. A 1,000 m2 facility was constructed which consists of 24 individual 33.6 m2 field plots, each equipped for measuring total runoff volumes with time and collection of runoff subsamples at selected intervals for quantification of chemical constituents in the runoff water from simulated urban landscapes. Runoff volumes from the first and second trials had coefficient of variability (CV) values of 38.2 and 28.7%, respectively. CV values for runoff pH, EC, and Na concentration for both trials were all under 10%. Concentrations of DOC, TDN, DON, PO4-P, K+, Mg2+, and Ca2+ had CV values less than 50% in both trials. Overall, the results of testing performed after sod installation at the facility indicated good uniformity between plots for runoff volumes and chemical constituents. The large plot size is sufficient to include much of the natural variability and therefore provides better simulation of urban landscape ecosystems. PMID:25146420
Variability of Jump Kinetics Related to Training Load in Elite Female Basketball.
Legg, Jan; Pyne, David B; Semple, Stuart; Ball, Nick
2017-11-04
The purpose of this study was to quantify changes in jump performance and variability in elite female basketballers. Junior and senior female representative basketball players ( n = 10) aged 18 ± 2 years participated in this study. Countermovement jump (CMJ) data was collected with a Gymaware™ optical encoder at pre-, mid-, and post-season time points across 10 weeks. Jump performance was maintained across the course of the full season (from pre to post). Concentric peak velocity, jump height, and dip showed the most stability from pre- to post-season, with the %CV ranging from 5.6⁻8.9%. In the period of the highest training load (mid-season), the variability of within-subject performance was reduced by approximately 2⁻4% in all measures except for jump height. Altered jump mechanics through a small (0.26 effect size) increase in dip were evident at mid-season, suggesting that CMJ analysis is useful for coaches to use as an in-season monitoring tool. The highest coefficient of variation (8⁻22%CV) in inter-set scores in all measures except eccentric peak velocity also occurred mid-season. It appears that in-season load not only impairs jump performance, but also movement variability in basketball players.
NASA Astrophysics Data System (ADS)
Zhang, Lulu; Liu, Jingling; Li, Yi
2015-03-01
The influence of spatial differences, which are caused by different anthropogenic disturbances, and temporal changes, which are caused by natural conditions, on macroinvertebrates with periphyton communities in Baiyangdian Lake was compared. Periphyton and macrobenthos assemblage samples were simultaneously collected on four occasions during 2009 and 2010. Based on the physical and chemical attributes in the water and sediment, the 8 sampling sites can be divided into 5 habitat types by using cluster analysis. According to coefficients variation analysis (CV), three primary conclusions can be drawn: (1) the metrics of Hilsenhoff Biotic Index (HBI), Percent Tolerant Taxa (PTT), Percent dominant taxon (PDT), and community loss index (CLI), based on macroinvertebrates, and the metrics of algal density (AD), the proportion of chlorophyta (CHL), and the proportion of cyanophyta (CYA), based on periphytons, were mostly constant throughout our study; (2) in terms of spatial variation, the CV values in the macroinvertebratebased metrics were lower than the CV values in the periphyton-based metrics, and these findings may be caused by the effects of changes in environmental factors; whereas, the CV values in the macroinvertebrate-based metrics were higher than those in the periphyton-based metrics, and these results may be linked to the influences of phenology and life history patterns of the macroinvertebrate individuals; and (3) the CV values for the functionalbased metrics were higher than those for the structuralbased metrics. Therefore, spatial and temporal variation for metrics should be considered when assessing applying the biometrics.
Concentration fluctuations and dilution in aquifers
NASA Astrophysics Data System (ADS)
Kapoor, Vivek; Kitanidis, Peter K.
1998-05-01
The concentration of solute undergoing advection and local dispersion in a random hydraulic conductivity field is analyzed to quantify its variability and dilution. Detailed numerical evaluations of the concentration variance σc2 are compared to an approximate analytical description, which is based on a characteristic variance residence time (VRT), over which local dispersion destroys concentration fluctuations, and effective dispersion coefficients that quantify solute spreading rates. Key features of the analytical description for a finite size impulse input of solute are (1) initially, the concentration fields become more irregular with time, i.e., coefficient of variation, CV=σc/
Batterham, Philip J; Bunce, David; Mackinnon, Andrew J; Christensen, Helen
2014-01-01
very few studies have examined the association between intra-individual reaction time variability and subsequent mortality. Furthermore, the ability of simple measures of variability to predict mortality has not been compared with more complex measures. a prospective cohort study of 896 community-based Australian adults aged 70+ were interviewed up to four times from 1990 to 2002, with vital status assessed until June 2007. From this cohort, 770-790 participants were included in Cox proportional hazards regression models of survival. Vital status and time in study were used to conduct survival analyses. The mean reaction time and three measures of intra-individual reaction time variability were calculated separately across 20 trials of simple and choice reaction time tasks. Models were adjusted for a range of demographic, physical health and mental health measures. greater intra-individual simple reaction time variability, as assessed by the raw standard deviation (raw SD), coefficient of variation (CV) or the intra-individual standard deviation (ISD), was strongly associated with an increased hazard of all-cause mortality in adjusted Cox regression models. The mean reaction time had no significant association with mortality. intra-individual variability in simple reaction time appears to have a robust association with mortality over 17 years. Health professionals such as neuropsychologists may benefit in their detection of neuropathology by supplementing neuropsychiatric testing with the straightforward process of testing simple reaction time and calculating raw SD or CV.
Ramos, M C; Jones, G V; Yuste, J
2015-12-01
The aim of this work was to analyze spatial phenology and grape quality variability related to the climatic characteristics within the Ribera del Duero Designation of Origin (DO). Twenty plots planted with cv. Tempranillo and distributed within the DO were analyzed for phenology from 2004 to 2013. Grape quality parameters at ripening (berry weight, sugar content, acidity and pH, and anthocyanins) were analyzed in 26 plots for the period 2003-2013. The relationships between phenology and grape parameters with different climatic variables were confirmed with a multivariate analysis. On average, bud break was April 27(th), bloom June 17(th), and veraison August 12th. However, phenology during the time period showed high variability, with differences between years of up to 21 days for a phenology stage. The earliest dates were observed in dry years (2005, 2006, and to a lesser degree in 2009) while the later phenology dates occurred in the wettest year of the period (2008). High correlations were found between veraison date and temperature variables as well as with precipitation-evapotranspiration recorded during the bloom-veraison period. These effects tended to be higher in the central part of the DO. Grape quality parameters also showed high variability among the dry and the wet years, and the influence of extreme temperatures on color development as well as the effect of available water on acidity were observed.
Ushigome, Emi; Matsumoto, Shinobu; Oyabu, Chikako; Kitagawa, Noriyuki; Tanaka, Toru; Hasegawa, Goji; Ohnishi, Masayoshi; Tsunoda, Sei; Ushigome, Hidetaka; Yokota, Isao; Nakamura, Naoto; Oda, Yohei; Asano, Mai; Tanaka, Muhei; Yamazaki, Masahiro; Fukui, Michiaki
2018-05-01
Previously, we have shown in cross-sectional analysis of patients with type 2 diabetes mellitus that the presence of diabetic nephropathy is associated with increased home blood pressure (HBP) variability. We now examine the prognostic significance of HBP variability in substantially the same cohort. We performed a prospective cohort study of type 2 diabetes patients. We analyzed 714 patients. Major exclusion criteria are missing data of urinary albumin excretion and newly prescribed or stopped renin-angiotensin system inhibitors during 2-year follow-up. Patients were instructed to perform triplicate morning and evening HBP measurements for 14 consecutive days. We computed day-by-day HBP variability as within-patient standard deviation (SD) and coefficient of variation (CV) of measurements. During the follow-up period of 2 years, 23 patients progressed to macroalbuminuria. The changing risk of progression to macroalbuminuria with increasing day-by-day variability of morning SBP was better depicted using smoothing spline analyses. Patients with greater SD of morning SBP tended to significantly progress to macroalbuminuria [odds ratio: 5.24 (95% confidence interval: 2.10-13.03; P > 0.001)]. Patients with greater CV of morning SBP also tended to significantly progress to macroalbuminuria [odds ratio: 3.36 (95% confidence interval: 1.39-8.12; P = 0.007)]. Day-by-day variability of morning SBP was proven as an independent predictor for progression to macroalbuminuria in patients with type 2 diabetes.
NASA Astrophysics Data System (ADS)
Ramos, M. C.; Jones, G. V.; Yuste, J.
2015-12-01
The aim of this work was to analyze spatial phenology and grape quality variability related to the climatic characteristics within the Ribera del Duero Designation of Origin (DO). Twenty plots planted with cv. Tempranillo and distributed within the DO were analyzed for phenology from 2004 to 2013. Grape quality parameters at ripening (berry weight, sugar content, acidity and pH, and anthocyanins) were analyzed in 26 plots for the period 2003-2013. The relationships between phenology and grape parameters with different climatic variables were confirmed with a multivariate analysis. On average, bud break was April 27th, bloom June 17th, and veraison August 12th. However, phenology during the time period showed high variability, with differences between years of up to 21 days for a phenology stage. The earliest dates were observed in dry years (2005, 2006, and to a lesser degree in 2009) while the later phenology dates occurred in the wettest year of the period (2008). High correlations were found between veraison date and temperature variables as well as with precipitation-evapotranspiration recorded during the bloom-veraison period. These effects tended to be higher in the central part of the DO. Grape quality parameters also showed high variability among the dry and the wet years, and the influence of extreme temperatures on color development as well as the effect of available water on acidity were observed.
Unequal cluster sizes in stepped-wedge cluster randomised trials: a systematic review.
Kristunas, Caroline; Morris, Tom; Gray, Laura
2017-11-15
To investigate the extent to which cluster sizes vary in stepped-wedge cluster randomised trials (SW-CRT) and whether any variability is accounted for during the sample size calculation and analysis of these trials. Any, not limited to healthcare settings. Any taking part in an SW-CRT published up to March 2016. The primary outcome is the variability in cluster sizes, measured by the coefficient of variation (CV) in cluster size. Secondary outcomes include the difference between the cluster sizes assumed during the sample size calculation and those observed during the trial, any reported variability in cluster sizes and whether the methods of sample size calculation and methods of analysis accounted for any variability in cluster sizes. Of the 101 included SW-CRTs, 48% mentioned that the included clusters were known to vary in size, yet only 13% of these accounted for this during the calculation of the sample size. However, 69% of the trials did use a method of analysis appropriate for when clusters vary in size. Full trial reports were available for 53 trials. The CV was calculated for 23 of these: the median CV was 0.41 (IQR: 0.22-0.52). Actual cluster sizes could be compared with those assumed during the sample size calculation for 14 (26%) of the trial reports; the cluster sizes were between 29% and 480% of that which had been assumed. Cluster sizes often vary in SW-CRTs. Reporting of SW-CRTs also remains suboptimal. The effect of unequal cluster sizes on the statistical power of SW-CRTs needs further exploration and methods appropriate to studies with unequal cluster sizes need to be employed. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.
Variability of activity profile during medium-sided games in professional soccer.
Rago, Vincenzo; Silva, João R; Mohr, Magni; Barreira, Daniel; Krustrup, Peter; Rebelo, António N
2018-04-24
In Southern European countries it is very frequent to perform medium-sized games (MSG) as last training drill. We analyzed the individual variability and changes in activity patterns during MSG throughout the preseason. Activity profile during MSGs (10v10+goalkeepers, duration: 10-min, field length: 50 m, width: 90 m, area per player: 204.5 m2) was quantified using a GPS in 14 professional male players (6 defenders, 5 midfielders 5 and attackers). Inter-individual variability was higher for high-intensity (HIR), very-high speed (VHS), maximum acceleration (Accmax) and maximum deceleration (Decmax) distance (CV=25.2 to 43.3%), compared to total distance (TD), total acceleration (Acctot) and total deceleration (Dectot) distance (CV= 8.3 to 18.3 %). Defenders showed higher variability in TD, HIR, VHS, Acctot and Dectot (ES= 1.30 to 11.28) compared to the other field positions, whereas attackers showed higher variability in HIR, VHS Accmax and Decmax (ES=-4.92 to 2.07) than other the field positions. Variability in TD regularly increased (ES= -2.13 to -0.91) towards the end of the preseason, while HIR and VHS variability tended to increase over the 3rd and the 4th preseason week (ES=-0.94 to -3.05). However, the behavior of variability across the preseason period was more unpredictable for Acctot and Dectot, both decreasing in the 3rd week (ES= 0.70 to 1.20), while Decmax increased in the 4th week (ES=-0.91±0.59). During MSGs, individual variability of activity differs among field positions, and tends to increase with either speed or acceleration intensity, underlining the need of an individualized approach for training load monitoring.
On the Nature of the Hard X-ray Sources SWIFT J1907.3-2050, IGR J12123-5802 and IGR J19552+0044
NASA Technical Reports Server (NTRS)
Bernardini, F.; De Martino, D.; Mukai, K.; Falanga, M.; Andruchow, I.; Bonnet-Bidaud, J.-M.; Masetti, N.; Gonzalez Buitrago, D. H.; Mouchet, M.; Tovmassian, G.
2013-01-01
The INTEGRAL and Swift hard X-ray surveys have identified a large number of new sources, among which many are proposed as Cataclysmic Variables (CVs). Here we present the first detailed study of three X-ray selected CVs, Swift J1907.3-2050, IGRJ12123-5802, and IGRJ19552+0044 based on XMM-Newton, Suzaku, Swift observations and ground based optical and archival near-infrared/infrared data. Swift J1907.3-2050 is highly variable from hours to months-years at all wavelengths. No coherent X-ray pulses are detected but rather transient features. The X-ray spectrum reveals a multi-temperature optically thin plasma absorbed by complex neutral material and a soft black body component arising from a small area. These characteristics are remarkably similar to those observed in magnetic CVs. A supra-solar abundance of nitrogen could arise from nuclear processed material from the donor star. Swift J1907.3-2050 could be a peculiar magnetic CV with the second longest (20.82 hours) binary period. IGRJ12123-5802 is variable in the X-rays on a timescale of greater than or approximately 7.6 hours. No coherent pulsations are detected, but its spectral characteristics suggest that it could be a magnetic CV of the Intermediate Polar (IP) type. IGRJ19552+0044 shows two X-ray periods, approximately 1.38 hours and approximately 1.69 hours and a X-ray spectrum characterized by a multi-temperature plasma with little absorption. We derive a low accretion rate, consistent with a CV below the orbital period gap. Its peculiar near-infrared/infrared spectrum suggests a contribution from cyclotron emission. It could either be a pre-polar or an IP with the lowest degree of asynchronism.
On the Nature of the Hard X-Ray Sources SWIFT J1907.3-2050, IGR J12123-5802 and IGR J19552+0044
NASA Technical Reports Server (NTRS)
Bernardini, F.; deMartino, D; Mukai, K.; Falanga, M.; Andruchow, I.; Bonnet-Bidaud, J.-M.; Masetti, N.; GonzalezBuitrago, D. H.; Mouchet, M.; Tovmassian, G.
2014-01-01
The INTEGRAL and Swift hard X-ray surveys have identified a large number of new sources, among which many are proposed as Cataclysmic Variables (CVs). Here we present the first detailed study of three X-ray selected CVs, Swift J1907.3-2050, IGRJ12123-5802, and IGRJ19552+0044 based on XMM-Newton, Suzaku, Swift observations and ground based optical and archival nIR/IR data. Swift J1907.3-2050 is highly variable from hours to monthsyears at all wavelengths. No coherent X-ray pulses are detected but rather transient features. The X-ray spectrum reveals a multi-temperature optically thin plasma absorbed by complex neutral material and a soft black body component arising from a small area. These characteristics are remarkably similar to those observed in magnetic CVs. A supra-solar abundance of nitrogen could arise from nuclear processed material from the donor star. Swift J1907.3-2050 could be a peculiar magnetic CV with the second longest (20.82 h) binary period. IGRJ12123-5802 is variable in the X-rays on a timescale of approximately or greater than 7.6 h. No coherent pulsations are detected, but its spectral characteristics suggest that it could be a magnetic CV of the Intermediate Polar (IP) type. IGRJ19552+0044 shows two X-ray periods, approximately 1.38 h and approximately 1.69 h and a X-ray spectrum characterized by a multi-temperature plasma with little absorption.We derive a low accretion rate, consistent with a CV below the orbital period gap. Its peculiar nIR/IR spectrum suggests a contribution from cyclotron emission. It could either be a pre-polar or an IP with the lowest degree of asynchronism.
Nix, D E David E; Adam, R D Rodney D; Auclair, Barbara; Krueger, T S Todd S; Godo, P G Paul G; Peloquin, C A Charles A
2004-01-01
Clofazimine is potentially useful for the treatment of disease due to multidrug resistant Mycobacterium tuberculosis, as well as leprosy and certain chronic skin diseases. Its pharmacokinetics have been incompletely characterized. This study was conducted to explore issues relating to bioavailability in the presence of food, orange juice, and antacid. A 5 drug regimen consisting of clofazimine, cycloserine, ethionamide, para-aminosalicyclic acid, and pyridoxime was administered to healthy subjects four times using a four period cross-over design with two weeks washout between treatments. Subjects also received orange juice, a high fat meal, aluminum/magnesium antacid, or only water in random order with the drug regimen. The pharmacokinetics of clofazimine were assessed using individual- and population-based methods and relative bioavailability compared to fasting administration was determined. Clofazimine exhibited a sometimes prolonged and variable lag-time and considerable variability in plasma concentrations. From the population analysis (one-compartment model), the mean oral clearance was 76.7 l/h (CV=74.2%) and mean apparent volume of distribution was 1470 l (CV=36.3%). The first-order absorption rate constant ranged from 0.716 to 1.33 h(-1) (pooled CV=61.7%). Residual (proportional) error was 49.1%. Estimates of bioavailability compared to fasting administration were 145% (90% CI, 107-183%) for administration with high fat food, 82.0% (63.2-101%) for administration with orange juice, and 78.5% (55.1-102%) for administration with antacid. Administration of clofazimine with a high fat meal provides the greatest bioavailability, however, bioavailability is associated with high inter- and intra-subject variability. Both orange juice and aluminum-magnesium antacid produced a reduction in mean bioavailability of clofazimine.
READ, PAUL; OLIVER, JON L.; DE STE CROIX, MARK B.A.; MYER, GREGORY D.; LLOYD, RHODRI S.
2016-01-01
Deficits in neuromuscular control during movement patterns such as landing are suggested pathomechanics that underlie sport-related injury. A common mode of assessment is measurement of landing forces during jumping tasks; however, these measures have been used less frequently in male youth soccer players and reliability data is sparse. The aim of this study was to examine the reliability of a field-based neuromuscular control screening battery using force plate diagnostics in this cohort. Twenty six pre-peak height velocity (PHV) and twenty five post-PHV elite male youth soccer players completed a drop vertical jump (DVJ), single leg 75% horizontal hop and stick (75%HOP) and single leg countermovement jump (SLCMJ). Measures of peak landing vertical ground reaction force (pVGRF), time to stabilisation (TTS), time to pVGRF, and pVGRF asymmetry were recorded. A test, re-test design was used and reliability statistics included: change in mean, intraclass correlation coefficient (ICC) and coefficient of variation (CV). No significant differences in mean score were reported for any of the assessed variables between test sessions. In both groups, pVGRF and asymmetry during the 75%HOP and SLCMJ demonstrated largely acceptable reliability (CV ≤ 10%). Greater variability was evident in DVJ pVGRF and all other assessed variables, across the three protocols (CV range = 13.8 – 49.7%). ICC values ranged from small to large and were generally higher in the post-PHV players. The results of this study suggest that pVGRF and asymmetry can be reliably assessed using a 75%HOP and SLCMJ in this cohort. These measures could be utilized to support a screening battery for elite male youth soccer players and for test re-test comparison. PMID:27075641
Oribatid mites in soil toxicity testing-the use of Oppia nitens (C.L. Koch) as a new test species.
Princz, Juliska I; Behan-Pelletier, Valerie M; Scroggins, Richard P; Siciliano, Steven D
2010-04-01
Few soil invertebrate species are available for the toxic assessment of soils from boreal or other northern ecozones, yet these soils cover the majority of Canada's landmass as well as significant portions of Eurasia. Oppia nitens (C.L. Koch) is an herbivorous and fungivorous oribatid mite found in soil throughout Holarctic regions, including Canada. Soil tests using O. nitens were performed using 15 different forest soil types and horizons to investigate test variability in adult survival and reproduction. Adult survival (86.1 +/- 1.1%) was consistent across soil types, with a coefficient of variation (CV) of 15%. However, reproduction varied significantly, ranging from 2.9 (+/-1.1) to 86.2 (+/-11.7) individuals, with a corresponding CV of 118 and 30%, respectively. Of the soil factors assessed (NH(3), NO(3), pH, phosphorus [P], organic matter content (OM), carbon:nitrogen (C:N), sand, silt, clay, and sodium adsorption ratio), soil organic matter (OM) explained 68% of the variation observed for reproduction. Increasing the OM using Sphagnum sp. peat moss resulted in optimal reproduction at 7% OM (8% peat content) with the lowest variability (CV of 20%). When assessing the toxicity of a reference chemical, boric acid, the effect of peat amendment reduced lethality to adults with no observable difference on reproduction. The use an age-synchronized culture reduced the test variability for reproduction relative to the use of unsynchronized cultures. Oppia nitens is a good candidate species for a standardized test design, with adult survival easily assessed in a relatively simple design. A long-term reproduction test with O. nitens will require the use of a synchronized population and, on occasion, OM amendment when testing soils with low organic matter content. (c) 2009 SETAC.
Howard, Charla L; Wallace, Chris; Abbas, James; Stokic, Dobrivoje S
2017-01-01
We developed and evaluated properties of a new measure of variability in stride length and cadence, termed residual standard deviation (RSD). To calculate RSD, stride length and cadence are regressed against velocity to derive the best fit line from which the variability (SD) of the distance between the actual and predicted data points is calculated. We examined construct, concurrent, and discriminative validity of RSD using dual-task paradigm in 14 below-knee prosthesis users and 13 age- and education-matched controls. Subjects walked first over an electronic walkway while performing separately a serial subtraction and backwards spelling task, and then at self-selected slow, normal, and fast speeds used to derive the best fit line for stride length and cadence against velocity. Construct validity was demonstrated by significantly greater increase in RSD during dual-task gait in prosthesis users than controls (group-by-condition interaction, stride length p=0.0006, cadence p=0.009). Concurrent validity was established against coefficient of variation (CV) by moderate-to-high correlations (r=0.50-0.87) between dual-task cost RSD and dual-task cost CV for both stride length and cadence in prosthesis users and controls. Discriminative validity was documented by the ability of dual-task cost calculated from RSD to effectively differentiate prosthesis users from controls (area under the receiver operating characteristic curve, stride length 0.863, p=0.001, cadence 0.808, p=0.007), which was better than the ability of dual-task cost CV (0.692, 0.648, respectively, not significant). These results validate RSD as a new measure of variability in below-knee prosthesis users. Future studies should include larger cohorts and other populations to ascertain its generalizability. Copyright © 2016 Elsevier B.V. All rights reserved.
Performance of computer vision in vivo flow cytometry with low fluorescence contrast
NASA Astrophysics Data System (ADS)
Markovic, Stacey; Li, Siyuan; Niedre, Mark
2015-03-01
Detection and enumeration of circulating cells in the bloodstream of small animals are important in many areas of preclinical biomedical research, including cancer metastasis, immunology, and reproductive medicine. Optical in vivo flow cytometry (IVFC) represents a class of technologies that allow noninvasive and continuous enumeration of circulating cells without drawing blood samples. We recently developed a technique termed computer vision in vivo flow cytometry (CV-IVFC) that uses a high-sensitivity fluorescence camera and an automated computer vision algorithm to interrogate relatively large circulating blood volumes in the ear of a mouse. We detected circulating cells at concentrations as low as 20 cells/mL. In the present work, we characterized the performance of CV-IVFC with low-contrast imaging conditions with (1) weak cell fluorescent labeling using cell-simulating fluorescent microspheres with varying brightness and (2) high background tissue autofluorescence by varying autofluorescence properties of optical phantoms. Our analysis indicates that CV-IVFC can robustly track and enumerate circulating cells with at least 50% sensitivity even in conditions with two orders of magnitude degraded contrast than our previous in vivo work. These results support the significant potential utility of CV-IVFC in a wide range of in vivo biological models.
NMDA receptor content of synapses in stratum radiatum of the hippocampal CA1 area.
Racca, C; Stephenson, F A; Streit, P; Roberts, J D; Somogyi, P
2000-04-01
Glutamate receptors activated by NMDA (NMDARs) or AMPA (AMPARs) are clustered on dendritic spines of pyramidal cells. Both the AMPAR-mediated postsynaptic responses and the synaptic AMPAR immunoreactivity show a large intersynapse variability. Postsynaptic responses mediated by NMDARs show less variability. To assess the variability in NMDAR content and the extent of their coexistence with AMPARs in Schaffer collateral-commissural synapses of adult rat CA1 pyramidal cells, electron microscopic immunogold localization of receptors has been used. Immunoreactivity of NMDARs was detected in virtually all synapses on spines, but AMPARs were undetectable, on average, in 12% of synapses. A proportion of synapses had a very high AMPAR content relative to the mean content, resulting in a distribution more skewed toward larger values than that of NMDARs. The variability of synaptic NMDAR content [coefficient of variation (CV), 0.64-0.70] was much lower than that of the AMPAR content (CV, 1.17-1.45). Unlike the AMPAR content, the NMDAR content showed only a weak correlation with synapse size. As reported previously for AMPARs, the immunoreactivity of NMDARs was also associated with the spine apparatus within spines. The results demonstrate that the majority of the synapses made by CA3 pyramidal cells onto spines of CA1 pyramids express both NMDARs and AMPARs, but with variable ratios. A less-variable NMDAR content is accompanied by a wide variability of AMPAR content, indicating that the regulation of expression of the two receptors is not closely linked. These findings support reports that fast excitatory transmission at some of these synapses is mediated by activation mainly of NMDARs.
Mounir, Majid; Shafiei, Rasoul; Zarmehrkhorshid, Raziyeh; Hamouda, Allal; Ismaili Alaoui, Mustapha; Thonart, Philippe
2016-02-01
The activity of bacterial strains significantly influences the quality and the taste of vinegar. Previous studies of acetic acid bacteria have primarily focused on the ability of bacterial strains to produce high amounts of acetic acid. However, few studies have examined the production of gluconic acid during acetous fermentation at high temperatures. The production of vinegar at high temperatures by two strains of acetic acid bacteria isolated from apple and cactus fruits, namely AF01 and CV01, respectively, was evaluated in this study. The simultaneous production of gluconic and acetic acids was also examined in this study. Biochemical and molecular identification based on a 16s rDNA sequence analysis confirmed that these strains can be classified as Acetobacter pasteurianus. To assess the ability of the isolated strains to grow and produce acetic acid and gluconic acid at high temperatures, a semi-continuous fermentation was performed in a 20-L bioreactor. The two strains abundantly grew at a high temperature (41°C). At the end of the fermentation, the AF01 and CV01 strains yielded acetic acid concentrations of 7.64% (w/v) and 10.08% (w/v), respectively. Interestingly, CV01 was able to simultaneously produce acetic and gluconic acids during acetic fermentation, whereas AF01 mainly produced acetic acid. In addition, CV01 was less sensitive to ethanol depletion during semi-continuous fermentation. Finally, the enzymatic study showed that the two strains exhibited high ADH and ALDH enzyme activity at 38°C compared with the mesophilic reference strain LMG 1632, which was significantly susceptible to thermal inactivation. Copyright © 2015 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.
NASA Astrophysics Data System (ADS)
Wei, Dandan; Ren, Dong
2013-08-01
Although cockroaches were the dominant insects in various Paleozoic and Mesozoic insect assemblages, their general morphology was extremely conservative. One of the most common of them, the Jurassic-Cretaceous family Mesoblattinidae, is described here for the first time on the basis of completely preserved specimens. Ninety-two specimens of Perlucipecta aurea gen. et sp. n. reveal details of head, mandible, male tergal glands and terminal hook; cercal, leg and antennal sensilla. Its congener, P. vrsanskyi is described from the same sediments of the Yixian Formation (Upper Jurassic-Lower Cretaceous). The forewing venation variability of P. aurea, analysed for the first time in this family is nearly identical (CV = 6.23 %) with variability of two species of family Blattulidae that occur at the same locality (CV = 6.22 %; 5.72 %). The transitional nature of morphological characters represented by asymmetry between left and right wings (simple/branched forewing SC and hind wing M) in P. aurea documents the phylogenetic relation between the families Mesoblattinidae and Ectobiidae
NASA Astrophysics Data System (ADS)
Belloni, Diogo; Schreiber, Matthias R.; Zorotovic, Mónica; Iłkiewicz, Krystian; Hurley, Jarrod R.; Giersz, Mirek; Lagos, Felipe
2018-06-01
The predicted and observed space density of cataclysmic variables (CVs) have been for a long time discrepant by at least an order of magnitude. The standard model of CV evolution predicts that the vast majority of CVs should be period bouncers, whose space density has been recently measured to be ρ ≲ 2 × 10-5 pc-3. We performed population synthesis of CVs using an updated version of the Binary Stellar Evolution (BSE) code for single and binary star evolution. We find that the recently suggested empirical prescription of consequential angular momentum loss (CAML) brings into agreement predicted and observed space densities of CVs and period bouncers. To progress with our understanding of CV evolution it is crucial to understand the physical mechanism behind empirical CAML. Our changes to the BSE code are also provided in details, which will allow the community to accurately model mass transfer in interacting binaries in which degenerate objects accrete from low-mass main-sequence donor stars.
Radtke, Thomas; Böni, Lukas; Bohnacker, Peter; Fischer, Peter; Benden, Christian; Dressel, Holger
2018-04-21
We evaluated test-retest reliability of sputum viscoelastic properties in clinically stable patients with cystic fibrosis (CF). Data from a prospective, randomized crossover study was used to determine within-subject variability of sputum viscoelasticity (G', storage modulus and G", loss modulus at 1 and 10 rad s -1 ) and solids content over three consecutive visits. Precision of sputum properties was quantified by within-subject standard deviation (SD ws ), coefficient of variation (CV) and intraclass correlation coefficients (ICC). Fifteen clinically stable adults with CF (FEV 1 range 24-94% predicted) were included. No differences between study visits (mean ± SD 8 ± 2 days) were observed for any sputum rheology measure. CV's for G', G" and solids content ranged between 40.3-45.3% and ICC's between 0.21-0.42 indicating poor to fair test-retest reliability. Short-term within-subject variability of sputum properties is high in clinically stable adults with CF. Investigators applying shear rheology experiments in future prospective studies should consider using multiple measurements aiming to increase precision of sputum rheological outcomes. Copyright © 2018 Elsevier B.V. All rights reserved.
Ricotta, C.; Reed, Bradley C.; Tieszen, Larry L.
2003-01-01
Time integrated normalized difference vegetation index (ΣNDVI) derived from National Oceanic and Atmospheric Administration (NOAA) Advanced Very High Resolution Radiometer (AVHRR) multi-temporal imagery over a 10-year period (1989–1998) was used as a surrogate for primary production to investigate the impact of interannual climate variability on grassland performance for central and northern US Great Plains. First, the contribution of C3 and C4 species abundance to the major grassland ecosystems of the US Great Plains is described. Next, the relation between mean ΣNDVI and the ΣNDVI coefficient of variation (CV ΣNDVI) used as a proxy for interannual climate variability is analysed. Results suggest that the differences in the long-term climatic control over ecosystem performance approximately coincide with changes between C3- and C4-dominant grassland classes. Variation in remotely sensed net primary production over time is higher for the southern and western plains grasslands (primarily C4 grasslands), whereas the C3-dominated classes in the northern and eastern portion of the US Great Plains, generally show lower CV ΣNDVI values.
Exploring the SDSS Data Set with Linked Scatter Plots. I. EMP, CEMP, and CV Stars
DOE Office of Scientific and Technical Information (OSTI.GOV)
Carbon, Duane F.; Henze, Christopher; Nelson, Bron C., E-mail: Duane.F.Carbon@nasa.gov
We present the results of a search for extremely metal-poor (EMP), carbon-enhanced metal-poor (CEMP), and cataclysmic variable (CV) stars using a new exploration tool based on linked scatter plots (LSPs). Our approach is especially designed to work with very large spectrum data sets such as the SDSS, LAMOST, RAVE, and Gaia data sets, and it can be applied to stellar, galaxy, and quasar spectra. As a demonstration, we conduct our search using the SDSS DR10 data set. We first created a 3326-dimensional phase space containing nearly 2 billion measures of the strengths of over 1600 spectral features in 569,738 SDSSmore » stars. These measures capture essentially all the stellar atomic and molecular species visible at the resolution of SDSS spectra. We show how LSPs can be used to quickly isolate and examine interesting portions of this phase space. To illustrate, we use LSPs coupled with cuts in selected portions of phase space to extract EMP stars, CEMP stars, and CV stars. We present identifications for 59 previously unrecognized candidate EMP stars and 11 previously unrecognized candidate CEMP stars. We also call attention to 2 candidate He ii emission CV stars found by the LSP approach that have not yet been discussed in the literature.« less
VizieR Online Data Catalog: Exploring the SDSS data set. I. EMP & CV stars (Carbon+, 2017)
NASA Astrophysics Data System (ADS)
Carbon, D. F.; Henze, C.; Nelson, B. C.
2017-08-01
We present the results of a search for extremely metal-poor (EMP), carbon-enhanced metal-poor (CEMP), and cataclysmic variable (CV) stars using a new exploration tool based on linked scatter plots (LSPs). Our approach is especially designed to work with very large spectrum data sets such as the SDSS, LAMOST, RAVE, and Gaia data sets, and it can be applied to stellar, galaxy, and quasar spectra. As a demonstration, we conduct our search using the SDSS DR10 data set. We first created a 3326-dimensional phase space containing nearly 2 billion measures of the strengths of over 1600 spectral features in 569738 SDSS stars. These measures capture essentially all the stellar atomic and molecular species visible at the resolution of SDSS spectra. We show how LSPs can be used to quickly isolate and examine interesting portions of this phase space. To illustrate, we use LSPs coupled with cuts in selected portions of phase space to extract EMP stars, CEMP stars, and CV stars. We present identifications for 59 previously unrecognized candidate EMP stars and 11 previously unrecognized candidate CEMP stars. We also call attention to 2 candidate He II emission CV stars found by the LSP approach that have not yet been discussed in the literature. (3 data files).
Exploring the SDSS Data Set with Linked Scatter Plots. I. EMP, CEMP, and CV Stars
NASA Astrophysics Data System (ADS)
Carbon, Duane F.; Henze, Christopher; Nelson, Bron C.
2017-02-01
We present the results of a search for extremely metal-poor (EMP), carbon-enhanced metal-poor (CEMP), and cataclysmic variable (CV) stars using a new exploration tool based on linked scatter plots (LSPs). Our approach is especially designed to work with very large spectrum data sets such as the SDSS, LAMOST, RAVE, and Gaia data sets, and it can be applied to stellar, galaxy, and quasar spectra. As a demonstration, we conduct our search using the SDSS DR10 data set. We first created a 3326-dimensional phase space containing nearly 2 billion measures of the strengths of over 1600 spectral features in 569,738 SDSS stars. These measures capture essentially all the stellar atomic and molecular species visible at the resolution of SDSS spectra. We show how LSPs can be used to quickly isolate and examine interesting portions of this phase space. To illustrate, we use LSPs coupled with cuts in selected portions of phase space to extract EMP stars, CEMP stars, and CV stars. We present identifications for 59 previously unrecognized candidate EMP stars and 11 previously unrecognized candidate CEMP stars. We also call attention to 2 candidate He II emission CV stars found by the LSP approach that have not yet been discussed in the literature.
Corrao, Giovanni; Soranna, Davide; Merlino, Luca; Mancia, Giuseppe
2014-10-01
Although generic and earlier brand-name counterparts are bioequivalent, their equivalence in preventing relevant clinical outcomes is of concern. To compare effectiveness of generic and brand-name antihypertensive drugs for preventing the onset of cardiovascular (CV) outcomes. A population-based, nested case-control study was carried out by including the cohort of 78 520 patients from Lombardy (Italy) aged 18 years or older who were newly treated with antihypertensive drugs during 2005. Cases were the 2206 patients who experienced a hospitalization for CV disease from initial prescription until 2011. One control for each case was randomly selected from the same cohort that generated cases. Logistic regression was used to model the CV risk associated with starting on and/or continuing with generic or brand-name agents. There was no evidence that patients who started on generics experienced different CV risk than those on brand-name product (OR 0·86; 95% CI 0·63-1·17). Patients at whom generics were main dispensed had not significantly difference in CV outcomes than those mainly on brand-name agents (OR 1·19; 95% CI 0·86-1·63). Compared with patients who kept initial brand-name therapy, those who experienced brand-to-generic or generic-to-brand switches, and those always on generics, did not show differential CV risks, being the corresponding ORs (and 95% CIs), 1·18 (0·96-1·47), 0·87 (0·63-1·21) and 1·08 (0·80-1·46). Our findings do not support the notion that brand-name antihypertensive agents are superior to generics for preventing CV outcomes in the real-world clinical practice. © 2014 Stichting European Society for Clinical Investigation Journal Foundation.
Harkema, Susan J.; Wang, Siqi; Angeli, Claudia A.; Chen, Yangsheng; Boakye, Maxwell; Ugiliweneza, Beatrice; Hirsch, Glenn A.
2018-01-01
Chronic low blood pressure and orthostatic hypotension remain challenging clinical issues after severe spinal cord injury (SCI), affecting health, rehabilitation, and quality of life. We previously reported that targeted lumbosacral spinal cord epidural stimulation (scES) could promote stand and step functions and restore voluntary movement in patients with chronic motor complete SCI. This study addresses the effects of targeted scES for cardiovascular function (CV-scES) in individuals with severe SCI who suffer from chronic hypotension. We tested the hypothesis that CV-scES can increase resting blood pressure and attenuate chronic hypotension in individuals with chronic cervical SCI. Four research participants with chronic cervical SCI received an implant of a 16-electrode array on the dura (L1–S1 cord segments, T11–L1 vertebrae). Individual-specific CV-scES configurations (anode and cathode electrode selection, voltage, frequency, and pulse width) were identified to maintain systolic blood pressure within targeted normative ranges without skeletal muscle activity of the lower extremities as assessed by electromyography. These individuals completed five 2-h sessions using CV-scES in an upright, seated position during measurement of blood pressure and heart rate. Noninvasive continuous blood pressure was measured from a finger cuff by plethysmograph technique. For each research participant there were statistically significant increases in mean arterial pressure in response to CV-scES that was maintained within normative ranges. This result was reproducible over the five sessions with concomitant decreases or no changes in heart rate using individual-specific CV-scES that was modulated with modest amplitude changes throughout the session. Our study shows that stimulating dorsal lumbosacral spinal cord can effectively and safely activate mechanisms to elevate blood pressures to normal ranges from a chronic hypotensive state in humans with severe SCI with individual-specific CV-scES. PMID:29568266
CardioScape mapping the cardiovascular funding landscape in Europe.
Pries, Axel Radlach; Naoum, Anastasia; Habazettl, Helmut; Dunkel, Mathias; Preissner, Robert; Coats, Caroline J; Tornada, Ana; Orso, Francesco; Van de Werf, Frans; Wood, David A
2017-04-25
The burden of cardiovascular disease is increasing worldwide, which has to be reflected by cardiovascular (CV) research in Europe. CardioScape, a FP7 funded project initiated by the European Society of Cardiology (ESC), identified where CV research is performed, how it is funded and by whom. It could be transformed into an on-line and up-to-date resource of great relevance for researchers, funding bodies and policymakers and could be a role model for mapping CV research funding in Europe and beyond. Relevant funding bodies in 28 European Union (EU) countries were identified by a multistep process involving experts in each country. Projects above a funding threshold of 100 k€ during the period 2010-2012 were included using a standard questionnaire. Results were classified by experts and an adaptive text analysis software to a CV-research taxonomy, integrating existing schemes from ESC journals and congresses. An on-line query portal was set up to allow different users to interrogate the database according to their specific viewpoints. CV-research funding varies strongly between different nations with the EU providing 37% of total available project funding and clear geographical gradients exist. Data allow in depth comparison of funding for different research areas and led to a number of recommendations by the consortium. CardioScape can support CV research by aiding researchers, funding agencies and policy makers in their strategic decisions thus improving research quality if CardioScape strategy and technology becomes the basis of a continuously updated and expanded European wide publicly accessible database. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2017. For permissions, please email: journals.permissions@oup.com.
Provocative issues in heart disease prevention.
Juneau, Martin; Hayami, Douglas; Gayda, Mathieu; Lacroix, Sébastien; Nigam, Anil
2014-12-01
In this article, new areas of cardiovascular (CV) prevention and rehabilitation research are discussed: high-intensity interval training (HIIT) and new concepts in nutrition. HIIT consists of brief periods of high-intensity exercise interspersed by periods of low-intensity exercise or rest. The optimal mode according our work (15-second exercise intervals at peak power with passive recovery intervals of the same duration) is associated with longer total exercise time, similar time spent near peak oxygen uptake (VO2 peak) VO2 peak, and lesser perceived exertion relative to other protocols that use longer intervals and active recovery periods. Evidence also suggests that compared with moderate-intensity continuous exercise training, HIIT has superior effects on cardiorespiratory function and on the attenuation of multiple cardiac and peripheral abnormalities. With respect to nutrition, a growing body of evidence suggests that the gut microbiota is influenced by lifestyle choices and might play a pivotal role in modulating CV disease development. For example, recent evidence linking processed (but not unprocessed) meats to increased CV risk pointed to the gut microbial metabolite trimethylamine N-oxide as a potential culprit. In addition, altered gut microbiota could also mediate the proinflammatory and cardiometabolic abnormalities associated with excess added free sugar consumption, and in particular high-fructose corn syrup. Substantially more research is required, however, to fully understand how and which alterations in gut flora can prevent or lead to CV disease and other chronic illnesses. We conclude with thoughts about the appropriate role for HIIT in CV training and future research in the role of gut flora-directed interventions in CV prevention. Copyright © 2014 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.
2011-03-01
The aim of this study was to test the hypothesis that patients with atherosclerotic cardiovascular (CV) disease optimally treated on a statin but with residual atherogenic dyslipidemia (low high-density lipoprotein cholesterol [HDL-C] and high triglycerides) will benefit from addition of niacin with fewer CV events compared with placebo. Statin monotherapy trials have found 25%-35% CV risk reduction relative to placebo, leaving significant residual risk. Patients with atherogenic dyslipidemia have substantially increased CV risk. Participants were men and women with established CV disease and atherogenic dyslipidemia. Lipid entry criteria varied by gender and statin dose at screening. All participants received simvastatin (or simvastatin plus ezetimibe) at a dose sufficient to maintain low-density lipoprotein cholesterol (LDL-C) 40-80 mg/dL (1.03-2.07 mmol/L). Participants were randomized to extended-release niacin or matching placebo. The primary end point was time to occurrence of the first of the following: coronary heart disease death, nonfatal myocardial infarction, ischemic stroke, hospitalization for acute coronary syndrome, or symptom-driven coronary or cerebral revascularization. This event-driven trial will have 85% power to show a 25% reduction in primary event frequency after 850 patients have experienced a primary outcome event. AIM-HIGH completed enrollment in April 2010. Follow-up is expected to continue through 2012. AIM-HIGH was designed to determine whether treating residual dyslipidemia with niacin further reduces cardiovascular events in patients with CV disease on a statin at target levels of low-density lipoprotein cholesterol. Copyright © 2011 Mosby, Inc. All rights reserved.
Al Haddad, Hani; Méndez-Villanueva, Alberto; Torreño, Nacho; Munguía-Izquierdo, Diego; Suárez-Arrones, Luis
2017-09-22
The aim of this study was to assess the match-to-match variability obtained using GPS devices, collected during official games in professional soccer players. GPS-derived data from nineteen elite soccer players were collected over two consecutive seasons. Time-motion data for players with more than five full-match were analyzed (n=202). Total distance covered (TD), TD >13-18 km/h, TD >18-21 km/h, TD >21 km/h, number of acceleration >2.5-4 m.s-2 and >4 m.s-2 were calculated. The match-to-match variation in running activity was assessed by the typical error expressed as a coefficient of variation (CV,%) and the magnitude of the CV was calculated (effect size). When all players were pooled together, CVs ranged from 5% to 77% (first half) and from 5% to 90% (second half), for TD and number of acceleration >4 m.s-2, and the magnitude of the CVs were rated from small to moderate (effect size = 0.57-0.98). The CVs were likely to increase with running/acceleration intensity, and were likely to differ between playing positions (e.g., TD > 13-18 km/h 3.4% for second strikers vs 14.2% for strikers and 14.9% for wide-defenders vs 9.7% for wide-midfielders). Present findings indicate that variability in players' running performance is high in some variables and likely position-dependent. Such variability should be taken into account when using these variables to prescribe and/or monitor training intensity/load. GPS-derived match-to-match variability in official games' locomotor performance of professional soccer players is high in some variables, particularly for high-speed running, due to the complexity of match running performance and its most influential factors and reliability of the devices.
Oviedo-Ocaña, E R; Torres-Lozada, P; Marmolejo-Rebellon, L F; Torres-López, W A; Dominguez, I; Komilis, D; Sánchez, A
2017-04-01
Biowaste is commonly the largest fraction of municipal solid waste (MSW) in developing countries. Although composting is an effective method to treat source separated biowaste (SSB), there are certain limitations in terms of operation, partly due to insufficient control to the variability of SSB quality, which affects process kinetics and product quality. This study assesses the variability of the SSB physicochemical quality in a composting facility located in a small town of Colombia, in which SSB collection was performed twice a week. Likewise, the influence of the SSB physicochemical variability on the variability of compost parameters was assessed. Parametric and non-parametric tests (i.e. Student's t-test and the Mann-Whitney test) showed no significant differences in the quality parameters of SSB among collection days, and therefore, it was unnecessary to establish specific operation and maintenance regulations for each collection day. Significant variability was found in eight of the twelve quality parameters analyzed in the inlet stream, with corresponding coefficients of variation (CV) higher than 23%. The CVs for the eight parameters analyzed in the final compost (i.e. pH, moisture, total organic carbon, total nitrogen, C/N ratio, total phosphorus, total potassium and ash) ranged from 9.6% to 49.4%, with significant variations in five of those parameters (CV>20%). The above indicate that variability in the inlet stream can affect the variability of the end-product. Results suggest the need to consider variability of the inlet stream in the performance of composting facilities to achieve a compost of consistent quality. Copyright © 2017 Elsevier Ltd. All rights reserved.
Partial melting of the Allende (CV3) meteorite - Implications for origins of basaltic meteorites
NASA Technical Reports Server (NTRS)
Jurewicz, A. J. G.; Mittlefehldt, D. W.; Jones, J. H.
1991-01-01
Eucrites and angrites are distinct types of basaltic meteorites whose origins are poorly known. Experiments in which samples of the Allende (CV3) carbonaceous chondrite were partially melted indicate that partial melts can resemble either eucrites or angrites, depending only on the oxygen fugacity. Melts are eucritic if this variable is below that of the iron-wuestite buffer or angritic if above it. With changing pressure, the graphite-oxygen redox reaction can produce oxygen fugacities that are above or below those of the iron-wuestite buffer. Therefore, a single, homogeneous, carbonaceous planetoid greater than 110 kilometers in radius could produce melts of drastically different composition, depending on the depth of melting.
Dargaville, P A; South, M; McDougall, P N
1997-12-01
To test the hypothesis that conventional mechanical ventilation (CV) provides a greater stimulus to secretion of pulmonary surfactant than high frequency oscillatory ventilation (HFO). Sequential examination of surfactant indices in lung lavage fluid in a group of six infants with severe lung disease (group 1), ventilated with HFO and then converted back to CV as their lung disease recovered. A similar group of 10 infants (group 2) ventilated conventionally throughout the course of their illness were studied for comparison. In groups 1 and 2, two sequential tracheal aspirate samples were taken, the first once lung disease was noted to be improving, and the second 48-72 h later. Group 1 infants had converted from HFO to CV during this time. A marked increase in concentration of total surfactant phospholipid (PL) and disaturated phosphatidylcholine (DSPC) was seen in group 1 after transition from HFO to CV; the magnitude of this increase was significantly greater than that sequentially observed in group II (total PL: 9.4-fold increase in group 1 vs 1.8-fold in group 2, P = 0.006; DSPC: group 1 6.4-fold increase vs. group 2 1.7-fold, P = 0.02). These findings suggest that intermittent lung inflation during CV produces more secretion of surfactant phospholipid than continuous alveolar distension on HFO, and raise the possibility that conservation and additional maturation of surfactant elements may occur when the injured lung is ventilated with HFO.
Population pharmacokinetic study of teicoplanin in severely neutropenic patients.
Lortholary, O; Tod, M; Rizzo, N; Padoin, C; Biard, O; Casassus, P; Guillevin, L; Petitjean, O
1996-01-01
The teicoplanin pharmacokinetics (PK) of 30 febrile and severely neutropenic patients (polymorphonuclear count, < 500/mm3) with hematologic malignancies were compared with those determined for five healthy volunteers (HV). Neutropenic patients were given piperacillin combined with amikacin, and teicoplanin was added to the regimen the day fever developed in patients suspected of having a staphylococcal infection or 48 h later. Teicoplanin was given intravenously at a dosage of 6 mg/kg of body weight at 0, 12, and 24 h and once a day thereafter. Five to eleven blood samples per patient were collected. Teicoplanin concentrations were measured by liquid chromatography. A bicompartmental model was fitted to the data by a nonlinear mixed-effect-model approach. Multiple-linear regression analysis was applied in an attempt to correlate PK parameters to nine covariates. The mean trough concentrations of teicoplanin 48 h after the onset of treatment and 24 h after the last injection (last trough) +/- standard deviations were 8.8 +/- 4.1 and 17.5 +/- 13.5 mg/liter, respectively. A significant increase was noted in the mean rate of elimination clearance of teicoplanin in neutropenic patients compared with that of HV (0.86 versus 0.73 liter/h, P = 0.002), as was the case with rates of distribution clearance (5.89 versus 4.94 liter/h, P = 0.002); the mean half-life of distribution was significantly shorter in patients than in HV (0.43 versus 0.61 h, P = 0.002). In contrast, the volumes of the central compartment (ca. 5.8 liters for both groups), the volumes of distribution at steady state (HV, 37.6 liters; patients, 55.9 liters), and the elimination half-lives (HV, 39.6 h; patients, 52.7 h) were not significantly different between HV and neutropenic patients. Interindividual variabilities of rates of clearance (coefficient of variation [CV], 43%) and elimination half-lives (CV, 56%) were mainly explained by the variabilities among rates of creatinine clearance. Interindividual variabilities of the volumes of the central compartment (CV, 33%) and the volumes of distribution at steady state (CV = 51%) were correlated to interindividual variabilities among numbers of leukocytes and the ages of patients, respectively. On the basis of the population PK model of teicoplanin, simulations were made to optimize the dosing schedule. A supplemental 6 mg/kg dose of teicoplanin at 36 h resulted in a trough concentration at 48 h of 16.0 +/- 4.5 mg/liter, with only 7% of patients having a trough concentration of less than 10 mg/liter, compared with 46% of patients on the usual schedule. PMID:8723474
Hurt, Christopher P.; Brown, David A.
2018-01-01
Background Step kinematic variability has been characterized during gait using spatial and temporal kinematic characteristics. However, people can adopt different trajectory paths both between individuals and even within individuals at different speeds. Single point measures such as minimum toe clearance (MTC) and step length (SL) do not necessarily account for the multiple paths that the foot may take during the swing phase to reach the same foot fall endpoint. The purpose of this study was to test a step-by-step foot trajectory area (SBS-FTA) variability measure that is able to characterize sagittal plane foot trajectories of varying areas, and compare this measure against MTC and SL variability at different speeds. We hypothesize that the SBS-FTA variability would demonstrate increased variability with speed. Second, we hypothesize that SBS-FTA would have a stronger curvilinear fit compared with the CV and SD of SL and MTC. Third, we hypothesize SBS-FTA would be more responsive to change in the foot trajectory at a given speed compared to SL and MTC. Fourth, SBS-FTA variability would not strongly co-vary with SL and MTC variability measures since it represents a different construct related to foot trajectory area variability. Methods We studied 15 nonimpaired individuals during walking at progressively faster speeds. We calculated SL, MTC, and SBS-FTA area. Results SBS-FTA variability increased with speed, had a stronger curvilinear fit compared with the CV and SD of SL and MTC, was more responsive at a given speed, and did not strongly co-vary with SL and MTC variability measures. Conclusion SBS foot trajectory area variability was sensitive to change with faster speeds, captured a relationship that the majority of the other measures did not demonstrate, and did not co-vary strongly with other measures that are also components of the trajectory. PMID:29370202
Using the orbiting companion to trace WR wind structures in the 29d WC8d + O8-9IV binary CV Ser
NASA Astrophysics Data System (ADS)
David-Uraz, Alexandre; Moffat, Anthony F. J.
2011-07-01
We have used continuous, high-precision, broadband visible photometry from the MOST satellite to trace wind structures in the WR component of CV Ser over more than a full orbit. Most of the small-scale light-curve variations are likely due to extinction by clumps along the line of sight to the O companion as it orbits and shines through varying columns of the WR wind. Parallel optical spectroscopy from the Mont Megantic Observatory is used to refine the orbital and wind-collision parameters, as well as to reveal line emission from clumps.
Tracing WR wind structures by using the orbiting companion in the 29d WC8d + O8-9IV binary CV Ser
NASA Astrophysics Data System (ADS)
David-Uraz, Alexandre; Moffat, Anthony F. J.; Chené, André Nicolas; Lange, Nicholas
2011-01-01
We have obtained continuous, high-precision, broadband visible photometry from the MOST satellite of CV Ser over more than a full orbit in order to link the small-scale light-curve variations to extinction due to wind structures in the WR component, thus permitting us to trace these structures. The light-curve presented unexpected characteristics, in particular eclipses with a varying depth. Parallel optical spectroscopy from the Mont Megantic Observatory and Dominion Astrophysical Observatory was obtained to refine the orbital and wind-collision parameters, as well as to reveal line emission from clumps.
Ohara, Makoto; Nagaike, Hiroe; Goto, Satoshi; Fukase, Ayako; Tanabe, Yuki; Tomoyasu, Masako; Yamamoto, Takeshi; Hayashi, Toshiyuki; Fukui, Tomoyasu; Hirano, Tsutomu
2018-05-01
We aimed to evaluate which parameters of improvement in glucose metabolism reduce oxidative stress for patients with Type 2 diabetes mellitus (T2DM). Sixty-seven outpatients with T2DM underwent 72 h of continuous glucose monitoring (CGM) and were measured for oxidative stress before and after a 24-week intervention with the following targets: fasting plasma glucose (FPG), <130 mg/dl; postprandial plasma glucose (PPG), <180 mg/dl; and glycated hemoglobin (HbA1c), <7% (53 mmol/mol). The mean glucose level (MGL), mean amplitude of glycemic excursions (MAGE), mean of daily differences (MODD), percentage coefficient of variation for glucose (%CV) and area under the postprandial plasma glucose curve (AUC PP ) were calculated from the CGM data. Oxidative stress was estimated using the diacron-reactive oxygen metabolites (d-ROMs) test. Finally, the association between the improvements in glucose metabolism and oxidative stress was evaluated. FPG, MGL, HbA1c, MAGE, MODD, %CV, AUC PP , and d-ROMs significantly improved after 24 weeks of intervention. The change in d-ROMs was significantly correlated with that in FPG (r = 0.414), MGL (r = 0.402), HbA1c (r = 0.271), MAGE (r = 0.457), MODD (r = 0.371), and AUC PP (r = 0.352). The correlation of the change in d-ROMs with that in FPG, MAGE, and MODD and the use of glucose-like peptide 1 receptor agonists and statins remained significant after adjustment for other markers of diabetes control (multiple R 2 = 0.406). Improvements in glucose metabolism, including FPG and daily and day-to-day glucose variability, were all correlated with reduced oxidative stress for patients with T2DM. Published by Elsevier B.V.
The application of simple metrics in the assessment of glycaemic variability.
Monnier, L; Colette, C; Owens, D R
2018-03-06
The assessment of glycaemic variability (GV) remains a subject of debate with many indices proposed to represent either short- (acute glucose fluctuations) or long-term GV (variations of HbA 1c ). For the assessment of short-term within-day GV, the coefficient of variation for glucose (%CV) defined as the standard deviation adjusted on the 24-h mean glucose concentration is easy to perform and with a threshold of 36%, recently adopted by the international consensus on use of continuous glucose monitoring, separating stable from labile glycaemic states. More complex metrics such as the Low Blood Glucose Index (LBGI) or High Blood Glucose Index (HBGI) allow the risk of hypo or hyperglycaemic episodes, respectively to be assessed although in clinical practice its application is limited due to the need for more complex computation. This also applies to other indices of short-term intraday GV including the mean amplitude of glycemic excursions (MAGE), Shlichtkrull's M-value and CONGA. GV is important clinically as exaggerated glucose fluctuations are associated with an enhanced risk of adverse cardiovascular outcomes due primarily to hypoglycaemia. In contrast, there is at present no compelling evidence that elevated short-term GV is an independent risk factor of microvascular complications of diabetes. Concerning long-term GV there are numerous studies supporting its association with an enhanced risk of cardiovascular events. However, this association raises the question as to whether the impact of long-term variability is not simply the consequence of repeated exposure to short-term GV or ambient chronic hyperglycaemia. The renewed emphasis on glucose monitoring with the introduction of continuous glucose monitoring technologies can benefit from the introduction and application of simple metrics for describing GV along with supporting recommendations. Copyright © 2018 Elsevier Masson SAS. All rights reserved.
Walker, G S; Chen, J Y; Hopkinson, H; Sainsbury, C A R; Jones, G C
2018-06-01
Previous evidence has demonstrated that participation in the Dose Adjustment for Normal Eating (DAFNE) education programme can reduce HbA 1c and severe hypoglycaemia in people with Type 1 diabetes. In a number of studies, increased HbA 1c variability has been associated with higher diabetic morbidity and mortality. No studies have examined the impact of structured education on HbA 1c variability in Type 1 diabetes. People with Type 1 diabetes who had attended DAFNE were identified for inclusion from the Scottish Care Information-Diabetes dataset. HbA 1c median and variability, expressed as coefficient of variation (CV) before and after DAFNE was calculated. Some 1061 individuals participated in DAFNE education and 687 met the inclusion criteria. A significant median reduction in HbA 1c [-3.5 mmol/mol (-0.3%)] was seen at 12 months with a significant reduction [-1.5 mmol/mol (-0.1%)] still seen at 60 months of follow-up. HbA 1c variability as measured by CV was significantly lower during the post-DAFNE period: 0.08 (IQR 0.05-0.12) reduced to 0.07 (IQR 0.05-0.10); P = 0.002. The data confirm that DAFNE participation improves glycaemic control in Type 1 diabetes with benefits being sustained for 5 years. This study is the first to demonstrate reduced HbA 1c variability after completion of structured education. This is new evidence of the beneficial impact of DAFNE on glycaemic profile. © 2018 Diabetes UK.
Extent of, and variables associated with, blood pressure variability among older subjects.
Morano, Arianna; Ravera, Agnese; Agosta, Luca; Sappa, Matteo; Falcone, Yolanda; Fonte, Gianfranco; Isaia, Gianluca; Isaia, Giovanni Carlo; Bo, Mario
2018-02-23
Blood pressure variability (BPV) may have prognostic implications for cardiovascular risk and cognitive decline; however, BPV has yet to be studied in old and very old people. Aim of the present study was to evaluate the extent of BPV and to identify variables associated with BPV among older subjects. A retrospective study of patients aged ≥ 65 years who underwent 24-h ambulatory blood pressure monitoring (ABPM) was carried out. Three different BPV indexes were calculated for systolic and diastolic blood pressure (SBP and DBP): standard deviation (SD), coefficient of variation (CV), and average real variability (ARV). Demographic variables and use of antihypertensive medications were considered. The study included 738 patients. Mean age was 74.8 ± 6.8 years. Mean SBP and DBP SD were 20.5 ± 4.4 and 14.6 ± 3.4 mmHg. Mean SBP and DBP CV were 16 ± 3 and 20 ± 5%. Mean SBP and DBP ARV were 15.7 ± 3.9 and 11.8 ± 3.6 mmHg. At multivariate analysis older age, female sex and uncontrolled mean blood pressure were associated with both systolic and diastolic BPV indexes. The use of calcium channel blockers and alpha-adrenergic antagonists was associated with lower systolic and diastolic BPV indexes, respectively. Among elderly subjects undergoing 24-h ABPM, we observed remarkably high indexes of BPV, which were associated with older age, female sex, and uncontrolled blood pressure values.
Westera, Liset; van Viegen, Tanja; Jeyarajah, Jenny; Azad, Azar; Bilsborough, Janine; van den Brink, Gijs R; Cremer, Jonathan; Danese, Silvio; D'Haens, Geert; Eckmann, Lars; Faubion, William; Filice, Melissa; Korf, Hannelie; McGovern, Dermot; Panes, Julian; Salas, Azucena; Sandborn, William J; Silverberg, Mark S; Smith, Michelle I; Vermeire, Severine; Vetrano, Stefania; Shackelton, Lisa M; Stitt, Larry; Jairath, Vipul; Levesque, Barrett G; Spencer, David M; Feagan, Brian G; Vande Casteele, Niels
2017-11-02
Flow cytometry (FC) aids in characterization of cellular and molecular factors involved in pathologic immune responses. Although FC has potential to facilitate early drug development in inflammatory bowel disease, interlaboratory variability limits its use in multicenter trials. Standardization of methods may address this limitation. We compared variability in FC-aided quantitation of T-cell responses across international laboratories using three analytical strategies. Peripheral blood mononuclear cells (PBMCs) were isolated from three healthy donors, stimulated with phorbol 12-myristate 13-acetate and ionomycin at a central laboratory, fixed, frozen, and shipped to seven international laboratories. Permeabilization and staining was performed in triplicate at each laboratory using a common protocol and centrally provided reagents. Gating was performed using local gating with a local strategy (LGLS), local gating with a central strategy (LGCS), and central gating (CG). Median cell percentages were calculated across triplicates and donors, and reported for each condition and strategy. The coefficient of variation (CV) was calculated across laboratories. Between-strategy comparisons were made using a two-way analysis of variance adjusting for donor. Mean interlaboratory CV ranged from 1.8 to 102.1% depending on cell population and gating strategy (LGLS, 4.4-102.1%; LGCS, 10.9-65.6%; CG, 1.8-20.9%). Mean interlaboratory CV differed significantly across strategies and was consistently lower with CG. Central gating was the only strategy with mean CVs consistently lower than 25%, which is a proposed standard for pharmacodynamic and exploratory biomarker assays.
Colored noise and memory effects on formal spiking neuron models
NASA Astrophysics Data System (ADS)
da Silva, L. A.; Vilela, R. D.
2015-06-01
Simplified neuronal models capture the essence of the electrical activity of a generic neuron, besides being more interesting from the computational point of view when compared to higher-dimensional models such as the Hodgkin-Huxley one. In this work, we propose a generalized resonate-and-fire model described by a generalized Langevin equation that takes into account memory effects and colored noise. We perform a comprehensive numerical analysis to study the dynamics and the point process statistics of the proposed model, highlighting interesting new features such as (i) nonmonotonic behavior (emergence of peak structures, enhanced by the choice of colored noise characteristic time scale) of the coefficient of variation (CV) as a function of memory characteristic time scale, (ii) colored noise-induced shift in the CV, and (iii) emergence and suppression of multimodality in the interspike interval (ISI) distribution due to memory-induced subthreshold oscillations. Moreover, in the noise-induced spike regime, we study how memory and colored noise affect the coherence resonance (CR) phenomenon. We found that for sufficiently long memory, not only is CR suppressed but also the minimum of the CV-versus-noise intensity curve that characterizes the presence of CR may be replaced by a maximum. The aforementioned features allow to interpret the interplay between memory and colored noise as an effective control mechanism to neuronal variability. Since both variability and nontrivial temporal patterns in the ISI distribution are ubiquitous in biological cells, we hope the present model can be useful in modeling real aspects of neurons.
Quillet, Edwige; Bégout, Marie-Laure; Aupérin, Benoit; Khaw, Hooi Ling; Millot, Sandie; Valotaire, Claudiane; Kernéis, Thierry; Labbé, Laurent; Prunet, Patrick; Dupont-Nivet, Mathilde
2017-01-01
Adaptive phenotypic plasticity is a key component of the ability of organisms to cope with changing environmental conditions. Fish have been shown to exhibit a substantial level of phenotypic plasticity in response to abiotic and biotic factors. In the present study, we investigate the link between environmental sensitivity assessed globally (revealed by phenotypic variation in body weight) and more targeted physiological and behavioral indicators that are generally used to assess the sensitivity of a fish to environmental stressors. We took advantage of original biological material, the rainbow trout isogenic lines, which allowed the disentangling of the genetic and environmental parts of the phenotypic variance. Ten lines were characterized for the changes of body weight variability (weight measurements taken every month during 18 months), the plasma cortisol response to confinement stress (3 challenges) and a set of selected behavioral indicators. This study unambiguously demonstrated the existence of genetic determinism of environmental sensitivity, with some lines being particularly sensitive to environmental fluctuations and others rather insensitive. Correlations between coefficient of variation (CV) for body weight and behavioral and physiological traits were observed. This confirmed that CV for body weight could be used as an indicator of environmental sensitivity. As the relationship between indicators (CV weight, risk-taking, exploration and cortisol) was shown to be likely depending on the nature and intensity of the stressor, the joint use of several indicators should help to investigate the biological complexity of environmental sensitivity. PMID:29253015
Historical forest patterns of Oregon's central Coast Range
Ripple, W.J.; Hershey, K.T.; Anthony, R.G.
2000-01-01
To describe the composition and pattern of unmanaged forestland in Oregon's central Coast Range, we analyzed forest conditions from a random sample of 18 prelogging (1949 and earlier) landscapes. We also compared the amount and variability of old forest (conifer-dominated stands > 53 cm dbh) in the prelogging landscapes with that in the current landscapes. Sixty-three percent of the prelogging landscape comprised old forest, approximately 21% of which also had a significant (> 20% cover) hardwood component. The proportions of forest types across the 18 prelogging landscapes varied greatly for both early seral stages (cv = 81194) and hardwoods (cv = 127) and moderately for old forest (cv = 39). With increasing distance from streams, the amount of hardwoods and nonforest decreased, whereas the amount of seedling/sapling/pole and young conifers increased. The amount of old forest was significantly greater (p < 0.002) in prelogging forests than in current landscapes. Old-forest patterns also differed significantly (p < 0.015) between prelogging and current landscapes; patch density, coefficient of variation of patch size, edge density, and fragmentation were greater in current landscapes and mean patch size, largest patch size, and core habitat were greater in prelogging forests. Generally, old-forest landscape pattern variables showed a greater range in prelogging landscapes than in current landscapes. Management strategies designed to increase the amount of old forest and the range in landscape patterns would result in a landscape more closely resembling that found prior to intensive logging. (C) 2000 Elsevier Science Ltd.
The influence of landscape features on road development in a loess region, China.
Bi, Xiaoli; Wang, Hui; Zhou, Rui
2011-10-01
Many ecologists focus on the effects of roads on landscapes, yet few consider how landscapes affect road systems. In this study, therefore, we quantitatively evaluated how land cover, topography, and building density affected the length density, node density, spatial pattern, and location of roads in Dongzhi Yuan, a typical loess region in China. Landscape factors and roads were mapped using images from SPOT satellite (Système Probatoire d'Observation de la Terre), initiated by the French space agency and a digital elevation model (DEM). Detrended canonical correspondence analysis (DCCA), a useful ordination technique to explain species-environment relations in community ecology, was applied to evaluate the ways in which landscapes may influence roads. The results showed that both farmland area and building density were positively correlated with road variables, whereas gully density and the coefficient of variation (CV of DEM) showed negative correlations. The CV of DEM, farmland area, grassland area, and building density explained variation in node density, length density, and the spatial pattern of roads, whereas gully density and building density explained variation in variables representing road location. In addition, node density, rather than length density, was the primary road variable affected by landscape variables. The results showed that the DCCA was effective in explaining road-landscape relations. Understanding these relations can provide information for landscape managers and transportation planners.
van der Ploeg, Melanie M.; Brosschot, Jos F.; Thayer, Julian F.; Verkuil, Bart
2016-01-01
Self-report, i.e., explicit, measures of affect cannot fully explain the cardiovascular (CV) responses to stressors. Measuring affect beyond self-report, i.e., using implicit measures, could add to our understanding of stress-related CV activity. The Implicit Positive and Negative Affect Test (IPANAT) was administered in two studies to test its ecological validity and relation with CV responses and self-report measures of affect. In Study 1 students (N = 34) viewed four film clips inducing anger, happiness, fear, or no emotion, and completed the IPANAT and the Positive And Negative Affect Scale at baseline and after each clip. Implicit negative affect (INA) was higher and implicit positive affect (IPA) was lower after the anger inducing clip and vice versa after the happiness inducing clip. In Study 2 students performed a stressful math task with (n = 14) or without anger harassment (n = 15) and completed the IPANAT and a Visual Analog Scale as an explicit measure afterwards. Systolic (SBP), diastolic (DBP) blood pressure, heart rate (HR), heart rate variability (HRV), and total peripheral resistance (TPR) were recorded throughout. SBP and DBP were higher and TPR was lower in the harassment condition during the task with a prolonged effect on SBP and DBP during recovery. As expected, explicit negative affect (ENA) was higher and explicit positive affect (EPA) lower after harassment, but ENA and EPA were not related to CV activity. Although neither INA nor IPA differed between the tasks, during both tasks higher INA was related to higher SBP, lower HRV and lower TPR and to slower recovery of DBP after both tasks. Low IPA was related to slower recovery of SBP and DBP after the tasks. Implicit affect was not related to recovery of HR, HRV, and TPR. In conclusion, the IPANAT seems to respond to film clip-induced negative and positive affect and was related to CV activity during and after stressful tasks. These findings support the theory that implicitly measured affect can add to the explanation of prolonged stress-related CV responses that influence CV health. PMID:27065908
van der Ploeg, Melanie M; Brosschot, Jos F; Thayer, Julian F; Verkuil, Bart
2016-01-01
Self-report, i.e., explicit, measures of affect cannot fully explain the cardiovascular (CV) responses to stressors. Measuring affect beyond self-report, i.e., using implicit measures, could add to our understanding of stress-related CV activity. The Implicit Positive and Negative Affect Test (IPANAT) was administered in two studies to test its ecological validity and relation with CV responses and self-report measures of affect. In Study 1 students (N = 34) viewed four film clips inducing anger, happiness, fear, or no emotion, and completed the IPANAT and the Positive And Negative Affect Scale at baseline and after each clip. Implicit negative affect (INA) was higher and implicit positive affect (IPA) was lower after the anger inducing clip and vice versa after the happiness inducing clip. In Study 2 students performed a stressful math task with (n = 14) or without anger harassment (n = 15) and completed the IPANAT and a Visual Analog Scale as an explicit measure afterwards. Systolic (SBP), diastolic (DBP) blood pressure, heart rate (HR), heart rate variability (HRV), and total peripheral resistance (TPR) were recorded throughout. SBP and DBP were higher and TPR was lower in the harassment condition during the task with a prolonged effect on SBP and DBP during recovery. As expected, explicit negative affect (ENA) was higher and explicit positive affect (EPA) lower after harassment, but ENA and EPA were not related to CV activity. Although neither INA nor IPA differed between the tasks, during both tasks higher INA was related to higher SBP, lower HRV and lower TPR and to slower recovery of DBP after both tasks. Low IPA was related to slower recovery of SBP and DBP after the tasks. Implicit affect was not related to recovery of HR, HRV, and TPR. In conclusion, the IPANAT seems to respond to film clip-induced negative and positive affect and was related to CV activity during and after stressful tasks. These findings support the theory that implicitly measured affect can add to the explanation of prolonged stress-related CV responses that influence CV health.
Chang, Tae Ik; Streja, Elani; Soohoo, Melissa; Kim, Tae Woo; Rhee, Connie M; Kovesdy, Csaba P; Kashyap, Moti L; Vaziri, Nosratola D; Kalantar-Zadeh, Kamyar; Moradi, Hamid
2017-04-03
Elevated serum triglyceride/HDL cholesterol (TG/HDL-C) ratio has been identified as a risk factor for cardiovascular (CV) disease and mortality in the general population. However, the association of this important clinical index with mortality has not been fully evaluated in patients with ESRD on maintenance hemodialysis (MHD). We hypothesized that the association of serum TG/HDL-C ratio with all-cause and CV mortality in patients with ESRD on MHD is different from the general population. We studied the association of serum TG/HDL-C ratio with all-cause and CV mortality in a nationally representative cohort of 50,673 patients on incident hemodialysis between January 1, 2007 and December 31, 2011. Association of baseline and time-varying TG/HDL-C ratios with mortality was assessed using Cox proportional hazard regression models, with adjustment for multiple variables, including statin therapy. During the median follow-up of 19 months (interquartile range, 11-32 months), 12,778 all-cause deaths and 4541 CV deaths occurred, respectively. We found that the 10th decile group (reference: sixth deciles of TG/HDL-C ratios) had significantly lower risk of all-cause mortality (hazard ratio, 0.91 [95% confidence interval, 0.83 to 0.99] in baseline and 0.86 [95% confidence interval, 0.79 to 0.94] in time-varying models) and CV mortality (hazard ratio, 0.83 [95% confidence interval, 0.72 to 0.96] in baseline and 0.77 [95% confidence interval, 0.66 to 0.90] in time-varying models). These associations remained consistent and significant across various subgroups. Contrary to the general population, elevated TG/HDL-C ratio was associated with better CV and overall survival in patients on hemodialysis. Our findings provide further support that the nature of CV disease and mortality in patients with ESRD is unique and distinct from other patient populations. Hence, it is vital that future studies focus on identifying risk factors unique to patients on MHD and decipher the underlying mechanisms responsible for poor outcomes in patients with ESRD. Copyright © 2017 by the American Society of Nephrology.
Chang, Tae Ik; Streja, Elani; Soohoo, Melissa; Kim, Tae Woo; Rhee, Connie M.; Kovesdy, Csaba P.; Kashyap, Moti L.; Vaziri, Nosratola D.; Kalantar-Zadeh, Kamyar
2017-01-01
Background and objectives Elevated serum triglyceride/HDL cholesterol (TG/HDL-C) ratio has been identified as a risk factor for cardiovascular (CV) disease and mortality in the general population. However, the association of this important clinical index with mortality has not been fully evaluated in patients with ESRD on maintenance hemodialysis (MHD). We hypothesized that the association of serum TG/HDL-C ratio with all-cause and CV mortality in patients with ESRD on MHD is different from the general population. Design, setting, participants, & measurements We studied the association of serum TG/HDL-C ratio with all-cause and CV mortality in a nationally representative cohort of 50,673 patients on incident hemodialysis between January 1, 2007 and December 31, 2011. Association of baseline and time-varying TG/HDL-C ratios with mortality was assessed using Cox proportional hazard regression models, with adjustment for multiple variables, including statin therapy. Results During the median follow-up of 19 months (interquartile range, 11–32 months), 12,778 all-cause deaths and 4541 CV deaths occurred, respectively. We found that the 10th decile group (reference: sixth deciles of TG/HDL-C ratios) had significantly lower risk of all-cause mortality (hazard ratio, 0.91 [95% confidence interval, 0.83 to 0.99] in baseline and 0.86 [95% confidence interval, 0.79 to 0.94] in time-varying models) and CV mortality (hazard ratio, 0.83 [95% confidence interval, 0.72 to 0.96] in baseline and 0.77 [95% confidence interval, 0.66 to 0.90] in time-varying models). These associations remained consistent and significant across various subgroups. Conclusions Contrary to the general population, elevated TG/HDL-C ratio was associated with better CV and overall survival in patients on hemodialysis. Our findings provide further support that the nature of CV disease and mortality in patients with ESRD is unique and distinct from other patient populations. Hence, it is vital that future studies focus on identifying risk factors unique to patients on MHD and decipher the underlying mechanisms responsible for poor outcomes in patients with ESRD. PMID:28193609
Patients with Parkinson disease present high ambulatory blood pressure variability.
Kanegusuku, Hélcio; Silva-Batista, Carla; Peçanha, Tiago; Silva-Junior, Natan; Queiroz, Andreia; Costa, Luiz; Mello, Marco; Piemonte, Maria; Ugrinowitsch, Carlos; Forjaz, Cláudia
2017-09-01
Patients with Parkinson disease (PD) present blunted nocturnal blood pressure fall and similar ambulatory blood pressure variability (ABPV) measured by standard deviation (SD) and coefficient of variation (CV) compared with healthy subjects. However, these classical indices of ABPV have limited validity in individuals with circadian blood pressure alterations. New indices, such as the average of daytime and night-time standard deviation weighted by the duration of the daytime and night-time intervals (SD dn ) and the average real variability (ARV), remove the influence of the daytime and the night-time periods on ABPV. This study assessed ABPV by SD dn and ARV in PD. Twenty-one patients with PD (11 men, 66 ± 2 years, stages 2-3 of modified Hoehn & Yahr) and 21 matched controls without Parkinson disease (9 men, 64 ± 1 years old) underwent blood pressure monitoring for 24 h. ABPV was analysed by 24 h, daytime and night-time SD and CV, and by the SD dn and ARV. Systolic/diastolic 24-h and night-time SD and CV were similar between the patients with PD and the controls. The patients with PD presented higher daytime systolic/diastolic CV and SD than the controls (10·4 ± 0·9/12·3 ± 0·8 versus 7·0 ± 0·3/9·9 ± 0·5%, P<0·05; 12·6 ± 1·0/9·1 ± 0·5 versus 8·6 ± 0·4/7·5 ± 0·3 mmHg, P<0·05, respectively) as well as higher systolic/diastolic SD dn (10·9 ± 0·8/8·2 ± 0·5 versus 8·2 ± 0·3/7·1 ± 0·2 mmHg, P<0·05, respectively) and ARV (8·8 ± 0·6/6·9 ± 0·3 versus 7·2 ± 0·2/6·0 ± 0·2 mmHg, P<0·05, respectively). In conclusion, patients with PD have higher ABPV than control subjects as assessed by SD d , CV d , SD dn and AVR. © 2016 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.
Altawalbeh, Shoroq M; Thorpe, Carolyn T; Zgibor, Janice C; Kane-Gill, Sandra; Kang, Yihuang; Thorpe, Joshua M
2016-08-01
To compare the effectiveness and cardiovascular safety of long-acting beta-agonists (LABAs) with those of leukotriene receptor antagonists (LTRAs) as add-on treatments in older adults with asthma already taking inhaled corticosteroids (ICSs). Retrospective cohort study. Medicare fee-for-service (FFS) claims (2009-10) for a 10% random sample of beneficiaries continuously enrolled in Parts A, B, and D in 2009. Medicare beneficiaries aged 66 and older continuously enrolled in FFS Medicare with Part D coverage with a diagnosis of asthma before 2009 treated exclusively with ICSs plus LABAs or ICSs plus LTRAs (N = 14,702). The augmented inverse propensity-weighted estimator was used to compare the effect of LABA add-on therapy with that of LTRA add-on therapy on asthma exacerbations requiring inpatient, emergency, or outpatient care and on cardiovascular (CV) events, adjusting for demographic characteristics, comorbidities, and county-level healthcare-access variables. The primary analysis showed that LTRA add-on treatment was associated with greater odds of asthma-related hospitalizations or emergency department visits (odds ratio (OR) = 1.4, P < .001), as well as outpatient exacerbations requiring oral corticosteroids or antibiotics (OR = 1.41, P < .001) than LABA treatment. LTRA add-on therapy was also less effective in controlling acute symptoms, as indicated by greater use of short-acting beta agonists (rate ratio = 1.58, P < .001). LTRA add-on treatment was associated with lower odds of experiencing a CV event than LABA treatment (OR = 0.86, P = .006). This study provides new evidence specific to older adults to help healthcare providers weigh the risks and benefits of these add-on treatments. Further subgroup analysis is needed to personalize asthma treatments in this high-risk population. © 2016, Copyright the Authors Journal compilation © 2016, The American Geriatrics Society.
Exploratory Spectroscopy of Magnetic Cataclysmic Variables Candidates and Other Variable Objects
NASA Astrophysics Data System (ADS)
Oliveira, A. S.; Rodrigues, C. V.; Cieslinski, D.; Jablonski, F. J.; Silva, K. M. G.; Almeida, L. A.; Rodríguez-Ardila, A.; Palhares, M. S.
2017-04-01
The increasing number of synoptic surveys made by small robotic telescopes, such as the photometric Catalina Real-Time Transient Survey (CRTS), provides a unique opportunity to discover variable sources and improves the statistical samples of such classes of objects. Our goal is the discovery of magnetic Cataclysmic Variables (mCVs). These are rare objects that probe interesting accretion scenarios controlled by the white-dwarf magnetic field. In particular, improved statistics of mCVs would help to address open questions on their formation and evolution. We performed an optical spectroscopy survey to search for signatures of magnetic accretion in 45 variable objects selected mostly from the CRTS. In this sample, we found 32 CVs, 22 being mCV candidates, 13 of which were previously unreported as such. If the proposed classifications are confirmed, it would represent an increase of 4% in the number of known polars and 12% in the number of known IPs. A fraction of our initial sample was classified as extragalactic sources or other types of variable stars by the inspection of the identification spectra. Despite the inherent complexity in identifying a source as an mCV, variability-based selection, followed by spectroscopic snapshot observations, has proved to be an efficient strategy for their discoveries, being a relatively inexpensive approach in terms of telescope time. Based on observations obtained at the Observatório do Pico dos Dias/LNA, and at the Southern Astrophysical Research (SOAR) telescope, which is a joint project of the Ministério da Ciência, Tecnologia, e Inovação (MCTI) da República Federativa do Brasil, the U.S. National Optical Astronomy Observatory (NOAO), the University of North Carolina at Chapel Hill (UNC), and Michigan State University (MSU).
Variability in Rheumatology day care hospitals in Spain: VALORA study.
Hernández Miguel, María Victoria; Martín Martínez, María Auxiliadora; Corominas, Héctor; Sanchez-Piedra, Carlos; Sanmartí, Raimon; Fernandez Martinez, Carmen; García-Vicuña, Rosario
To describe the variability of the day care hospital units (DCHUs) of Rheumatology in Spain, in terms of structural resources and operating processes. Multicenter descriptive study with data from a self-completed questionnaire of DCHUs self-assessment based on DCHUs quality standards of the Spanish Society of Rheumatology. Structural resources and operating processes were analyzed and stratified by hospital complexity (regional, general, major and complex). Variability was determined using the coefficient of variation (CV) of the variable with clinical relevance that presented statistically significant differences when was compared by centers. A total of 89 hospitals (16 autonomous regions and Melilla) were included in the analysis. 11.2% of hospitals are regional, 22,5% general, 27%, major and 39,3% complex. A total of 92% of DCHUs were polyvalent. The number of treatments applied, the coordination between DCHUs and hospital pharmacy and the post graduate training process were the variables that showed statistically significant differences depending on the complexity of hospital. The highest rate of rheumatologic treatments was found in complex hospitals (2.97 per 1,000 population), and the lowest in general hospitals (2.01 per 1,000 population). The CV was 0.88 in major hospitals; 0.86 in regional; 0.76 in general, and 0.72 in the complex. there was variability in the number of treatments delivered in DCHUs, being greater in major hospitals and then in regional centers. Nonetheless, the variability in terms of structure and function does not seem due to differences in center complexity. Copyright © 2016 Elsevier España, S.L.U. and Sociedad Española de Reumatología y Colegio Mexicano de Reumatología. All rights reserved.
Yang, Juan; Liu, Ying; Huang, Jian; Xu, Jinbang; You, Xiumi; Lin, Qiuping; Zhang, Junxin; Dun, Jingjing; Huang, Shan
2017-11-12
To explore the effect difference between acupuncture combined with Chinese medicine of artificial cycle therapy on the basis of western medication and simple western medication for polycystic ovarian syndrome (PCOS) of phlegm damp type with insulin resistance, and to explore its mechanism. Sixty patients were randomly assigned into an observation group and a control group, 30 cases in each group. Patients of the control group began to take letrozole and metformin orally on the third menstrual day. Patients of the observation group were treated with acupuncture combined with Chinese medicine of artificial cycle therapy on the basis of the treatment of the control group. The main acupoints were Guanyuan (CV 4), Qihai (CV 6) and bilateral Zigong (EX-CA 1), Luanchao (Extra), Fenglong (ST 40), Yinlingquan (SP 9), Zusanli (ST 36), Sanyinjiao (SP 6). Dahe (KI 12) was matched in the follicular phase, and warm acupuncture was applied at Guanyuan (CV 4) and Qihai (CV 6); Zhongji (CV 3) and Xuehai (SP 10) were matched in the ovulatory phase, and electroacupuncture were used at Qihai (CV 6) and Zhongji (CV 3), Xuehai (SP 10) and Yinlingquan (SP 9), 2 Hz and continuous wave; The acupoints in the luteal phase were the above main acupoints, at the same time, moxibustion was used at Guanyuan (CV 4) and Qihai (CV 6), the treatment was given once every other day, 30 min a time. There was no treatment in the menstrual phase. Chinese medicine was applied for tonifying kidney and nourishing blood, strengthening spleen and eliminating phlegm. The patients of the two groups were treated for continuous three menstrual cycles. The indexes before and after treatment were detected, including serum microRNA-29 (miR-29) expression, TCM symptom score, insulin (INS), blood-sugar content and homeostasis model assessment-insulin resistance (HOMA-IR) index, the endocrine hormone values of follicle stimulating hormone (FSH), luteinizing hormone (LH), testosterone (T), LH/FSH ratio, prolactin (PRL). The pregnancy rates of the two groups were compared. After treatment the expressions of miR-29 and TCM symptom scores of the two groups were lower than those before treatment ( P <0.01, P <0.05), with better results in the observation group ( P <0.01, P <0.05). The levels of LH LH/FSH and T of the observation group were lower than those before treatment ( P <0.01, P <0.05), and the T value in the control group decreased after treatment ( P <0.05). The changes of LH and LH/FSH in the observation group were better than those in the control group (both P <0.05). After treatment, The INS, blood-sugar content and HOMA-IR were lower than those before treatment in the two groups ( P <0.05, P <0.01), with better results for INS and HOMA-IR improvements in the observation group (both P <0.05). The pregnancy rate in the observation group was 56.7% (17/30), which was significantly higher than 30.0% (9/30) in the control group ( P <0.05). Acupuncture combined with Chinese medicine of artificial cycle therapy can improve the endocrine levels and insulin resistance of PCOS with phlegm damp type. At the same time, the pregnancy rate is improved. By the view of molecular biology, there may be a pathway trough changing serum miR-29 expression.
Milk Flow Rates from bottle nipples used after hospital discharge.
Pados, Britt Frisk; Park, Jinhee; Thoyre, Suzanne M; Estrem, Hayley; Nix, W Brant
To test the milk flow rates and variability in flow rates of bottle nipples used after hospital discharge. Twenty-six nipple types that represented 15 common brands as well as variety in price per nipple and store location sold (e.g., Babies R' Us, Walmart, Dollar Store) were chosen for testing. Ten of each nipple type (n = 260 total) were tested by measuring the amount of infant formula expressed in 1 minute using a breast pump. Mean milk flow rate (mL/min) and coefficient of variation (CV) were calculated. Flow rates of nipples within brand were compared statistically. Milk flow rates varied from 1.68 mL/min for the Avent Natural Newborn Flow to 85.34 mL/min for the Dr. Brown's Standard Y-cut. Variability between nipple types also varied widely, from .03 for the Dr. Brown's Standard Level 3 to .37 for MAM Nipple 1 Slow Flow. The extreme range of milk flow rates found may be significant for medically fragile infants being discharged home who are continuing to develop oral feeding skills. The name of the nipple does not provide clear information about the flow rate to guide parents in decision making. Variability in flow rates within nipples of the same type may complicate oral feeding for the medically fragile infant who may not be able to adapt easily to change in flow rates. Both flow rate and variability should be considered when guiding parents to a nipple choice.
Performance of computer vision in vivo flow cytometry with low fluorescence contrast
Markovic, Stacey; Li, Siyuan; Niedre, Mark
2015-01-01
Abstract. Detection and enumeration of circulating cells in the bloodstream of small animals are important in many areas of preclinical biomedical research, including cancer metastasis, immunology, and reproductive medicine. Optical in vivo flow cytometry (IVFC) represents a class of technologies that allow noninvasive and continuous enumeration of circulating cells without drawing blood samples. We recently developed a technique termed computer vision in vivo flow cytometry (CV-IVFC) that uses a high-sensitivity fluorescence camera and an automated computer vision algorithm to interrogate relatively large circulating blood volumes in the ear of a mouse. We detected circulating cells at concentrations as low as 20 cells/mL. In the present work, we characterized the performance of CV-IVFC with low-contrast imaging conditions with (1) weak cell fluorescent labeling using cell-simulating fluorescent microspheres with varying brightness and (2) high background tissue autofluorescence by varying autofluorescence properties of optical phantoms. Our analysis indicates that CV-IVFC can robustly track and enumerate circulating cells with at least 50% sensitivity even in conditions with two orders of magnitude degraded contrast than our previous in vivo work. These results support the significant potential utility of CV-IVFC in a wide range of in vivo biological models. PMID:25822954
NASA Astrophysics Data System (ADS)
Bender, Amanda L. D.; Chitwood, Daniel H.; Bradley, Alexander S.
2017-06-01
Leaf wax n-alkanes are broadly used to reconstruct paleoenvironmental information. However, the utility of n-alkanes as a paleoenvironmental proxy may be modulated by the extent to which biological as well as environmental factors influence the structural and isotopic variability of leaf waxes. In paleoclimate applications, there is usually an implicit assumption that most variation of leaf wax traits through a time series can be attributed to environmental change and that biological sources of variability within plant communities are small. For example, changes in hydrology affect the δ2H of waxes via rainwater and the δ13C of leaf waxes by changing plant communities. We measured the degree of genetic control over δ13C variation in leaf waxes within closely related species with an experimental greenhouse growth study. We measured the proportion of variability in structural and isotopic leaf wax traits that is attributable to genetic variation using a set of 76 introgression lines (ILs) between two interfertile Solanum (tomato) species: S. lycopersicum cv M82 (hereafter cv M82) and S. pennellii. Leaves of S. pennellii, a wild desert tomato relative, produced significantly more iso-alkanes than cv M82, a domesticated tomato cultivar adapted to water-replete conditions. We report a methylation index to summarize the ratio of branched (iso- and anteiso-) to total alkanes. Between S. pennellii and cv M82, the iso-alkanes were found to be enriched in 13C by 1.2-1.4‰ over n-alkanes. The broad-sense heritability values (H2) of leaf wax traits describe the degree to which genetic variation contributes to variation of these traits. Variation of individual carbon isotopic compositions of alkanes were of low heritability (H2 = 0.13-0.19), suggesting that most variation in δ13C of leaf waxes in this study can be attributed to environmental variance. This supports the interpretation that variation in the δ13C of wax compounds recorded in sediments reflects paleoenvironmental and vegetation changes. Average chain length (ACL) values of n-alkanes were of intermediate heritability (H2 = 0.30), suggesting that ACL values are more strongly influenced by genetic cues.
Martínez-Jabaloyas, José M
2014-08-01
Low testosterone levels (low T) increase the cardiovascular (CV) risk of men with erectile dysfunction (ED). T levels associated with a higher CV risk are unknown. To determine the prevalence of CV risk factors associated with low T as defined by European Guidelines and their contribution to low T, overall and at different ages. Multicenter, cross-sectional, observational study conducted in Spain among men with ED aged ≥ 18 years visiting Urology/Andrology offices for sexual dysfunction. Anthropometric, clinical, and laboratory data, including total T (TT) values, were collected for 1,278 men. Risk factors were assessed in men with TT ≤ 8, 8-12, and ≥ 12 nmol/L, and two-group comparisons were made. Bivariate and multivariate logistic regression analyses were performed to calculate odds ratios for low T after adjusting for possible confounding factors. Mean age (standard deviation) was 58.0 (9.2) years. Age and prevalence of CV risk factors was similar in men with TT ≤ 8 nmol/L or 8-12 nmol/L and significantly higher than in men with TT >12 nmol/L. Low T was therefore considered as TT ≤ 12 nmol/L, with a prevalence of 33.3%. Obesity, hypertension, hyperlipidemia, and severe ED were the variables most strongly associated with low T: obesity in middle-aged men; hyperlipidemia, and hypertension in older men. Severe ED was a risk factor in both groups. Hypolipidemic therapy had the greater effect in young men. Multivariate analysis showed that severe ED and obesity were the strongest predictors of low T. T levels associated with increased CV risk could go as high as 12 nmol/L in men with ED, with distribution of risk factors showing differences according to age. Obesity and severe ED are the best predictors of low T-related CV risk. © 2014 International Society for Sexual Medicine.
Aubin, Carl-Éric; Clin, Julien; Rawlinson, Jeremy
2018-01-01
Compression-based fusionless tethers are an alternative to conventional surgical treatments of pediatric scoliosis. Anterior approaches place an anterior (ANT) tether on the anterolateral convexity of the deformed spine to modify growth. Posterior, or costo-vertebral (CV), approaches have not been assessed for biomechanical and corrective effectiveness. The objective was to biomechanically assess CV and ANT tethers using six patient-specific, finite element models of adolescent scoliotic patients (11.9 ± 0.7 years, Cobb 34° ± 10°). A validated algorithm simulated the growth and Hueter-Volkmann growth modulation over a period of 2 years with the CV and ANT tethers at two initial tensions (100, 200 N). The models without tethering also simulated deformity progression with Cobb angle increasing from 34° to 56°, axial rotation 11° to 13°, and kyphosis 28° to 32° (mean values). With the CV tether, the Cobb angle was reduced to 27° and 20° for tensions of 100 and 200 N, respectively, kyphosis to 21° and 19°, and no change in axial rotation. With the ANT tether, Cobb was reduced to 32° and 9° for 100 and 200 N, respectively, kyphosis unchanged, and axial rotation to 3° and 0°. While the CV tether mildly corrected the coronal curve over a 2-year growth period, it had sagittal lordosing effect, particularly with increasing initial axial rotation (>15°). The ANT tether achieved coronal correction, maintained kyphosis, and reduced the axial rotation, but over-correction was simulated at higher initial tensions. This biomechanical study captured the differences between a CV and ANT tether and indicated the variability arising from the patient-specific characteristics. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:254-264, 2018. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.
Su, Mengna; Venkatachalam, Mahesh; Liu, Changqi; Zhang, Ying; Roux, Kenneth H; Sathe, Shridhar K
2013-11-13
A sandwich enzyme-linked immunosorbent assay (ELISA) using anti-almond soluble protein rabbit polyclonal antibodies as capture antibodies and murine monoclonal antibody 4C10 as the detection antibodies was developed. The assay is specific and sensitive (3-200 ng almond protein/mL) for almond detection. The standardized assay is accurate (<15% CV) and reproducible (intra- and inter assay variability <15% CV). The assay did not register any cross-reactivity with the tested food matrices, suggesting the assay to be almond amandin specific. The assay could detect the presence of declared almond in the tested matched commercial samples. Further, the assay reliably detected the presence of almonds in the laboratory prepared food samples spiked with almond flour.
Short-term reliability of inflammatory mediators and response to exercise in the heat.
Guy, Joshua H; Edwards, Andrew M; Miller, Catherine M; Deakin, Glen B; Pyne, David B
2017-08-01
Prospective application of serum cytokines, lipopolysaccharide (LPS), and heat shock proteins (eHSPs) requires reliable measurement of these biomarkers that can signify exercise-induced heat stress in hot conditions. To accomplish this, both short-term (7 day) reliability (at rest, n = 12) and the acute responsiveness of each biomarker to exercise in the heat (pre and post 60-min cycling, 34.5°C and 70% RH, n = 20) were evaluated. Serum was analysed for the concentration of C-reactive protein (CRP), interleukin-6 (IL-6), heat shock protein 72 (eHSP72), immunoglobulin M (IgM) and LPS. Test-retest reliability was determined as the coefficient of variation (CV). Biomarkers with the least short-term within-participant variation were IL-6 (19%, ±20%; CV, ±95% confidence limits (CL)) and LPS (23%, ±13%). Greater variability was observed for IgM, eHSP72 and CRP (CV range 28-38%). IL-6 exhibited the largest increase in response to acute exercise (95%, ±11%, P = < 0.001) and although CRP had a modest CV (12%, ±7%), it increased substantially post-exercise (P = 0.02, ES; 0.78). In contrast, eHSP72 and LPS exhibited trivial changes post-exercise. It appears variation of common inflammatory markers after exercise in the heat is not always discernible from short-term (weekly) variation.
The value of urban open space: meta-analyses of contingent valuation and hedonic pricing results.
Brander, Luke M; Koetse, Mark J
2011-10-01
Urban open space provides a number of valuable services to urban populations, including recreational opportunities, aesthetic enjoyment, environmental functions, and may also be associated with existence values. In separate meta-analyses of the contingent valuation (CV) and hedonic pricing (HP) literature we examine which physical, socio-economic, and study characteristics determine the value of open space. The dependent variable in the CV meta-regression is defined as the value of open space per hectare per year in 2003 US$, and in the HP model as the percentage change in house price for a 10 m decrease in distance to open space. Using a multi-level modelling approach we find in both the CV and HP analyses that there is a positive and significant relationship between the value of urban open space and population density, indicating that scarcity and crowdedness matter, and that the value of open space does not vary significantly with income. Further, urban parks are more highly valued than other types of urban open space (forests, agricultural and undeveloped land) and methodological differences in study design have a large influence on estimated values from both CV and HP. We also find important regional differences in preferences for urban open space, which suggests that the potential for transferring estimated values between regions is likely to be limited. Copyright © 2011 Elsevier Ltd. All rights reserved.
Valdez, Ernest W.; Bogan, Michael A.
2009-01-01
Few studies have investigated the relationship between morphological variation and local feeding habits of bats in the United States. We used discriminant function analysis (DFA) to compare cranial morphology of Myotis occultus from southern Colorado, and central, and southern New Mexico. We analyzed guano collected from maternity colonies in southern Colorado and central New Mexico to compare food habits. Bats from southern Colorado had the smallest values on the first canonical variate (CV1) that also reflected the smallest measurements of key cranial and dental variables, including height of coronoid process, width of molar, and dentary thickness. Bats from central and southern New Mexico had intermediate and large CV1 values, respectively. Overall, CV1 discriminated individuals occurring in southern Colorado and central New Mexico from those in southern New Mexico. CV2 served best at discriminating bats of southern Colorado from those of central New Mexico. Comparison of food habits revealed that individuals from southern Colorado ate more soft-bodied prey items (e.g., flies) whereas bats from central New Mexico ate more hard-bodied prey items (e.g., beetles). As shown in earlier studies that investigated relationships between morphology and diet of insectivorous bats, we found differences in skull morphology of M. occultusthat were correlated with differences in food habits.
Reliability of heart rate measures during walking before and after running maximal efforts.
Boullosa, D A; Barros, E S; del Rosso, S; Nakamura, F Y; Leicht, A S
2014-11-01
Previous studies on HR recovery (HRR) measures have utilized the supine and the seated postures. However, the most common recovery mode in sport and clinical settings after running exercise is active walking. The aim of the current study was to examine the reliability of HR measures during walking (4 km · h(-1)) before and following a maximal test. Twelve endurance athletes performed an incremental running test on 2 days separated by 48 h. Absolute (coefficient of variation, CV, %) and relative [Intraclass correlation coefficient, (ICC)] reliability of time domain and non-linear measures of HR variability (HRV) from 3 min recordings, and HRR parameters over 5 min were assessed. Moderate to very high reliability was identified for most HRV indices with short-term components of time domain and non-linear HRV measures demonstrating the greatest reliability before (CV: 12-22%; ICC: 0.73-0.92) and after exercise (CV: 14-32%; ICC: 0.78-0.91). Most HRR indices and parameters of HRR kinetics demonstrated high to very high reliability with HR values at a given point and the asymptotic value of HR being the most reliable (CV: 2.5-10.6%; ICC: 0.81-0.97). These findings demonstrate these measures as reliable tools for the assessment of autonomic control of HR during walking before and after maximal efforts. © Georg Thieme Verlag KG Stuttgart · New York.
Just, Sarah; Toschkoff, Gregor; Funke, Adrian; Djuric, Dejan; Scharrer, Georg; Khinast, Johannes; Knop, Klaus; Kleinebudde, Peter
2013-11-30
The objective of this study was to enhance the inter-tablet coating uniformity in an active coating process at lab and pilot scale by statistical design of experiments. The API candesartan cilexetil was applied onto gastrointestinal therapeutic systems containing the API nifedipine to obtain fixed dose combinations of these two drugs with different release profiles. At lab scale, the parameters pan load, pan speed, spray rate and number of spray nozzles were examined. At pilot scale, the parameters pan load, pan speed, spray rate, spray time, and spray pressure were investigated. A low spray rate and a high pan speed improved the coating uniformity at both scales. The number of spray nozzles was identified as the most influential variable at lab scale. With four spray nozzles, the highest CV value was equal to 6.4%, compared to 13.4% obtained with two spray nozzles. The lowest CV of 4.5% obtained with two spray nozzles was further reduced to 2.3% when using four spray nozzles. At pilot scale, CV values between 2.7% and 11.1% were achieved. Since the test of uniformity of dosage units accepts CV values of up to 6.25%, this active coating process is well suited to comply with the pharmacopoeial requirements. Copyright © 2013 Elsevier B.V. All rights reserved.
A critical thinking disposition scale for nurses: short form.
Hwang, Shiow-Y; Yen, Miaofen; Lee, Bih-O; Huang, Mei-C; Tseng, Hung-F
2010-11-01
The aim of this study was to test the Chinese version of the Critical Thinking Disposition Inventory (CTDI-CV) among nurses in Taiwan. Critical thinking is the use of purposeful self-regulatory judgments to identify patient's problems and provide patient care. Critical thinking influences nurses' decision making. To date, no inventory to understand nurse's critical thinking disposition has been developed. This was a survey design with a stratified random sampling to test the reliability and validity of the CTDI-CV. The participants comprised 864 registered nurses who were chosen by stratified random sampling from seven hospitals in Taiwan. Data were collected through self-administered structured questionnaires. A new scale, short form (SF) CTDI-CV, contains 18 items with three subscales: 'systematic analysis', 'thinking within the box' and 'thinking out of the box', was generated from the analysis with 44% explained variance. Cronbach's alpha coefficients and intra-class correlation coefficients for overall and subscale were above 0.8. Goodness-of-fit test for the final model of SF-CTDI-CV revealed an acceptable result in the overall fit (χ(2)/df = 4.04, p < 0.05, GFI = 0.93, AGFI = 0.91, SRMR = 0.076, RMSEA = 0.059). On the basis of these results, the SF-CTDI-CV is a reliable instrument for assessing critical thinking disposition for nurses. A short and valid critical thinking instrument for nurses will facilitate critical thinking research in the clinical practice arena. When designing continuing education activities, clinical educators will be able to efficiently and effectively evaluate the quality of critical thinking among practicing nurses. © 2010 Blackwell Publishing Ltd.
Sobhani-Nasab, Ali; Rahimi-Nasrabadi, Mehdi; Naderi, Hamid Reza; Pourmohamadian, Vafa; Ahmadi, Farhad; Ganjali, Mohammad Reza; Ehrlich, Hermann
2018-07-01
Sonochemically prepared nanoparticles of terbium tungstate (TWNPs) were evaluated through scanning electron microscopy (SEM), thermogravimetric analysis (TGA), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR), UV-Vis spectroscopy, and the optimal products were further characterized in terms of their electrochemical properties using conventional and continuous cyclic voltammetry (CV, and CCV), galvanostatic charge/discharge technique, and electrochemical impedance spectroscopy (EIS). The CV studies indicated the TWNPs to have specific capacitance (SC) values of 336 and 205 F g -1 at 1 and 200 mV s -1 , and galvanostatic charge-discharge tests revealed the SC of the TWNP-based electrodes to be 300 F g -1 at 1 Ag -1 . Also continuous cyclic voltammetry evaluations proved the sample as having a capacitance retention value of 95.3% after applying 4000 potential cycles. In the light of the results TWNPs were concluded as favorable electrode materials for use in hybrid vehicle systems. Copyright © 2018 Elsevier B.V. All rights reserved.
Hypertension and cardiovascular risk assessment in dialysis patients.
Locatelli, Francesco; Covic, Adrian; Chazot, Charles; Leunissen, Karel; Luño, José; Yaqoob, Mohammed
2004-05-01
Cardiovascular (CV) disease is the main cause of morbidity and mortality in dialysis patients. Hypertension in patients affected by chronic renal insufficiency (CRI) has been recognized as one of the major classical CV risk factors in CRI from the very beginning of the dialysis era. However, its treatment is still unsatisfactory. A discussion is employed to achieve a consensus on key points relating to the epidemiological, pathophysiological and clinical characteristics of hypertension in renal patients, in the light of global CV risk assessment. CV disease is accelerated by CRI, in particular by uraemia-specific risk factors. This is reflected by the fact that general population-based equations for calculating CV risk underestimate the real CV risk in CRI and dialysis patients. Hypertension in dialysis patients is clearly a major CV risk factor. Isolated systolic hypertension with increased pulse pressure is the most prevalent blood pressure (BP) anomaly in dialysis patients, due to stiffening of the arterial tree. BP should be assessed by clinical measurements on a routine basis, leaving 24 h monitoring for selected cases. The targets of BP control should be those recommended by the present guidelines, i.e. <140/90 mmHg, or the lowest possible values that are well tolerated. The pathophysiological cornerstone of hypertension in dialysis patients is extra-cellular volume expansion, which is typically sodium-sensitive, given the loss of renal function. Therefore, the principles of hypertension treatment in dialysis are an achievement of dry body weight, proper dialysis prescription with respect to dialysis time and intra-dialytic sodium balance, and dietary sodium and water restriction. Pharmacological treatment should only be the second option, after the adequate and complete application of all other means. No comparative pharmacological trials have specifically addressed the issue of hypertension control in dialysis patients. Therefore, this workshop group had to rely largely on data obtained in the general population. Drugs interfering with the renin-angiotensin system were felt to be the first choice, as they have widely been shown to interfere significantly with CV remodelling. Despite long-standing concerns, beta-blockers are being used increasingly even in patients with congestive heart failure and ischaemic cardiomyopathy. Other drug classes may be used in association or as first-line agents according to clinical requirements. Hypertension in renal patients has to be given particular and continued attention, and it should be adequately treated in light of the increased CV risk of this patient population. Research into the mechanisms of uraemic cardiomyopathy and cardiovascular remodelling should provide a precious new insight and lead to more precisely targeted and more effective therapies than in the past.
NASA Astrophysics Data System (ADS)
Majari Kasmaee, L.; Gobal, F.
Electrochemical oxidation of L-ascorbic acid on polycrystalline silver in alkaline aqueous solutions is studied by cyclic voltammetry (CV), chronoamperometry (CA) and impedance spectroscopy (IS). The anodic electro-oxidation starts at -500 mV versus SCE and shows continued anodic oxidation in the cathodic half cycle in the CV regime signifying slowly oxidizing adsorbates. Diffusion coefficient of ascorbate ion measured under both voltammetric regimes is around 1.4 × 10 -5 cm 2 s -1. Impedance spectroscopy measures the capacitances associated with double layer and adsorption around 50 μF cm -2 and 4 mF cm -2 as well as the adsorption and decomposition resistances (rates).
Naccarato, Attilio; Furia, Emilia; Sindona, Giovanni; Tagarelli, Antonio
2016-09-01
Four class-modeling techniques (soft independent modeling of class analogy (SIMCA), unequal dispersed classes (UNEQ), potential functions (PF), and multivariate range modeling (MRM)) were applied to multielement distribution to build chemometric models able to authenticate chili pepper samples grown in Calabria respect to those grown outside of Calabria. The multivariate techniques were applied by considering both all the variables (32 elements, Al, As, Ba, Ca, Cd, Ce, Co, Cr, Cs, Cu, Dy, Fe, Ga, La, Li, Mg, Mn, Na, Nd, Ni, Pb, Pr, Rb, Sc, Se, Sr, Tl, Tm, V, Y, Yb, Zn) and variables selected by means of stepwise linear discriminant analysis (S-LDA). In the first case, satisfactory and comparable results in terms of CV efficiency are obtained with the use of SIMCA and MRM (82.3 and 83.2% respectively), whereas MRM performs better than SIMCA in terms of forced model efficiency (96.5%). The selection of variables by S-LDA permitted to build models characterized, in general, by a higher efficiency. MRM provided again the best results for CV efficiency (87.7% with an effective balance of sensitivity and specificity) as well as forced model efficiency (96.5%). Copyright © 2016 Elsevier Ltd. All rights reserved.
Indicators of Cardiovascular Risk in Metabolic Syndrome: Long Term Follow-up in Italian Patients.
Mombelli, Giuliana; Pavanello, Chiara; Castelnuovo, Samuela; Bosisio, Raffaella; Simonelli, Sara; Pazzucconi, Franco; Sirtori, Cesare Riccardo
2017-01-01
Cardiovascular risk (CV) factors associated with the metabolic syndrome (MetS) may vary in different populations. In some, hypertension may be the major determinant, in others are low high-density lipoprotein cholesterol (HDL-C), high triglycerides, or another component. Subjects included in this analysis were identified in 2006, among those attending the Lipid Clinic of the Niguarda Hospital, and followed up through to 2013. Patient characteristics (including the occurrence of CV events) were obtained from electronic medical records. MetS was diagnosed according to the American Heart Association/National Heart, Lung and Blood Institute (AHA/NHLBI) guidelines. The carotid intima media thickness (cIMT) was also followed in these patients over the years. After 7 years a total of 858 subjects had a complete follow-up; 271 of those had MetS. Patients developing a CV event showed elevated baseline cIMT (e.g. cIMTmax ≥ 2.4 mm in males and ≥ 2.2 mm in females); moreover the cIMT in MetS patients was higher at baseline and the rise over 7 years was larger compared with patients without MetS. By examining each body variable for MetS we found that a waist to height ratio (WHtR) ≥ 0.5 was present in nearly all subjects with a CV event. The follow-up data of a series of Italian patients with and without MetS, clearly indicates that the former have a raised cIMT and their arterial IMT progression is greater and the presence of a larger WHtR is apparently linked to a higher incidence of CV events. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.
The effect of light touch on balance control during overground walking in healthy young adults.
Oates, A R; Unger, J; Arnold, C M; Fung, J; Lanovaz, J L
2017-12-01
Balance control is essential for safe walking. Adding haptic input through light touch may improve walking balance; however, evidence is limited. This research investigated the effect of added haptic input through light touch in healthy young adults during challenging walking conditions. Sixteen individuals walked normally, in tandem, and on a compliant, low-lying balance beam with and without light touch on a railing. Three-dimensional kinematic data were captured to compute stride velocity (m/s), relative time spent in double support (%DS), a medial-lateral margin of stability (MOS ML ) and its variance (MOS ML CV), as well as a symmetry index (SI) for the MOS ML . Muscle activity was evaluated by integrating electromyography signals for the soleus, tibialis anterior, and gluteus medius muscles bilaterally. Adding haptic input decreased stride velocity, increased the %DS, had no effect on the MOS ML magnitude, decreased the MOS ML CV, had no effect on the SI, and increased activity of most muscles examined during normal walking. During tandem walking, stride velocity and the MOS ML CV decreased, while %DS, MOS ML magnitude, SI, and muscle activity did not change with light touch. When walking on a low-lying, compliant balance beam, light touch had no effect on walking velocity, MOS ML magnitude, or muscle activity; however, the %DS increased and the MOS ML CV and SI decreased when lightly touching a railing while walking on the balance beam. The decreases in the MOS ML CV with light touch across all walking conditions suggest that adding haptic input through light touch on a railing may improve balance control during walking through reduced variability.
Kishima, Hideyuki; Mine, Takanao; Takahashi, Satoshi; Ashida, Kenki; Ishihara, Masaharu; Masuyama, Tohru
2018-04-24
The a-wave in left atrial pressure (LAP) is often not observed after cardioversion (CV). We hypothesized that repeated atrial fibrillation (AF) occurs in patients who do not show a-wave pattern after CV. We investigated the impact of "LAP pattern without a-wave" on the outcome after catheter ablation (CA) for AF. We studied 100 patients (64 males, age 66 ± 8 years, 42 with non-paroxysmal AF) who underwent CA for AF. Sustained- or induced-AF were terminated with internal CV, and LAP was measured during sinus rhythm (SR) after CV. LAP pattern without a-wave was defined as absence of a-wave (the "a-wave" was defined as a protruding part by 0.2 mmHg or more from the baseline) in LAP wave form. AF was terminated with CV in all patients. Recurrent AF was detected in 35/100 (35%) during the follow-up period (13.1 ± 7.8 month). Univariate analysis revealed higher prevalence of LAP pattern without a-wave (71 vs. 17%, P < 0.0001), larger left atrial volume, elevated E wave, and decreased deceleration time as significant variables. On multivariate analysis, LAP pattern without a-wave was only independently associated with recurrent AF (P = 0.0014, OR 9.865, 95% CI 2.327-54.861). Moreover, patients with LAP pattern without a-wave had a higher risk of recurrent AF than patients with a-wave (25/36 patients, 69 vs. 10/64 patients, 16%, log-rank P < 0.0001). Left atrial pressure pattern without a-wave in sinus rhythm after cardioversion could predict recurrence after catheter ablation for AF.
Expression of NUCB2/nesfatin-1 in the taste buds of rats.
Cao, Xun; Zhou, Xiao; Cao, Yang; Liu, Xiao-Min; Zhou, Li-Hong
2016-01-01
Nesfatin-1, an anorexigenic peptide derived from nucleobindin 2 (NUCB2), is closely involved in feeding behavior, glycometabolism, and satiety regulation. Some studies show that NUCB2/nesfatin-1 is highly expressed and interacts with many appetite-regulating peptides that are co-expressed in the gastrointestinal tract. However, it remains unclear whether nesfatin-1 is expressed and interacts similarly in taste buds. Glucagon-like peptide-1 (GLP-1), a well-known appetite down-regulating peptide, is associated with changes in the expression of nesfatin-1. Therefore, we measured the expression of the NUCB2 gene and the distribution of nesfatin-1-immunoreactive cells and investigated whether these variables change in taste buds of circumvallate papillae (CV) from rats with type 2 diabetes (T2DM) after treatment with liraglutide, a GLP-1 receptor agonist. The results showed that nesfatin-1 immunoreactive cells were localized in the taste buds of rat CV. Quantitative RT-PCR showed a significantly lower expression of NUCB2 mRNA in the taste buds of diabetic control rats (T2DM-C) than in those of the normal control group (NC) and a higher level of NUCB2 in the liraglutide treated group (T2DM + LIR) than either the T2DM-C or the NC groups. Changes in the expression of NUCB2 in the rat hypothalamus were opposite to those in CV taste buds. In summary, we found that rat CV taste buds express NUCB2/nesfatin-1, and that this expression decreases significantly in T2DM and increases after treatment with liraglutide in rat CV. This indicates that nesfatin-1 could be an important factor in the regulation of gustatory function, feeding and perhaps energy homeostasis.
Santos, Maria José; Pedro, Luís Mendes; Canhão, Helena; Fernandes E Fernandes, José; Canas da Silva, José; Fonseca, João Eurico; Saldanha, Carlota
2011-12-01
Rheological characteristics of blood are strongly linked to atherothrombosis in the general population, but its contribution to atherosclerosis in systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA) is currently unclear. This work examines the relationship between blood rheology, traditional cardiovascular (CV) risk factors, inflammation and subclinical atherosclerosis in SLE and RA. Whole blood viscosity (WBV), plasma viscosity (PV), erythrocyte deformability (ED), aggregation (EA) and erythrocyte NO production were measured in 197 patients (96 SLE and 101 RA) and compared to 97 controls, all females without previous CV events. Clinical information was obtained and fasting lipids and acute phase reactants were measured. The relationship between hemorheological parameters, CV risk factors and inflammation was assessed in patients and the impact of these variables on carotid intima-media thickness (cIMT) was evaluated in univariate followed by multivariate regression analyses. WBV and ED are significantly lower in patients, while EA is elevated as compared with controls. Hemorheological disturbances correlate with CV risk factors and markers of inflammation and are more profound in patients with metabolic syndrome. Multivariable analysis showed that menopause (OR 34.72, 95%CI 4.44-271.77), obesity (OR 4.09, 95%CI 1.00-16.68) and WBV (OR 3.98; 95%CI 1.23-12.83) are positively associated whereas current corticosteroid dose (OR 0.87; 95%CI 0.78-0.98), and erythrocyte NO production (OR 0.16; 95%CI 0.05-0.52) are negatively associated with cIMT. Disturbed hemorheological parameters in SLE and RA women are related to the presence of CV risk factors and inflammation. WBV and erythrocyte NO are independently associated with the early stages of atherosclerosis. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.
Saha, Supradip; Hedau, Nirmal K; Mahajan, Vinay; Singh, Gyanendra; Gupta, Hari S; Gahalain, Anita
2010-01-30
Screening of natural biodiversity for their better quality attributes is of prime importance for quality breeding programmes. A set of 53 tomato genotypes was measured for their textural [skin firmness, pericarp thickness, total soluble solids (TSS)], nutritional [phosphorus (P), potassium (K), iron (Fe), zinc (Zn), copper (Cu), manganese (Mn) and titrable acidity (TA)] and functional (beta-carotene, lycopene and ascorbic acid) quality attributes. Three sets of data (textural, nutritional and functional attributes) were obtained and analysed for their mutual relationships. Wide variations were observed in most of the measurements, e.g. skin firmness (coefficient of variability (CV) 269-612 g), pericarp thickness (CV 1.4-4.9 mm), potassium (CV 229-371 mg 100 g(-1)), iron (CV 611-1772 mg 100 g(-1)), ascorbic acid (CV 12-86 mg 100 g(-1)), suggesting that there are considerable levels of genetic diversity. Significant correlations (P < 0.05, 0.01) were also detected among different attributes of tomato genotypes, such as phosphorus and zinc with a correlation coefficient of 0.74, ascorbic acid and copper of 0.57, pericarp thickness and lycopene of - 0.52. However, there were no correlations between textural and nutritional attributes. Five factors were computed by principal component analysis that explained 66% of the variation in the attributes, among which all micronutrients other than iron, TSS, firmness and beta-carotene were most important. Functional attributes except beta-carotene played a less important role in explaining total variation. This knowledge could aid in the efficient conservation of important parts of the agricultural biodiversity of India. These results are also potentially useful for tomato breeders working on the development of new varieties. (c) 2009 Society of Chemical Industry.
Montero, R; Mundy, D; Albright, A; Grose, C; Trought, M C T; Cohen, D; Chooi, K M; MacDiarmid, R; Flexas, J; Bota, J
2016-04-15
In order to determine the effects of Grapevine Leafroll associated Virus 3 (GLRaV-3) on fruit composition and chemical profile of juice and wine from Vitis vinifera L. cv. Sauvignon blanc grown in New Zealand, composition variables were measured on fruit from vines either infected with GLRaV-3 (established or recent infections) or uninfected vines. Physiological ripeness (20.4°Brix) was the criterion established to determine the harvest date for each of the three treatments. Date of grape ripeness was strongly affected by virus infection. In juice and wine, GLRaV-3 infection prior to 2008 reduced titratable acidity compared with the uninfected control. Differences observed in amino acids from the three infection status groups did not modify basic wine chemical properties. In conclusion, GLRaV-3 infection slowed grape ripening, but at equivalent ripeness to result in minimal effects on the juice and wine chemistry. Time of infection produced differences in specific plant physiological variables. Copyright © 2015 Elsevier Ltd. All rights reserved.
NASA Astrophysics Data System (ADS)
Musdalifah, N.; Handajani, S. S.; Zukhronah, E.
2017-06-01
Competition between the homoneous companies cause the company have to keep production quality. To cover this problem, the company controls the production with statistical quality control using control chart. Shewhart control chart is used to normal distributed data. The production data is often non-normal distribution and occured small process shift. Grand median control chart is a control chart for non-normal distributed data, while cumulative sum (cusum) control chart is a sensitive control chart to detect small process shift. The purpose of this research is to compare grand median and cusum control charts on shuttlecock weight variable in CV Marjoko Kompas dan Domas by generating data as the actual distribution. The generated data is used to simulate multiplier of standard deviation on grand median and cusum control charts. Simulation is done to get average run lenght (ARL) 370. Grand median control chart detects ten points that out of control, while cusum control chart detects a point out of control. It can be concluded that grand median control chart is better than cusum control chart.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Craciunescu, Oana I., E-mail: oana.craciunescu@duke.edu; Yoo, David S.; Cleland, Esi
2012-03-01
Purpose: Dynamic contrast-enhanced (DCE) MRI-extracted parameters measure tumor microvascular physiology and are usually calculated from an intratumor region of interest (ROI). Optimal ROI delineation is not established. The valid clinical use of DCE-MRI requires that the variation for any given parameter measured within a tumor be less than that observed between tumors in different patients. This work evaluates the impact of tumor ROI selection on the assessment of intra- and interpatient variability. Method and Materials: Head and neck cancer patients received initial targeted therapy (TT) treatment with erlotinib and/or bevacizumab, followed by radiotherapy and concurrent cisplatin with synchronous TT. DCE-MRImore » data from Baseline and the end of the TT regimen (Lead-In) were analyzed to generate the vascular transfer function (K{sup trans}), the extracellular volume fraction (v{sub e}), and the initial area under the concentration time curve (iAUC{sub 1min}). Four ROI sampling strategies were used: whole tumor or lymph node (Whole), the slice containing the most enhancing voxels (SliceMax), three slices centered in SliceMax (Partial), and the 5% most enhancing contiguous voxels within SliceMax (95Max). The average coefficient of variation (aCV) was calculated to establish intrapatient variability among ROI sets and interpatient variability for each ROI type. The average ratio between each intrapatient CV and the interpatient CV was calculated (aRCV). Results: Baseline primary/nodes aRCVs for different ROIs not including 95Max were, for all three MR parameters, in the range of 0.14-0.24, with Lead-In values between 0.09 and 0.2, meaning a low intrapatient vs. interpatient variation. For 95Max, intrapatient CVs approximated interpatient CVs, meaning similar data dispersion and higher aRCVs (0.6-1.27 for baseline) and 0.54-0.95 for Lead-In. Conclusion: Distinction between different patient's primary tumors and/or nodes cannot be made using 95Max ROIs. The other three strategies are viable and equivalent for using DCE-MRI to measure head and neck cancer physiology.« less
Liu, Ruimin; Men, Cong; Yu, Wenwen; Xu, Fei; Wang, Qingrui; Shen, Zhenyao
2018-01-01
To examine the variabilities of source contributions in the Yangtze River Estuary (YRE), the uncertainty based on the positive matrix factorization (PMF) was applied to the source apportionment of the 16 priority PAHs in 120 surface sediment samples from four seasons. Based on the signal-to-noise ratios, the PAHs categorized as "Bad" might drop out of the estimation of bootstrap. Next, the spatial variability of residuals was applied to determine which species with non-normal curves should be excluded. The median values from the bootstrapped solutions were chosen as the best estimate of the true factor contributions, and the intervals from 5th to 95th percentile represent the variability in each sample factor contribution. Based on the results, the median factor contributions of wood grass combustion and coke plant emissions were highly correlated with the variability (R 2 = 0.6797-0.9937) in every season. Meanwhile, the factor of coal and gasoline combustion had large variability with lower R 2 values in every season, especially in summer (0.4784) and winter (0.2785). The coefficient of variation (CV) values based on the Bootstrap (BS) simulations were applied to indicate the uncertainties of PAHs in every factor of each season. Acy, NaP and BgP always showed higher CV values, which suggested higher uncertainties in the BS simulations, and the PAH with the lowest concentration among all PAHs usually became the species with higher uncertainties. Copyright © 2017 Elsevier Ltd. All rights reserved.
MAP Estimators for Piecewise Continuous Inversion
2016-08-08
MAP estimators for piecewise continuous inversion M M Dunlop1 and A M Stuart Mathematics Institute, University of Warwick, Coventry, CV4 7AL, UK E...Published 8 August 2016 Abstract We study the inverse problem of estimating a field ua from data comprising a finite set of nonlinear functionals of ua...then natural to study maximum a posterior (MAP) estimators. Recently (Dashti et al 2013 Inverse Problems 29 095017) it has been shown that MAP
González-Heredia, Tonatiuh; Hernández-Corona, Diana M; González-Ortiz, Manuel; Martínez-Abundis, Esperanza
2017-08-01
Impaired glucose tolerance (IGT) and glycemic variability may be associated with increased risk of micro- and macrovascular complications. The aim of this study was to assess the effect of linagliptin versus metformin on glycemic variability in patients with IGT. A randomized, double-blind clinical trial with parallel groups was carried out in 16 adult patients with IGT, overweight or obesity. All patients signed an informed consent. The therapies were randomly assigned: (a) metformin 500 mg bid (n = 8) or (b) linagliptin 5 mg a.m. and placebo p.m. (n = 8), both for 90 days. At the beginning of the trial and 3 months later, fasting glucose, glycated hemoglobin A1c, oral glucose tolerance test (OGTT), and glycemic variability [area under the curve (AUC) of glucose, mean amplitude of glycemic excursion (MAGE), standard deviation (SD) of glucose, coefficient of variation (CV) of glucose, and mean blood glucose (MBG)] were measured. Mann-Whitney U, Wilcoxon, and Fisher exact tests were used for statistical analyses. Both groups were similar in basal characteristics. After linagliptin administration, a significant decrease in glucose levels at 120 min of OGTT (9.0 ± 0.9 vs. 6.9 ± 2.2 mmol/L, P = 0.012) was observed. Glycemic variability showed a similar behavior and there were no significant differences in the AUC, MAGE, SD of glucose, CV of glucose, and MBG between groups. Linagliptin administration resulted in better glycemic control according to the decrease of glucose levels by the OGTT at 120 min in patients with IGT. Meanwhile, glycemic variability was not modified in any of the study groups.
Khoo, Benjamin C C; Beck, Thomas J; Qiao, Qi-Hong; Parakh, Pallav; Semanick, Lisa; Prince, Richard L; Singer, Kevin P; Price, Roger I
2005-07-01
Hip structural analysis (HSA) is a technique for extracting strength-related structural dimensions of bone cross-sections from two-dimensional hip scan images acquired by dual energy X-ray absorptiometry (DXA) scanners. Heretofore the precision of the method has not been thoroughly tested in the clinical setting. Using paired scans from two large clinical trials involving a range of different DXA machines, this study reports the first precision analysis of HSA variables, in comparison with that of conventional bone mineral density (BMD) on the same scans. A key HSA variable, section modulus (Z), biomechanically indicative of bone strength during bending, had a short-term precision percentage coefficient of variation (CV%) in the femoral neck of 3.4-10.1%, depending on the manufacturer or model of the DXA equipment. Cross-sectional area (CSA), a determinant of bone strength during axial loading and closely aligned with conventional DXA bone mineral content, had a range of CV% from 2.8% to 7.9%. Poorer precision was associated with inadequate inclusion of the femoral shaft or femoral head in the DXA-scanned hip region. Precision of HSA-derived BMD varied between 2.4% and 6.4%. Precision of DXA manufacturer-derived BMD varied between 1.9% and 3.4%, arising from the larger analysis region of interest (ROI). The precision of HSA variables was not generally dependent on magnitude, subject height, weight, or conventional femoral neck densitometric variables. The generally poorer precision of key HSA variables in comparison with conventional DXA-derived BMD highlights the critical roles played by correct limb repositioning and choice of an adequate and appropriately positioned ROI.
Increased ventilatory variability and complexity in patients with hyperventilation disorder.
Bokov, Plamen; Fiamma, Marie-Noëlle; Chevalier-Bidaud, Brigitte; Chenivesse, Cécile; Straus, Christian; Similowski, Thomas; Delclaux, Christophe
2016-05-15
It has been hypothesized that hyperventilation disorders could be characterized by an abnormal ventilatory control leading to enhanced variability of resting ventilation. The variability of tidal volume (VT) often depicts a nonnormal distribution that can be described by the negative slope characterizing augmented breaths formed by the relationship between the probability density distribution of VT and VT on a log-log scale. The objectives of this study were to describe the variability of resting ventilation [coefficient of variation (CV) of VT and slope], the stability in respiratory control (loop, controller and plant gains characterizing ventilatory-chemoresponsiveness interactions) and the chaotic-like dynamics (embedding dimension, Kappa values characterizing complexity) of resting ventilation in patients with a well-defined dysfunctional breathing pattern characterized by air hunger and constantly decreased PaCO2 during a cardiopulmonary exercise test. Compared with 14 healthy subjects with similar anthropometrics, 23 patients with hyperventilation were characterized by increased variability of resting tidal ventilation (CV of VT median [interquartile]: 26% [19-35] vs. 36% [28-48], P = 0.020; slope: -6.63 [-7.65; -5.36] vs. -3.88 [-5.91; -2.66], P = 0.004) that was not related to increased chemical drive (loop gain: 0.051 [0.039-0.221] vs. 0.044 [0.012-0.087], P = 0.149) but that was related to an increased ventilatory complexity (Kappa values, P < 0.05). Plant gain was decreased in patients and correlated with complexity (with Kappa 5 - degree 5: Rho = -0.48, P = 0.006). In conclusion, well-defined patients suffering from hyperventilation disorder are characterized by increased variability of their resting ventilation due to increased ventilatory complexity with stable ventilatory-chemoresponsiveness interactions. Copyright © 2016 the American Physiological Society.
Shen, Cimin; Xu, Jinsen; Zheng, Shuxia; Lin, Lijiao; Yang, Xiaomei; Liu, Chunlan
2016-02-01
To observe the effect of electroacupuncture(EA) at Zhongwan(CV 12) on the energy metabolism along the conception vessel(CV) in volunteers with yang-deficiency constitution,and to explore the relationship of electroacupuncture regulation and body constitution. Eighteen volunteers with mild constitution and 18 volunteers with yang-deficiency constitution were collected out of 200 students of Fujian University of TCM by body constitution questionnaire. Skin microcirculatory blood perfusion units (MBPU) at Danzhong (CV 17), Xiawan(CV 10) and Qihai(CV 6) of CV were measured by a laser Doppler flowmetry in the normal condition and after EA stimulation at Zhongwan(CV 12) for 20 min. (1)Before treatment, (1)MBPU values at Danzhong(CV 17), Xiawan(CV 10) and Qihai(CV 6) in the yang-deficiency constitution group were lower than those in the mild constitution group,but there was no statistical significance (both P>0. 05) except Danzhong(CV 17) (P<0. 01). (Z)As for the three acupoints in the mild constitution group, MBPU level of Danzhong(CV 17) was higher than that of Xiawan(CV 10) without statistical significance(P->0. 05),and MBPU values of Danzhong(CV 17) and Xiawan(CV 10) were higher than that of Qihai(CV 6) (both P<0. 01). (3About the three acupoints in the yang-deficiency constitution group, MBPU result of Danzhong(CV 17) was lower than the value of Xiawan(CV 10), but higher compared with Qihai(CV 6)(P<0. 05, P<0. 01). MBPU of Xiawan(CV 10) was higher than Qihai (CV 6) as well(P<0. 01). (2) MBPU values of Danzhong(CV 17), Xiawan(CV 10) and Qihai(CV 6) were increased apparently compared with those before treatment after EA stimulation at Zhongwan(CV 12) for 20 min in the two groups(all P<0. 01). (3) The rise rates of MBPU level about Danzhong(CV 17) and Qihai(CV 6) in the yang-deficiency constitution group were higher than those in the mild constitution group without statistical significance after EA at Zhongwan(CV 12) for 20 min(both P>0. 05). The energy metabolism in CV of volunteers with yang-deficiency constitution is declined, especially Danzhong(CV 17). EA can rise energy metabolism in CV of mild or yang-deficiency constitution volunteers through regulating MBPU along meridian.
Bożek, Agnieszka; Reich, Adam
2017-08-01
A wide variety of psoriasis assessment tools have been proposed to evaluate the severity of psoriasis in clinical trials and daily practice. The most frequently used clinical instrument is the psoriasis area and severity index (PASI); however, none of the currently published severity scores used for psoriasis meets all the validation criteria required for an ideal score. The aim of this study was to compare and assess the reliability of 3 commonly used assessment instruments for psoriasis severity: the psoriasis area and severity index (PASI), body surface area (BSA) and physician global assessment (PGA). On the scoring day, 10 trained dermatologists evaluated 9 adult patients with plaque-type psoriasis using the PASI, BSA and PGA. All the subjects were assessed twice by each physician. Correlations between the assessments were analyzed using the Pearson correlation coefficient. Intra-class correlation coefficient (ICC) was calculated to analyze intra-rater reliability, and the coefficient of variation (CV) was used to assess inter-rater variability. Significant correlations were observed among the 3 scales in both assessments. In all 3 scales the ICCs were > 0.75, indicating high intra-rater reliability. The highest ICC was for the BSA (0.96) and the lowest one for the PGA (0.87). The CV for the PGA and PASI were 29.3 and 36.9, respectively, indicating moderate inter-rater variability. The CV for the BSA was 57.1, indicating high inter-rater variability. Comparing the PASI, PGA and BSA, it was shown that the PGA had the highest inter-rater reliability, whereas the BSA had the highest intra-rater reliability. The PASI showed intermediate values in terms of interand intra-rater reliability. None of the 3 assessment instruments showed a significant advantage over the other. A reliable assessment of psoriasis severity requires the use of several independent evaluations simultaneously.
Multiwavelength study of RX J2015.6+3711: a magnetic cataclysmic variable with a 2-h spin period
NASA Astrophysics Data System (ADS)
Coti Zelati, F.; Rea, N.; Campana, S.; de Martino, D.; Papitto, A.; Safi-Harb, S.; Torres, D. F.
2016-02-01
The X-ray source RX J2015.6+3711 was discovered by ROSAT in 1996 and recently proposed to be a cataclysmic variable (CV). Here, we report on an XMM-Newton observation of RX J2015.6+3711 performed in 2014, where we detected a coherent X-ray modulation at a period of 7196 ± 11 s and discovered other significant (>6σ) small-amplitude periodicities which we interpret as the CV spin period and the sidebands of a possible ˜12-h periodicity, respectively. The 0.3-10 keV spectrum can be described by a power law (Γ = 1.15 ± 0.04) with a complex absorption pattern, a broad emission feature at 6.60 ± 0.01 keV, and an unabsorbed flux of (3.16 ± 0.05) × 10-12 erg cm-2 s-1. We observed a significant spectral variability along the spin phase, which can be ascribed mainly to changes in the density of a partial absorber and the power law normalization. Archival X-ray observations carried out by the Chandra satellite, and two simultaneous X-ray and UV/optical pointings with Swift, revealed a gradual fading of the source in the soft X-rays over the last 13 yr, and a rather stable X-ray-to-optical flux ratio (FX/FV ≈ 1.4-1.7). Based on all these properties, we identify this source with a magnetic CV, most probably of the intermediate polar type. The 2-h spin period makes RX J2015.6+3711, the second slowest rotator of the class, after RX J0524+4244 (`Paloma'; Pspin ˜ 2.3 h). Although we cannot unambiguously establish the true orbital period with these observations, RX J2015.6+3711 appears to be a key system in the evolution of magnetic CVs.
Read, Paul J; Oliver, Jon L; Croix, Mark Ba De Ste; Myer, Gregory D; Lloyd, Rhodri S
2016-12-01
Read, P, Oliver, JL, Croix, MD, Myer, GD, and Lloyd, RS. Consistency of field-based measures of neuromuscular control using force-plate diagnostics in elite male youth soccer players. J Strength Cond Res 30(12): 3304-3311, 2016-Deficits in neuromuscular control during movement patterns such as landing are suggested pathomechanics that underlie sport-related injury. A common mode of assessment is measurement of landing forces during jumping tasks; however, these measures have been used less frequently in male youth soccer players, and reliability data are sparse. The aim of this study was to examine the reliability of a field-based neuromuscular control screening battery using force-plate diagnostics in this cohort. Twenty-six pre-peak height velocity (PHV) and 25 post-PHV elite male youth soccer players completed a drop vertical jump (DVJ), single-leg 75% horizontal hop and stick (75%HOP), and single-leg countermovement jump (SLCMJ). Measures of peak landing vertical ground reaction force (pVGRF), time to stabilization, time to pVGRF, and pVGRF asymmetry were recorded. A test-retest design was used, and reliability statistics included change in mean, intraclass correlation coefficient, and coefficient of variation (CV). No significant differences in mean score were reported for any of the assessed variables between test sessions. In both groups, pVGRF and asymmetry during the 75%HOP and SLCMJ demonstrated largely acceptable reliability (CV ≤ 10%). Greater variability was evident in DVJ pVGRF and all other assessed variables, across the 3 protocols (CV range = 13.8-49.7%). Intraclass correlation coefficient values ranged from small to large and were generally higher in the post-PHV players. The results of this study suggest that pVGRF and asymmetry can be reliably assessed using a 75%HOP and SLCMJ in this cohort. These measures could be used to support a screening battery for elite male youth soccer players and for test-retest comparison.
Schmölzer, Georg M; O Reilly, Megan; Fray, Caroline; van Os, Sylvia; Cheung, Po-Yin
2017-10-07
Current neonatal resuscitation guidelines recommend 3:1 compression:ventilation (C:V) ratio. Recently, animal studies reported that continuous chest compressions (CC) during a sustained inflation (SI) significantly improved return of spontaneous circulation (ROSC). The approach of CC during SI (CC+SI) has not been examined in the delivery room during neonatal resuscitation. It is a feasibility study to compare CC+SI versus 3:1 C:V ratio during neonatal resuscitation in the delivery room. We hypothesised that during neonatal resuscitation, CC+SI will reduce the time to ROSC. Our aim was to examine if CC+SI reduces ROSC compared with 3:1 C:V CPR in preterm infants <33 weeks of gestation. Randomised feasibility trial. Once CC was indicated all eligible infants were immediately and randomly allocated to either CC+SI group or 3:1 C:V group. A sequentially numbered, brown, sealed envelope contained a folded card box with the treatment allocation was opened by the clinical team at the start of CC. Infants in the CC+SI group received CC at a rate of 90/min during an SI with a duration of 20 s (CC+SI). After 20 s, the SI was interrupted for 1 s and the next SI was started for another 20 s until ROSC. Infants in the '3:1 group' received CC using 3:1 C:V ratio until ROSC. Overall the mean (SD) time to ROSC was significantly shorter in the CC+SI group with 31 (9) s compared with 138 (72) s in the 3:1 C:V group (p=0.011). CC+SI is feasible in the delivery room. Clinicaltrials.gov NCT02083705, pre-results. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.
New cataclysmic variables and other exotic binaries in the globular cluster 47 Tucanae*
NASA Astrophysics Data System (ADS)
Rivera Sandoval, L. E.; van den Berg, M.; Heinke, C. O.; Cohn, H. N.; Lugger, P. M.; Anderson, J.; Cool, A. M.; Edmonds, P. D.; Wijnands, R.; Ivanova, N.; Grindlay, J. E.
2018-04-01
We present 22 new (+3 confirmed) cataclysmic variables (CVs) in the non-core-collapsed globular cluster 47 Tucanae (47 Tuc). The total number of CVs in the cluster is now 43, the largest sample in any globular cluster so far. For the identifications we used near-ultraviolet (NUV) and optical images from the Hubble Space Telescope, in combination with X-ray results from the Chandra X-ray Observatory. This allowed us to build the deepest NUV CV luminosity function of the cluster to date. We found that the CVs in 47 Tuc are more concentrated towards the cluster centre than the main-sequence turn-off stars. We compared our results to the CV populations of the core-collapsed globular clusters NGC 6397 and NGC 6752. We found that 47 Tuc has fewer bright CVs per unit mass than those two other clusters. That suggests that dynamical interactions in core-collapsed clusters play a major role creating new CVs. In 47 Tuc, the CV population is probably dominated by primordial and old dynamically formed systems. We estimated that the CVs in 47 Tuc have total masses of ˜1.4 M⊙. We also found that the X-ray luminosity function of the CVs in the three clusters is bimodal. Additionally, we discuss a possible double degenerate system and an intriguing/unclassified object. Finally, we present four systems that could be millisecond pulsar companions given their X-ray and NUV/optical colours. For one of them we present very strong evidence for being an ablated companion. The other three could be CO or He white dwarfs.
Cunha, Pedro Guimarães; Cotter, Jorge; Oliveira, Pedro; Vila, Isabel; Sousa, Nuno
2014-06-01
Cardiovascular disease and dementia are growing medical and social problems in aging societies. Appropriate knowledge of cardiovascular disease and cognitive decline risk factors (RFs) are critical for global CVR health preventive intervention. Many epidemiological studies use case definition based on data collected/measured in a single visit, a fact that can overestimate prevalence rates and distant from clinical practice demanding criteria. Portugal displays an elevated stroke mortality rate. However, population's global CV risk characterization is limited, namely, considering traditional/nontraditional RF and new intermediate phenotypes of CV and renal disease. Association of hemodynamic variables (pulse wave velocity and central blood pressure) with global CVR stratification, cognitive performance, and kidney disease are practically inexistent at a dwelling population level. After reviewing published data, we designed a population-based cohort study to analyze the prevalence of these cardiovascular RFs and intermediate phenotypes, using random sampling of adult dwellers living in 2 adjacent cities. Strict definition of phenotypes was planned: subjects were observed twice, and several hemodynamic and other biological variables measured at least 3 months apart. Three thousand thirty-eight subjects were enrolled, and extensive data collection (including central and peripheral blood pressure, pulse wave velocity), sample processing, and biobank edification were carried out. One thousand forty-seven cognitive evaluations were performed. Seeking for CV risk reclassification, early identification of subjects at risk, and evidence of early vascular aging and cognitive and renal function decline, using the strict daily clinical practice criteria, will lead to better resource allocation in preventive measures at a population level.
NASA Astrophysics Data System (ADS)
Meena, Hari Mohan; Machiwal, Deepesh; Santra, Priyabrata; Moharana, Pratap Chandra; Singh, D. V.
2018-05-01
Knowledge of rainfall variability is important for regional-scale planning and management of water resources in agriculture. This study explores spatio-temporal variations, trends, and homogeneity in monthly, seasonal, and annual rainfall series of 62 stations located in arid region of Rajasthan, India using 55 year (1957-2011) data. Box-whisker plots indicate presence of outliers and extremes in annual rainfall, which made the distribution of annual rainfall right-skewed. Mean and coefficient of variation (CV) of rainfall reveals a high inter-annual variability (CV > 200%) in the western portion where the mean annual rainfall is very low. A general gradient of the mean monthly, seasonal, and annual rainfall is visible from northwest to southeast direction, which is orthogonal to the gradient of CV. The Sen's innovative trend test is found over-sensitive in evaluating statistical significance of the rainfall trends, while the Mann-Kendall test identifies significantly increasing rainfall trends in June and September. Rainfall in July shows prominently decreasing trends although none of them are found statistically significant. Monsoon and annual rainfall show significantly increasing trends at only four stations. The magnitude of trends indicates that the rainfall is increasing at a mean rate of 1.11, 2.85, and 2.89 mm year-1 in August, monsoon season, and annual series. The rainfall is found homogeneous over most of the area except for few stations situated in the eastern and northwest portions where significantly increasing trends are observed. Findings of this study indicate that there are few increasing trends in rainfall of this Indian arid region.
Corneal endothelial cell density and morphology in normal Filipino eyes.
Padilla, Ma Dominga B; Sibayan, Santiago Antonio B; Gonzales, Clarissa S A
2004-03-01
To describe the corneal endothelial cell density and morphology in normal adult Filipino eyes. Specular microscopy was performed in 640 eyes of 320 normal Filipino volunteers aged 20 to 86 years. Of these, 163 were male, and 157 were female. Mean cell density (MCD), mean cell area (MCA), coefficient of variation (CV) in cell size (polymegathism), and hexagonality were recorded and analyzed in relation to fellow eyes, gender, and age. MCD was 2798 +/- 307.2 cells/mm, and MCA was 363.0 +/- 40.3 microm. Results showed that women had a MCD 7.8% greater than men (P < 0.01). Regression analysis showed a consistent decrease in MCD (r = -0.47) and increase in MCA (r = 0.45) from 20 to 60 years of age. This was followed by a marked decrease in correlation and apparent trend reversal for both variables in the groups above 60 years (MCD r = 0.18, MCA r = -0.04) accompanied by a marked increase in CV in cell size (20-60 years r = -0.04, >60 years r = 0.33). A very low negative correlation (r = -0.10) was noted between hexagonality and increasing age through all age groups. The first normative data for the endothelium of Filipino eyes are reported. There are statistically significant differences in MCD between genders, and a consistent decrease in MCD and increase in MCA with age only until 60 years old, after which correlation between age and these variables decreases. Polymegathism and correlation between CV in cell size and age markedly increase after age 60.
Westera, Liset; van Viegen, Tanja; Jeyarajah, Jenny; Azad, Azar; Bilsborough, Janine; van den Brink, Gijs R; Cremer, Jonathan; Danese, Silvio; D'Haens, Geert; Eckmann, Lars; Faubion, William; Filice, Melissa; Korf, Hannelie; McGovern, Dermot; Panes, Julian; Salas, Azucena; Sandborn, William J; Silverberg, Mark S; Smith, Michelle I; Vermeire, Severine; Vetrano, Stefania; Shackelton, Lisa M; Stitt, Larry; Jairath, Vipul; Levesque, Barrett G; Spencer, David M; Feagan, Brian G; Vande Casteele, Niels
2017-01-01
Objectives: Flow cytometry (FC) aids in characterization of cellular and molecular factors involved in pathologic immune responses. Although FC has potential to facilitate early drug development in inflammatory bowel disease, interlaboratory variability limits its use in multicenter trials. Standardization of methods may address this limitation. We compared variability in FC-aided quantitation of T-cell responses across international laboratories using three analytical strategies. Methods: Peripheral blood mononuclear cells (PBMCs) were isolated from three healthy donors, stimulated with phorbol 12-myristate 13-acetate and ionomycin at a central laboratory, fixed, frozen, and shipped to seven international laboratories. Permeabilization and staining was performed in triplicate at each laboratory using a common protocol and centrally provided reagents. Gating was performed using local gating with a local strategy (LGLS), local gating with a central strategy (LGCS), and central gating (CG). Median cell percentages were calculated across triplicates and donors, and reported for each condition and strategy. The coefficient of variation (CV) was calculated across laboratories. Between-strategy comparisons were made using a two-way analysis of variance adjusting for donor. Results: Mean interlaboratory CV ranged from 1.8 to 102.1% depending on cell population and gating strategy (LGLS, 4.4–102.1% LGCS, 10.9–65.6% CG, 1.8–20.9%). Mean interlaboratory CV differed significantly across strategies and was consistently lower with CG. Conclusions: Central gating was the only strategy with mean CVs consistently lower than 25%, which is a proposed standard for pharmacodynamic and exploratory biomarker assays. PMID:29095427
Raisis, A L; Young, L E; Meire, H; Walsh, K; Taylor, P M; Lekeux, P
2000-05-01
The purpose of this study was to determine the repeatability of femoral blood flow recorded using Doppler ultrasound in anaesthetised horses. Doppler ultrasound of the femoral artery and vein was performed in 6 horses anaesthetised with halothane and positioned in left lateral recumbency. Velocity spectra, recorded using low pulse repetition frequency, were used to calculate time-averaged mean velocity (TAV), velocity of component a (TaVa), velocity of component b (TaVb), volumetric flow, early diastolic deceleration slope (EDDS) and pulsatility index (PI). Within-patient variability was determined for sequential Doppler measurements recorded during a single standardised anaesthetic episode. Within-patient variability was also determined for Doppler and cardiovascular measurements recorded during 4 separate standardised anaesthetic episodes performed at intervals of at least one month. Within-patient variation during a single anaesthetic episode was small. Coefficients of variation (cv) were <12.5% for arterial measurements and <17% for venous measurements. Intraclass correlation coefficient was >0.75 for all measurements. No significant change was observed in measurements of cardiovascular function suggesting that within-patient variation observed during a single anaesthetic episode was due to measurement error. In contrast, within-patient variation during 4 separate anaesthetic episodes was marked (cv>17%) for most Doppler measurements obtained from arteries and veins. Variation in measurements of cardiovascular function were marked (cv>20%), suggesting that there is marked biological variation in central and peripheral observed. Further studies are warranted to determine the ability of this technique to detect differences in blood flow during administration of different anaesthetic agents.
Radiative Reverse Shock Laser Experiments Relevant to Accretion Processes in Cataclysmic Variables
NASA Astrophysics Data System (ADS)
Krauland, Christine
2012-10-01
We present results from experiments that explore radiative reverse shock waves and their contribution to the evolving dynamics of the cataclysmic variable (CV) system in which they reside. CVs are close binary star systems containing a white dwarf (WD) that accretes matter from its late-type main sequence companion star. In the process of accretion, a reverse shock forms when the supersonic infalling plasma is impeded. It provides the main source of radiation in the binary systems. In the case of a non-magnetic CV, the impact on an accretion disk produces this ``hot spot,'' where the flow obliquely strikes the rotating accretion disk. This collision region has many ambiguities as a radiation hydrodynamic system, but shock development in the infalling flow can be modeled [1]. We discuss the production of radiative reverse shocks in experiments at the Omega-60 laser facility. The ability of this high-intensity laser to create large energy densities in targets having millimeter-scale volumes makes it feasible to create supersonic plasma flows. Obtaining a radiative reverse shock in the laboratory requires a sufficiently fast flow (> 60 km/s) within a material whose opacity is large enough to produce energetically significant emission from experimentally achievable layers. We will show the radiographic and emission data from three campaigns on Omega-60 with accompanying CRASH [2] simulations, and will discuss the implications in the context of the CV system. [4pt] [1] Armitage, P. J. and Livio, M., ApJ, 493, 898 (1998).[0pt] [2] van der Holst, B., Toth, G., Sokolov, I.V., et al., ApJS, 194, 23 (2011).
New pulsating white dwarfs in cataclysmic variables
NASA Astrophysics Data System (ADS)
Nilsson, R.; Uthas, H.; Ytre-Eide, M.; Solheim, J.-E.; Warner, B.
2006-07-01
The number of discovered non-radially pulsating white dwarfs (WDs) in cataclysmic variables (CVs) is increasing rapidly by the aid of the Sloan Digital Sky Survey (SDSS). We performed photometric observations of two additional objects, SDSS J133941.11+484727.5 (SDSS 1339), independently discovered as a pulsator by Gänsicke et al., and SDSS J151413.72+454911.9, which we identified as a CV/ZZ Ceti hybrid. In this Letter we present the results of the remote observations of these targets performed with the Nordic Optical Telescope (NOT) during the Nordic-Baltic Research School at Molėtai Observatory, and follow-up observations executed by NOT in service mode. We also present three candidates we found to be non-pulsating. The results of our observations show that the main pulsation frequencies agree with those found in previous CV/ZZ Ceti hybrids, but specifically for SDSS 1339 the principal period differs slightly between individual observations and also from the recent independent observation by Gänsicke et al. Analysis of SDSS colour data for the small sample of pulsating and non-pulsating CV/ZZ Ceti hybrids found so far seems to indicate that the r - i colour could be a good marker for the instability strip of this class of pulsating WDs. Based on observations made with the Nordic Optical Telescope, operated on the island of La Palma jointly by Denmark, Finland, Iceland, Norway, and Sweden, in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias. E-mail: ricky@astro.lu.se
Berridge, Brian R; Schultze, A Eric; Heyen, Jon R; Searfoss, George H; Sarazan, R Dustan
2016-12-01
Cardiovascular (CV) safety liabilities are significant concerns for drug developers and preclinical animal studies are predominately where those liabilities are characterized before patient exposures. Steady progress in technology and laboratory capabilities is enabling a more refined and informative use of animals in those studies. The application of surgically implantable and telemetered instrumentation in the acute assessment of drug effects on CV function has significantly improved historical approaches that involved anesthetized or restrained animals. More chronically instrumented animals and application of common clinical imaging assessments like echocardiography and MRI extend functional and in-life structural assessments into the repeat-dose setting. A growing portfolio of circulating CV biomarkers is allowing longitudinal and repeated measures of cardiac and vascular injury and dysfunction better informing an understanding of temporal pathogenesis and allowing earlier detection of undesirable effects. In vitro modeling systems of the past were limited by their lack of biological relevance to the in vivo human condition. Advances in stem cell technology and more complex in vitro modeling platforms are quickly creating more opportunity to supplant animals in our earliest assessments for liabilities. Continuing improvement in our capabilities in both animal and nonanimal modeling should support a steady decrease in animal use for primary liability identification and optimize the translational relevance of the animal studies we continue to do. © The Author 2016. Published by Oxford University Press on behalf of the Institute for Laboratory Animal Research. All rights reserved. For permissions, please email: journals.permissions@oup.com.
Hong, Samin; Kim, Chan Yun; Lee, Won Seok; Seong, Gong Je
2010-01-01
To assess the reproducibility of the new spectral domain Cirrus high-definition optical coherence tomography (HD-OCT; Carl Zeiss Meditec, Dublin, CA, USA) for analysis of peripapillary retinal nerve fiber layer (RNFL) thickness in healthy eyes. Thirty healthy Korean volunteers were enrolled. Three optic disc cube 200 x 200 Cirrus HD-OCT scans were taken on the same day in discontinuous sessions by the same operator without using the repeat scan function. The reproducibility of the calculated RNFL thickness and probability code were determined by the intraclass correlation coefficient (ICC), coefficient of variation (CV), test-retest variability, and Fleiss' generalized kappa (kappa). Thirty-six eyes were analyzed. For average RNFL thickness, the ICC was 0.970, CV was 2.38%, and test-retest variability was 4.5 microm. For all quadrants except the nasal, ICCs were 0.972 or higher and CVs were 4.26% or less. Overall test-retest variability ranged from 5.8 to 8.1 microm. The kappa value of probability codes for average RNFL thickness was 0.690. The kappa values of quadrants and clock-hour sectors were lower in the nasal areas than in other areas. The reproducibility of Cirrus HD-OCT to analyze peripapillary RNFL thickness in healthy eyes was excellent compared with the previous reports for time domain Stratus OCT. For the calculated RNFL thickness and probability code, variability was relatively higher in the nasal area, and more careful analyses are needed.
Takao, Toshiko; Suka, Machi; Yanagisawa, Hiroyuki; Matsuyama, Yutaka; Iwamoto, Yasuhiko
2017-06-01
We explored whether visit-to-visit variability in both glycated hemoglobin (HbA1c) and systolic blood pressure (SBP) simultaneously predicted the development of microalbuminuria and retinopathy, and whether the predictive ability of these measurements changed according to mean HbA1c and SBP levels in people with type 2 diabetes. A retrospective observational cohort study was conducted on 243 type 2 diabetes patients with normoalbuminuria and 486 without retinopathy at the first visit and within 1year thereafter. The two cohorts were followed up from 1995 until 2012. Multivariate and stratified analyses were performed using Cox proportional hazard models. Microalbuminuria developed in 84 patients and retinopathy in 108. Hazard ratios (HRs) for the development of microalbuminuria associated with the coefficient of variation (CV) and variation independent of mean (VIM) of both HbA1c and SBP significantly increased. In participants with a mean SBP <130mmHg, the HRs for the development of retinopathy associated with CV and VIM of HbA1c were abruptly elevated and significant compared with those with a mean SBP ≥130mmHg. Visit-to-visit variability in both HbA1c and SBP simultaneously predict the development of microalbuminuria. HbA1c variability may predict the development of retinopathy when the mean SBP is normal (<130mmHg). Copyright © 2017 Elsevier B.V. All rights reserved.
NASA Astrophysics Data System (ADS)
Semena, Andrey N.; Revnivtsev, Mikhail G.; Buckley, David A. H.; Kotze, Marissa M.; Khabibullin, Ildar I.; Breytenbach, Hannes; Gulbis, Amanda A. S.; Coppejans, Rocco; Potter, Stephen B.
2014-08-01
We present results of a study of the fast timing variability of the magnetic cataclysmic variable (mCV) EX Hya. It was previously shown that one may expect the rapid flux variability of mCVs to be smeared out at time-scales shorter than the cooling time of hot plasma in the post-shock region of the accretion curtain near the white dwarf (WD) surface. Estimates of the cooling time and the mass accretion rate, thus provide us with a tool to measure the density of the post-shock plasma and the cross-sectional area of the accretion funnel at the WD surface. We have probed the high frequencies in the aperiodic noise of one of the brightest mCV EX Hya with the help of optical telescopes, namely Southern African Large Telescope and the South African Astronomical Observatory 1.9 m telescope. We place upper limits on the plasma cooling time-scale τ < 0.3 s, on the fractional area of the accretion curtain footprint f < 1.6 × 10-4, and a lower limit on the specific mass accretion rate Ṁ/A>3 g s-1 cm-2. We show that measurements of accretion column footprints via eclipse mapping highly overestimate their areas. We deduce a value of Δr/r ≲ 10- 3 as an upper limit to the penetration depth of the accretion disc plasma at the boundary of the magnetosphere.
Practicality of quantum information processing
NASA Astrophysics Data System (ADS)
Lau, Hoi-Kwan
Quantum Information Processing (QIP) is expected to bring revolutionary enhancement to various technological areas. However, today's QIP applications are far from being practical. The problem involves both hardware issues, i.e., quantum devices are imperfect, and software issues, i.e., the functionality of some QIP applications is not fully understood. Aiming to improve the practicality of QIP, in my PhD research I have studied various topics in quantum cryptography and ion trap quantum computation. In quantum cryptography, I first studied the security of position-based quantum cryptography (PBQC). I discovered a wrong assumption in the previous literature that the cheaters are not allowed to share entangled resources. I proposed entanglement attacks that could cheat all known PBQC protocols. I also studied the practicality of continuous-variable (CV) quantum secret sharing (QSS). While the security of CV QSS was considered by the literature only in the limit of infinite squeezing, I found that finitely squeezed CV resources could also provide finite secret sharing rate. Our work relaxes the stringent resources requirement of implementing QSS. In ion trap quantum computation, I studied the phase error of quantum information induced by dc Stark effect during ion transportation. I found an optimized ion trajectory for which the phase error is the minimum. I also defined a threshold speed, above which ion transportation would induce significant error. In addition, I proposed a new application for ion trap systems as universal bosonic simulators (UBS). I introduced two architectures, and discussed their respective strength and weakness. I illustrated the implementations of bosonic state initialization, transformation, and measurement by applying radiation fields or by varying the trap potential. When comparing with conducting optical experiments, the ion trap UBS is advantageous in higher state initialization efficiency and higher measurement accuracy. Finally, I proposed a new method to re-cool ion qubits during quantum computation. The idea is to transfer the motional excitation of a qubit to another ion that is prepared in the motional ground state. I showed that my method could be ten times faster than current laser cooling techniques, and thus could improve the speed of ion trap quantum computation.
Physico-chemical characteristics of shallot New-Superior Varieties (NSV) from Indonesia
NASA Astrophysics Data System (ADS)
Sukasih, E.; Setyadjit; Musadad, D.
2018-01-01
Shallot is one of the priority agricultural commodities to be developed in Indonesia to reduce import and to stabilize domestic supply. The efforts include the selection of varieties, seed technology, agronomy, handling and processing to extend the supply and added value. Indonesian Agency for Agricultural Research and Development (IAARD) has purified, cross-pollinated, selected and released new varieties called New Superior Varieties (NSV) to farmers. The purpose of this research was to investigate the characteristic of fresh shallot NSV by understanding its potential for raw material of processed product. A completely randomized design (CRD) of single factor of ten local varieties of shallot such as Cv. Sembrani, Cv. Kuning, Cv. Pancasona, Cv. Bima, Cv. Trisula, Cv. Pikatan, Cv. Katumi, Cv. Kramat-2, Cv. Mentes and Cv. Majalok of three replication was used to arrange the experiment. The results showed that shallot New Superior Varieties (NSV) were significant by effect the physico-chemical parameters, such as diameter, length, weight of both in main bulb and tiller bulb, fat total, carbohydrate, crude fiber, starch content, antioxidant capacity and quercetin. Of the ten varieties of shallot characterized, the largest bulbs are Cv. Sembrani i.e 5.30 ± 0.3g per bulb, the best red color for shallot peeled was Cv. Kuning. Furthermore Cv. Pancasona have the highest protein content of 4.23 ± 0.2%, Cv. Mentes have the highest functional properties of quercetin 1766.4 ± 134 ppm. Shallot varieties such as Cv. Sembrani, Cv. Bima, Cv. Kuning and Cv. Trisula suitable for use as fresh product. Shallot varieties such as Cv. Pikatan, Cv. Pancasona, Cv. Katumi and Cv. Kramat-2 are suitable as raw materials for processed products. Cv. Mentes and Cv. Majalok were potential for raw materials of functional food and pharmaceutical industries.
Atherothrombotic Risk Stratification and Ezetimibe for Secondary Prevention.
Bohula, Erin A; Morrow, David A; Giugliano, Robert P; Blazing, Michael A; He, Ping; Park, Jeong-Gun; Murphy, Sabina A; White, Jennifer A; Kesaniemi, Y Antero; Pedersen, Terje R; Brady, Adrian J; Mitchel, Yale; Cannon, Christopher P; Braunwald, Eugene
2017-02-28
Ezetimibe improves cardiovascular (CV) outcomes in patients stabilized after acute coronary syndrome (ACS) when added to statin therapy. After ACS, patients vary considerably in their risk for recurrent CV events. This study tested the hypothesis that atherothrombotic risk stratification may be useful to identify post-ACS patients who have the greatest potential for benefit from the addition of ezetimibe to statin therapy. The TIMI (Thrombolysis In Myocardial Infarction) Risk Score for Secondary Prevention (TRS 2°P) is a simple 9-point risk stratification tool, previously developed in a large population with atherothrombosis to predict CV death, myocardial infarction (MI), and ischemic stroke (CV death/MI/ischemic cerebrovascular accident [iCVA]). The current study applied this tool prospectively to 17,717 post-ACS patients randomized either to ezetimibe and simvastatin or to placebo and simvastatin in IMPROVE-IT (Improved Reduction of Outcomes: Vytorin Efficacy International Trial). Treatment efficacy was assessed by baseline risk for CV death/MI/iCVA, the IMPROVE-IT composite endpoints (CE), and individual component endpoints at 7 years. All 9 clinical variables in the TRS 2°P were independent risk indicators for CV death/MI/iCVA (p < 0.001). The integer-based scheme showed a strong graded relationship with the rate of CV death/MI/iCVA, the trial CE, and the individual components (p trend <0.0001 for each). High-risk patients (n = 4,393; 25%), defined by ≥3 risk indicators, had a 6.3% (95% confidence interval: 2.9% to 9.7%) absolute risk reduction in CV death/MI/iCVA at 7 years with ezetimibe/simvastatin, thus translating to a number-needed-to-treat of 16. Intermediate-risk patients (2 risk indicators; n = 5,292; 30%) had a 2.2% (95% confidence interval: -0.3% to 4.6%) absolute risk reduction. Low-risk patients (0 to 1 risk indicators; n = 8,032; 45%) did not appear to derive benefit from the addition of ezetimibe (p interaction = 0.010). Similar findings were observed for the IMPROVE-IT primary CE. Atherothrombotic risk stratification using the TRS 2°P identifies high-risk patients who derive greatest benefit from the addition of ezetimibe to statin therapy for secondary prevention after ACS. (Improved Reduction of Outcomes: Vytorin Efficacy International Trial [IMPROVE-IT]; NCT00202878). Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.
Saha, Papita Das; Chakraborty, Sagnik; Chowdhury, Shamik
2012-04-01
In this study, batch and fixed-bed column experiments were performed to investigate the biosorption potential of Artocarpus heterophyllus (jackfruit) leaf powder (JLP) to remove crystal violet (CV) from aqueous solutions. Batch biosorption studies were carried out as a function of solution pH, contact time, initial dye concentration and temperature. The biosorption equilibrium data showed excellent fit to the Langmuir isotherm model with maximum monolayer biosorption capacity of 43.39 mg g(-1) at pH 7.0, initial dye concentration=50 mg L(-1), temperature=293 K and contact time=120 min. According to Dubinin-Radushkevich (D-R) isotherm model, biosorption of CV by JLP was chemisorption. The biosorption kinetics followed the pseudo-second-order kinetic model. Thermodynamic analysis revealed that biosorption of CV from aqueous solution by JLP was a spontaneous and exothermic process. In order to ascertain the practical applicability of the biosorbent, fixed-bed column studies were also performed. The breakthrough time increased with increasing bed height and decreased with increasing flow rate. The Thomas model as well as the BDST model showed good agreement with the experimental results at all the process parameters studied. It can be concluded that JLP is a promising biosorbent for removal of CV from aqueous solutions. Copyright © 2011 Elsevier B.V. All rights reserved.
Reliability and day-to-day variability of peak fat oxidation during treadmill ergometry.
De Souza Silveira, Raul; Carlsohn, Anja; Langen, Georg; Mayer, Frank; Scharhag-Rosenberger, Friederike
2016-01-01
Exercising at intensities where fat oxidation rates are high has been shown to induce metabolic benefits in recreational and health-oriented sportsmen. The exercise intensity (Fatpeak) eliciting peak fat oxidation rates is therefore of particular interest when aiming to prescribe exercise for the purpose of fat oxidation and related metabolic effects. Although running and walking are feasible and popular among the target population, no reliable protocols are available to assess Fatpeak as well as its actual velocity (VPFO) during treadmill ergometry. Our purpose was therefore, to assess the reliability and day-to-day variability of VPFO and Fatpeak during treadmill ergometry running. Sixteen recreational athletes (f = 7, m = 9; 25 ± 3 y; 1.76 ± 0.09 m; 68.3 ± 13.7 kg; 23.1 ± 2.9 kg/m(2)) performed 2 different running protocols on 3 different days with standardized nutrition the day before testing. At day 1, peak oxygen uptake (VO2peak) and the velocities at the aerobic threshold (VLT) and respiratory exchange ratio (RER) of 1.00 (VRER) were assessed. At days 2 and 3, subjects ran an identical submaximal incremental test (Fat-peak test) composed of a 10 min warm-up (70 % VLT) followed by 5 stages of 6 min with equal increments (stage 1 = VLT, stage 5 = VRER). Breath-by-breath gas exchange data was measured continuously and used to determine fat oxidation rates. A third order polynomial function was used to identify VPFO and subsequently Fatpeak. The reproducibility and variability of variables was verified with an intraclass correlation coefficient (ICC), Pearson's correlation coefficient, coefficient of variation (CV) and the mean differences (bias) ± 95 % limits of agreement (LoA). ICC, Pearson's correlation and CV for VPFO and Fatpeak were 0.98, 0.97, 5.0 %; and 0.90, 0.81, 7.0 %, respectively. Bias ± 95 % LoA was -0.3 ± 0.9 km/h for VPFO and -2 ± 8 % of VO2peak for Fatpeak. In summary, relative and absolute reliability indicators for VPFO and Fatpeak were found to be excellent. The observed LoA may now serve as a basis for future training prescriptions, although fat oxidation rates at prolonged exercise bouts at this intensity still need to be investigated.
a Fast Segmentation Algorithm for C-V Model Based on Exponential Image Sequence Generation
NASA Astrophysics Data System (ADS)
Hu, J.; Lu, L.; Xu, J.; Zhang, J.
2017-09-01
For the island coastline segmentation, a fast segmentation algorithm for C-V model method based on exponential image sequence generation is proposed in this paper. The exponential multi-scale C-V model with level set inheritance and boundary inheritance is developed. The main research contributions are as follows: 1) the problems of the "holes" and "gaps" are solved when extraction coastline through the small scale shrinkage, low-pass filtering and area sorting of region. 2) the initial value of SDF (Signal Distance Function) and the level set are given by Otsu segmentation based on the difference of reflection SAR on land and sea, which are finely close to the coastline. 3) the computational complexity of continuous transition are successfully reduced between the different scales by the SDF and of level set inheritance. Experiment results show that the method accelerates the acquisition of initial level set formation, shortens the time of the extraction of coastline, at the same time, removes the non-coastline body part and improves the identification precision of the main body coastline, which automates the process of coastline segmentation.
May, Heidi T; Anderson, Jeffrey L; Winegar, Deborah A; Rollo, Jeffrey; Connelly, Margery A; Otvos, James D; Muhlestein, Joseph B
2016-10-01
HDL-C is recognized to be inversely associated with cardiovascular (CV) risk. However, attenuation of the association of HDL-C with CV risk may occur after adjustment for other lipoprotein parameters and in various disease states, especially in the setting of acute coronary syndrome (ACS). Recently, the number of HDL particles (HDL-P) has been suggested to improve CV risk prediction. Patients (n=2999) in the Intermountain Heart Collaborative Study who underwent angiography and had lipoprotein particle measurements determined by nuclear magnetic resonance (NMR) spectroscopy were studied. Multivariable Cox hazard regression was utilized to evaluate the association of HDL-C, HDL-P, and HDL-P subclasses with future major adverse CV events (MACE: death, myocardial infarction, heart failure, and stroke). Patients averaged 64±12years, 66% male, 26% diabetic, and 42% ACS. At angiography, 65% of patients were diagnosed with coronary artery disease (CAD). HDL-C and HDL-P averaged 41±13mg/dL and 28±8μmol/L, respectively. HDL-P (HR=0.903, p=0.001), but not HDL-C (HR=0.947, p=0.102) was significantly associated with MACE. In a model that included all HDL-P subclasses, both small (HR=0.862, p<0.0001) and medium (HR=0.922, p=0.020) were associated with CV risk, but not large HDL-P (HR=1.0042, p=0.185). Small HDL-P continued to be associated with all of the individual components of MACE, but not stroke. In this study of patients undergoing angiography, HDL-P was a strong, independent predictor of future MACE, with the smaller HDL-P accounting for this association. Copyright © 2016 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.
van der Ploeg, Melanie M; Brosschot, Jos F; Verkuil, Bart; Gillie, Brandon L; Williams, DeWayne P; Koenig, Julian; Vasey, Michael W; Thayer, Julian F
2017-10-01
Stress-related cognitive processes may occur outside of awareness, here referred to as unconscious stress, and affect one's physiological state. Evidence supporting this idea would provide necessary clarification of the relationship between psychological stress and cardiovascular (CV) health problems. We tested the hypothesis that increases in mean arterial pressure (MAP) and total peripheral resistance (TPR) and decreases in heart rate variability (HRV) would be larger when threatening stimuli are presented outside of awareness, or subliminally, compared with neutral stimuli. Additionally, it was expected that trait worry and resting HRV, as common risk factors for CV disease, would moderate the effect. We presented a subliminal semantic priming paradigm to college students that were randomly assigned to the threat (n = 56) or neutral condition (n = 60) and assessed changes from baseline of MAP, TPR, and HRV. Level of trait worry was assessed with the Penn State Worry Questionnaire. The findings indicate that CV activity changed according to the hypothesized pattern: A higher MAP and TPR and a lower HRV in the threat condition compared with the neutral condition were found with practically meaningful effect sizes. However, these findings were only statistically significant for TPR. Furthermore, changes in CV activity were not moderated by trait worry or resting HRV. This is the first study to explicitly address the role of subliminally presented threat words on health-relevant outcome measures and suggests that unconscious stress can influence peripheral vascular resistance. © 2017 Society for Psychophysiological Research.
Precision of hard structures used to estimate age of mountain Whitefish (Prosopium williamsoni)
Watkins, Carson J.; Ross, Tyler J.; Hardy, Ryan S.; Quist, Michael C.
2015-01-01
The mountain whitefish (Prosopium williamsoni) is a widely distributed salmonid in western North America that has decreased in abundance over portions of its distribution due to anthropogenic disturbances. In this investigation, we examined precision of age estimates derived from scales, pectoral fin rays, and sagittal otoliths from 167 mountain whitefish. Otoliths and pectoral fin rays were mounted in epoxy and cross-sectioned before examination. Scales were pressed onto acetate slides and resulting impressions were examined. Between-reader precision (i.e., between 2 readers), between-reader variability, and reader confidence ratings were compared among hard structures. Coefficient of variation (CV) in age estimates was lowest and percentage of exact agreement (PA-0) was highest for scales (CV = 5.9; PA-0 = 70%) compared to pectoral fin rays (CV =11.0; PA-0 = 58%) and otoliths (CV = 12.3; PA-0 = 55%). Median confidence ratings were significantly different (P ≤ 0.05) among all structures, with scales having the highest median confidence. Reader confidence decreased with fish age for scales and pectoral fin rays, but reader confidence increased with fish age for otoliths. In general, age estimates were more precise and reader confidence was higher for scales compared to pectoral fin rays and otoliths. This research will help fisheries biologists in selecting the most appropriate hard structure to use for future age and growth studies on mountain whitefish. In turn, selection of the most precise hard structure will lead to better estimates of dynamic rate functions.
Ferredoxin and ferredoxin-NADP reductase from photosynthetic and nonphotosynthetic tissues of tomato
NASA Technical Reports Server (NTRS)
Green, L. S.; Yee, B. C.; Buchanan, B. B.; Kamide, K.; Sanada, Y.; Wada, K.
1991-01-01
Ferredoxin and ferredoxin-NADP+ oxidoreductase (FNR) were purified from leaves, roots, and red and green pericarp of tomato (Lycopersicon esculentum, cv VFNT and cv Momotaro). Four different ferredoxins were identified on the basis of N-terminal amino acid sequence and charge. Ferredoxins I and II were the most prevalent forms in leaves and green pericarp, and ferredoxin III was the most prevalent in roots. Red pericarp of the VFNT cv yielded variable amounts of ferredoxins II and III plus a unique form, ferredoxin IV. Red pericarp of the Momotaro cv contained ferredoxins I, II, and IV. This represents the first demonstration of ferredoxin in a chromoplast-containing tissue. There were no major differences among the tomato ferredoxins in absorption spectrum or cytochrome c reduction activity. Two forms of FNR were present in tomato as judged by anion exchange chromatography and by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. FNR II had a lower apparent relative molecular weight, a slightly altered absorption spectrum, and a lower specific activity for cytochrome c reduction than FNR I. FNR II could be a partially degraded form of FNR I. The FNRs from the different tissues of tomato plants all showed diaphorase activity, with FNR II being more active than FNR I. The presence of ferredoxin and FNR in heterotrophic tissues of tomato is consistent with the existence of a nonphotosynthetic ferredoxin/FNR redox pathway to support the function of ferredoxin-dependent enzymes.
Lucchese, Fernando A; Koenig, Harold G
2013-03-01
In this paper we comprehensively review published quantitative research on the relationship between religion, spirituality (R/S), and cardiovascular (CV) disease, discuss mechanisms that help explain the associations reported, examine the clinical implications of those findings, and explore future research needed in Brazil on this topic. First, we define the terms religion, spirituality, and secular humanism. Next, we review research examining the relationships between R/S and CV risk factors (smoking, alcohol/drug use, physical inactivity, poor diet, cholesterol, obesity, diabetes, blood pressure, and psychosocial stress). We then review research on R/S, cardiovascular functions (CV reactivity, heart rate variability, etc.), and inflammatory markers (IL-6, IFN-γ, CRP, fibrinogen, IL-4, IL-10). Next we examine research on R/S and coronary artery disease, hypertension, stroke, dementia, cardiac surgery outcomes, and mortality (CV mortality in particular). We then discuss mechanisms that help explain these relationships (focusing on psychological, social, and behavioral pathways) and present a theoretical causal model based on a Western religious perspective. Next we discuss the clinical applications of the research, and make practical suggestions on how cardiologists and cardiac surgeons can sensitively and sensibly address spiritual issues in clinical practice. Finally, we explore opportunities for future research. No research on R/S and cardiovascular disease has yet been published from Brazil, despite the tremendous interest and involvement of the population in R/S, making this an area of almost unlimited possibilities for researchers in Brazil.
Egyptian plant species as new ozone indicators.
Madkour, Samia A; Laurence, J A
2002-01-01
The aim of this study was to test and select one or more highly sensitive, specific and environmentally successful Egyptian bioindicator plants for ozone (O3). For that purpose more than 30 Egyptian species and cultivars were subjected to extensive screening studies under controlled environmental and pollutant exposure conditions to mimic the Egyptian environmental conditions and O3 levels in urban and rural sites. Four plant species were found to be more sensitive to O3 than the universally used O3-bioindicator, tobacco Bel W3, under the Egyptian environmental conditions used. These plant species, jute (Corchorus olitorius c.v. local), clover (Trifolium alexandrinum L. c.v. Masry), garden rocket (Eruca sativa c.v. local) and alfalfa (Medicago sativa L. c.v. local), ranked in order of decreasing sensitivity, exhibited typical O3 injury symptoms faster and at lower 03 concentrations than Bel W3. Three variables were tested in search of a reliable tool for the diagnosis and prediction of O3 response prior to the appearance of visible foliar symptoms: pigment degradation, stomatal conductance (g(s)) and net photosynthetic CO2 assimilation (Pnet). Pigment degradation was found to be unreliable in predicting species sensitivity to O3. Evidence supporting stomatal conductance involvement in 03 tolerance was found only in tolerant species. A good correlation was found between g(s), restriction of O3 and CO2 influx into the mesophyll tissues, and Pnet. Changes in Pnet seemed to depend largely on fluctuations in g(s).
Milk flow rates from bottle nipples used after hospital discharge
Pados, Britt Frisk; Park, Jinhee; Thoyre, Suzanne M.; Estrem, Hayley; Nix, W. Brant
2016-01-01
Purpose To test the milk flow rates and variability in flow rates of bottle nipples used after hospital discharge. Study Design and Methods Twenty-six nipple types that represented 15 common brands as well as variety in price per nipple and store location sold (e.g., Babies R’ Us, Walmart, Dollar Store) were chosen for testing. Ten of each nipple type (n=260 total) were tested by measuring the amount of infant formula expressed in one minute using a breast pump. Mean milk flow rate (mL/min) and coefficient of variation (CV) were calculated. Flow rates of nipples within brand were compared statistically. Results Milk flow rates varied from 1.68 mL/min for the Avent Natural Newborn Flow to 85.34 mL/min for the Dr. Brown’s Standard Y-cut. Variability between nipple types also varied widely, from .03 for the Dr. Brown’s Standard Level 3 to .37 for MAM Nipple 1 Slow Flow. Clinical Implications The extreme range of milk flow rates found may be significant for medically fragile infants being discharged home who are continuing to develop oral feeding skills. The name of the nipple does not provide clear information about the flow rate to guide parents in decision-making. Variability in flow rates within nipples of the same type may complicate oral feeding for the medically fragile infant who may not be able to adapt easily to change in flow rates. Both flow rate and variability should be considered when guiding parents to a nipple choice. PMID:27008466
CPAP and hypertension in nonsleepy patients.
Phillips, Barbara; Shafazand, Shirin
2013-02-01
Is continuous positive airway pressure (CPAP) therapy better than no therapy in reducing the incidence of hypertension or cardiovascular (CV) events in a cohort of nonsleepy patients with obstructive sleep apnea (OSA)? Randomized, controlled trial; no placebo CPAP used. ClinicalTrials.gov Identifier: NCT00127348. Randomization was performed using a computer generated list of random numbers in the coordinating center and results were mailed to participating centers in numbered opaque envelopes. Primary outcome was evaluated by individuals not involved in the study and who were blinded to patient allocation. Patients, investigators, and the statistician were not blinded. median 4 (interquartile range, 2.7-4.4) years. 14 academic medical centers in Spain. 725 adults (mean age 51.8 y, 14% women) who were diagnosed with OSA with apnea hypopnea index (AHI) ≥ 20 events per hour and Epworth sleepiness score (ESS) ≤ 10 were randomized. Subjects with previous CV events were excluded. However, patients with a history of hypertension were not excluded (50% of the sample were hypertensive at baseline). Patients were randomized to receive CPAP treatment or no active intervention. All participants received dietary counseling and advice about sleep hygiene. The primary outcome was the incidence of either systemic hypertension (among participants who were normotensive at baseline) or CV events (among all participants). The secondary outcome was the association between the incidence of hypertension or CV events (nonfatal myocardial infarction, nonfatal stroke, transient ischemic attack, hospitalization for unstable angina or arrhythmia, heart failure, and CV death) and the severity of OSA assessed by the AHI and oxygen saturation. The sample size was calculated assuming that the incidence of hypertension or new CV event in this population over a period of 3 years would be 10% annually; 345 patients per group were needed to detect a 60% reduction in incidence of new hypertension or CV events (90% power, 2-sided α = 0.05, assuming 10% study dropout). 83% complete (only patients who received the allocated intervention were included in analysis of primary outcome). A total of 147 patients with new hypertension and 59 cardiovascular events were identified (Table). In the CPAP group, there were 68 patients with incident hypertension and 28 CV events. Of the 357 participants in the CPAP group, 127 used CPAP < 4 hours/night (36%). In the control group, there were 79 patients with new hypertension and 31 CV events. There was no statistically significant difference between the groups in the primary outcome. TableRisk for incident hypertension or cardiovascular event In adults with moderate to severe OSA and no symptoms of daytime sleepiness, CPAP therapy did not reduce incident hypertension or CV event compared with no active therapy. Instituto de Salud Carlos III (PI 04/0165) (Fondo de Investigaciones Sanitarios, Ministerio de Sanidad y Consumo, Spain), Spanish Respiratory Society (SEPAR) (Barcelona), Resmed (Bella Vista, Australia), Air Products-Carburos Metalicos (Barcelona), Respironics (Murrysville, Pennsylvania), and Breas Medical (Madrid, Spain).
Zinman, Bernard; Inzucchi, Silvio E; Wanner, Christoph; Hehnke, Uwe; George, Jyothis T; Johansen, Odd Erik; Fitchett, David
2018-04-30
The global epidemic of type 2 diabetes affects women and men equally; however, the relative impact on the cardiovascular (CV) system appears greater for women than men when compared with peers without diabetes. Furthermore, women are often under-represented in CV outcome trials, resulting in less certainty about the impact of CV prevention therapies across the sexes. The EMPA-REG OUTCOME® trial, which included 28.5% women, found that empagliflozin, given in addition to standard of care, reduced the risk of CV death by 38%, heart failure (HF) hospitalisation by 35% and a composite endpoint for incident or worsening nephropathy by 39%. Here we report a secondary analysis of the trial to determine the relative effects of empagliflozin in women vs men. The population studied were individuals with type 2 diabetes (HbA 1c 53-86 mmol/mol [7-10%] and eGFR >30 ml min -1 [1.73 m] -2 ), with established atherosclerotic CV disease. Individuals were randomised to receive empagliflozin 10 mg or 25 mg, or placebo once daily in addition to standard of care, and followed. The trial continued until ≥691 individuals had experienced an adjudicated event included in the primary outcome. All CV outcome events, including HF hospitalisations and deaths were prospectively adjudicated by blinded clinical events committees. At baseline, the demographic profile of the 2004 women (age ± standard deviation 63.6 ± 8.8 years) compared with the 5016 men (age 63.0 ± 8.6 years) in the trial was largely similar, with the exception that LDL-cholesterol was numerically higher in women (2.5 ± 1.0 vs 2.1 ± 0.9 mmol/l), consistent with lower rates of lipid-lowering therapies (75.4% vs 83.2%). Women were also less likely to have smoked (31.5% vs 69.9%). The annualised incidence rate for women in the placebo group was numerically lower than in men for CV death (1.58% vs 2.19%), numerically higher for HF hospitalisation (1.75% vs 1.33%) and similar for renal events (7.22% vs 7.75%). We did not detect any effect modification by sex within the statistical power restrictions of the analysis for CV death, HF hospitalisation and incident or worsening nephropathy (interaction p values 0.32, 0.20 and 0.85, respectively). Compared with placebo, empagliflozin increased the rates of genital infections in both women (2.5% vs 10.0%) and men (1.5% vs 2.6%). CV death, HF hospitalisation and incident or worsening nephropathy rate reductions induced by empagliflozin were not different between women and men.
Bradshaw, Elizabeth Jane; Hume, Patria Anne; Aisbett, Brad
2012-01-01
We determined the inter-day variability in elite-standard women's artistic gymnastics competition scores. National (50 gymnasts for up to three days) and Olympic (24 gymnasts for up to five days) competition scores published in the public domain ('Giant poster pull-out', 2010 ; Gymnastics Australia, 2008 ) were evaluated using three statistical measures. Analyses of the inter-day differences in the mean scores as a percentage (MDiff%), coefficient of variation percentages for the mean score across both days (CV%), and Pearson correlation coefficients for the inter-day score (r) were interpreted using thresholds from trivial to large. National-class gymnasts' two-day performance variation was trivial for vault, small for floor and beam, and moderate for bars. When senior gymnasts competed for a third day the performance variation increased to moderate for vault. Across five days of Olympic competition there were trivial (e.g. CV%: vault = 0.8) to small (e.g. CV%: bars = 2.0) variations in performances between days on all apparatus. Olympians' performance score consistency is superior to senior, national-class competitors. The performance score consistency required for gymnasts who aspire to participate at the Olympics as a top-24 competitor is better than 3%.
The Spatial Variations and Hotspots of Ecosystem Service Values in India During 1985 - 2005
NASA Astrophysics Data System (ADS)
Sannigrahi, S.; Bhatt, S.; Paul, S. K.; Sen, S.; Rahmat, S.; Uniyal, B.
2017-12-01
Ecosystem services can be defined as the processes and functions of the natural ecosystem through which the basic needs and demands of human well-being are sustained and fulfilled. In this study, the spatiotemporal variation and clusters of ESV are analyzed during 1985 - 2005 using benefits transfer approach. The spatial heterogeneity of ESV was assessed through Local Morans I, Getis-Ord-Gi hotspot, and Geary's I statistics, respectively. The temporal uncertainty of ESV was estimated through Ecosystem Service Change Index (ESCI), Ecosystem Service Status Index (ESSI). The sensitivity of ESV to land use/land cover changes were estimated using the Coefficient of Elasticity (CE) approach. The variability of ESV in different land-use categories was examined through Coefficient of Variation (CV), Theil Index (TI), Ginni Coefficient and Entropy method. The contribution of ESV to GDP was quantified using the percent of ESV (%ESV) approach. Total eight ecoregions were considered for estimating the changing dynamics of high and low ESV clusters during 1985 - 2005. Among the eight ecoregions, grassland shows the minimum CV of ESV (1.15) during 1985 - 2005, indicating the most stable and undisturbed eco-regions in India during this study period, followed by cropland (CV= 2.0), forest land (2.32), water bodies (3.27), mangrove (3.5) respectively. While, the urban built-up (CV = 15.89) and wetland (CV = 10.91) exhibits the highest CV during 1985 - 2005. The ESCI was found highly negative (-0.05) over forested region, and negative (-0.02) for water bodies, while a very highly positive (0.38), highly positive (0.24), moderate positive (0.06), weakly positive (0.03) and very weak positive (0.02) values have quantified for urban built-up, wetland, mangrove, cropland and, grassland, respectively. The overall ESSI was very good for urban built-up categories (0.24), followed by wetland (0.15), mangrove (0.04), cropland (0.02) and, grassland (0.01), respectively. During this period (1985 - 2005), the changes of ESV were found statistically significant for urban built-up (t = 10.90, P = 0.008), and wetland (t = 15.88, P = 0.004), while the changes were insignificant for rest of the ecoregions.
Cluster AgeS Experiment (CASE): deficiency of observed dwarf novae in globular clusters
NASA Astrophysics Data System (ADS)
Pietrukowicz, P.; Kaluzny, J.; Schwarzenberg-Czerny, A.; Thompson, I. B.; Pych, W.; Krzeminski, W.; Mazur, B.
2008-08-01
We present the results of a search for dwarf novae (DNe) in globular clusters (GCs). It is based on the largest available homogeneous sample of observations, in terms of the time-span, number of observations and number of clusters. It includes 16 Galactic GCs and yielded two new certain DNe: M55-CV1 and M22-CV2. All previously known systems located in our fields were recovered, too. We surveyed M4, M5, M10, M12, M22, M30, M55, NGC 288, NGC 362, NGC 2808, NGC 3201, NGC 4372, NGC 6362, NGC 6752, ω Centauri (NGC 5139) and 47 Tucanae (NGC 104). The discovery of two DNe, namely M55-CV1 and M22-CV2, was already reported by Kaluzny et al. and Pietrukowicz et al., respectively. In the remaining 14 GCs, we found no certain new DNe. Our result raises the total number of known DNe in the Galactic GCs to 12 DNe, distributed among seven clusters. Our survey recovered all three already known erupting cataclysmic variables (CVs) located in our fields, namely M5-V101, M22-CV1, and V4 in the foreground of M30. To assess the efficiency of the survey, we analysed images with inserted artificial stars mimicking outbursts of the prototype DNe SS Cygni and U Geminorum. Depending on the conditions, we recovered between 16-100 per cent of these artificial stars. The efficiency seems to be predominantly affected by duty cycle/time-sampling and much less by distance/magnitude. Except for saturated tiny collapsed cores of M30, NGC 362 and NGC 6752 (and also the dense core of NGC 2808), crowding effects in the V band were avoided by our image subtraction technique augmented with auxiliary unsaturated B-band images. Our results clearly demonstrate that in GCs common types of DNe are very rare indeed. However, great care must be taken before these conclusions can be extended to the CV population in GCs.
EARTH, MOON, SUN, AND CV ACCRETION DISKS
DOE Office of Scientific and Technical Information (OSTI.GOV)
Montgomery, M. M.
2009-11-01
Net tidal torque by the secondary on a misaligned accretion disk, like the net tidal torque by the Moon and the Sun on the equatorial bulge of the spinning and tilted Earth, is suggested by others to be a source to retrograde precession in non-magnetic, accreting cataclysmic variable (CV) dwarf novae (DN) systems that show negative superhumps in their light curves. We investigate this idea in this work. We generate a generic theoretical expression for retrograde precession in spinning disks that are misaligned with the orbital plane. Our generic theoretical expression matches that which describes the retrograde precession of Earths'more » equinoxes. By making appropriate assumptions, we reduce our generic theoretical expression to those generated by others, or to those used by others, to describe retrograde precession in protostellar, protoplanetary, X-ray binary, non-magnetic CV DN, quasar, and black hole systems. We find that spinning, tilted CV DN systems cannot be described by a precessing ring or by a precessing rigid disk. We find that differential rotation and effects on the disk by the accretion stream must be addressed. Our analysis indicates that the best description of a retrogradely precessing spinning, tilted, CV DN accretion disk is a differentially rotating, tilted disk with an attached rotating, tilted ring located near the innermost disk annuli. In agreement with the observations and numerical simulations by others, we find that our numerically simulated CV DN accretion disks retrogradely precess as a unit. Our final, reduced expression for retrograde precession agrees well with our numerical simulation results and with selective observational systems that seem to have main-sequence secondaries. Our results suggest that a major source to retrograde precession is tidal torques like that by the Moon and the Sun on the Earth. In addition, these tidal torques should be common to a variety of systems where one member is spinning and tilted, regardless if accretion disks are present or not. Our results suggest that the accretion disk's geometric shape directly affects the disk's precession rate.« less
Jha, Pankaj; Das, Arup Jyoti; Deka, Sankar Chandra
2017-11-01
Phenolic compounds were extracted from the husk of milled black rice (cv. Poireton) by using a combination of ultrasound assisted extraction and microwave assisted extraction. Extraction parameters were optimized by response surface methodology according to a three levels, five variables Box-Behnken design. The appropriate process variables (extraction temperature and extraction time) to maximize the ethanolic extraction of total phenolic compounds, flavonoids, anthocyanins and antioxidant activity of the extracts were obtained. Extraction of functional components with varying ethanol concentration and microwave time were significantly affected by the process variables. The best possible conditions obtained by RSM for all the factors included 10.02 min sonication time, 49.46 °C sonication temperature, 1:40.79 (w/v) solute solvent ratio, 67.34% ethanol concentration, and 31.11 s microwave time. Under the given solutions, the maximum extraction of phenolics (1.65 mg/g GAE), flavonoids (3.04 mg/100 g), anthocyanins (3.39 mg/100 g) and antioxidants (100%) were predicted, while the experimental values included 1.72 mg/g GAE of total phenolics, 3.01 mg/100 g of flavonoids, 3.36 mg/100 g of anthocyanins and 100% antioxidant activity. The overall results indicated positive impact of co-application of microwave and ultrasound assisted extractions of phenolic compounds from black rice husk.
Performance evaluation of the microINR® point-of-care INR-testing system.
Joubert, J; van Zyl, M C; Raubenheimer, J
2018-04-01
Point-of-care International Normalised Ratio (INR) testing is used frequently. We evaluated the microINR ® POC system for accuracy, precision and measurement repeatability, and investigated instrument and test chip variability and error rates. Venous blood INRs of 210 patients on warfarin were obtained with Thromborel ® S on the Sysmex CS-2100i ® analyser and compared with capillary blood microINR ® values. Precision was assessed using control materials. Measurement repeatability was calculated on 51 duplicate finger-prick INRs. Triplicate finger-prick INRs using three different instruments (30 patients) and three different test chip lots (29 patients) were used to evaluate instrument and test chip variability. Linear regression analysis of microINR ® and Sysmex CS2100i ® values showed a correlation coefficient of 0.96 (P < .0001) and a positive proportional bias of 4.4%. Dosage concordance was 93.8% and clinical agreement 95.7%. All acceptance criteria based on ISO standard 17593:2007 system accuracy requirements were met. Control material coefficients of variation (CV) varied from 6.2% to 16.7%. The capillary blood measurement repeatability CV was 7.5%. No significant instrument (P = .93) or test chip (P = .81) variability was found, and the error rate was low (2.8%). The microINR ® instrument is accurate and precise for monitoring warfarin therapy. © 2017 John Wiley & Sons Ltd.
Hassel, Chervin; Mirand, Audrey; Farkas, Agnes; Diedrich, Sabine; Huemer, Hartwig P; Peigue-Lafeuille, Hélène; Archimbaud, Christine; Henquell, Cécile; Bailly, Jean-Luc
2017-09-15
Coxsackievirus A16 (CV-A16; Picornaviridae ) is an enterovirus (EV) type associated with hand, foot, and mouth disease (HFMD) in children. To investigate the spatial spread of CV-A16, we used viral sequence data sampled during a prospective sentinel surveillance of HFMD in France (2010 to 2014) and phylogenetic reconstruction. A data set of 168 VP1 sequences was assembled with 416 publicly available sequences of various geographic origins. The CV-A16 sequences reported were assigned to two clades, genogroup B and a previously uncharacterized clade D. The time origins of clades B and D were assessed in 1978 (1973 to 1981) and 2004 (2001 to 2007), respectively. The shape of the global CV-A16 phylogeny indicated worldwide cocirculation of genetically distinct virus lineages over time and across geographic regions. Phylogenetic tree topologies and Bayes factor analysis indicated virus migration. Virus transportation events in clade B within Europe and Asia and between countries of the two geographic regions were assessed. The sustained transmission of clade D viruses over 4 years was analyzed at the township level in France and traced back to Peru in South America. Comparative genomics provided evidence of recombination between CV-A16 clades B and D and suggested an intertype recombinant origin for clade D. Time-resolved phylogenies and HFMD surveillance data indicated that CV-A16 persistence is sustained by continuing virus migration at different geographic scales, from community transmission to virus transportation between distant countries. The results showed a significant impact of virus movements on the epidemiological dynamics of HFMD that could have implications for disease prevention. IMPORTANCE Coxsackievirus A16 is one of the most prevalent enterovirus types in hand, foot, and mouth disease outbreaks reported in Southeast Asia. This study is based on epidemiological and viral data on HFMD caused by CV-A16 in a European country. The phylogeographic data complemented the syndromic surveillance with virus migration patterns between geographic regions in France. The results show how viral evolutionary dynamics and global virus spread interact to shape the worldwide pattern of an EV disease. CV-A16 transmission is driven by movements of infected individuals at different geographic levels: within a country (local dynamics), between neighboring countries (regional dynamics), and between distant countries (transcontinental dynamics). The results are consistent with our earlier data on EV-A71 and confirm the epidemiological interconnection of Asia and Europe with regard to EV infections. Copyright © 2017 American Society for Microbiology.
Estimation of intra-operator variability in perfusion parameter measurements using DCE-US
Gauthier, Marianne; Leguerney, Ingrid; Thalmensi, Jessie; Chebil, Mohamed; Parisot, Sarah; Peronneau, Pierre; Roche, Alain; Lassau, Nathalie
2011-01-01
AIM: To investigate intra-operator variability of semi-quantitative perfusion parameters using dynamic contrast-enhanced ultrasonography (DCE-US), following bolus injections of SonoVue®. METHODS: The in vitro experiments were conducted using three in-house sets up based on pumping a fluid through a phantom placed in a water tank. In the in vivo experiments, B16F10 melanoma cells were xenografted to five nude mice. Both in vitro and in vivo, images were acquired following bolus injections of the ultrasound contrast agent SonoVue® (Bracco, Milan, Italy) and using a Toshiba Aplio® ultrasound scanner connected to a 2.9-5.8 MHz linear transducer (PZT, PLT 604AT probe) (Toshiba, Japan) allowing harmonic imaging (“Vascular Recognition Imaging”) involving linear raw data. A mathematical model based on the dye-dilution theory was developed by the Gustave Roussy Institute, Villejuif, France and used to evaluate seven perfusion parameters from time-intensity curves. Intra-operator variability analyses were based on determining perfusion parameter coefficients of variation (CV). RESULTS: In vitro, different volumes of SonoVue® were tested with the three phantoms: intra-operator variability was found to range from 2.33% to 23.72%. In vivo, experiments were performed on tumor tissues and perfusion parameters exhibited values ranging from 1.48% to 29.97%. In addition, the area under the curve (AUC) and the area under the wash-out (AUWO) were two of the parameters of great interest since throughout in vitro and in vivo experiments their variability was lower than 15.79%. CONCLUSION: AUC and AUWO appear to be the most reliable parameters for assessing tumor perfusion using DCE-US as they exhibited the lowest CV values. PMID:21512654
Variability in EIT Images of Lung Ventilation as a Function of Electrode Planes and Body Positions
Zhang, Jie; Patterson, Robert
2014-01-01
This study is aimed at investigating the variability in resistivity changes in the lung region as a function of air volume, electrode plane and body position. Six normal subjects (33.8 ± 4.7 years, range from 26 to 37 years) were studied using the Sheffield Electrical Impedance Tomography (EIT) portable system. Three transverse planes at the level of second intercostal space, the level of the xiphisternal joint, and midway between upper and lower locations were chosen for measurements. For each plane, sixteen electrodes were uniformly positioned around the thorax. Data were collected with the breath held at end expiration and after inspiring 0.5, 1.0, or 1.5 liters of air from end expiration, with the subject in both the supine and sitting position. The average resistivity change in five regions, two 8x8 pixel local regions in the right lung, entire right, entire left and total lung regions, were calculated. The results show the resistivity change averaged over electrode positions and subject positions was 7-9% per liter of air, with a slightly larger resistivity change of 10 % per liter air in the lower electrode plane. There was no significant difference (p>0.05) between supine and sitting. The two 8x8 regions show a larger inter individual variability (coefficient of variation, CV, is from 30% to 382%) compared to the entire left, entire right and total lung (CV is from 11% to 51%). The results for the global regions are more consistent. The large inter individual variability appears to be a problem for clinical applications of EIT, such as regional ventilation. The variability may be mitigated by choosing appropriate electrode plane, body position and region of interest for the analysis. PMID:25110529
Estimation of intra-operator variability in perfusion parameter measurements using DCE-US.
Gauthier, Marianne; Leguerney, Ingrid; Thalmensi, Jessie; Chebil, Mohamed; Parisot, Sarah; Peronneau, Pierre; Roche, Alain; Lassau, Nathalie
2011-03-28
To investigate intra-operator variability of semi-quantitative perfusion parameters using dynamic contrast-enhanced ultrasonography (DCE-US), following bolus injections of SonoVue(®). The in vitro experiments were conducted using three in-house sets up based on pumping a fluid through a phantom placed in a water tank. In the in vivo experiments, B16F10 melanoma cells were xenografted to five nude mice. Both in vitro and in vivo, images were acquired following bolus injections of the ultrasound contrast agent SonoVue(®) (Bracco, Milan, Italy) and using a Toshiba Aplio(®) ultrasound scanner connected to a 2.9-5.8 MHz linear transducer (PZT, PLT 604AT probe) (Toshiba, Japan) allowing harmonic imaging ("Vascular Recognition Imaging") involving linear raw data. A mathematical model based on the dye-dilution theory was developed by the Gustave Roussy Institute, Villejuif, France and used to evaluate seven perfusion parameters from time-intensity curves. Intra-operator variability analyses were based on determining perfusion parameter coefficients of variation (CV). In vitro, different volumes of SonoVue(®) were tested with the three phantoms: intra-operator variability was found to range from 2.33% to 23.72%. In vivo, experiments were performed on tumor tissues and perfusion parameters exhibited values ranging from 1.48% to 29.97%. In addition, the area under the curve (AUC) and the area under the wash-out (AUWO) were two of the parameters of great interest since throughout in vitro and in vivo experiments their variability was lower than 15.79%. AUC and AUWO appear to be the most reliable parameters for assessing tumor perfusion using DCE-US as they exhibited the lowest CV values.
Cirilli, Natalia; Raia, Valeria; Rocco, Ilaria; De Gregorio, Fabiola; Tosco, Antonella; Salvadori, Laura; Sepe, Angela Ornella; Buzzetti, Roberto; Minicuci, Nadia; Castaldo, Giuseppe
2018-04-02
The sweat test is one of the main diagnostic tools used in newborn screening programs and as a confirmatory test, in case of suspect of Cystic Fibrosis (CF). Since sweat chloride (Cl) concentration is also considered an appropriate parameter to explore the efficacy of CFTR modulators in clinical trials, it is crucial to evaluate the biological variability of this test in healthy and pathological conditions. The aim of this pilot study was to determine the intra-individual biological variability of sweat Cl, both in healthy individuals and CF patients and to assess its correlation with diet, season, and menstrual cycle. Thirty-five out of 36 selected subjects (6-18 years) were enrolled by 2 CF care centers and assigned to 3 cohorts: CF, CFTR-related disorder (CFTR-RD) and healthy volunteers. Each participant was subjected to eight sweat tests in different conditions and time of the year. Data were analyzed using linear mixed effects models for repeated measures, taking also into account intra-individual correlations. We observed a high intra-individual variability of sweat Cl, with the lowest mean CV% values among CF patients (20.21 in CF, 29.74 in CFTR-RD, and 31.15 in healthy subjects). Gender and diet had no influence on sweat Cl variability, nor had pubertal age and menstrual phase. Results of this pilot study confirmed that sweat Cl variability is high in CF patients, although non-CF individuals displayed even higher mean CV% values. Season significantly influenced sweat test values only in CF patients, likely due to changes in their hydration status. © 2018 Wiley Periodicals, Inc.
Variability in EIT Images of Lung Ventilation as a Function of Electrode Planes and Body Positions.
Zhang, Jie; Patterson, Robert
2014-01-01
This study is aimed at investigating the variability in resistivity changes in the lung region as a function of air volume, electrode plane and body position. Six normal subjects (33.8 ± 4.7 years, range from 26 to 37 years) were studied using the Sheffield Electrical Impedance Tomography (EIT) portable system. Three transverse planes at the level of second intercostal space, the level of the xiphisternal joint, and midway between upper and lower locations were chosen for measurements. For each plane, sixteen electrodes were uniformly positioned around the thorax. Data were collected with the breath held at end expiration and after inspiring 0.5, 1.0, or 1.5 liters of air from end expiration, with the subject in both the supine and sitting position. The average resistivity change in five regions, two 8x8 pixel local regions in the right lung, entire right, entire left and total lung regions, were calculated. The results show the resistivity change averaged over electrode positions and subject positions was 7-9% per liter of air, with a slightly larger resistivity change of 10 % per liter air in the lower electrode plane. There was no significant difference (p>0.05) between supine and sitting. The two 8x8 regions show a larger inter individual variability (coefficient of variation, CV, is from 30% to 382%) compared to the entire left, entire right and total lung (CV is from 11% to 51%). The results for the global regions are more consistent. The large inter individual variability appears to be a problem for clinical applications of EIT, such as regional ventilation. The variability may be mitigated by choosing appropriate electrode plane, body position and region of interest for the analysis.
Symbolic Architectures for Cognition
1989-01-01
Perceptual and mnotor interfaces b. Buffering and interrupts c. Real-time demands for action c. Continuous acquis;ition of knowledge We stress that...memorie- Workin.g menmki ’cv I REGULAR I LINE LONG JS18 17265SSSS6 U3 0411- 09583 Pa 1 1 DEK Coportio 11 Cumins Prk Wo burn, MA 01801 (617)935-8070
Evaluation of impact of length of calibration time period on the APEX model streamflow simulation
USDA-ARS?s Scientific Manuscript database
Due to resource constraints, continuous long-term measured data for model calibration and validation (C/V) are rare. As a result, most hydrologic and water quality models are calibrated and, if possible, validated using limited available measured data. However, little research has been carried out t...
USDA-ARS?s Scientific Manuscript database
A two-year study was conducted in a citrus orchard [Citrus sinensis (L.) Osbeck cv. ‘Valencia’] to determine influence of plant water stress on population dynamics of glassy-winged sharpshooter (GWSS), Homalodisca vitripennis (Germar). Experimental treatments included irrigation at 100% of the crop...
Shang, Bo; Feng, Zhaozhong; Li, Pin; Calatayud, Vicent
2018-03-01
The effects of elevated ozone on C (carbon), N (nitrogen) and P (phosphorus) ecological stoichiometry and nutrient resorption in different organs including leaves, stems and roots were investigated in poplar clones 546 (P. deltoides cv. '55/56' × P. deltoides cv. 'Imperial') and 107 (P. euramericana cv. '74/76') with a different sensitivity to ozone. Plants were exposed to two ozone treatments, NF (non-filtered ambient air) and NF60 (NF with targeted ozone addition of 60 ppb), for 96 days in open top chambers (OTCs). Significant ozone effects on most variables of C, N and P ecological stoichiometry were found except for the C concentration and the N/P in different organs. Elevated ozone increased both N and P concentrations of individual organs while for C/N and C/P ratios a reduction was observed. On these variables, ozone had a greater effect for clone 546 than for clone 107. N concentrations of different leaf positions ranked in the order upper > middle > lower, showing that N was transferred from the lower senescent leaves to the upper ones. This was also indicative of N resorption processes, which increased under elevated ozone. N resorption of clone 546 was 4 times larger than that of clone 107 under ambient air (NF). However, elevated ozone (NF60) had no significant effect on P resorption for both poplar clones, suggesting that their growth was only limited by N, while available P in the soil was enough to sustain growth. Understanding ecological stoichiometric responses under ozone stress is crucial to predict future effects on ecological processes and biogeochemical cycles. Copyright © 2017 Elsevier Ltd. All rights reserved.
Pearce, Mark S.; Wincenciak, Joanna; Kerr, Simon R.J.; Newton, Julia L.
2016-01-01
Abstract BACKGROUND Greater ambulatory blood pressure variability (ABPV) is associated with end-organ damage and increased mortality. Age-related changes in the cardiovascular and autonomic nervous systems make age-associated increases in ABPV likely. Cross-sectional studies support this hypothesis, showing greater ABPV among older compared to younger adults. The only longitudinal study to examine changes in ABPV, however, found ABPV decreased over 5 years follow-up. This unexpected observation probably reflected the highly selected nature of the study participants. METHODS In this longitudinal study, we assessed changes in ABPV over 10 years in a community-cohort of older people. In addition, we examined the extent to which ABPV was predicted by demographics, cardiovascular risk factors, and medication. Clinical examination and 24-hour ambulatory blood pressure monitoring were carried out at baseline and at 10 years follow-up in 83 people, median age 70 years. ABPV was calculated using SD and coefficient of variation (Cv). Three time periods were examined: daytime, nighttime, and 24 hours. RESULTS Daytime and 24-hour, systolic and diastolic, SD, and Cv were significantly greater at follow-up than at baseline ( P < 0.001 in all cases). Mean BP did not change. CONCLUSIONS Multilevel modeling showed follow-up interval had a significant, positive effect on SD and Cv ( P < 0.004), independent of age, sex, and medication. ABPV increased over a 10-year follow-up despite stable mean BP. ABPV may therefore be an additional target for treatment in older people. Future studies should examine what degree of ABPV is harmful and if control of ABPV reduces adverse outcome. PMID:26310662
Rengo, Giuseppe; Pagano, Gennaro; Filardi, Pasquale Perrone; Femminella, Grazia Daniela; Parisi, Valentina; Cannavo, Alessandro; Liccardo, Daniela; Komici, Klara; Gambino, Giuseppina; D’Amico, Maria Loreta; de Lucia, Claudio; Paolillo, Stefania; Trimarco, Bruno; Vitale, Dino Franco; Ferrara, Nicola; Koch, Walter J; Leosco, Dario
2016-01-01
Rationale Sympathetic nervous system (SNS) hyperactivity is associated with poor prognosis in patients with HF, yet routine assessment of SNS activation is not recommended for clinical practice. Myocardial G protein-coupled receptor kinase 2 (GRK2) is up-regulated in heart failure (HF) patients, causing dysfunctional β-adrenergic receptor signaling. Importantly, myocardial GRK2 levels correlate with levels found in peripheral lymphocytes of HF patients. Objective The independent prognostic value of blood GRK2 measurements in HF patients has never been investigated, thus, the purpose of the present study was to evaluate whether lymphocyte GRK2 levels predict clinical outcome in HF patients. Methods and Results We prospectively studied 257 HF patients with mean left ventricular ejection fraction (LVEF) of 31.4±8.5%. At the time of enrollment, plasma norepinephrine, serum NT-proBNP and lymphocyte GRK2 levels, as well as clinical and instrumental variables were measured. The prognostic value of GRK2 to predict cardiovascular (CV) death and all-cause mortality was assessed using the Cox proportional hazard model including demographic, clinical, instrumental and laboratory data. Over a mean follow-up period of 37.5±20.2 months (range: 3–60 months) there were 102 CV deaths. Age, LVEF, NYHA class, Chronic Obstructive Pulmonary Disease, Chronic Kidney Disease, N-terminal-pro Brain Natriuretic Peptide, and lymphocyte GRK2 protein levels were independent predictors of CV mortality in HF patients. GRK2 levels showed an additional prognostic and clinical value over demographic and clinical variables. The independent prognostic value of lymphocyte GRK2 levels was also confirmed for all-cause mortality. Conclusion Lymphocyte GRK2 protein levels can independently predict prognosis in patients with HF. PMID:26884616
Flatt, Andrew A; Hornikel, Bjoern; Esco, Michael R
2017-06-01
The purpose of this study was to evaluate cardiac-parasympathetic and psychometric responses to competition preparation in collegiate sprint-swimmers. Additionally, we aimed to determine the relationship between average vagal activity and its daily fluctuation during each training phase. Observational. Ten Division-1 collegiate sprint-swimmers performed heart rate variability recordings (i.e., log transformed root mean square of successive RR intervals, lnRMSSD) and completed a brief wellness questionnaire with a smartphone application daily after waking. Mean values for psychometrics and lnRMSSD (lnRMSSD mean ) as well as the coefficient of variation (lnRMSSD cv ) were calculated from 1 week of baseline (BL) followed by 2 weeks of overload (OL) and 2 weeks of tapering (TP) leading up to a championship competition. Competition preparation resulted in improved race times (p<0.01). Moderate decreases in lnRMSSD mean , and Large to Very Large increases in lnRMSSD cv , perceived fatigue and soreness were observed during the OL and returned to BL levels or peaked during TP (p<0.05). Inverse correlations between lnRMSSD mean and lnRMSSD cv were Very Large at BL and OL (p<0.05) but only Moderate at TP (p>0.05). OL training is associated with a reduction and greater daily fluctuation in vagal activity compared with BL, concurrent with decrements in perceived fatigue and muscle soreness. These effects are reversed during TP where these values returned to baseline or peaked leading into successful competition. The strong inverse relationship between average vagal activity and its daily fluctuation weakened during TP. Copyright © 2016 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.
Quantifying the effects of stream channels on storm water quality in a semi-arid urban environment
NASA Astrophysics Data System (ADS)
Gallo, Erika L.; Lohse, Kathleen A.; Brooks, Paul D.; McIntosh, Jennifer C.; Meixner, Thomas; McLain, Jean E. T.
2012-11-01
SummaryStormwater drainage systems can have a large effect on urban runoff quality, but it is unclear how ephemeral urban streams alter runoff hydrochemistry. This problem is particularly relevant in semi-arid regions, where urban storm runoff is considered a renewable water resource. Here we address the question: how do stream channels alter urban runoff hydrochemistry? We collected synoptic stormwater samples during three rainfall-runoff events from nine ephemeral streams reaches (three concrete or metal, three grass, three gravel) in Tucson, Arizona. We identified patterns of temporal and spatial (longitudinal) variability in concentrations of conservative (chloride and isotopes of water) and reactive solutes (inorganic-N, soluble reactive phosphorous, sulfate-S, dissolved organic carbon (DOC) and nitrogen, and fecal indicator bacteria). Water isotopes and chloride (Cl) concentrations indicate that solute flushing and evapoconcentration alter temporal patterns in runoff hydrochemistry, but not spatial hydrochemical responses. Solute concentrations and stream channel solute sourcing and retention during runoff were significantly more variable at the grass reaches (CV = 2.3 - 144%) than at the concrete or metal (CV = 1.6 - 107%) or gravel reaches (CV = 1.9 - 60%), which functioned like flow-through systems. Stream channel soil Cl and DOC decreased following a runoff event (Cl: 12.1-7.3 μg g-1 soil; DOC: 87.7-30.1 μg g-1 soil), while soil fecal indicator bacteria counts increased (55-215 CFU g-1 soil). Finding from this study suggest that the characteristics of the ephemeral stream channel substrate control biogeochemical reactions between runoff events, which alter stream channel soil solute stores and the hydrochemistry of subsequent runoff events.
Kim, Sang-Young; Kim, Ki-Hong; Cho, Jae-Hoon
2015-01-01
Objective The objective of this study was to find out the clinical variables correlated with repeated intra-arterial (IA) nimodipine infusions in patients with medically refractory cerebral vasospasm (CV) following subarachnoid hemorrhage (SAH). Materials and Methods During the 36 months between January 2011 and December 2013, 275 patients were treated at our institute for SAH due to a ruptured intracranial aneurysm. Of the 275 patients, 26 patients (9.5%) met the inclusion criteria. For each patient, a retrospective review of their medical records was conducted. Results Eleven patients underwent a single IA nimodipine infusion and 15 patients underwent more than two IA nimodipine infusions. Multiple IA nimodipine infusion patients had poor improvement (2 of 15 patients, 13.3%) in Glasgow coma scale (GCS) scores after the first IA nimodipine infusion compared to patients of single IA nimodipine infusion (6 of 11 patients, 54.6%) (p = 0.038). The mean middle cerebral artery (MCA) Lindegaard ratio of multiple IA nimodipine infusion patients was 4.3 ± 1.1 after the first IA nimodipine infusion (p = 0.039). In multiple IA nimodipine infusion patients, CV occurred more often bilaterally (p = 0.035) and distally (p = 0.001). More vessel segments were affected in multiple IA nimodipine infusion patients (3.1 ± 1.0) (p < 0.001). Conclusion The following factors correlated with multiple IA nimodipine infusions: 1) no improvement in GCS after the IA nimodipine infusion; 2) no decrease of MCA velocity on transcranial doppler over 50 cm/s or Lindegaard ratio over 4.3 after the IA nimodipine infusion; 3) distal, bilateral, or diffuse involvement of CV. PMID:26523251
Yang, Xiao-Xing; Critchley, Lester A; Joynt, Gavin M
2011-01-01
Thermodilution cardiac output using a pulmonary artery catheter is the reference method against which all new methods of cardiac output measurement are judged. However, thermodilution lacks precision and has a quoted precision error of ± 20%. There is uncertainty about its true precision and this causes difficulty when validating new cardiac output technology. Our aim in this investigation was to determine the current precision error of thermodilution measurements. A test rig through which water circulated at different constant rates with ports to insert catheters into a flow chamber was assembled. Flow rate was measured by an externally placed transonic flowprobe and meter. The meter was calibrated by timed filling of a cylinder. Arrow and Edwards 7Fr thermodilution catheters, connected to a Siemens SC9000 cardiac output monitor, were tested. Thermodilution readings were made by injecting 5 mL of ice-cold water. Precision error was divided into random and systematic components, which were determined separately. Between-readings (random) variability was determined for each catheter by taking sets of 10 readings at different flow rates. Coefficient of variation (CV) was calculated for each set and averaged. Between-catheter systems (systematic) variability was derived by plotting calibration lines for sets of catheters. Slopes were used to estimate the systematic component. Performances of 3 cardiac output monitors were compared: Siemens SC9000, Siemens Sirecust 1261, and Philips MP50. Five Arrow and 5 Edwards catheters were tested using the Siemens SC9000 monitor. Flow rates between 0.7 and 7.0 L/min were studied. The CV (random error) for Arrow was 5.4% and for Edwards was 4.8%. The random precision error was ± 10.0% (95% confidence limits). CV (systematic error) was 5.8% and 6.0%, respectively. The systematic precision error was ± 11.6%. The total precision error of a single thermodilution reading was ± 15.3% and ± 13.0% for triplicate readings. Precision error increased by 45% when using the Sirecust monitor and 100% when using the Philips monitor. In vitro testing of pulmonary artery catheters enabled us to measure both the random and systematic error components of thermodilution cardiac output measurement, and thus calculate the precision error. Using the Siemens monitor, we established a precision error of ± 15.3% for single and ± 13.0% for triplicate reading, which was similar to the previous estimate of ± 20%. However, this precision error was significantly worsened by using the Sirecust and Philips monitors. Clinicians should recognize that the precision error of thermodilution cardiac output is dependent on the selection of catheter and monitor model.
Mehrnoush, Amid; Mustafa, Shuhaimi; Yazid, Abdul Manap Mohd
2012-01-01
Response surface methodology (RSM) along with central composite design (CCD) was applied to optimize the freeze drying conditions for purified pectinase from mango (Mangifera indica cv. Chokanan) peel. The effect of pectinase content (−2.66, 62.66 mg/mL), Arabic gum (−1.21, 10.21%, w/v), and maltodextrin (0.73, 7.26%, w/v) as independent variables on activity, yield, and storage stability of freeze-dried enzyme was evaluated. Storage stability of pectinase was investigated after one week at 4 °C and yield percentage of the enzyme after encapsulation was also determined. The independent variables had the most significant (p < 0.05) effect on pectinase activity and yield of the enzyme. It was observed that the interaction effect of Arabic gum and maltodextrin improved the enzymatic properties of freeze-dried pectinase. The optimal conditions for freeze-dried pectinase from mango peel were obtained using 30 mg/mL of pectinase content, 4.5 (%, w/v) of Arabic gum, and 4 (%, w/v) of maltodextrin. Under these conditions, the maximum activity (11.12 U/mL), yield (86.4%) and storage stability (84.2%) of encapsulated pectinase were achieved. PMID:22489134
Whiteaker, Jeffrey R.; Zhao, Lei; Yan, Ping; Ivey, Richard G.; Voytovich, Uliana J.; Moore, Heather D.; Lin, Chenwei; Paulovich, Amanda G.
2015-01-01
In most cell signaling experiments, analytes are measured one Western blot lane at a time in a semiquantitative and often poorly specific manner, limiting our understanding of network biology and hindering the translation of novel therapeutics and diagnostics. We show the feasibility of using multiplex immuno-MRM for phospho-pharmacodynamic measurements, establishing the potential for rapid and precise quantification of cell signaling networks. A 69-plex immuno-MRM assay targeting the DNA damage response network was developed and characterized by response curves and determinations of intra- and inter-assay repeatability. The linear range was ≥3 orders of magnitude, the median limit of quantification was 2.0 fmol/mg, the median intra-assay variability was 10% CV, and the median interassay variability was 16% CV. The assay was applied in proof-of-concept studies to immortalized and primary human cells and surgically excised cancer tissues to quantify exposure–response relationships and the effects of a genomic variant (ATM kinase mutation) or pharmacologic (kinase) inhibitor. The study shows the utility of multiplex immuno-MRM for simultaneous quantification of phosphorylated and nonmodified peptides, showing feasibility for development of targeted assay panels to cell signaling networks. PMID:25987412
Variation of gene expression in Bacillus subtilis samples of fermentation replicates.
Zhou, Ying; Yu, Wen-Bang; Ye, Bang-Ce
2011-06-01
The application of comprehensive gene expression profiling technologies to compare wild and mutated microorganism samples or to assess molecular differences between various treatments has been widely used. However, little is known about the normal variation of gene expression in microorganisms. In this study, an Agilent customized microarray representing 4,106 genes was used to quantify transcript levels of five-repeated flasks to assess normal variation in Bacillus subtilis gene expression. CV analysis and analysis of variance were employed to investigate the normal variance of genes and the components of variance, respectively. The results showed that above 80% of the total variation was caused by biological variance. For the 12 replicates, 451 of 4,106 genes exhibited variance with CV values over 10%. The functional category enrichment analysis demonstrated that these variable genes were mainly involved in cell type differentiation, cell type localization, cell cycle and DNA processing, and spore or cyst coat. Using power analysis, the minimal biological replicate number for a B. subtilis microarray experiment was determined to be six. The results contribute to the definition of the baseline level of variability in B. subtilis gene expression and emphasize the importance of replicate microarray experiments.
Mehrnoush, Amid; Mustafa, Shuhaimi; Yazid, Abdul Manap Mohd
2012-01-01
Response surface methodology (RSM) along with central composite design (CCD) was applied to optimize the freeze drying conditions for purified pectinase from mango (Mangifera indica cv. Chokanan) peel. The effect of pectinase content (-2.66, 62.66 mg/mL), Arabic gum (-1.21, 10.21%, w/v), and maltodextrin (0.73, 7.26%, w/v) as independent variables on activity, yield, and storage stability of freeze-dried enzyme was evaluated. Storage stability of pectinase was investigated after one week at 4 °C and yield percentage of the enzyme after encapsulation was also determined. The independent variables had the most significant (p < 0.05) effect on pectinase activity and yield of the enzyme. It was observed that the interaction effect of Arabic gum and maltodextrin improved the enzymatic properties of freeze-dried pectinase. The optimal conditions for freeze-dried pectinase from mango peel were obtained using 30 mg/mL of pectinase content, 4.5 (%, w/v) of Arabic gum, and 4 (%, w/v) of maltodextrin. Under these conditions, the maximum activity (11.12 U/mL), yield (86.4%) and storage stability (84.2%) of encapsulated pectinase were achieved.
Jekova, Irena; Krasteva, Vessela; Leber, Remo; Schmid, Ramun; Twerenbold, Raphael; Müller, Christian; Reichlin, Tobias; Abächerli, Roger
Electrocardiogram (ECG) biometrics is an advanced technology, not yet covered by guidelines on criteria, features and leads for maximal authentication accuracy. This study aims to define the minimal set of morphological metrics in 12-lead ECG by optimization towards high reliability and security, and validation in a person verification model across a large population. A standard 12-lead resting ECG database from 574 non-cardiac patients with two remote recordings (>1year apart) was used. A commercial ECG analysis module (Schiller AG) measured 202 morphological features, including lead-specific amplitudes, durations, ST-metrics, and axes. Coefficient of variation (CV, intersubject variability) and percent-mean-absolute-difference (PMAD, intrasubject reproducibility) defined the optimization (PMAD/CV→min) and restriction (CV<30%) criteria for selection of the most stable and distinctive features. Linear discriminant analysis (LDA) validated the non-redundant feature set for person verification. Maximal LDA verification sensitivity (85.3%) and specificity (86.4%) were validated for 11 optimal features: R-amplitude (I,II,V1,V2,V3,V5), S-amplitude (V1,V2), Tnegative-amplitude (aVR), and R-duration (aVF,V1). Copyright © 2016 Elsevier Inc. All rights reserved.
Ayanlade, Ayansina; Radeny, Maren; Morton, John F; Muchaba, Tabitha
2018-07-15
This paper examines drought characteristics as an evidence of climate change in two agro-climatic zones of Nigeria and farmers' climate change perceptions of impacts and adaptation strategies. The results show high spatial and temporal rainfall variability for the stations. Consequently, there are several anomalies in rainfall in recent years but much more in the locations around the Guinea savanna. The inter-station and seasonality statistics reveal less variable and wetter early growing seasons and late growing seasons in the Rainforest zone, and more variable and drier growing seasons in other stations. The probability (p) of dry spells exceeding 3, 5 and 10 consecutive days is very high with 0.62≤p≥0.8 in all the stations, though, the p-values for 10day spells drop below 0.6 in Ibadan and Osogbo. The results further show that rainfall is much more reliable from the month of May until July with the coefficient of variance for rainy days <0.30, but less reliable in the months of March, August and October (CV-RD>0.30), though CV-RD appears higher in the month of August for all the stations. It is apparent that farmers' perceptions of drought fundamentally mirror climatic patterns from historical weather data. The study concludes that the adaptation facilities and equipment, hybrids of crops and animals are to be provided to farmers, at a subsidized price by the government, for them to cope with the current condition of climate change. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.
Ceres model application for increasing preparedness to climate variability in agricultural planning
NASA Astrophysics Data System (ADS)
Popova, Z.; Kercheva, M.
2003-04-01
The paper should demonstrate how knowledge of climate variability and simulation analyses over 30 years could be used to study the vulnerability of maize and wheat ecosystems in the region of Sofia. The procedure of stepwise calibration and validation of agricultural simulation CERES-maize and CERES-wheat models was used at two fields of contrastive soil conditions (Chromic Luvisol and Vertisol). Lysimeters observations under "Chromic Luvisol-maize" combination enabled to test integrally the prediction capacity of CERES-maize, including water and nitrogen fluxes at the boundaries of this vulnerable system over "1.05.1997-1.10.1999" period. The role of soil, crop, climate and irrigation scheduling (under maize only) on drought consequences and groundwater pollution was quantified for four "soil-crop" combinations by CERES models. Four water supply treatments of maize were considered on both soils: one under rainfed conditions and three with varied irrigation application. Water application in initial, development, and mid season growth stages was scheduled by CROPWAT model at any day that soil matrix suction fell to 3.0-3.2 pF with one irrigation scenario and 2.4-2.6 pF with another one. The third drainage-controlling scenario was developed on the basis of 50-75% of the required irrigation depth by satisfying most sensible phases of maize. It was established that "Chromic Luvisol -maize - dry land" combination was associated with the greatest coefficient of variability of yields (Cv=42%) and drought frequency (75% of the years with yield losses more than 20%). Average yield losses in dry vegetation seasons were 60% of the productivity potential under sufficient soil moisture. As a consequence maize cultivation under these conditions was inefficient in 20% of the years when production expenses were greater than losses. Any irrigation practice, even the drainage controlling scenario, mitigated drought consequences on risky soils as Chromic Luvisol by reducing year-to-year variability of yield (CV=5.6-6%). Long-term wheat yields were much more stable (CV=17-23% on Chromic Luvisol) than those of maize. In this case droughts covered 40% of the years when yield losses were 25-30% on the average. Soils of high water holding capacity (as Vertisol) provided additionally 50-150mm-water storage for evapotranspiration and thus reduced frequency of drought under both crops to 20-25% of the years. Agriculture on this soil should be more sustainable (CV=8-8.5% for yield under wheat and CV=14.6% respectively under maize). Reduction of yield during dry vegetation periods was 10-15% under wheat and 22% under maize if compared with productivity under sufficient soil water. Risk assessment of groundwater pollution showed that N-leaching hazards were associated mostly with moderately permeable Chromic Luvisol and high precipitation during the periods of low transpiration rate of both crops. Frequency analyses of seasonal N- losses, proved that half of the wheat and 3% of maize vegetation seasons were susceptible to significant N-leaching (10-45 kg N/ha for "N200" fertilization level) on Chromic Luvisol. Simulated irrigation scenarios did not influence vegetation drainage. Another risky situations occurred in 3% of the years of wet fallow after dry rainfed maize vegetation when up to 30% of fertilization dose might be leached on Chromic Luvisol. Earlier wheat sowing (on the 1st of October) and adjusted fertilization rates and timing to maximum N-uptake under both crops mitigated environmental hazards. Drainage-controlling irrigation scheduling decreased maize fallow state drainage by 30-40 % in half of the years and proved to be economically optimal. Such measure though may tend to increase vulnerability of ecosystem to climate variability by increasing residual soil nitrogen at the end of vegetation.
Zhang, Jing; Yang, Yingchao; Lou, Jun
2016-09-09
Hexagonal boron nitride (h-BN) atomic layers were utilized as a passivation coating in this study. A large-area continuous h-BN thin film was grown on nickel foil using a chemical vapor deposition method and then transferred onto sputtered copper as a corrosion passivation coating. The corrosion passivation performance in a Na2SO4 solution of bare and coated copper was investigated by electrochemical methods including cyclic voltammetry (CV), Tafel polarization and electrochemical impedance spectroscopy (EIS). CV and Tafel analysis indicate that the h-BN coating could effectively suppress the anodic dissolution of copper. The EIS fitting result suggests that defects are the dominant leakage source on h-BN films, and improved anti-corrosion performances could be achieved by further passivating these defects.
Conwell, Darwin L; Banks, Peter A; Sandhu, Bimaljit S; Sherman, Stuart; Al-Kaade, Samer; Gardner, Timothy B; Anderson, Michelle A; Wilcox, C Mel; Lewis, Michele D; Muniraj, Thiruvengadam; Forsmark, Christopher E; Cote, Gregory A; Guda, Nalini M; Tian, Ye; Romagnuolo, Joseph; Wisniewski, Stephen R; Brand, Randall; Gelrud, Andres; Slivka, Adam; Whitcomb, David C; Yadav, Dhiraj
2017-08-01
Our aim was to validate recent epidemiologic trends and describe the distribution of TIGAR-O risk factors in chronic pancreatitis (CP) patients. The NAPS-2 Continuation and Validation (NAPS2-CV) study prospectively enrolled 521 CP patients from 13 US centers from 2008 to 2012. CP was defined by definitive changes in imaging, endoscopy, or histology. Data were analyzed after stratification by demographic factors, physician-defined etiology, participating center, and TIGAR-O risk factors. Demographics and physician-defined etiology in the NAPS2-CV study were similar to the original NAPS2 study. Mean age was 53 years (IQR 43, 62) with 55% males and 87% white. Overall, alcohol was the single most common etiology (46%) followed by idiopathic etiology (24%). Alcohol etiology was significantly more common in males, middle-aged (35-65 years), and non-whites. Females and elderly (≥65 years) were more likely to have idiopathic etiology, while younger patients (<35 years) to have genetic etiology. Variability in etiology was noted by participating centers (e.g., alcohol etiology ranged from 27 to 67% among centers enrolling ≥25 patients). Smoking was the most commonly identified (59%) risk factor followed by alcohol (53%), idiopathic (30%), obstructive (19%), and hyperlipidemia (13%). The presence of multiple TIGAR-O risk factors was common, with 1, 2, ≥3 risk factors observed in 27.6, 47.6, and 23.6% of the cohort, respectively. Our data validate the current epidemiologic trends in CP. Alcohol remains the most common physician-defined etiology, while smoking was the most commonly identified TIGAR-O risk factor. Identification of multiple risk factors suggests CP to be a complex disease.
Payvar, Saeed; Spertus, John A; Miller, Alan B; Casscells, S Ward; Pang, Peter S; Zannad, Faiez; Swedberg, Karl; Maggioni, Aldo P; Reid, Kimberly J; Gheorghiade, Mihai
2013-12-01
Risk stratification in patients admitted with worsening heart failure (HF) is essential for tailoring therapy and counselling. Risk models are available but rarely used, in part because many require laboratory and imaging results that are not routinely available. Body temperature is associated with prognosis in other illnesses, and we hypothesized that low body temperature would be associated with worse outcomes in patients admitted with worsening HF. The Efficacy of Vasopressin Antagonism in Heart Failure Outcome Study with Tolvaptan (EVEREST) trial was an event-driven, randomized, double-blind, placebo-controlled study of tolvaptan in 4133 patients hospitalized for worsening HF with an EF <40%. Co-primary endpoints were all-cause mortality and cardiovascular (CV) death or HF rehospitalization. Body temperature was measured orally at randomization and entered in analyses both as a continuous variable and categorized into three groups (<36 °C, 36-36.5 °C, and >36.5 °C) using Cox regression models. The composite of CV death or HF rehospitalization occurred in 1544 patients within 1 year. For every 1 °C decrease in body temperature, the risk of adverse outcomes increased by 16% [hazard raio (HR) 1.16, 95% confidence interval (CI) 1.04-1.28], after adjustment for age, gender, race, systolic blood pressure, EF, blood urea nitrogen, and serum sodium. In fully adjusted analysis, the risk of adverse outcomes in the lowest body temperature group (<36 °C) was 51% higher than that of the index group (>36.5 °C) (HR 1.35, 95% CI 1.15-1.58). Low body temperature is an independent marker of poor cardiovascular outcomes in patients admitted with worsening HF and reduced EF.
Shah, Amil M.; Claggett, Brian; Sweitzer, Nancy K.; Shah, Sanjiv J.; Anand, Inder S.; Liu, Li; Pitt, Bertram; Pfeffer, Marc A.; Solomon, Scott D.
2015-01-01
Background Impairment in left ventricular (LV) systolic function has been described in heart failure with preserved ejection fraction (HFpEF), but its prognostic relevance is not known. We determined whether LV longitudinal strain (LS) is predictive of cardiovascular (CV) outcomes in HFpEF beyond clinical and conventional echocardiographic measures. Methods and Results LS was assessed by 2D speckle-tracking echocardiography at baseline in 447 HFpEF patients enrolled in the Treatment Of Preserved Cardiac Function Heart Failure with an Aldosterone Antagonist (TOPCAT) trial. At a median follow-up of 2.6 (IQR 1.5–3.9) years, 115 patients experienced the primary composite outcome of CV death, HF hospitalization, or aborted cardiac arrest. Impaired LS, defined as an absolute LS<15.8%, was present in 52% of patients and was predictive of the composite outcome (adjusted HR 2.14, 95% CI 1.26–3.66; p=0.005), CV death alone (adjusted HR 3.20, 95% CI 1.44–7.12; p=0.004), and HF hospitalization alone (adjusted HR 2.23, 95% CI 1.16–4.28; p=0.016) after adjusting for clinical and conventional echocardiographic variables. LS was the strongest echocardiographic predictor of the composite outcome. Exploratory analysis in a subset of 131 patients with follow-up LS assessed after 12–18 months demonstrated a trend towards improvement in LS associated with spironolactone in patients enrolled in the Americas but not in Russia or Georgia. Conclusions Impaired LV systolic function is a powerful predictor of HF hospitalization, CV death, or aborted cardiac arrest in HFpEF, independent of clinical predictors. Impaired LS represents a novel imaging biomarker to identify HFpEF patients at particularly high risk for CV morbidity and mortality. Clinical Trial Registration Information Clinicaltrials.gov. Identifier NCT00094302. PMID:26130119
2010-01-01
Background The cardiac troponins are biomarkers used for diagnosis of myocardial injury. They are also powerful prognostic markers in many diseases and settings. Recently introduced high-sensitivity assays indicate that chronic cardiac troponin elevations are common in response to cardiovascular (CV) morbidity. Type 2 diabetes mellitus (T2DM) confers a high risk of CV disease, but little is known about chronic cardiac troponin elevations in diabetic subjects. Accordingly, we aimed to understand the prevalence, determinants, and prognostic implications of cardiac troponin T (cTnT) elevations measured with a high-sensitivity assay in patients with T2DM. Methods cTnT was measured in stored, frozen serum samples from 124 subjects enrolled in the Asker and Bærum Cardiovascular Diabetes trial at baseline and at 2-year follow-up, if availabe (96 samples available). Results were analyzed in relation to baseline variables, hospitalizations, and group assignment (multifactorial intensive versus conventional diabetes care for lowering CV risk). Results One-hundred thirteen (90 %) had detectable cTnT at baseline and of those, 22 (18 % of the total population) subjects had values above the 99th percentile for healthy controls (13.5 ng/L). Levels at baseline were associated with conventional CV risk factors (age, renal function, gender). There was a strong correlation between cTnT levels at the two time-points (r = 0.92, p > 0.001). Risk for hospitalizations during follow-up increased step-wise by quartiles of hscTnT measured at baseline (p = 0.058). Conclusions Elevations of cTnT above the 99th percentile measured by a highly sensitive assay were encountered frequently in a population of T2DM patients. cTnT levels appeared to be stable over time and associated with conventional CV risk factors. Although a clear trend was present, no statistically robust associations with adverse outcomes could be found. PMID:20843304
Hallén, Jonas; Johansen, Odd Erik; Birkeland, Kåre I; Gullestad, Lars; Aakhus, Svend; Endresen, Knut; Tjora, Solve; Jaffe, Allan S; Atar, Dan
2010-09-15
The cardiac troponins are biomarkers used for diagnosis of myocardial injury. They are also powerful prognostic markers in many diseases and settings. Recently introduced high-sensitivity assays indicate that chronic cardiac troponin elevations are common in response to cardiovascular (CV) morbidity. Type 2 diabetes mellitus (T2DM) confers a high risk of CV disease, but little is known about chronic cardiac troponin elevations in diabetic subjects. Accordingly, we aimed to understand the prevalence, determinants, and prognostic implications of cardiac troponin T (cTnT) elevations measured with a high-sensitivity assay in patients with T2DM. cTnT was measured in stored, frozen serum samples from 124 subjects enrolled in the Asker and Bærum Cardiovascular Diabetes trial at baseline and at 2-year follow-up, if available (96 samples available). Results were analyzed in relation to baseline variables, hospitalizations, and group assignment (multifactorial intensive versus conventional diabetes care for lowering CV risk). One-hundred thirteen (90%) had detectable cTnT at baseline and of those, 22 (18% of the total population) subjects had values above the 99th percentile for healthy controls (13.5 ng/L). Levels at baseline were associated with conventional CV risk factors (age, renal function, gender). There was a strong correlation between cTnT levels at the two time-points (r=0.92, p>0.001). Risk for hospitalizations during follow-up increased step-wise by quartiles of hscTnT measured at baseline (p=0.058). Elevations of cTnT above the 99th percentile measured by a highly sensitive assay were encountered frequently in a population of T2DM patients. cTnT levels appeared to be stable over time and associated with conventional CV risk factors. Although a clear trend was present, no statistically robust associations with adverse outcomes could be found.
Descamps, Olivier; Tomassini, Joanne E; Lin, Jianxin; Polis, Adam B; Shah, Arvind; Brudi, Philippe; Hanson, Mary E; Tershakovec, Andrew M
2015-06-01
We compared the variability of LDL-C-lowering responses to treatment with ezetimibe + statins versus statins in hypercholesterolemic patients. An analysis of patient-level data pooled from 27 double-blind, placebo and/or active-controlled studies in 21,671 patients treated with ezetimibe + statins versus statins on first-line (statin-naïve/wash-out) or second-line (on statin, randomized to ezetimibe versus placebo [add-on] or ezetimibe versus uptitrated statin [uptitrate]) for 6-24 wks. Variances (standard deviation [SD], coefficient of variation [CV], and root mean squared error [RMSE] adjusted for various factors) for % change from baseline in LDL-C were compared. In first-line and second-line add-on studies, the variability (SD, RMSE) of % change from baseline in LDL-C was lower in ezetimibe + statin-treated patients versus statin-treated patients, ±covariates. Differences were small but statistically significant due to the large sample size. In second-line uptitrate studies, ezetimibe + statin treatment resulted in greater unadjusted variability (SD) versus statin therapy, while the adjusted variability (RMSE) was significantly lower. Relative variability (CV=SD/mean) was lower for ezetimibe + statins versus statin therapy for all study types, being more pronounced in second-line add-on and uptitrate studies, attributed to larger mean LDL-C reductions for ezetimibe + statins versus statin groups. When assessed by individual study/type, statin brand, potency or dose, the CVs remained lower for ezetimibe + statins versus statins in second-line studies. The SDs showed no consistent trend for either therapy. In hypercholesterolemic patients, the absolute variability of LDL-C-lowering responses to ezetimibe + statins was not greater versus statins alone and appeared lower when adjusted for other factors. Relative variability was lower in patients treated with statins + ezetimibe. A better understanding of the variability of the LDL-C lowering response may help guide clinicians in making therapeutic decisions. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
Force Plate Gait Analysis in Doberman Pinschers with and without Cervical Spondylomyelopathy
Foss, K.; da Costa, R.C.; Rajala-Shultz, P.J.; Allen, M.J.
2014-01-01
Background The most accepted means of evaluating the response of a patient with cervical spondylomyelopathy (CSM) to treatment is subjective and based on the owner and clinician's perception of the gait. Objective To establish and compare kinetic parameters based on force plate gait analysis between normal and CSM-affected Dobermans. Animals Nineteen Doberman Pinschers: 10 clinically normal and 9 with CSM. Methods Force plate analysis was prospectively performed in all dogs. At least 4 runs of ipsilateral limbs were collected from each dog. Eight force platform parameters were evaluated, including peak vertical force (PVF) and peak vertical impulse (PVI), peak mediolateral force (PMLF) and peak mediolateral impulse, peak braking force and peak braking impulse, and peak propulsive force (PPF) and peak propulsive impulse. In addition, the coefficient of variation (CV) for each limb was calculated for each parameter. Data analysis was performed by a repeated measures approach. Results PMLF (P = .0062), PVI (P = .0225), and PPF (P = .0408) were found to be lower in CSM-affected dogs compared with normal dogs. Analysis by CV as the outcome indicated more variability in PVF in CSM-affected dogs (P = 0.0045). The largest difference in the CV of PVF was seen in the thoracic limbs of affected dogs when compared with the thoracic limbs of normal dogs (P = 0.0019). Conclusions and Clinical Importance The CV of PVF in all 4 limbs, especially the thoracic limbs, distinguished clinically normal Dobermans from those with CSM. Other kinetic parameters less reliably distinguished CSM-affected from clinically normal Dobermans. PMID:23278957
A Performance Comparison of Color Vision Tests for Military Screening.
Walsh, David V; Robinson, James; Jurek, Gina M; Capó-Aponte, José E; Riggs, Daniel W; Temme, Leonard A
2016-04-01
Current color vision (CV) tests used for aviation screening in the U.S. Army only provide pass-fail results, and previous studies have shown variable sensitivity and specificity. The purpose of this study was to evaluate seven CV tests to determine an optimal CV test screener that potentially could be implemented by the U.S. Army. There were 133 subjects [65 Color Vision Deficits (CVD), 68 Color Vision Normal (CVN)] who performed all of the tests in one setting. CVD and CVN determination was initially assessed with the Oculus anomaloscope. Each test was administered monocularly and according to the test protocol. The main outcome measures were test sensitivity, specificity, and administration time (automated tests). Three of the four Pseudoisochromatic Plate (PIP) tests had a sensitivity/specificity > 0.90 OD/OS, whereas the FALANT tests had a sensitivity/specificity > 0.80 OD/OS. The Cone Contrast Test (CCT) demonstrated sensitivity/specificity > 0.90 OD/OS, whereas the Color Assessment and Diagnosis (CAD) test demonstrated sensitivity/specificity > 0.85 OD/OS. Comparison with the anomaloscope ("gold standard") revealed no significant difference of sensitivity and specificity OD/OS with the CCT, Dvorine PIP, and PIPC tests. Finally, the CCT administration time was significantly faster than the CAD test. The current U.S. Army CV screening tests demonstrated good sensitivity and specificity, as did the automated tests. In addition, some current PIP tests (Dvorine, PIPC), and the CCT performed no worse statistically than the anomaloscope with regard to sensitivity/specificity. The CCT letter presentation is randomized and results would not be confounded by potential memorization, or fading, of book plates.
NASA Astrophysics Data System (ADS)
Anwar, Sarkar R. M.
High mobility alternative channel materials to silicon are critical to the continued scaling of metal oxide semiconductor (MOS) devices. However, before they can be incorporated into advanced devices, some major issues need to be solved. The high mobility materials suffer from lower allowable thermal budgets compared to Si (before desorption and defect formation becomes an issue) and the absence of a good quality native oxide has further increased the interest in the use of high-k dielectrics. However, the high interface state density and high electric fields at these semiconductor/high-k interfaces can significantly impact the capacitance-voltage (C-V) profile, and current C-V modeling software cannot account for these effects. This in turn affects the parameters extracted from the C-V data of the high mobility semiconductor/high-k interface, which are crucial to fully understand the interface properties and expedite process development. To address this issue, we developed a model which takes into account quantum corrections which can be applied to a number of these alternative channel materials including SixGe1-x, Ge, InGaAs, and GaAs. The C-V simulation using this QM correction model is orders of magnitude faster compared to a full band Schrodinger-Poisson solver. The simulated C-V is directly benchmarked to a self consistent Schrodinger-Poisson solution for each bulk semiconductor material, and from the benchmarking process the QM correction parameters are extracted. The full program, C-V Alternative Channel Extraction (CV ACE), incorporates a quantum mechanical correction model, along with the interface state density model, and can extract device parameters such as equivalent oxide thickness (EOT), doping density and flat band voltage (Vfb) as well as the interface state density profile using multiple measurements performed at different frequencies and temperatures, simultaneously. The program was used to analyze experimentally measured C-V profiles and the extracted device parameters show excellent agreement with the known device structure and previously published results. CV ACE has been applied in the development of a process flow for germanium interface passivation in Ge based MOS devices using a GeOx interlayer. A post atomic layer deposition (ALD) plasma oxidation (PPO) process was developed using radio frequency (RF) plasma in a plasma enhanced chemical vapor deposition (PECVD) chamber and demonstrated significant surface passivation. Various gases were investigated and 1% O2/Ar was found to reduce the growth rate and provide excellent control over the degradation of EOT. A 100 W plasma with 1% O2/Ar was found to provide the best combination of EOT and low Dit and is concluded to be the optimum process for PPO of germanium surfaces. CV ACE and PPO were also utilized to investigate other process development challenges. A study of the impact of low temperature anneals on Ge-based MOS devices was found to result in a degradation of the electrical thickness and a change in fixed charge, indicating that the process window is very narrow and at much lower temperatures than for Si.
Measuring Variability in the Presence of Noise
NASA Astrophysics Data System (ADS)
Welsh, W. F.
Quantitative measurements of a variable signal in the presence of noise requires very careful attention to subtle affects which can easily bias the measurements. This is not limited to the low-count rate regime, nor is the bias error necessarily small. In this talk I will mention some of the dangers in applying standard techniques which are appropriate for high signal to noise data but fail in the cases where the S/N is low. I will discuss methods for correcting the bias in the these cases, both for periodic and non-periodic variability, and will introduce the concept of the ``filtered de-biased RMS''. I will also illustrate some common abuses of power spectrum interpretation. All of these points will be illustrated with examples from recent work on CV and AGN variability.
Geriatric Cardiology: An Emerging Discipline.
Dodson, John A; Matlock, Daniel D; Forman, Daniel E
2016-09-01
Given changing demographics, patients with cardiovascular (CV) disease in developed countries are now older and more complex than even a decade ago. This trend is expected to continue into the foreseeable future; accordingly, cardiologists are encountering patients with a greater number of comorbid illnesses as well as "geriatric conditions," such as cognitive impairment and frailty, which complicate management and influence outcomes. Simultaneously, technological advances have widened the therapeutic options available for patients, including those with the most advanced CV disease. In the setting of these changes, geriatric cardiology has recently emerged as a discipline that aims to adapt principles from geriatric medicine to everyday cardiology practice. Accordingly, the tasks of a "geriatric cardiologist" may include both traditional evidence-based CV management plus comprehensive geriatric assessment, medication reduction, team-based coordination of care, and explicit incorporation of patient goals into management. Given that the field is still in its relative infancy, the training pathways and structure of clinical programs in geriatric cardiology are still being delineated. In this review, we highlight the rationale behind geriatric cardiology as a discipline, several current approaches by geriatric cardiology programs, and future directions for the field. Copyright © 2016 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.
Geriatric Cardiology: An Emerging Discipline
Dodson, John A.; Matlock, Daniel D.; Forman, Daniel E.
2017-01-01
Given changing demographics, patients with cardiovascular (CV) disease in developed countries are now older and more complex than even a decade ago. This trend is expected to continue into the foreseeable future; accordingly, cardiologists in practice are encountering patients with a greater number of comorbid illnesses as well as “geriatric conditions” such as cognitive impairment and frailty which complicate management and influence outcomes. Simultaneously, technological advances have widened the therapeutic options available for patients, including those with the most advanced CV disease. In the setting of these changes, geriatric cardiology has recently emerged as a discipline that aims to adapt principles from geriatric medicine into everyday cardiology practice. Accordingly, the tasks of a “geriatric cardiologist” may include both traditional evidence-based CV management plus comprehensive geriatric assessment, medication reduction, team-based coordination of care, and explicit incorporation of patient goals into management. Given that the field is still in its relative infancy, the training pathways and structure of clinical programs in geriatric cardiology are still being delineated. In this review we highlight the rationale behind geriatric cardiology as a discipline, several current approaches by geriatric cardiology programs, and future directions for the field. PMID:27476988
Quantification of retinal pigment epithelial phenotypic variation using laser scanning cytometry.
Hjelmeland, L M; Fujikawa, A; Oltjen, S L; Smit-McBride, Z; Braunschweig, D
2010-06-16
Quantifying phenotypic variation at the level of protein expression (variegation) within populations of retinal pigment epithelium (RPE) cells may be important in the study of pathologies associated with this variation. The lack of quantitative methods for examining single cells, however, and the variable presence of pigment and/or lipofuscin complicate this experimental goal. We have applied the technique of laser scanning cytometry (LSC) to paraffin sections of mouse and human eyes to evaluate the utility of LSC for these measurements. Mouse eyes were perfusion fixed in 4% paraformaldehyde and embedded in paraffin. Postmortem human eyes were fixed and dissected to obtain a 9-mm punch, which was then embedded in paraffin. A laser scanning cytometer equipped with violet, argon, and helium-neon lasers and the detectors for blue, green, and long red were used to record the fluorescence of each individual cell at all three wavelengths. Raw data were recorded and processed using the WinCyte software. Individual nuclei were identified by the fluorescence of the 4',6-diamidino-2-phenylindole (DAPI) nuclear counterstain. Next, RPE cells were uniquely identified in the green channel using an anti-retinal pigment epithelium-specific protein 65 kDa (anti-RPE65) monoclonal antibody with an Alexa Fluor 488-labeled secondary antibody. Mn-superoxide dismutase (MnSOD) was quantified in the long-red channel using an anti-MnSOD antibody and an Alexa Fluor 647-labeled secondary antibody. MnSOD(+) and RPE65(+) cells exhibited peaks in the plot of fluorescence intensity versus cell number, which could be characterized by the mean fluorescence intensity (MFI), the coefficient of variation (CV), and the percentage of total RPE cells that were also labeled for MnSOD. RPE cells can be uniquely identified in human and mouse paraffin sections by immunolabeling with anti-RPE65 antibody. A second antigen, such as MnSOD, can then be probed only within this set of RPE. Results are plotted primarily with the population frequency diagram, which can be subdivided into multiple regions. The data collected for each region include the MFI, the CV, and the number of cells that are immunolabeled in that region. Background interference from pigment or autofluorescent material can be successfully overcome by elevating the concentrations of fluorescent secondary antibodies. In the human and mouse eyes, age-related changes in MFI, CV, and percent RPE cells immunolabeled for MnSOD were observed. The extent of the variability of gene expression in RPE cells at the protein level can be quantified by LSC. Relative changes in the MFI, the CV, and/or percentage of RPE cells double labeled for a second antigen quantify the changes observed. The analysis of these data also suggest whether the effects observed are related to local changes in transcription (alterations of CV) or major changes of protein expression (MFI), which are likely to be due to changes in the chromatin structure. The changes of these variables with age suggest that the observed age-related variegation is primarily due to changes in the chromatin structure in individual cells.
32 CFR Appendix A to Part 323 - Instructions for Preparation of System Notices
Code of Federal Regulations, 2011 CFR
2011-07-01
... DEFENSE (CONTINUED) PRIVACY PROGRAM DEFENSE LOGISTICS AGENCY PRIVACY PROGRAM Pt. 323, App. A Appendix A to... Copies may be obtained from the Defense Logistics Agency, ATTN: DSS-CV, 8725 John J. Kingman Road, Suite... Secretary of Defense has issued DoD Directive 5105.22 (32 CFR part 398), Defense Logistics Agency (DLA), the...
32 CFR Appendix A to Part 323 - Instructions for Preparation of System Notices
Code of Federal Regulations, 2012 CFR
2012-07-01
... DEFENSE (CONTINUED) PRIVACY PROGRAM DEFENSE LOGISTICS AGENCY PRIVACY PROGRAM Pt. 323, App. A Appendix A to... Copies may be obtained from the Defense Logistics Agency, ATTN: DSS-CV, 8725 John J. Kingman Road, Suite... Secretary of Defense has issued DoD Directive 5105.22 (32 CFR part 398), Defense Logistics Agency (DLA), the...
32 CFR Appendix A to Part 323 - Instructions for Preparation of System Notices
Code of Federal Regulations, 2010 CFR
2010-07-01
... DEFENSE (CONTINUED) PRIVACY PROGRAM DEFENSE LOGISTICS AGENCY PRIVACY PROGRAM Pt. 323, App. A Appendix A to... Copies may be obtained from the Defense Logistics Agency, ATTN: DSS-CV, 8725 John J. Kingman Road, Suite... Secretary of Defense has issued DoD Directive 5105.22 (32 CFR part 398), Defense Logistics Agency (DLA), the...
Exfoliated, Nitrogen-Doped Graphene Nanosheet Cathode for Lithium-Oxygen Batteries
2014-06-01
scanning electron microscopy; oxygen reduction reaction; cyclic voltammetry ; lithium-oxygen battery. Introduction The continuous...77 K (Micromeritics ASAP 2020). The porosity of cathode material was characterized by a gas pycnometer (Micromeritis, Accu Pyc II 1340). Cyclic ... voltammetry (CV) and galvanostatic charge-discharge measurements of the specimens were conducted using a computer controlled VersaSTAT 4 (Princeton
Intrinsic Variability in Shell and Soft Tissue Growth of the Freshwater Mussel Lampsilis siliquoidea
Larson, James H.; Eckert, Nathan L.; Bartsch, Michelle R.
2014-01-01
Freshwater mussels are ecologically and economically important members of many aquatic ecosystems, but are globally among the most imperiled taxa. Propagation techniques for mussels have been developed and used to boost declining and restore extirpated populations. Here we use a cohort of propagated mussels to estimate the intrinsic variability in size and growth rate of Lampsilis siliquoidea (a commonly propagated species). Understanding the magnitude and pattern of variation in data is critical to determining whether effects observed in nature or experimental treatments are likely to be important. The coefficient of variation (CV) of L. siliquoidea soft tissues (6.0%) was less than the CV of linear shell dimensions (25.1–66.9%). Size-weight relationships were best when mussel width (the maximum left-right dimension with both valves appressed) was used as a predictor, but 95% credible intervals on these predictions for soft tissues were ∼145 mg wide (about 50% of the mean soft tissue mass). Mussels in this study were treated identically, raised from a single cohort and yet variation in soft tissue mass at a particular size class (as determined by shell dimensions) was still high. High variability in mussel size is often acknowledged, but seldom discussed in the context of mussel conservation. High variability will influence the survival of stocked juvenile cohorts, may affect the ability to experimentally detect sublethal stressors and may lead to incongruities between the effects that mussels have on structure (via hard shells) and biogeochemical cycles (via soft tissue metabolism). Given their imperiled status and longevity, there is often reluctance to destructively sample unionid mussel soft tissues even in metabolic studies (e.g., studies of nutrient cycling). High intrinsic variability suggests that using shell dimensions (particularly shell length) as a response variable in studies of sublethal stressors or metabolic processes will make confident identifications of smaller effect sizes difficult. PMID:25411848
NASA Astrophysics Data System (ADS)
Soundharajan, Bankaru-Swamy; Adeloye, Adebayo J.; Remesan, Renji
2016-07-01
This study employed a Monte-Carlo simulation approach to characterise the uncertainties in climate change induced variations in storage requirements and performance (reliability (time- and volume-based), resilience, vulnerability and sustainability) of surface water reservoirs. Using a calibrated rainfall-runoff (R-R) model, the baseline runoff scenario was first simulated. The R-R inputs (rainfall and temperature) were then perturbed using plausible delta-changes to produce simulated climate change runoff scenarios. Stochastic models of the runoff were developed and used to generate ensembles of both the current and climate-change-perturbed future runoff scenarios. The resulting runoff ensembles were used to force simulation models of the behaviour of the reservoir to produce 'populations' of required reservoir storage capacity to meet demands, and the performance. Comparing these parameters between the current and the perturbed provided the population of climate change effects which was then analysed to determine the variability in the impacts. The methodology was applied to the Pong reservoir on the Beas River in northern India. The reservoir serves irrigation and hydropower needs and the hydrology of the catchment is highly influenced by Himalayan seasonal snow and glaciers, and Monsoon rainfall, both of which are predicted to change due to climate change. The results show that required reservoir capacity is highly variable with a coefficient of variation (CV) as high as 0.3 as the future climate becomes drier. Of the performance indices, the vulnerability recorded the highest variability (CV up to 0.5) while the volume-based reliability was the least variable. Such variabilities or uncertainties will, no doubt, complicate the development of climate change adaptation measures; however, knowledge of their sheer magnitudes as obtained in this study will help in the formulation of appropriate policy and technical interventions for sustaining and possibly enhancing water security for irrigation and other uses served by Pong reservoir.
Intrinsic variability in shell and soft tissue growth of the freshwater mussel Lampsilis siliquoidea
Larson, James H.; Eckert, Nathan L.; Bartsch, Michelle
2014-01-01
Freshwater mussels are ecologically and economically important members of many aquatic ecosystems, but are globally among the most imperiled taxa. Propagation techniques for mussels have been developed and used to boost declining and restore extirpated populations. Here we use a cohort of propagated mussels to estimate the intrinsic variability in size and growth rate of Lampsilis siliquoidea (a commonly propagated species). Understanding the magnitude and pattern of variation in data is critical to determining whether effects observed in nature or experimental treatments are likely to be important. The coefficient of variation (CV) of L. siliquoidea soft tissues (6.0%) was less than the CV of linear shell dimensions (25.1-66.9%). Size-weight relationships were best when mussel width (the maximum left-right dimension with both valves appressed) was used as a predictor, but 95% credible intervals on these predictions for soft tissues were ~145 mg wide (about 50% of the mean soft tissue mass). Mussels in this study were treated identically, raised from a single cohort and yet variation in soft tissue mass at a particular size class (as determined by shell dimensions) was still high. High variability in mussel size is often acknowledged, but seldom discussed in the context of mussel conservation. High variability will influence the survival of stocked juvenile cohorts, may affect the ability to experimentally detect sublethal stressors and may lead to incongruities between the effects that mussels have on structure (via hard shells) and biogeochemical cycles (via soft tissue metabolism). Given their imperiled status and longevity, there is often reluctance to destructively sample unionid mussel soft tissues even in metabolic studies (e.g., studies of nutrient cycling). High intrinsic variability suggests that using shell dimensions (particularly shell length) as a response variable in studies of sublethal stressors or metabolic processes will make confident identifications of smaller effect sizes difficult.
USDA-ARS?s Scientific Manuscript database
Microclimate variables were integrated over a six-month period during which blueberry (Vaccinium corymbosum cv. Liberty) bushes were grown in 51-cm high, 20-cm diameter round grow tubes (opaque or translucent) on a sawdust mulch-covered raised bed with the mulch incorporated into tilled soil. Grow t...
IVIM diffusion-weighted imaging of the liver at 3.0 T: Comparison with 1.5 T
Cui, Yong; Dyvorne, Hadrien; Besa, Cecilia; Cooper, Nancy; Taouli, Bachir
2015-01-01
Purpose To compare intravoxel incoherent motion (IVIM) diffusion-weighted imaging (DWI) of the liver between 1.5 T and 3.0 T in terms of parameter quantification and inter-platform reproducibility. Materials and methods In this IRB approved prospective study, 19 subjects (17 patients with chronic liver disease and 2 healthy volunteers) underwent two repeat scans at 1.5 T and 3.0 T. Each scan included IVIM DWI using 16 b values from 0 to 800 s/mm2. A single observer measured IVIM parameters for each platform and estimated signal to noise ratio (eSNR) at b0, 200, 400 and 800 s/mm2. Wilcoxon paired tests were used to compare liver eSNR and IVIM parameters. Inter-platform reproducibility was assessed by calculating within-subject coefficient of variation (CV) and Bland–Altman limits of agreement. An ice water phantom was used to test ADC variability between the two MRI systems. Results The mean invitro difference in ADC between the two platforms was 6.8%. eSNR was significantly higher at 3.0T for all selected b values (p = 0.006–0.020), except for b0 (p = 0.239). Liver IVIM parameters were significantly different between 1.5 T and 3.0 T (p = 0.005–0.044), except for ADC (p = 0.748). The inter-platform reproducibility of true diffusion coefficient (D) and ADC were good, with mean CV of 10.9% and 11.1%, respectively. Perfusion fraction (PF) and pseudodiffusion coefficient (D*) showed more limited inter-platform reproducibility (mean CV of 22.6% for PF and 46.9% for D*). Conclusion Liver D and ADC values showed good reproducibility between 1.5 T and 3.0 T platforms; while there was more variability in PF, and large variability in D* parameters between the two platforms. These findings may have implications for drug trials assessing the role of IVIM DWI in tumor response and liver fibrosis. PMID:26393236
Analysis of Darwin Rainfall Data: Implications on Sampling Strategy
NASA Technical Reports Server (NTRS)
Rafael, Qihang Li; Bras, Rafael L.; Veneziano, Daniele
1996-01-01
Rainfall data collected by radar in the vicinity of Darwin, Australia, have been analyzed in terms of their mean, variance, autocorrelation of area-averaged rain rate, and diurnal variation. It is found that, when compared with the well-studied GATE (Global Atmospheric Research Program Atlantic Tropical Experiment) data, Darwin rainfall has larger coefficient of variation (CV), faster reduction of CV with increasing area size, weaker temporal correlation, and a strong diurnal cycle and intermittence. The coefficient of variation for Darwin rainfall has larger magnitude and exhibits larger spatial variability over the sea portion than over the land portion within the area of radar coverage. Stationary, and nonstationary models have been used to study the sampling errors associated with space-based rainfall measurement. The nonstationary model shows that the sampling error is sensitive to the starting sampling time for some sampling frequencies, due to the diurnal cycle of rain, but not for others. Sampling experiments using data also show such sensitivity. When the errors are averaged over starting time, the results of the experiments and the stationary and nonstationary models match each other very closely. In the small areas for which data are available for I>oth Darwin and GATE, the sampling error is expected to be larger for Darwin due to its larger CV.
In silico segmentations of lentivirus envelope sequences
Boissin-Quillon, Aurélia; Piau, Didier; Leroux, Caroline
2007-01-01
Background The gene encoding the envelope of lentiviruses exhibits a considerable plasticity, particularly the region which encodes the surface (SU) glycoprotein. Interestingly, mutations do not appear uniformly along the sequence of SU, but they are clustered in restricted areas, called variable (V) regions, which are interspersed with relatively more stable regions, called constant (C) regions. We look for specific signatures of C/V regions, using hidden Markov models constructed with SU sequences of the equine, human, small ruminant and simian lentiviruses. Results Our models yield clear and accurate delimitations of the C/V regions, when the test set and the training set were made up of sequences of the same lentivirus, but also when they were made up of sequences of different lentiviruses. Interestingly, the models predicted the different regions of lentiviruses such as the bovine and feline lentiviruses, not used in the training set. Models based on composite training sets produce accurate segmentations of sequences of all these lentiviruses. Conclusion Our results suggest that each C/V region has a specific statistical oligonucleotide composition, and that the C (respectively V) regions of one of these lentiviruses are statistically more similar to the C (respectively V) regions of the other lentiviruses, than to the V (respectively C) regions of the same lentivirus. PMID:17376229
Density, Velocity and Ionization Structure in Accretion-Disc Winds
NASA Technical Reports Server (NTRS)
Sonneborn, George (Technical Monitor); Long, Knox
2004-01-01
This was a project to exploit the unique capabilities of FUSE to monitor variations in the wind- formed spectral lines of the luminous, low-inclination, cataclysmic variables(CV) -- RW Sex. (The original proposal contained two additional objects but these were not approved.) These observations were intended to allow us to determine the relative roles of density and ionization state changes in the outflow and to search for spectroscopic signatures of stochastic small-scale structure and shocked gas. By monitoring the temporal behavior of blue-ward extended absorption lines with a wide range of ionization potentials and excitation energies, we proposed to track the changing physical conditions in the outflow. We planned to use a new Monte Carlo code to calculate the ionization structure of and radiative transfer through the CV wind. The analysis therefore was intended to establish the wind geometry, kinematics and ionization state, both in a time-averaged sense and as a function of time.
Review of Occupational Therapy Research in the Practice Area of Children and Youth
Bendixen, Roxanna M.; Kreider, Consuelo M.
2011-01-01
A systematic review was conducted focusing on articles in the Occupational Therapy (OT) practice category of Childhood and Youth (C&Y) published in the American Journal of Occupational Therapy (AJOT) over the two-year period of 2009–2010. The frameworks of the International Classification of Functioning, Disability and Health (ICF) and Positive Youth Development (PYD) were used to explore OT research progress toward the goals of the Centennial Vision (CV). Forty-six research articles were organized by research type and were classified within these two frameworks. The majority of reviewed published research investigated variables representing constructs falling within the ICF domains of Body Functioning and Activity. The effect of OT interventions on PYD resided primarily in building competence. In order to meet the tenets of the CV, OTs must document changes in children’s engagement in everyday life situations and build the evidence of OT’s efficacy in facilitating participation. PMID:21675342
ELF: An Extended-Lagrangian Free Energy Calculation Module for Multiple Molecular Dynamics Engines.
Chen, Haochuan; Fu, Haohao; Shao, Xueguang; Chipot, Christophe; Cai, Wensheng
2018-06-18
Extended adaptive biasing force (eABF), a collective variable (CV)-based importance-sampling algorithm, has proven to be very robust and efficient compared with the original ABF algorithm. Its implementation in Colvars, a software addition to molecular dynamics (MD) engines, is, however, currently limited to NAMD and LAMMPS. To broaden the scope of eABF and its variants, like its generalized form (egABF), and make them available to other MD engines, e.g., GROMACS, AMBER, CP2K, and openMM, we present a PLUMED-based implementation, called extended-Lagrangian free energy calculation (ELF). This implementation can be used as a stand-alone gradient estimator for other CV-based sampling algorithms, such as temperature-accelerated MD (TAMD) and extended-Lagrangian metadynamics (MtD). ELF provides the end user with a convenient framework to help select the best-suited importance-sampling algorithm for a given application without any commitment to a particular MD engine.
Pestaña-Melero, Francisco Luis; Haff, G Gregory; Rojas, Francisco Javier; Pérez-Castilla, Alejandro; García-Ramos, Amador
2017-12-18
This study aimed to compare the between-session reliability of the load-velocity relationship between (1) linear vs. polynomial regression models, (2) concentric-only vs. eccentric-concentric bench press variants, as well as (3) the within-participants vs. the between-participants variability of the velocity attained at each percentage of the one-repetition maximum (%1RM). The load-velocity relationship of 30 men (age: 21.2±3.8 y; height: 1.78±0.07 m, body mass: 72.3±7.3 kg; bench press 1RM: 78.8±13.2 kg) were evaluated by means of linear and polynomial regression models in the concentric-only and eccentric-concentric bench press variants in a Smith Machine. Two sessions were performed with each bench press variant. The main findings were: (1) first-order-polynomials (CV: 4.39%-4.70%) provided the load-velocity relationship with higher reliability than second-order-polynomials (CV: 4.68%-5.04%); (2) the reliability of the load-velocity relationship did not differ between the concentric-only and eccentric-concentric bench press variants; (3) the within-participants variability of the velocity attained at each %1RM was markedly lower than the between-participants variability. Taken together, these results highlight that, regardless of the bench press variant considered, the individual determination of the load-velocity relationship by a linear regression model could be recommended to monitor and prescribe the relative load in the Smith machine bench press exercise.
Peng, Yifeng; Tellier, Liane E; Temenoff, Johnna S
2016-08-16
Sustained release of anti-inflammatory agents remains challenging for small molecule drugs due to their low molecular weight and hydrophobicity. Therefore, the goal of this study was to control the release of a small molecule anti-inflammatory agent, crystal violet (CV), from hydrogels fabricated with heparin, a highly sulfated glycosaminoglycan capable of binding positively-charged molecules such as CV. In this system, both electrostatic interactions between heparin and CV and hydrogel degradation were tuned simultaneously by varying the level of heparin sulfation and varying the amount of dithiothreitol within hydrogels, respectively. It was found that heparin sulfation significantly affected CV release, whereby more sulfated heparin hydrogels (Hep and Hep(-N)) released CV with near zero-order release kinetics (R-squared values between 0.96-0.99). Furthermore, CV was released more quickly from fast-degrading hydrogels than slow-degrading hydrogels, providing a method to tune total CV release between 5-15 days while maintaining linear release kinetics. In particular, N-desulfated heparin hydrogels exhibited efficient CV loading (∼90% of originally included CV), near zero-order CV release kinetics, and maintenance of CV bioactivity after release, making this hydrogel formulation a promising CV delivery vehicle for a wide range of inflammatory diseases.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bozlar, Ugur; Edmunds, J. Stewart; Turba, Ulku C.
The objective of this study was to explore the role of three-dimensional (3-D) rotational angiography (RA) of the inferior vena cava (IVC; 3-D CV) before filter retrieval and its impact on treatment planning compared with standard anteroposterior cavography (sCV). Thirty patients underwent sCV and 3-D CV before IVC filter retrieval. Parameters assessed were: projection of filter arms or legs beyond the caval lumen, thrombus burden within the filter and IVC, and orientation of the filter within IVC. Skin and effective radiation doses were calculated. Statistical analysis was performed using paired Student t test and nonparametric McNemar's test. Standard anteroposterior cavographymore » detected 49 filter arms or legs projecting beyond the caval lumen in 25 patients. Three-dimensional CV demonstrated 89 filter arms or legs projecting beyond the caval lumen in 28 patients. Twenty-two patients had additional filter arms or legs projecting beyond the caval lumen detected on 3-D CV that were not detected on sCV (p < 0.001). Filter apex tilt detection differed significantly (p < 0.001) between sCV and 3-D CV, with 3-D CV being more accurate. The filter apex abutted the IVC wall in 10 patients (33%) on 3-D CV, but this was diagnosed in only 3 patients (10%) with sCV. Thrombus was detected in 8 patients (27%), 1 thrombus of which was seen only on 3-D CV, and treatment was changed in this patient because of thrombus size. Mean effective radiation doses for 3-D CV were approximately two times higher than for sCV (1.68 vs. 0.86 mSv), whereas skin doses were three times lower (12.87 vs. 35.86 mGy). Compared with sCV, performing 3-D CV before optional IVC filter retrieval has the potential to improve assessment of filter arms or legs projecting beyond the caval lumen, filter orientation, and thrombus burden.« less
Longitudinal safety evaluation of connected vehicles' platooning on expressways.
Rahman, Md Sharikur; Abdel-Aty, Mohamed
2018-08-01
Connected vehicles (CV) technology has recently drawn an increasing attention from governments, vehicle manufacturers, and researchers. One of the biggest issues facing CVs popularization associates it with the market penetration rate (MPR). The full market penetration of CVs might not be accomplished recently. Therefore, traffic flow will likely be composed of a mixture of conventional vehicles and CVs. In this context, the study of CV MPR is worthwhile in the CV transition period. The overarching goal of this study was to evaluate longitudinal safety of CV platoons by comparing the implementation of managed-lane CV platoons and all lanes CV platoons (with same MPR) over non-CV scenario. This study applied the CV concept on a congested expressway (SR408) in Florida to improve traffic safety. The Intelligent Driver Model (IDM) along with the platooning concept were used to regulate the driving behavior of CV platoons with an assumption that the CVs would follow this behavior in real-world. A high-level control algorithm of CVs in a managed-lane was proposed in order to form platoons with three joining strategies: rear join, front join, and cut-in joint. Five surrogate safety measures, standard deviation of speed, time exposed time-to-collision (TET), time integrated time-to-collision (TIT), time exposed rear-end crash risk index (TERCRI), and sideswipe crash risk (SSCR) were utilized as indicators for safety evaluation. The results showed that both CV approaches (i.e., managed-lane CV platoons, and all lanes CV platoons) significantly improved the longitudinal safety in the studied expressway compared to the non-CV scenario. In terms of surrogate safety measures, the managed-lane CV platoons significantly outperformed all lanes CV platoons with the same MPR. Different time-to-collision (TTC) thresholds were also tested and showed similar results on traffic safety. Results of this study provide useful insight for the management of CV MPR as managed-lane CV platoons. Copyright © 2017 Elsevier Ltd. All rights reserved.
Ruiz-Vera, Ursula M; De Souza, Amanda P; Long, Stephen P; Ort, Donald R
2017-01-01
Down-regulation of photosynthesis is among the most common responses observed in C 3 plants grown under elevated atmospheric CO 2 concentration ([CO 2 ]). Down-regulation is often attributed to an insufficient capacity of sink organs to use or store the increased carbohydrate production that results from the stimulation of photosynthesis by elevated [CO 2 ]. Down-regulation can be accentuated by inadequate nitrogen (N) supply, which may limit sink development. While there is strong evidence for down-regulation of photosynthesis at elevated [CO 2 ] in enclosure studies most often involving potted plants, there is little evidence for this when [CO 2 ] is elevated fully under open-air field treatment conditions. To assess the importance of sink strength on the down-regulation of photosynthesis and on the potential of N to mitigate this down-regulation under agriculturally relevant field conditions, two tobacco cultivars ( Nicotiana tabacum L. cv. Petit Havana; cv. Mammoth) of strongly contrasting ability to produce the major sink of this crop, leaves, were grown under ambient and elevated [CO 2 ] and with two different N additions in a free air [CO 2 ] (FACE) facility. Photosynthetic down-regulation at elevated [CO 2 ] reached only 9% in cv. Mammoth late in the season likely reflecting sustained sink strength of the rapidly growing plant whereas down-regulation in cv. Petit Havana reached 25%. Increased N supply partially mitigated down-regulation of photosynthesis in cv. Petit Havana and this mitigation was dependent on plant developmental stage. Overall, these field results were consistent with the hypothesis that sustained sink strength, that is the ability to utilize photosynthate, and adequate N supply will allow C 3 crops in the field to maintain enhanced photosynthesis and therefore productivity as [CO 2 ] continues to rise.
Li, R S Y; Kwok, H W M; Deb, S; Chui, E M C; Chan, L K; Leung, D P K
2015-04-01
An increasing number of people with intellectual disabilities (ID) are at risk of developing age-related disorders such as dementia because of a dramatic increase in life expectancy in this population in the recent years. There is no validated dementia screening instrument for Chinese people with ID. The Dementia Screening Questionnaire for Individuals with Intellectual Disabilities (DSQIID) was reported to be a valid, user-friendly, easy-to-use observer-rated instrument. It was developed in the UK and has good psychometric properties. Validation of a Chinese version of the DSQIID will facilitate its application among the Chinese population. The DSQIID was translated into the Chinese version (DSQIID-CV). By purposive sampling, service users with ID aged 40 years or over were recruited through two large centres serving adults with ID in Hong Kong. Carers who had taken care of the participants continuously for the past 6 months were invited to complete the DSQIID-CV. All participants were examined by qualified psychiatrists to determine the presence or absence of dementia. Two hundred people with ID whose age ranged between 40 and 73 years (mean 51 years, SD=7.34 years) were recruited to the study. A clinical diagnosis of dementia was established in 13 participants. An overall total score of 22 as a screening cut-off provided the optimum levels of specificity (0.995) and sensitivity (0.923). The DSQIID-CV showed good internal consistency (alpha=0.945) for all its 53 items, and excellent test-retest reliability (0.978, n=46) and inter-rater reliability (1.000, n=47). Exploratory factor analysis resulted in a four-factor solution explaining 45% of the total variance. The DSQIID-CV is shown to have robust psychometric properties. It is the first valid and reliable dementia screening instrument for Chinese adults with ID. © 2014 MENCAP and International Association of the Scientific Study of Intellectual and Developmental Disabilities and John Wiley & Sons Ltd.
Progress of BeiDou time transfer at NTSC
NASA Astrophysics Data System (ADS)
Guang, Wei; Dong, Shaowu; Wu, Wenjun; Zhang, Jihai; Yuan, Haibo; Zhang, Shougang
2018-04-01
Time transfer using global navigation satellite system (GNSS) is a primary method of remote atomic clock comparisons. As of today, there are four operational GNSS systems, namely GPS, GLONASS, Galileo and BeiDou Navigation Satellite System (BDS or BeiDou). All of them can continuously provide position, navigation and time services. This paper mainly focuses on the progress of BeiDou time transfer at the National Time Service Center, Chinese Academy of Sciences (NTSC). In order to realize the BeiDou common view (CV) time comparison, we developed the Rinex2CGGTTS software according to the guidelines of the Common GNSS Generic Time Transfer Standard, Version 2E (CGGTTS V2E). By comparing the solutions of the Rinex2CGGTTS software to the solutions of the sbf2cggtts software provided by the manufacturer of our multi-GNSS receiver, we found the sbf2cggtts (version 1.0.5) solutions contained biases in measurements to different BeiDou satellites. The biases are most likely caused by sbf2cggtts’ timing group delay corrections in data processing. The noise of the observation data is analyzed by code multipath and common clock difference. Finally, the BeiDou CV results are compared to the GPS/GLONASS/Galileo CV results between NTSC and three European UTC(k) laboratories, including Royal Observatory of Belgium (ORB), Real Institute y Observatory de la Armada (ROA), Research Institutes of Sweden (RISE or SP). For the comparisons of each baseline, we aligned the BeiDou/Galileo/GLONASS links to the calibrated GPS link with the double-difference method. The results show that the performance of BeiDou CV is correlated to the number of BeiDou satellites available in common view. With the current BeiDou constellation, the standard deviation of the differences between all BeiDou CV satellites averaging result and the GPS PPP result is 2.03 ns, 2.90 ns and 4.06 ns for ORB-NTSC, SP-NTSC and ROA-NTSC links respectively.
NASA Technical Reports Server (NTRS)
Albee, Arden L.
1993-01-01
During the past three years we have received support to continue our research in elucidating the formation and alteration histories of selected meteoritic materials by a combination of petrographic, trace element, and isotopic analyses employing optical and scanning electron microscopes and electron and ion microprobes. The awarded research funds enabled the P.I. to attend the annual LPSC, the co-I to devote approximately 15 percent of his time to the research proposed in the grant, and partial support for a visiting summer post-doctoral fellow to conduct electron microprobe analyses of meteoritic samples in our laboratory. The research funds, along with support from the NASA Education Initiative awarded to P.I. G. Wasserburg, enabled the co-I to continue a mentoring program with inner-city minority youth. The support enabled us to achieve significant results in the five projects that we proposed (in addition to the Education Initiative), namely: studies of the accretional and post-accretional alteration and thermal histories in CV meteorites, characterization of periclase-bearing Fremdlinge in CV meteorites, characterization of Ni-Pt-Ge-Te-rich Fremdlinge in CV meteorites in an attempt to determine the constraints they place on the petrogenetic and thermal histories of their host CAI's, correlated electron and ion microprobe studies of silicate and phosphate inclusions in the Colomera meteorite in an attempt to determine the petrogenesis of the IE iron meteorites, and development of improved instrumental and correction procedures for improved accuracy of analysis of meteoritic materials with the electron microprobe. This grant supported, in part or whole, 18 publications so far by our research team, with at least three more papers anticipated. The list of these publications is included. The details of the research results are briefly summarized.
Influence of body variables in the development of metabolic syndrome—A long term follow-up study
Pavanello, Chiara; Zanaboni, Anna Maria; Gaito, Sabrina; Botta, Margherita; Mombelli, Giuliana; Sirtori, Cesare R.
2018-01-01
Objectives The body variable associated with the diagnosis of Metabolic Syndrome (MetS) is an elevated waist circumference (WC), although a number of other variables have been suggested. Among these, an elevated waist-to-height ratio (WHtR), ie a value higher than 0.5, that may identify abnormality, independently from height. An elevated WHtR provided the best correlation with MetS in a prior study in a large Italian population. In order to assess the validity of this conclusion, a long-term follow-up study re-examined this population, also in order to detect possible associations with cardiovascular (CV) risk. Methods and results 1,071 subjects with a complete follow-up of over 6 years were evaluated with a comparative assessment of the three anthropometric variables, namely WHtR, WC and body mass index (BMI). WHtR≥ 0.5 had the highest sensitivity for the identification of MetS, both in males and females (94.1% and 86.7% respectively). WHtR was of reduced specificity, occurring, yet less frequently (17.7% in males and 30% in females), in patients without MetS. By contrast, enlarged WC occurred with a lower frequency in male patients who developed MetS (30.2%) whereas in females, frequency was higher than in males (69.3%). Finally, a BMI≥ 25 kg/m2 had intermediate sensitivity and specificity regardless of gender. WC showed the highest odds ratio (2.62, 95%CI: 1.18–5.78) for the prediction of CV occurrence. Conclusion The present study confirms WHtR as an excellent screening tool in identifying MetS carriers, but, different from reports in other countries, it shows a lower specificity in our population. PMID:29432480
Influence of body variables in the development of metabolic syndrome-A long term follow-up study.
Pavanello, Chiara; Zanaboni, Anna Maria; Gaito, Sabrina; Botta, Margherita; Mombelli, Giuliana; Sirtori, Cesare R; Ruscica, Massimiliano
2018-01-01
The body variable associated with the diagnosis of Metabolic Syndrome (MetS) is an elevated waist circumference (WC), although a number of other variables have been suggested. Among these, an elevated waist-to-height ratio (WHtR), ie a value higher than 0.5, that may identify abnormality, independently from height. An elevated WHtR provided the best correlation with MetS in a prior study in a large Italian population. In order to assess the validity of this conclusion, a long-term follow-up study re-examined this population, also in order to detect possible associations with cardiovascular (CV) risk. 1,071 subjects with a complete follow-up of over 6 years were evaluated with a comparative assessment of the three anthropometric variables, namely WHtR, WC and body mass index (BMI). WHtR≥ 0.5 had the highest sensitivity for the identification of MetS, both in males and females (94.1% and 86.7% respectively). WHtR was of reduced specificity, occurring, yet less frequently (17.7% in males and 30% in females), in patients without MetS. By contrast, enlarged WC occurred with a lower frequency in male patients who developed MetS (30.2%) whereas in females, frequency was higher than in males (69.3%). Finally, a BMI≥ 25 kg/m2 had intermediate sensitivity and specificity regardless of gender. WC showed the highest odds ratio (2.62, 95%CI: 1.18-5.78) for the prediction of CV occurrence. The present study confirms WHtR as an excellent screening tool in identifying MetS carriers, but, different from reports in other countries, it shows a lower specificity in our population.
DOE Office of Scientific and Technical Information (OSTI.GOV)
McKone, Thomas E.; Maddalena, Randy L.
2007-01-01
The role of terrestrial vegetation in transferring chemicals from soil and air into specific plant tissues (stems, leaves, roots, etc.) is still not well characterized. We provide here a critical review of plant-to-soil bioconcentration ratio (BCR) estimates based on models and experimental data. This review includes the conceptual and theoretical formulations of the bioconcentration ratio, constructing and calibrating empirical and mathematical algorithms to describe this ratio and the experimental data used to quantify BCRs and calibrate the model performance. We first evaluate the theoretical basis for the BCR concept and BCR models and consider how lack of knowledge and datamore » limits reliability and consistency of BCR estimates. We next consider alternate modeling strategies for BCR. A key focus of this evaluation is the relative contributions to overall uncertainty from model uncertainty versus variability in the experimental data used to develop and test the models. As a case study, we consider a single chemical, hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), and focus on variability of bioconcentration measurements obtained from 81 experiments with different plant species, different plant tissues, different experimental conditions, and different methods for reporting concentrations in the soil and plant tissues. We use these observations to evaluate both the magnitude of experimental variability in plant bioconcentration and compare this to model uncertainty. Among these 81 measurements, the variation of the plant/soil BCR has a geometric standard deviation (GSD) of 3.5 and a coefficient of variability (CV-ratio of arithmetic standard deviation to mean) of 1.7. These variations are significant but low relative to model uncertainties--which have an estimated GSD of 10 with a corresponding CV of 14.« less
Estevan, Isaac; Freedman Silvernail, Julia; Jandacka, Daniel; Falco, Coral
2016-09-01
The initial stance position (ISP) has been observed as a factor affecting the execution technique during taekwondo kicks. In the present study, authors aimed to analyse a roundhouse kick to the chest by measuring movement coordination and the variability of coordination and comparing this across the different ISP (0°, 45° and 90°). Eight experienced taekwondo athletes performed consecutive kicking trials in random order from every of the three relative positions. The execution was divided into three phases (stance, first swing and second swing phase). A motion capture system was used to measure athletes' angular displacement of pelvis and thigh. A modified vector coding technique was used to quantify the coordination of the segments which contributed to the overall movement. The variability of this coordination (CV) for each ISP was also calculated. Comparative analysis showed that during the stance phase in the transverse plane, athletes coordinated movement of the trunk and thigh with a higher frequency of in-phase and lower frequency of exclusive thigh rotation in the 0° stance than the 90° stance position (P < 0.05). CV was also influenced by the different ISP. During the first swing and the majority of the second swing phase, predominant in-phase coordination of the pelvis and thigh was observed. Including exercises that require in-phase movement could not only help athletes to acquire coordination stability but also efficiency. The existence of a constraint such as ISP implies an increase of the variability when the athletes have to kick from ISP they are not used to adopt (i.e., 0° and 90° ISP) as an evidence of adaptability in the athletes' execution technique.
Dalmau Llorca, Maria Rosa; Boira Costa, Míriam; López Pablo, Carlos; Pepió Vilaubí, Josep Maria; Aguilar Martin, Carina; Forcadell Drago, Emma
2016-11-01
To estimate the prevalence of occult renal failure (RF) in DM2, by comparing two formulas for estimating glomerular filtration rate (GFR): Modification of Diet in Renal Disease 4 (MDRD-4) and Cockcroft-Gault (CG), as well as their associated clinical variables. Multicentre analytical cross-sectional. Two basic Primary Care areas in Terres de l'Ebre, in North-Eastern Spain. A total of 493 DM2 patients with age >18years with an assigned doctor in the areas studied. There was a loss of 9 and 11 cases in each formula due to lack of variables necessary for the GFR. Estimated GFR using the two formulas, plasma creatinine values, classification of patients with established RF, occult RF and without RF, and possible clinical-pathological variables associated with RF. Of the total, 45.2% were men, the mean age was 70.4 years, and mean time since onset of diabetes of 7.5 years. The prevalence of occult RF with MDRD-4 was 18%, and 22.6% with CG. The cases detected by GC and not by MDRD-4 were higher, and with lower weight. In both formulas, occult RF patients had more chronic diseases, hypertension, and cardiovascular events (CV) than those without RF. Risk factors associated with occult RF were female, increasing age, and LDL cholesterol. The prevalence of occult RF was 20% in DM2, independently of the formula. A poorer control of cardiovascular risk factors was observed, which makes them a group at higher risk of suffering a CV event. Copyright © 2016 Elsevier España, S.L.U. All rights reserved.
Oh, Hyung Jung; Lee, Mi Jung; Kwon, Young Eun; Park, Kyoung Sook; Park, Jung Tak; Han, Seung Hyeok; Yoo, Tae-Hyun; Kim, Yong-Lim; Kim, Yon Su; Yang, Chul Woo; Kim, Nam-Ho; Kang, Shin-Wook
2015-01-01
Abstract Although numerous previous studies have explored various biomarkers for their ability to predict mortality in end-stage renal disease (ESRD) patients, these studies have been limited by retrospective analyses, mostly prevalent dialysis patients, and the measurement of only 1 or 2 biomarkers. This prospective study was aimed to evaluate the association between 3 biomarkers and mortality in incident 335 ESRD patients starting continuous ambulatory peritoneal dialysis (CAPD) in Korea. According to the baseline NT-proBNP, cTnT, and hsCRP levels, the patients were stratified into tertiles, and cardiovascular (CV) and all-cause mortalities were compared. Additionally, time-dependent ROC curves were constructed, and the net reclassification index (NRI) and integrated discrimination improvement (IDI) of the models with various biomarkers were calculated. We found the upper tertile of NT-proBNP was significantly associated with increased risk of both CV and all-cause mortalities. However, the upper tertile of hsCRP was significantly related only to the high risk of all-cause mortality even after adjustment for age, sex, and white blood cell counts. Moreover, NT-proBNP had the highest predictive power for CV mortality, whereas hsCRP was the best prognostic marker for all-cause mortality among these biomarkers. In conclusions, NT-proBNP is a more significant prognostic factor for CV mortality than cTnT and hsCRP, whereas hsCRP is a more significant predictor than NT-proBNP and cTnT for all-cause mortality in incident peritoneal dialysis patients. PMID:26554763
Kao, Amy H.; Lertratanakul, Apinya; Elliott, Jennifer R.; Sattar, Abdus; Santelices, Linda; Shaw, Penny; Birru, Mehret; Avram, Zheni; Thompson, Trina; Sutton-Tyrrell, Kim; Ramsey-Goldman, Rosalind; Manzi, Susan
2013-01-01
Patients with systemic lupus erythematosus (SLE) are at increased risk for cardiovascular (CV) disease. The aim of this study was to investigate the association between subclinical CV disease as measured by carotid intima-media thickness (IMT) and plaque using B-mode carotid ultrasound and incident CV events in a combined cohort of female patients with SLE. This was a prospective, 2-center observational study of 392 adult women with SLE and no previous CV events with a mean 8 years of follow-up. Incident CV events confirmed by clinicians were defined as angina, myocardial infarction, percutaneous transluminal coronary angioplasty, coronary artery bypass graft, fatal cardiac arrest, transient ischemic attack, and cerebrovascular accident. Incident hard CV events excluded angina and transient ischemic attack. The mean age was 43.5 years, and most patients were Caucasian (77.3%). During follow-up, 38 patients had incident CV events, and 17 had incident hard CV events. Patients with incident hard CV events had higher mean carotid IMT (0.80 vs 0.64 mm, p <0.01) and presence of carotid plaque (76.5% vs 30.4%, p <0.01) compared with those without incident hard CV events. Baseline carotid IMT and presence of plaque were predictive of any incident hard CV event (hazard ratio 1.35, 95% confidence interval 1.12 to 1.64, and hazard ratio 4.26, 95% confidence interval 1.23 to 14.83, respectively), independent of traditional CV risk factors and medication use. In conclusion, in women with SLE without previous CV events, carotid IMT and plaque are predictive of future CV events. This suggests that carotid ultrasound may provide an additional tool for CV risk stratification in patients with SLE. PMID:23827400
Kao, Amy H; Lertratanakul, Apinya; Elliott, Jennifer R; Sattar, Abdus; Santelices, Linda; Shaw, Penny; Birru, Mehret; Avram, Zheni; Thompson, Trina; Sutton-Tyrrell, Kim; Ramsey-Goldman, Rosalind; Manzi, Susan
2013-10-01
Patients with systemic lupus erythematosus (SLE) are at increased risk for cardiovascular (CV) disease. The aim of this study was to investigate the association between subclinical CV disease as measured by carotid intima-media thickness (IMT) and plaque using B-mode carotid ultrasound and incident CV events in a combined cohort of female patients with SLE. This was a prospective, 2-center observational study of 392 adult women with SLE and no previous CV events with a mean 8 years of follow-up. Incident CV events confirmed by clinicians were defined as angina, myocardial infarction, percutaneous transluminal coronary angioplasty, coronary artery bypass graft, fatal cardiac arrest, transient ischemic attack, and cerebrovascular accident. Incident hard CV events excluded angina and transient ischemic attack. The mean age was 43.5 years, and most patients were Caucasian (77.3%). During follow-up, 38 patients had incident CV events, and 17 had incident hard CV events. Patients with incident hard CV events had higher mean carotid IMT (0.80 vs 0.64 mm, p <0.01) and presence of carotid plaque (76.5% vs 30.4%, p <0.01) compared with those without incident hard CV events. Baseline carotid IMT and presence of plaque were predictive of any incident hard CV event (hazard ratio 1.35, 95% confidence interval 1.12 to 1.64, and hazard ratio 4.26, 95% confidence interval 1.23 to 14.83, respectively), independent of traditional CV risk factors and medication use. In conclusion, in women with SLE without previous CV events, carotid IMT and plaque are predictive of future CV events. This suggests that carotid ultrasound may provide an additional tool for CV risk stratification in patients with SLE. Copyright © 2013 Elsevier Inc. All rights reserved.
Dynamical preparation of Einstein-Podolsky-Rosen entanglement in two-well Bose-Einstein condensates
NASA Astrophysics Data System (ADS)
Opanchuk, B.; He, Q. Y.; Reid, M. D.; Drummond, P. D.
2012-08-01
We propose to generate Einstein-Podolsky-Rosen (EPR) entanglement between groups of atoms in a two-well Bose-Einstein condensate using a dynamical process similar to that employed in quantum optics. A local nonlinear S-wave scattering interaction has the effect of creating spin squeezing at each well, while a tunneling coupling, analogous to a beam splitter in optics, introduces an interference between these fields that causes interwell entanglement. We consider two internal modes at each well so that the entanglement can be detected by measuring a reduction in the variances of the sums of local Schwinger spin observables. As is typical of continuous variable (CV) entanglement, the entanglement is predicted to increase with atom number. It becomes sufficiently strong at higher numbers of atoms so that the EPR paradox and steering nonlocality can be realized. The entanglement is predicted using an analytical approach and, for larger atom numbers, using stochastic simulations based on a truncated Wigner function approximation. We find generally that strong tunneling is favorable, and that entanglement persists and is even enhanced in the presence of realistic nonlinear losses.
Cardiovascular Safety of Biologics and JAK Inhibitors in Patients with Rheumatoid Arthritis.
Kang, Eun Ha; Liao, Katherine P; Kim, Seoyoung C
2018-05-30
Increased cardiovascular (CV) risk and associated mortality in rheumatoid arthritis (RA) are not fully explained by traditional CV risk factors. This review discusses the epidemiology and mechanisms of increased CV risk in RA and treatment effects on CV risk focusing on biologic disease-modifying anti-rheumatic drugs (DMARDs) and JAK inhibitors. Intermediary metabolic changes by inflammatory cytokines are observed in body composition, lipid profile, and insulin sensitivity of RA patients, leading to accelerated atherosclerosis and increased CV risk. Successful treatment with DMARDs has shown beneficial effects on these metabolic changes and ultimately CV outcomes, in proportion to the treatment efficacy in general but also with drug-specific mechanisms. Recent data provide further information on comparative CV safety between biologic DMARDs or JAK inhibitors as well as their safety signals for non-atherosclerotic CV events. CV benefits or safety signals associated with DMARD treatments can differ despite similar drug efficacy against RA, suggesting that both anti-inflammatory and drug-specific mechanisms are involved in altering CV risk.
DOE Office of Scientific and Technical Information (OSTI.GOV)
FINNEY, Charles E A; Edwards, Kevin Dean; Stoyanov, Miroslav K
2015-01-01
Combustion instabilities in dilute internal combustion engines are manifest in cyclic variability (CV) in engine performance measures such as integrated heat release or shaft work. Understanding the factors leading to CV is important in model-based control, especially with high dilution where experimental studies have demonstrated that deterministic effects can become more prominent. Observation of enough consecutive engine cycles for significant statistical analysis is standard in experimental studies but is largely wanting in numerical simulations because of the computational time required to compute hundreds or thousands of consecutive cycles. We have proposed and begun implementation of an alternative approach to allowmore » rapid simulation of long series of engine dynamics based on a low-dimensional mapping of ensembles of single-cycle simulations which map input parameters to output engine performance. This paper details the use Titan at the Oak Ridge Leadership Computing Facility to investigate CV in a gasoline direct-injected spark-ignited engine with a moderately high rate of dilution achieved through external exhaust gas recirculation. The CONVERGE CFD software was used to perform single-cycle simulations with imposed variations of operating parameters and boundary conditions selected according to a sparse grid sampling of the parameter space. Using an uncertainty quantification technique, the sampling scheme is chosen similar to a design of experiments grid but uses functions designed to minimize the number of samples required to achieve a desired degree of accuracy. The simulations map input parameters to output metrics of engine performance for a single cycle, and by mapping over a large parameter space, results can be interpolated from within that space. This interpolation scheme forms the basis for a low-dimensional metamodel which can be used to mimic the dynamical behavior of corresponding high-dimensional simulations. Simulations of high-EGR spark-ignition combustion cycles within a parametric sampling grid were performed and analyzed statistically, and sensitivities of the physical factors leading to high CV are presented. With these results, the prospect of producing low-dimensional metamodels to describe engine dynamics at any point in the parameter space will be discussed. Additionally, modifications to the methodology to account for nondeterministic effects in the numerical solution environment are proposed« less
Reliability and Validity of the Load-Velocity Relationship to Predict the 1RM Back Squat.
Banyard, Harry G; Nosaka, Kazunori; Haff, G Gregory
2017-07-01
Banyard, HG, Nosaka, K, and Haff, GG. Reliability and validity of the load-velocity relationship to predict the 1RM back squat. J Strength Cond Res 31(7): 1897-1904, 2017-This study investigated the reliability and validity of the load-velocity relationship to predict the free-weight back squat one repetition maximum (1RM). Seventeen strength-trained males performed three 1RM assessments on 3 separate days. All repetitions were performed to full depth with maximal concentric effort. Predicted 1RMs were calculated by entering the mean concentric velocity of the 1RM (V1RM) into an individualized linear regression equation, which was derived from the load-velocity relationship of 3 (20, 40, 60% of 1RM), 4 (20, 40, 60, 80% of 1RM), or 5 (20, 40, 60, 80, 90% of 1RM) incremental warm-up sets. The actual 1RM (140.3 ± 27.2 kg) was very stable between 3 trials (ICC = 0.99; SEM = 2.9 kg; CV = 2.1%; ES = 0.11). Predicted 1RM from 5 warm-up sets up to and including 90% of 1RM was the most reliable (ICC = 0.92; SEM = 8.6 kg; CV = 5.7%; ES = -0.02) and valid (r = 0.93; SEE = 10.6 kg; CV = 7.4%; ES = 0.71) of the predicted 1RM methods. However, all predicted 1RMs were significantly different (p ≤ 0.05; ES = 0.71-1.04) from the actual 1RM. Individual variation for the actual 1RM was small between trials ranging from -5.6 to 4.8% compared with the most accurate predictive method up to 90% of 1RM, which was more variable (-5.5 to 27.8%). Importantly, the V1RM (0.24 ± 0.06 m·s) was unreliable between trials (ICC = 0.42; SEM = 0.05 m·s; CV = 22.5%; ES = 0.14). The load-velocity relationship for the full depth free-weight back squat showed moderate reliability and validity but could not accurately predict 1RM, which was stable between trials. Thus, the load-velocity relationship 1RM prediction method used in this study cannot accurately modify sessional training loads because of large V1RM variability.
The effects of metronome breathing on the variability of autonomic activity measurements.
Driscoll, D; Dicicco, G
2000-01-01
Many chiropractors hypothesize that spinal manipulation affects the autonomic nervous system (ANS). However, the ANS responses to chiropractic manipulative therapy are not well documented, and more research is needed to support this hypothesis. This study represents a step toward the development of a reliable method by which to document that chiropractic manipulative therapy does affect the ANS by exploring the use of paced breathing as a way to reduce the inherent variability in ANS measurements. To examine the hypothesis that the variability of ANS measurements would be reduced if breathing were paced to a metronome at 12 breaths/min. The study was performed at Parker College Research Institute. Eight normotensive subjects were recruited from the student body and staff. Respiration frequency was measured through a strain gauge. A 3-lead electrocardiogram (ECG) was used to register the electric activity of the heart, and arterial tonometry monitors were used to record the left and right radial artery blood pressures. Signals were recorded on an IBM-compatible computer with a sampling frequency of 100 Hz. Normal breathing was used for the first 3 recordings, and breathing was paced to a metronome for the final 3 recordings at 12 breaths/min. Fourier analysis was performed on the beat-by-beat fluctuations of the ECG-determined R-R interval and systolic arterial pressure (SBP). Low-frequency fluctuations (LF; 0.04-0.15 Hz) reflected sympathetic activity, whereas high-frequency fluctuations (HF; 0.15-0.4 Hz) represented parasympathetic activity. Sympathovagal indices were determined from the ratio of the two bandwidths (LF/HF). The coefficient of variation (CV%) for autonomic parameters was calculated ([average/SD] x 100%) to compare breathing normally and breathing to a metronome with respect to variability. One-way analysis of variance was used to detect differences. A value of P < 0.05 was considered statistically significant; all results are presented as average +/- SD. Three male and 5 female normotensive subjects were studied. Metronome breathing did not produce any significant changes in blood pressure for the left and right radial arteries, heart rate, or pressure pulse transmission time. Breathing to a metronome increased ECG-HF power (0.25 +/- 0.07 vs 0.35 +/- 0.09, P < 0.04), decreased ECG-LF/HF (1.08 +/- 0.55 vs 0.57 +/- 0.35, P < 0.05), and reduced the CV% for ECG-LF (47.6% +/- 23.4% vs 23.8% +/- 14.6%, P < 0.03), ECG-HF (46.2% +/- 14.2% vs 25.8% +/- 17.0%, P < 0.03) and ECG-LF/HF (50.1% +/- 27.6% vs 23.4% +/- 12.3%, P < 0.03) in comparison with normal breathing. Metronome breathing increased the left and right radial artery SBP-HF fluctuations (left, 0.11 +/- 0.05 vs 0.30 +/- 0.16, P < 0.007; right, 0.09 +/- 0.05 vs 0.27 +/- 0.15, P < 0.008) and decreased the SBP-LF/HF components (left, 3.42 +/- 2.36 vs 1.14 +/- 0.88, P > 0.03; right, 3.08 +/- 1.77 vs 1.20 +/- 0.93, P < 0.02). Metronome breathing did not significantly alter the CV% for SBP-HF, SBP-LF, and SBP-LF/HF. Metronome breathing increased parasympathetic activity, as evidenced by augmented HF power in the ECG and SBP data. The variability (CV%) of ECG-determined ANS measurements was significantly reduced with paced breathing at 12 breaths/min, but no significant reductions were observed for the SBP-determined ANS measurements. These findings indicate that ECG data are more sensitive than SBP data for future clinical trials.
78 FR 66990 - Additional Designations, Foreign Narcotics Kingpin Designation Act
Federal Register 2010, 2011, 2012, 2013, 2014
2013-11-07
...) [SDNTK] (Linked To: ARRENDADORA TURIN, S.A.; Linked To: DESARROLLOS BIO GAS, S.A. DE C.V.; Linked To: ECA...] (Linked To: BLUE POINT SALT, S.A. DE C.V.; Linked To: DESARROLLOS BIO GAS, S.A. DE C.V.; Linked To: ECA ENERGETICOS, S.A. DE C.V.; Linked To: ORGANIC SALT, S.A. DE C.V.; Linked To: PETRO BIO, S. DE R.L. DE C.V...
A comparison of aphasic and non-brain-injured adults on a dichotic CV-syllable listening task.
Shanks, J; Ryan, W
1976-06-01
A dichotic CV-syllable listening task was administered to a group of eleven non-brain-injured adults and to a group of eleven adult aphasics. The results of this study may be summarized as follows: 1)The group of non-brain-injured adults showed a slight right ear advantage for dichotically presented CV-syllables. 2)In comparison with the control group the asphasic group showed a bilateral deficit in response to the dichotic CV-syllables, superimposed on a non-significant right ear advantage. 3) The asphasic group demonstrated a great deal of intersubject variability on the dichotic task with six aphasics showing a right ear preference for the stimuli. The non-brain-injured subjects performed more homogeneously on the task. 4) The two subgroups of aphasics, a right ear advantage group and a left ear advantage group, performed significantly different on the dichotic listening task. 5) Single correct data analysis proved valuable by deleting accuracy of report for an examination of trials in which there was true competition for the single left hemispheric speech processor. These results were analyzed in terms of a functional model of auditory processing. In view of this model, the bilateral deficit in dichotic performance of the asphasic group was accounted for by the presence of a lesion within the dominant left hemisphere, where the speech signals from both ears converge for final processing. The right ear advantage shown by one asphasic subgroup was explained by a lesion interfering with the corpus callosal pathways from the left hemisphere; the left ear advantage observed within the other subgroup was explained by a lesion in the area of the auditory processor of the left hemisphere.
Case study: Natural bodybuilding contest preparation.
Kistler, Brandon M; Fitschen, Peter J; Ranadive, Sushant M; Fernhall, Bo; Wilund, Kenneth R
2014-12-01
The purpose of this study was to document the physiological changes that occur in a natural bodybuilder during prolonged contest preparation for a proqualifying contest. During the 26-week preparation, the athlete undertook a calorically restrictive diet with 2 days of elevated carbohydrate intake per week, increased cardiovascular (CV) training, and attempted to maintain resistance-training load. The athlete was weighed twice a week and body composition was measured monthly by DXA. At baseline and every 2 weeks following CV structure and function was measured using a combination of ultrasound, applanation tonometry, and heart rate variability (HRV). Cardiorespiratory performance was measured by VO(2)peak at baseline, 13 weeks, and 26 weeks. Body weight (88.6 to 73.3 Kg, R(2) = .99) and percent body fat (17.5 to 7.4%) were reduced during preparation. CV measurements including blood pressure (128/61 to 113/54 mmHg), brachial pulse wave velocity (7.9 to 5.8m/s), and measures of wave reflection all improved. Indexed cardiac output was reduced (2.5 to 1.8L/m(2)) primarily due to a reduction in resting heart rate (71 to 44 bpm), and despite an increase in ejection faction (57.9 to 63.9%). Assessment of HRV found a shift in the ratio of low to high frequency (209.2 to 30.9%). Absolute VO2 was minimally reduced despite weight loss resulting in an increase in relative VO2 (41.9 to 47.7 ml/Kg). In general, this prolonged contest preparation technique helped the athlete to improve body composition and resulted in positive CV changes, suggesting that this method of contest preparation appears to be effective in natural male bodybuilders.
McCole, Steve D; Shuldiner, Alan R; Brown, Michael D; Moore, Geoffrey E; Ferrell, Robert E; Wilund, Kenneth R; Huberty, Andrea; Douglass, Larry W; Hagberg, James M
2004-02-01
We sought to determine whether common genetic variations at the beta2 (beta2-AR, Gln27Glu) and beta3 (beta3-AR, Trp64Arg) adrenergic receptor gene loci were associated with cardiovascular (CV) hemodynamics during maximal and submaximal exercise. CV hemodynamics were assessed in 62 healthy postmenopausal women (20 sedentary, 22 physically active, and 20 endurance athletes) during treadmill exercise at 40, 60, 80, and 100% maximal O2 uptake using acetylene rebreathing to quantify cardiac output. The beta2-AR genotype and habitual physical activity (PA) levels interacted to significantly associate with arteriovenous O2 difference (a-vDO2) during submaximal exercise (P = 0.05), with the highest submaximal exercise a-vDO2 in sedentary women homozygous for the beta2-AR Gln allele and no genotype-dependent differences in submaximal exercise a-vDO2 in physically active and athletic women. The beta2-AR genotype also was independently associated with a-vDO2 during submaximal (P = 0.004) and approximately 100% maximal O2 uptake exercise (P = 0.006), with a 1.2-2 ml/100 ml greater a-vDO2 in the Gln/Gln than in the Glu/Glu genotype women. The beta3-AR genotype, independently or interacting with habitual PA levels, was not significantly associated with any CV hemodynamic variables during submaximal or maximal exercise. Thus it appears that the beta2-AR genotype, both independently and interacting with habitual PA levels, is significantly associated with a-vDO2 during exercise in postmenopausal women, whereas the beta3-AR genotype does not appear to be associated with any maximal or submaximal exercise CV hemodynamic responses in postmenopausal women.
Elastography Study of Hamstring Behaviors during Passive Stretching
Le Sant, Guillaume; Ates, Filiz; Brasseur, Jean-Louis; Nordez, Antoine
2015-01-01
Introduction The mechanical properties of hamstring muscles are usually inferred from global passive torque/angle relationships, in combination with adjoining tissues crossing the joint investigated. Shear modulus measurement provides an estimate of changes in muscle-tendon stiffness and passive tension. This study aimed to assess the passive individual behavior of each hamstring muscle in different stretching positions using shear wave elastography. Methods/Results The muscle shear modulus of each hamstring muscle was measured during a standardized slow passive knee extension (PKE, 80% of maximal range of motion) on eighteen healthy male volunteers. Firstly, we assessed the reliability of the measurements. Results were good for semitendinosus (ST, CV: 8.9%-13.4%), semimembranosus (SM, CV: 10.3%-11.2%) and biceps femoris long-head (BF-lh, CV: 8.6%-13.3%), but not for biceps femoris short-head (BF-sh, CV: 20.3%-44.9%). Secondly, we investigated each reliable muscle in three stretch positions: 70°, 90° and 110° of hip flexion. The results showed different values of shear modulus for the same amount of perceived stretch, with the highest measurements in the high-flexed hip situation. Moreover, individual muscles displayed different values, with values increasing or BF-lh, SM and ST, respectively. The inter-subject variability was 35.3% for ST, 27.4% for SM and 30.2% for BF-lh. Conclusion This study showed that the hip needs to be high-flexed to efficiently tension the hamstrings, and reports a higher muscle-tendon stress tolerance at 110° of hip angle. In addition muscles have different passive behaviors, and future works will clarify if it can be linked with rate of injury. PMID:26418862
Validation of a multiplex electrochemiluminescent immunoassay platform in human and mouse samples
Bastarache, J.A.; Koyama, T.; Wickersham, N.E; Ware, L.B.
2014-01-01
Despite the widespread use of multiplex immunoassays, there are very few scientific reports that test the accuracy and reliability of a platform prior to publication of experimental data. Our laboratory has previously demonstrated the need for new assay platform validation prior to use of biologic samples from large studies in order to optimize sample handling and assay performance. In this study, our goal was to test the accuracy and reproducibility of an electrochemiluminescent multiplex immunoassay platform (Meso Scale Discovery, MSD®) and compare this platform to validated, singleplex immunoassays (R&D Systems®) using actual study subject (human plasma and mouse bronchoalveolar lavage fluid (BALF) and plasma) samples. We found that the MSD platform performed well on intra- and inter-assay comparisons, spike and recovery and cross-platform comparisons. The mean intra-assay CV% and range for MSD was 3.49 (0.0-10.4) for IL-6 and 2.04 (0.1-7.9) for IL-8. The correlation between values for identical samples measured on both MSD and R&D was R=0.97 for both analytes. The mouse MSD assay had a broader range of CV% with means ranging from 9.5-28.5 depending on the analyte. The range of mean CV% was similar for single plex ELISAs at 4.3-23.7 depending on the analyte. Regardless of species or sample type, CV% was more variable at lower protein concentrations. In conclusion, we validated a multiplex electrochemiluminscent assay system and found that it has superior test characteristics in human plasma compared to mouse BALF and plasma. Both human and MSD assays compared favorably to well-validated singleplex ELISA's PMID:24768796
The first mass and angular momentum loss measurements for a CV-like binary
NASA Astrophysics Data System (ADS)
Drake, Jeremy
2015-10-01
The period distribution of close binaries, cataclysmic variables, novae and single-degenerate SN1a progenitor candidates is largely controlled by magnetically-driven mass and angular momentum loss (AML) from the M dwarf secondary. The mass loss rates for these spun-up stars remain essentially unknown and impossible to observe directly, with likely values in the range 1e-12 to 1e-15 Msun/yr. AML presciptions for CVs differ by orders of magnitude. One way to measure the mass loss rate is to observe the dM wind accrete onto its WD companion in a pre-CV very close to Roche Lobe overflow but lacking the obscuring complications and emission from an accretion disk. The measurement can be combined with realistic MHD models to understand the accretion fraction, the mass that escapes, and the AML. The best-studied nearby pre-CV is QS Vir (48pc, P=3.6hr). However, its wind accretion rates measured from 1999 HST UV spectra of the WD metal absorption lines and 2006 XMM-Newton CCD spectroscopy differ by a factor of a thousand, pointing to either a dominant CME stochastic component, or a magnetic switch found in MHD simulations and driven by cyclic activity on the M dwarf. HST COS spectra combined with XMM-Newton monitoring on timescales from weeks to years will tease out CME vs cyclic accretion variations. UV and X-ray measurements will provide the first consistency check of both accretion rate measurement methods. MHD models tailored to the system will enable the first quasi-direct measurements of the mass loss and AML from a CV-like binary. Our project requires 6 HST/COS orbits in Cycles 22-24, and 60ksec on XMM in Cycle 22
The first mass and angular momentum loss measurements for a CV-like binary
NASA Astrophysics Data System (ADS)
Drake, Jeremy
2014-10-01
The period distribution of close binaries, cataclysmic variables, novae and single-degenerate SN1a progenitor candidates is largely controlled by magnetically-driven mass and angular momentum loss (AML) from the M dwarf secondary. The mass loss rates for these spun-up stars remain essentially unknown and impossible to observe directly, with likely values in the range 1e-12 to 1e-15 Msun/yr. AML presciptions for CVs differ by orders of magnitude. One way to measure the mass loss rate is to observe the dM wind accrete onto its WD companion in a pre-CV very close to Roche Lobe overflow but lacking the obscuring complications and emission from an accretion disk. The measurement can be combined with realistic MHD models to understand the accretion fraction, the mass that escapes, and the AML. The best-studied nearby pre-CV is QS Vir (48pc, P=3.6hr). However, its wind accretion rates measured from 1999 HST UV spectra of the WD metal absorption lines and 2006 XMM-Newton CCD spectroscopy differ by a factor of a thousand, pointing to either a dominant CME stochastic component, or a "magnetic switch" found in MHD simulations and driven by cyclic activity on the M dwarf. HST COS spectra combined with XMM-Newton monitoring on timescales from weeks to years will tease out CME vs cyclic accretion variations. UV and X-ray measurements will provide the first consistency check of both accretion rate measurement methods. MHD models tailored to the system will enable the first quasi-direct measurements of the mass loss and AML from a CV-like binary. Our project requires 6 HST/COS orbits in Cycles 22-24, and 60ksec on XMM in Cycle 22
The first mass and angular momentum loss measurements for a CV-like binary
NASA Astrophysics Data System (ADS)
Drake, Jeremy
2016-10-01
The period distribution of close binaries, cataclysmic variables, novae and single-degenerate SN1a progenitor candidates is largely controlled by magnetically-driven mass and angular momentum loss (AML) from the M dwarf secondary. The mass loss rates for these spun-up stars remain essentially unknown and impossible to observe directly, with likely values in the range 1e-12 to 1e-15 Msun/yr. AML presciptions for CVs differ by orders of magnitude. One way to measure the mass loss rate is to observe the dM wind accrete onto its WD companion in a pre-CV very close to Roche Lobe overflow but lacking the obscuring complications and emission from an accretion disk. The measurement can be combined with realistic MHD models to understand the accretion fraction, the mass that escapes, and the AML. The best-studied nearby pre-CV is QS Vir (48pc, P=3.6hr). However, its wind accretion rates measured from 1999 HST UV spectra of the WD metal absorption lines and 2006 XMM-Newton CCD spectroscopy differ by a factor of a thousand, pointing to either a dominant CME stochastic component, or a magnetic switch found in MHD simulations and driven by cyclic activity on the M dwarf. HST COS spectra combined with XMM-Newton monitoring on timescales from weeks to years will tease out CME vs cyclic accretion variations. UV and X-ray measurements will provide the first consistency check of both accretion rate measurement methods. MHD models tailored to the system will enable the first quasi-direct measurements of the mass loss and AML from a CV-like binary. Our project requires 6 HST/COS orbits in Cycles 22-24, and 60ksec on XMM in Cycle 22
Rossi, Maria C E; Lucisano, Giuseppe; Comaschi, Marco; Coscelli, Carlo; Cucinotta, Domenico; Di Blasi, Patrizia; Bader, Giovanni; Pellegrini, Fabio; Valentini, Umberto; Vespasiani, Giacomo; Nicolucci, Antonio
2011-02-01
The QUASAR (Quality Assessment Score and Cardiovascular Outcomes in Italian Diabetes Patients) study aimed to assess whether a quality-of-care summary score predicted the development of cardiovascular (CV) events in patients with type 2 diabetes. In 67 diabetes clinics, data on randomly selected patients were extracted from electronic medical records. The score was calculated using process and outcome indicators based on monitoring, targets, and treatment of A1C, blood pressure, LDL cholesterol, and microalbuminuria. The score ranged from 0 to 40. Overall, 5,181 patients were analyzed; 477 (9.2%) patients developed a CV event after a median follow-up of 28 months. The incidence rate (per 1,000 person-years) of CV events was 62.4 in patients with a score of <15, 41.0 in those with a score between 20 and 25 and 36.7 in those with a score of >25. Multilevel analysis, adjusted for clustering and case-mix, showed that the risk to develop a new CV event was 84% higher in patients with a score of <15 (incidence rate ratio [IRR] = 1.84; 95% confidence interval [CI] 1.29-2.62) and 17% higher in those with a score between 15 and 25 (IRR = 1.17; 95% CI 0.93-1.49) compared with those with a score of >25. Mean quality score varied across centers from 16.5 ± 7.5 to 29.1 ± 6.3. When the score was tested as the dependent variable, it emerged that 18% of the variance in the score could be attributed to setting characteristics. Our study documented a close relationship between quality of diabetes care and long-term outcomes. A simple score can be used to monitor quality of care and compare the performance of different centers/physicians.
Karsten, Bettina; Larumbe-Zabala, Eneko; Kandemir, Gokhan; Hazir, Tahir; Klose, Andreas; Naclerio, Fernando
2016-01-01
The objectives of this study were to examine the effects of a moderate intensity strength training on changes in critical velocity (CV), anaerobic running distance (D'), sprint performance and Yo-Yo intermittent running test (Yo-Yo IR1) performances. two recreational soccer teams were divided in a soccer training only group (SO; n = 13) and a strength and soccer training group (ST; n = 13). Both groups were tested for values of CV, D', Yo-Yo IR1 distance and 30-m sprint time on two separate occasions (pre and post intervention). The ST group performed a concurrent 6-week upper and lower body strength and soccer training, whilst the SO group performed a soccer only training. after the re-test of all variables, the ST demonstrated significant improvements for both, YoYo IR1 distance (p = 0.002) and CV values (p<0.001) with no significant changes in the SO group. 30-m sprint performance were slightly improved in the ST group with significantly decreased performance times identified in the SO group (p<0.001). Values for D' were slightly reduced in both groups (ST -44.5 m, 95% CI = -90.6 to 1.6; SO -42.6 m, 95% CI = -88.7 to 3.5). combining a 6-week moderate strength training with soccer training significantly improves CV, Yo-Yo IR1 whilst moderately improving 30-m sprint performances in non-previously resistance trained male soccer players. Critical Velocity can be recommended to coaches as an additional valid testing tool in soccer.
Martin, Nancy; Traboulsee, Anthony L; Machan, Lindsay; Klass, Darren; Ellchuk, Tasha; Zhao, Yinshan; Knox, Katherine B; Kopriva, David; Lala, Shantilal; Nickel, Darren; Otani, Robert; Perera, Warren R; Rauscher, Alexander; Sadovnick, A Dessa; Szkup, Peter; Li, David K
2017-05-01
The study sought to assess and compare the prevalence of narrowing of the major extracranial veins in subjects with multiple sclerosis and controls, and to assess the sensitivity and specificity of magnetic resonance venography (MRV) for describing extracranial venous narrowing as it applies to the chronic cerebrospinal venous insufficiency theory, using catheter venography (CV) as the gold standard. The jugular and azygos veins were assessed with time-of-flight MRV in this assessor-blinded, case-control study of subjects with multiple sclerosis, their unaffected siblings, and unrelated controls. The veins were evaluated by diameter and area, and compared with CV. Collateral vessels were also analyzed for maximal diameter, as a potential indicator of compensatory flow. A high prevalence of extracranial venous narrowing was demonstrated in all study groups, collectively up to 84% by diameter criteria and 90% by area, with no significant difference between the groups when assessed independently (P = .34 and .63, respectively). There was high interobserver variability in the reporting of vessel narrowing (kappa = 0.32), and poor vessel per vessel correlation between narrowing on MRV and CV (kappa = 0.064). Collateral neck veins demonstrated no convincing difference in maximum size or correlation with jugular narrowing. There is a high prevalence of narrowing of the major extracranial veins on MRV in all 3 study groups, with no significant difference between them. These findings do not support the chronic cerebrospinal venous insufficiency theory. Although MRV has shown a high sensitivity for identifying venous narrowing, time-of-flight imaging demonstrates poor interobserver agreement and poor specificity when compared with the gold standard CV. Copyright © 2016 Canadian Association of Radiologists. Published by Elsevier Inc. All rights reserved.
Janssen, Imke; Landay, Alan L.; Ruppert, Kristine; Powell, Lynda H.
2015-01-01
Moderate wine consumption has been associated with reduced cardiovascular (CV) risk, but most investigations have been conducted in Caucasian populations. To investigate the relationship of wine consumption to CV risk markers, we studied a multi-ethnic sample of middle-aged, healthy women (N = 2900; 48% white, 28% black, 7% Hispanic, 8% Chinese, 9% Japanese) participating in SWAN over 7 years with repeated assessments of CV risk factors. Consumption of wine was stable and common with 20% reporting none, 69% light (<1/day), 7% moderate ( = 1/day), and 4% heavy (>1/day). To guard against underreporting, we took the maximum reported wine consumption over 7 years as the predictor. We used mixed models with a random intercept and random time to assess the relationship between wine consumption and CV risk factors with moderate consumption as the reference. Outcome variables were log-transformed where necessary. Longitudinal models were adjusted for ethnicity, age, and time-varying menopausal status, hormone therapy use, overall alcohol consumption, high density lipoprotein (HDL), statin use, and a healthy lifestyle score based on physical activity, not smoking, and weight maintenance. Interactions of wine consumption with time were not significant. Moderate wine consumers had significantly lower levels of C-reactive protein (CRP, p < .001), fibrinogen (p < .001), factor VII (p < .01), and plasminogen activator inhibitor (PAI-1, p < .05) than women who drank no or little wine. These associations were independent of significant effects of healthy lifestyle and overall alcohol consumption and similar across ethnic groups. Moderate wine consumption may protect against CVD via inflammatory and clotting pathways. PMID:25705320
Symptomatic atrial fibrillation and risk of cardiovascular events: data from the Euro Heart Survey.
Guerra, Federico; Brambatti, Michela; Nieuwlaat, Robby; Marcucci, Maura; Dudink, Elton; Crijns, Harry J G M; Matassini, Maria Vittoria; Capucci, Alessandro
2017-12-01
Atrial fibrillation (AF) is associated with a wide range of clinical presentations. Whether and how AF symptoms can affect prognosis is still unclear. Aims of the present analysis were to investigate potential predictors of symptomatic AF and to determine if symptoms are associated with higher incidence of cardiovascular (CV) events at 1-year follow-up. The Euro Heart Survey on Atrial Fibrillation included 3607 consecutive patients with documented AF and available follow-up regarding symptoms status. Patients found symptomatic at baseline were classified into still symptomatic (SS group; n = 896) and asymptomatic (SA; n = 1556) at 1 year. Similarly, asymptomatic patients at baseline were classified into still asymptomatic (AA group; n = 903) and symptomatic (AS group; n = 252) at 1 year. Demographics, as well as clinical variables and medical treatments, were tested as potential predictors of symptoms persistence/development at 1-year. We also compared CV events between SS and SA groups, and AS and AA groups at 1-year follow-up. Both persistence and development of AF symptoms were associated with an increased risk of CV hospitalization, stroke, heart failure worsening, and thrombo-embolism. AF type, hypothyroidism, chronic heart failure, and chronic obstructive pulmonary disease (COPD), were independently associated with an increased risk of symptomatic status at 1-year follow-up between SS and SA groups. Persistence or development of symptoms after medical treatment are associated with an increased risk of CV events during a 1-year follow-up. Type of AF, along with hypothyroidism, COPD and chronic heart failure are significantly associated with symptoms persistence despite medical treatment. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2017. For Permissions, please email: journals.permissions@oup.com.
Alayli-Goebbels, Adrienne F G; van Exel, Job; Ament, André J H A; de Vries, Nanne K; Bot, Sandra D M; Severens, Johan L
2015-12-01
To use contingent valuation (CV) to derive individual consumer values for both health and broader benefits of a public-health intervention directed at lifestyle behaviour change (LBC) and to examine the feasibility and validity of the method. Participants of a lifestyle intervention trial (n = 515) were invited to complete an online CV survey. Respondents (n = 312) expressed willingness to invest money and time for changes in life expectancy, health-related quality of life (HRQOL) and broader quality of life aspects. Internal validity was tested for by exploring associations between explanatory variables (i.e. income, paid work, experience and risk factors for cardiovascular diseases) and willingness to invest, and by examining ordering effects and respondents' sensitivity to the scope of the benefits. The majority of respondents (94.3%) attached value to benefits of LBC, and 87.4% were willing to invest both money and time. Respondents were willing to invest more for improvements in HRQOL (€42/month; 3 h/week) and broader quality of life aspects (€40/month; 2.6 h/week) than for improvements in life expectancy (€24/month; 2 h/week). Protest answers were limited (3%) and findings regarding internal validity were mixed. The importance of broader quality of life outcomes to consumers suggests that these outcomes are relevant to be considered in the decision making. Our research showed that CV is a feasible method to value both health and broader outcomes of LBC, but generalizability to other areas of public health still needs to be examined. Mixed evidence regarding internal validity pleads for caution to use CV as only the base for decision making. © 2014 John Wiley & Sons Ltd.