HIV-1 transmission linkage in an HIV-1 prevention clinical trial

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

Leitner, Thomas; Campbell, Mary S; Mullins, James I

2009-01-01

HIV-1 sequencing has been used extensively in epidemiologic and forensic studies to investigate patterns of HIV-1 transmission. However, the criteria for establishing genetic linkage between HIV-1 strains in HIV-1 prevention trials have not been formalized. The Partners in Prevention HSV/HIV Transmission Study (ClinicaITrials.gov NCT00194519) enrolled 3408 HIV-1 serodiscordant heterosexual African couples to determine the efficacy of genital herpes suppression with acyclovir in reducing HIV-1 transmission. The trial analysis required laboratory confirmation of HIV-1 linkage between enrolled partners in couples in which seroconversion occurred. Here we describe the process and results from HIV-1 sequencing studies used to perform transmission linkage determinationmore » in this clinical trial. Consensus Sanger sequencing of env (C2-V3-C3) and gag (p17-p24) genes was performed on plasma HIV-1 RNA from both partners within 3 months of seroconversion; env single molecule or pyrosequencing was also performed in some cases. For linkage, we required monophyletic clustering between HIV-1 sequences in the transmitting and seroconverting partners, and developed a Bayesian algorithm using genetic distances to evaluate the posterior probability of linkage of participants sequences. Adjudicators classified transmissions as linked, unlinked, or indeterminate. Among 151 seroconversion events, we found 108 (71.5%) linked, 40 (26.5%) unlinked, and 3 (2.0%) to have indeterminate transmissions. Nine (8.3%) were linked by consensus gag sequencing only and 8 (7.4%) required deep sequencing of env. In this first use of HIV-1 sequencing to establish endpoints in a large clinical trial, more than one-fourth of transmissions were unlinked to the enrolled partner, illustrating the relevance of these methods in the design of future HIV-1 prevention trials in serodiscordant couples. A hierarchy of sequencing techniques, analysis methods, and expert adjudication contributed to the linkage determination process.« less

Single-trial effective brain connectivity patterns enhance discriminability of mental imagery tasks

NASA Astrophysics Data System (ADS)

Rathee, Dheeraj; Cecotti, Hubert; Prasad, Girijesh

2017-10-01

Objective. The majority of the current approaches of connectivity based brain-computer interface (BCI) systems focus on distinguishing between different motor imagery (MI) tasks. Brain regions associated with MI are anatomically close to each other, hence these BCI systems suffer from low performances. Our objective is to introduce single-trial connectivity feature based BCI system for cognition imagery (CI) based tasks wherein the associated brain regions are located relatively far away as compared to those for MI. Approach. We implemented time-domain partial Granger causality (PGC) for the estimation of the connectivity features in a BCI setting. The proposed hypothesis has been verified with two publically available datasets involving MI and CI tasks. Main results. The results support the conclusion that connectivity based features can provide a better performance than a classical signal processing framework based on bandpass features coupled with spatial filtering for CI tasks, including word generation, subtraction, and spatial navigation. These results show for the first time that connectivity features can provide a reliable performance for imagery-based BCI system. Significance. We show that single-trial connectivity features for mixed imagery tasks (i.e. combination of CI and MI) can outperform the features obtained by current state-of-the-art method and hence can be successfully applied for BCI applications.

Auxiliary-field-based trial wave functions in quantum Monte Carlo calculations

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

Chang, Chia -Chen; Rubenstein, Brenda M.; Morales, Miguel A.

2016-12-19

Quantum Monte Carlo (QMC) algorithms have long relied on Jastrow factors to incorporate dynamic correlation into trial wave functions. While Jastrow-type wave functions have been widely employed in real-space algorithms, they have seen limited use in second-quantized QMC methods, particularly in projection methods that involve a stochastic evolution of the wave function in imaginary time. Here we propose a scheme for generating Jastrow-type correlated trial wave functions for auxiliary-field QMC methods. The method is based on decoupling the two-body Jastrow into one-body projectors coupled to auxiliary fields, which then operate on a single determinant to produce a multideterminant trial wavemore » function. We demonstrate that intelligent sampling of the most significant determinants in this expansion can produce compact trial wave functions that reduce errors in the calculated energies. Lastly, our technique may be readily generalized to accommodate a wide range of two-body Jastrow factors and applied to a variety of model and chemical systems.« less

Polaron dynamics with a multitude of Davydov D{sub 2} trial states

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

Zhou, Nengji; Department of Physics, Hangzhou Normal University, Hangzhou 310046; Huang, Zhongkai

2015-07-07

We propose an extension to the Davydov D{sub 2} Ansatz in the dynamics study of the Holstein molecular crystal model with diagonal and off-diagonal exciton-phonon coupling using the Dirac-Frenkel time-dependent variational principle. The new trial state by the name of the “multi-D{sub 2} Ansatz” is a linear combination of Davydov D{sub 2} trial states, and its validity is carefully examined by quantifying how faithfully it follows the Schrödinger equation. Considerable improvements in accuracy have been demonstrated in comparison with the usual Davydov trial states, i.e., the single D{sub 1} and D{sub 2} Ansätze. With an increase in the number ofmore » the Davydov D{sub 2} trial states in the multi-D{sub 2} Ansatz, deviation from the exact Schrödinger dynamics is gradually diminished, leading to a numerically exact solution to the Schrödinger equation.« less

Immediate effect of couple relationship education on low-satisfaction couples: a randomized clinical trial plus an uncontrolled trial replication.

PubMed

Kim Halford, W; Pepping, Christopher A; Hilpert, Peter; Bodenmann, Guy; Wilson, Keithia L; Busby, Dean; Larson, Jeffry; Holman, Thomas

2015-05-01

Couple relationship education (RE) usually is conceived of as relationship enhancement for currently satisfied couples, with a goal of helping couples sustain satisfaction. However, RE also might be useful as a brief, accessible intervention for couples with low satisfaction. Two studies were conducted that tested whether couples with low relationship satisfaction show meaningful gains after RE. Study 1 was a three-condition randomized controlled trial in which 182 couples were randomly assigned to RELATE with Couple CARE (RCC), a flexible delivery education program for couples, or one of two control conditions. Couples with initially low satisfaction receiving RCC showed a moderate increase in relationship satisfaction (d=0.50) relative to the control. In contrast, couples initially high in satisfaction showed little change and there was no difference between RCC and the control conditions. Study 2 was an uncontrolled trial of the Couple Coping Enhancement Training (CCET) administered to 119 couples. Couples receiving CCET that had initially low satisfaction showed a moderate increase in satisfaction (g=.44), whereas initially highly satisfied couples showed no change. Brief relationship education can assist somewhat distressed couples to enhance satisfaction, and has potential as a cost-effective way of enhancing the reach of couple interventions. Copyright © 2015. Published by Elsevier Ltd.

Reconfigurable Solid-state Dye-doped Polymer Ring Resonator Lasers

NASA Astrophysics Data System (ADS)

Chandrahalim, Hengky; Fan, Xudong

2015-12-01

This paper presents wavelength configurable on-chip solid-state ring lasers fabricated by a single-mask standard lithography. The single- and coupled-ring resonator hosts were fabricated on a fused-silica wafer and filled with 3,3‧-Diethyloxacarbocyanine iodide (CY3), Rhodamine 6G (R6G), and 3,3‧-Diethylthiadicarbocyanine iodide (CY5)-doped polymer as the reconfigurable gain media. The recorded lasing threshold was ~220 nJ/mm2 per pulse for the single-ring resonator laser with R6G, marking the lowest threshold shown by solid-state dye-doped polymer lasers fabricated with a standard lithography process on a chip. A single-mode lasing from a coupled-ring resonator system with the lasing threshold of ~360 nJ/mm2 per pulse was also demonstrated through the Vernier effect. The renewability of the dye-doped polymer was examined by removing and redepositing the dye-doped polymer on the same resonator hosts for multiple cycles. We recorded consistent emissions from the devices for all trials, suggesting the feasibility of employing this technology for numerous photonic and biochemical sensing applications that entail for sustainable, reconfigurable, and low lasing threshold coherent light sources on a chip.

Reconfigurable Solid-state Dye-doped Polymer Ring Resonator Lasers

PubMed Central

Chandrahalim, Hengky; Fan, Xudong

2015-01-01

This paper presents wavelength configurable on-chip solid-state ring lasers fabricated by a single-mask standard lithography. The single- and coupled-ring resonator hosts were fabricated on a fused-silica wafer and filled with 3,3′-Diethyloxacarbocyanine iodide (CY3), Rhodamine 6G (R6G), and 3,3′-Diethylthiadicarbocyanine iodide (CY5)-doped polymer as the reconfigurable gain media. The recorded lasing threshold was ~220 nJ/mm2 per pulse for the single-ring resonator laser with R6G, marking the lowest threshold shown by solid-state dye-doped polymer lasers fabricated with a standard lithography process on a chip. A single-mode lasing from a coupled-ring resonator system with the lasing threshold of ~360 nJ/mm2 per pulse was also demonstrated through the Vernier effect. The renewability of the dye-doped polymer was examined by removing and redepositing the dye-doped polymer on the same resonator hosts for multiple cycles. We recorded consistent emissions from the devices for all trials, suggesting the feasibility of employing this technology for numerous photonic and biochemical sensing applications that entail for sustainable, reconfigurable, and low lasing threshold coherent light sources on a chip. PMID:26674508

Reconfigurable Solid-state Dye-doped Polymer Ring Resonator Lasers.

PubMed

Chandrahalim, Hengky; Fan, Xudong

2015-12-17

This paper presents wavelength configurable on-chip solid-state ring lasers fabricated by a single-mask standard lithography. The single- and coupled-ring resonator hosts were fabricated on a fused-silica wafer and filled with 3,3'-Diethyloxacarbocyanine iodide (CY3), Rhodamine 6G (R6G), and 3,3'-Diethylthiadicarbocyanine iodide (CY5)-doped polymer as the reconfigurable gain media. The recorded lasing threshold was ~220 nJ/mm(2) per pulse for the single-ring resonator laser with R6G, marking the lowest threshold shown by solid-state dye-doped polymer lasers fabricated with a standard lithography process on a chip. A single-mode lasing from a coupled-ring resonator system with the lasing threshold of ~360 nJ/mm(2) per pulse was also demonstrated through the Vernier effect. The renewability of the dye-doped polymer was examined by removing and redepositing the dye-doped polymer on the same resonator hosts for multiple cycles. We recorded consistent emissions from the devices for all trials, suggesting the feasibility of employing this technology for numerous photonic and biochemical sensing applications that entail for sustainable, reconfigurable, and low lasing threshold coherent light sources on a chip.

Neural substrate of the late positive potential in emotional processing

PubMed Central

Liu, Yuelu; Huang, Haiqing; McGinnis, Menton; Keil, Andreas; Ding, Mingzhou

2012-01-01

The late positive potential (LPP) is a reliable electrophysiological index of emotional perception in humans. Despite years of research the brain structures that contribute to the generation and modulation of LPP are not well understood. Recording EEG and fMRI simultaneously, and applying a recently proposed single-trial ERP analysis method, we addressed the problem by correlating the single-trial LPP amplitude evoked by affective pictures with the blood-oxygen-level-dependent (BOLD) activity. Three results were found. First, relative to neutral pictures, pleasant and unpleasant pictures elicited enhanced LPP, as well as heightened BOLD activity in both visual cortices and emotion-processing structures such as amygdala and prefrontal cortex, consistent with previous findings. Second, the LPP amplitude across three picture categories was significantly correlated with BOLD activity in visual cortices, temporal cortices, amygdala, orbitofrontal cortex, and insula. Third, within each picture category, LPP-BOLD coupling revealed category-specific differences. For pleasant pictures, the LPP amplitude was coupled with BOLD in occipitotemporal junction, medial prefrontal cortex, amygdala, and precuneus, whereas for unpleasant pictures, significant LPP-BOLD correlation was observed in ventrolateral prefrontal cortex, insula, and posterior cingulate cortex. These results suggest that LPP is generated and modulated by an extensive brain network comprised of both cortical and subcortical structures associated with visual and emotional processing and the degree of contribution by each of these structures to the LPP modulation is valence-specific. PMID:23077042

A novel biomarker of amnestic MCI based on dynamic cross-frequency coupling patterns during cognitive brain responses

PubMed Central

Dimitriadis, Stavros I.; Laskaris, Nikolaos A.; Bitzidou, Malamati P.; Tarnanas, Ioannis; Tsolaki, Magda N.

2015-01-01

The detection of mild cognitive impairment (MCI), the transitional stage between normal cognitive changes of aging and the cognitive decline caused by AD, is of paramount clinical importance, since MCI patients are at increased risk of progressing into AD. Electroencephalographic (EEG) alterations in the spectral content of brainwaves and connectivity at resting state have been associated with early-stage AD. Recently, cognitive event-related potentials (ERPs) have entered into the picture as an easy to perform screening test. Motivated by the recent findings about the role of cross-frequency coupling (CFC) in cognition, we introduce a relevant methodological approach for detecting MCI based on cognitive responses from a standard auditory oddball paradigm. By using the single trial signals recorded at Pz sensor and comparing the responses to target and non-target stimuli, we first demonstrate that increased CFC is associated with the cognitive task. Then, considering the dynamic character of CFC, we identify instances during which the coupling between particular pairs of brainwave frequencies carries sufficient information for discriminating between normal subjects and patients with MCI. In this way, we form a multiparametric signature of impaired cognition. The new composite biomarker was tested using data from a cohort that consists of 25 amnestic MCI patients and 15 age-matched controls. Standard machine-learning algorithms were employed so as to implement the binary classification task. Based on leave-one-out cross-validation, the measured classification rate was found reaching very high levels (95%). Our approach compares favorably with the traditional alternative of using the morphology of averaged ERP response to make the diagnosis and the usage of features from spectro-temporal analysis of single-trial responses. This further indicates that task-related CFC measurements can provide invaluable analytics in AD diagnosis and prognosis. PMID:26539070

IVF or IUI as first-line treatment in unexplained subfertility: the conundrum of treatment selection markers.

PubMed

Tjon-Kon-Fat, R I; Tajik, P; Zafarmand, M H; Bensdorp, A J; Bossuyt, P M M; Oosterhuis, G J E; van Golde, R; Repping, S; Lambers, M D A; Slappendel, E; Perquin, D; Pelinck, M J; Gianotten, J; Maas, J W M; Eijkemans, M J C; van der Veen, F; Mol, B W; van Wely, M

2017-05-01

Are there treatment selection markers that could aid in identifying couples, with unexplained or mild male subfertility, who would have better chances of a healthy child with IVF with single embryo transfer (IVF-SET) than with IUI with ovarian stimulation (IUI-OS)? We did not find any treatment selection markers that were associated with better chances of a healthy child with IVF-SET instead of IUI-OS in couples with unexplained or mild male subfertility. A recent trial, comparing IVF-SET to IUI-OS, found no evidence of a difference between live birth rates and multiple pregnancy rates. It was suggested that IUI-OS should remain the first-line treatment instead of IVF-SET in couples with unexplained or mild male subfertility and female age between 18 and 38 years. The question remains whether there are some couples that may have higher pregnancy chances if treated with IVF-SET instead of IUI. We performed our analyses on data from the INeS trial, where couples with unexplained or mild male subfertility and an unfavourable prognosis for natural conception were randomly allocated to IVF-SET, IVF in a modified natural cycle or IUI-OS. In view of the aim of this study, we only used data of the comparison between IVF-SET (201 couples) and IUI-OS (207 couples). We pre-defined the following baseline characteristics as potential treatment selection markers: female age, ethnicity, smoking status, type of subfertility (primary/secondary), duration of subfertility, BMI, pre-wash total motile count and Hunault prediction score. For each potential treatment selection marker, we explored the association with the chances of a healthy child after IVF-SET and IUI-OS and tested if there was an interaction with treatment. Given the exploratory nature of our analysis, we used a P-value of 0.1. None of the markers were associated with higher chances of a healthy child from IVF-SET compared to IUI-OS (P-value for interaction >0.10). Since this is the first large study that looked at potential treatment selection markers for IVF-SET compared to IUI-OS, we had no data on which to base a power calculation. The sample size was limited, making it difficult to detect any smaller associations. We could not identify couples with unexplained or mild male subfertility who would have had higher chances of a healthy child from immediate IVF-SET than from IUI-OS. As in the original trial IUI-OS had similar effectiveness and was less costly compared to IVF-SET, IUI-OS should remain the preferred first-line treatment in these couples. The study was supported by a grant from the Netherlands Organization for Health Research and Development, and a grant from the Netherlands' association of health care insurers. There are no conflicts of interest. The trial was registered at the Dutch trial registry (NTR939). © The Author 2017. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com

Marital Status and Satisfaction Five Years Following a Randomized Clinical Trial Comparing Traditional versus Integrative Behavioral Couple Therapy

ERIC Educational Resources Information Center

Christensen, Andrew; Atkins, David C.; Baucom, Brian; Yi, Jean

2010-01-01

Objective: To follow distressed married couples for 5 years after their participation in a randomized clinical trial. Method: A total of 134 chronically and seriously distressed married couples were randomly assigned to approximately 8 months of either traditional behavioral couple therapy (TBCT; Jacobson & Margolin, 1979) or integrative…

Evaluation of an effective multifaceted implementation strategy for elective single-embryo transfer after in vitro fertilization.

PubMed

Kreuwel, I A M; van Peperstraten, A M; Hulscher, M E J L; Kremer, J A M; Grol, R P T M; Nelen, W L D M; Hermens, R P M G

2013-02-01

What is the relationship between the rate of elective single-embryo transfer (eSET) and couples' exposure to different elements of a multifaceted implementation strategy? Additional elements in a multifaceted implementation strategy do not result in an increased eSET rate. A multifaceted eSET implementation strategy with four different elements is effective in increasing the eSET rate by 11%. It is unclear whether every strategy element contributes equally to the strategy's effectiveness. An observational study was performed among 222 subfertile couples included in a previously performed randomized controlled trial. Of the 222 subfertile couples included, 109 couples received the implementation strategy and 113 couples received standard IVF care. A multivariate regression analysis assessed the effectiveness of four different strategy elements on the decision about the number embryos to be transferred. Questionnaires evaluated the experiences of couples with the different elements. Of the couples who received the implementation strategy, almost 50% (52/109) were exposed to all the four elements of the strategy. The remaining 57 couples who received two or three elements of the strategy could be divided into two further classes of exposure. Our analysis demonstrated that additional elements do not result in an increased eSET rate. In addition to the physician's advice, couples rated a decision aid and a counselling session as more important for their decision to transfer one or two embryos, compared with a phone call and a reimbursement offer (P < 0.001). The differences in eSET rate between exposure groups failed to reach significance, probably because of the small numbers of couples in each exposure group. Adding more elements to an implementation strategy does not always result in an increased effectiveness, which is in concordance with recent literature. This in-depth evaluation of a multifaceted intervention strategy could therefore help to modify strategies, by making them more effective and less expensive.

Determination of calcium, copper, iron, magnesium, manganese, potassium, phosphorus, sodium, and zinc in fortified food products by microwave digestion and inductively coupled plasma-optical emission spectrometry: single-laboratory validation and ring trial.

PubMed

Poitevin, Eric

2012-01-01

A single-laboratory validation (SLV) and a ring trial (RT) were undertaken to determine nine nutritional elements in food products by inductively coupled plasma-optical emission spectrometry in order to modernize AOAC Official Method 984.27. The improvements involved extension of the scope to all food matrixes (including infant formula), optimized microwave digestion, selected analytical lines, internal standardization, and ion buffering. Simultaneous determination of nine elements (calcium, copper, iron, potassium, magnesium, manganese, sodium, phosphorus, and zinc) was made in food products. Sample digestion was performed through wet digestion of food samples by microwave technology with either closed- or open-vessel systems. Validation was performed to characterize the method for selectivity, sensitivity, linearity, accuracy, precision, recovery, ruggedness, and uncertainty. The robustness and efficiency of this method was proven through a successful RT using experienced independent food industry laboratories. Performance characteristics are reported for 13 certified and in-house reference materials, populating the AOAC triangle food sectors, which fulfilled AOAC criteria and recommendations for accuracy (trueness, recovery, and z-scores) and precision (repeatability and reproducibility RSD, and HorRat values) regarding SLVs and RTs. This multielemental method is cost-efficient, time-saving, accurate, and fit-for-purpose according to ISO 17025 Norm and AOAC acceptability criteria, and is proposed as an extended updated version of AOAC Official Method 984.27 for fortified food products, including infant formula.

Improvement of AOAC Official Method 984.27 for the determination of nine nutritional elements in food products by Inductively coupled plasma-atomic emission spectroscopy after microwave digestion: single-laboratory validation and ring trial.

PubMed

Poitevin, Eric; Nicolas, Marine; Graveleau, Laetitia; Richoz, Janique; Andrey, Daniel; Monard, Florence

2009-01-01

A single-laboratory validation (SLV) and a ring trial (RT) were undertaken to determine nine nutritional elements in food products by inductively coupled plasma-atomic emission spectroscopy in order to improve and update AOAC Official Method 984.27. The improvements involved optimized microwave digestion, selected analytical lines, internal standardization, and ion buffering. Simultaneous determination of nine elements (calcium, copper, iron, potassium, magnesium, manganese, sodium, phosphorus, and zinc) was made in food products. Sample digestion was performed through wet digestion of food samples by microwave technology with either closed or open vessel systems. Validation was performed to characterize the method for selectivity, sensitivity, linearity, accuracy, precision, recovery, ruggedness, and uncertainty. The robustness and efficiency of this method was proved through a successful internal RT using experienced food industry laboratories. Performance characteristics are reported for 13 certified and in-house reference materials, populating the AOAC triangle food sectors, which fulfilled AOAC criteria and recommendations for accuracy (trueness, recovery, and z-scores) and precision (repeatability and reproducibility RSD and HorRat values) regarding SLV and RT. This multielemental method is cost-efficient, time-saving, accurate, and fit-for-purpose according to ISO 17025 Norm and AOAC acceptability criteria, and is proposed as an improved version of AOAC Official Method 984.27 for fortified food products, including infant formula.

Methodological Overview of an African American Couple-Based HIV/STD Prevention Trial

PubMed Central

2010-01-01

Objective To provide an overview of the NIMH Multisite HIV/STD Prevention Trial for African American Couples conducted in four urban areas: Atlanta, Los Angeles, New York, and Philadelphia. The rationale, study design methods, proposed data analyses, and study management are described. Design This is a two arm randomized Trial, implementing a modified randomized block design, to evaluate the efficacy of a couples based intervention designed for HIV serodiscordant African American couples. Methods The study phases consisted of formative work, pilot studies, and a randomized clinical trial. The sample is 535 HIV serodiscordant heterosexual African American couples. There are two theoretically derived behavioral interventions with eight group and individual sessions: the Eban HIV/STD Risk Reduction Intervention (treatment) versus the Eban Health Promotion Intervention (control). The treatment intervention was couples based and focused on HIV/STD risk reduction while the control was individual based and focused on health promotion. The two study conditions were structurally similar in length and types of activities. At baseline, participants completed an Audio Computer-assisted Self Interview (ACASI) interview as well as interviewer-administered questionnaire, and provided biological specimens to assess for STDs. Similar follow-up assessments were conducted immediately after the intervention, at 6 months, and at 12 months. Results The Trial results will be analyzed across the four sites by randomization assignment. Generalized estimating equations (GEE) and mixed effects modeling (MEM) are planned to test: (1) the effects of the intervention on STD incidence and condom use as well as on mediator variables of these outcomes, and (2) whether the effects of the intervention differ depending on key moderator variables (e.g., gender of the HIV-seropositive partners, length of relationship, psychological distress, sexual abuse history, and substance abuse history). Conclusions The lessons learned from the design and conduct of this clinical trial provide guidelines for future couples based clinical trials in HIV/STD risk reduction and can be generalized to other couples based behavioral interventions. PMID:18724188

fMRI characterisation of widespread brain networks relevant for behavioural variability in fine hand motor control with and without visual feedback.

PubMed

Mayhew, Stephen D; Porcaro, Camillo; Tecchio, Franca; Bagshaw, Andrew P

2017-03-01

A bilateral visuo-parietal-motor network is responsible for fine control of hand movements. However, the sub-regions which are devoted to maintenance of contraction stability and how these processes fluctuate with trial-quality of task execution and in the presence/absence of visual feedback remains unclear. We addressed this by integrating behavioural and fMRI measurements during right-hand isometric compression of a compliant rubber bulb, at 10% and 30% of maximum voluntary contraction, both with and without visual feedback of the applied force. We quantified single-trial behavioural performance during 1) the whole task period and 2) stable contraction maintenance, and regressed these metrics against the fMRI data to identify the brain activity most relevant to trial-by-trial fluctuations in performance during specific task phases. fMRI-behaviour correlations in a bilateral network of visual, premotor, primary motor, parietal and inferior frontal cortical regions emerged during performance of the entire feedback task, but only in premotor, parietal cortex and thalamus during the stable contraction period. The trials with the best task performance showed increased bilaterality and amplitude of fMRI responses. With feedback, stronger BOLD-behaviour coupling was found during 10% compared to 30% contractions. Only a small subset of regions in this network were weakly correlated with behaviour without feedback, despite wider network activated during this task than in the presence of feedback. These findings reflect a more focused network strongly coupled to behavioural fluctuations when providing visual feedback, whereas without it the task recruited widespread brain activity almost uncoupled from behavioural performance. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Neuronal and oscillatory activity during reward processing in the human ventral striatum.

PubMed

Lega, Bradley C; Kahana, Michael J; Jaggi, Jurg; Baltuch, Gordon H; Zaghloul, Kareem

2011-11-16

Accumulated evidence from animal studies implicates the ventral striatum in the processing of reward information. Recently, deep brain stimulation (DBS) surgery has enabled researchers to analyze neurophysiological recordings from humans engaged in reward tasks. We present data recorded from the human ventral striatum during deep brain stimulation surgery as a participant played a video game coupled to the receipt of visual reward images. To our knowledge, we identify the first instances of reward-sensitive single unit activity in the human ventral striatum. Local field potential data suggest that alpha oscillations are sensitive to positive feedback, whereas beta oscillations exhibit significantly higher power during unrewarded trials. We report evidence of alpha-gamma cross-frequency coupling that differentiates between positive and negative feedback. © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins.

Dynamics of Coupled Electron-Boson Systems with the Multiple Davydov D1 Ansatz and the Generalized Coherent State.

PubMed

Chen, Lipeng; Borrelli, Raffaele; Zhao, Yang

2017-11-22

The dynamics of a coupled electron-boson system is investigated by employing a multitude of the Davydov D 1 trial states, also known as the multi-D 1 Ansatz, and a second trial state based on a superposition of the time-dependent generalized coherent state (GCS Ansatz). The two Ansätze are applied to study population dynamics in the spin-boson model and the Holstein molecular crystal model, and a detailed comparison with numerically exact results obtained by the (multilayer) multiconfiguration time-dependent Hartree method and the hierarchy equations of motion approach is drawn. It is found that the two methodologies proposed here have significantly improved over that with the single D 1 Ansatz, yielding quantitatively accurate results even in the critical cases of large energy biases and large transfer integrals. The two methodologies provide new effective tools for accurate, efficient simulation of many-body quantum dynamics thanks to a relatively small number of parameters which characterize the electron-nuclear wave functions. The wave-function-based approaches are capable of tracking explicitly detailed bosonic dynamics, which is absent by construct in approaches based on the reduced density matrix. The efficiency and flexibility of our methods are also advantages as compared with numerically exact approaches such as QUAPI and HEOM, especially at low temperatures and in the strong coupling regime.

The Effects of a Duathlon Simulation on Ventilatory Threshold and Running Economy

PubMed Central

Berry, Nathaniel T.; Wideman, Laurie; Shields, Edgar W.; Battaglini, Claudio L.

2016-01-01

Multisport events continue to grow in popularity among recreational, amateur, and professional athletes around the world. This study aimed to determine the compounding effects of the initial run and cycling legs of an International Triathlon Union (ITU) Duathlon simulation on maximal oxygen uptake (VO2max), ventilatory threshold (VT) and running economy (RE) within a thermoneutral, laboratory controlled setting. Seven highly trained multisport athletes completed three trials; Trial-1 consisted of a speed only VO2max treadmill protocol (SOVO2max) to determine VO2max, VT, and RE during a single-bout run; Trial-2 consisted of a 10 km run at 98% of VT followed by an incremental VO2max test on the cycle ergometer; Trial-3 consisted of a 10 km run and 30 km cycling bout at 98% of VT followed by a speed only treadmill test to determine the compounding effects of the initial legs of a duathlon on VO2max, VT, and RE. A repeated measures ANOVA was performed to determine differences between variables across trials. No difference in VO2max, VT (%VO2max), maximal HR, or maximal RPE was observed across trials. Oxygen consumption at VT was significantly lower during Trial-3 compared to Trial-1 (p = 0.01). This decrease was coupled with a significant reduction in running speed at VT (p = 0.015). A significant interaction between trial and running speed indicate that RE was significantly altered during Trial-3 compared to Trial-1 (p < 0.001). The first two legs of a laboratory based duathlon simulation negatively impact VT and RE. Our findings may provide a useful method to evaluate multisport athletes since a single-bout incremental treadmill test fails to reveal important alterations in physiological thresholds. Key points Decrease in relative oxygen uptake at VT (ml·kg-1·min-1) during the final leg of a duathlon simulation, compared to a single-bout maximal run. We observed a decrease in running speed at VT during the final leg of a duathlon simulation; resulting in an increase of more than 2 minutes to complete a 5 km run. During our study, highly trained athletes were unable to complete the final 5 km run at the same intensity that they completed the initial 10 km run (in a laboratory setting). A better understanding, and determination, of training loads during multisport training may help to better periodize training programs; additional research is required. PMID:27274661

Spin-state transition in LaCoO3 by variational cluster approximation

NASA Astrophysics Data System (ADS)

Eder, R.

2010-01-01

The variational cluster approximation (VCA) is applied to the calculation of thermodynamical quantities and single-particle spectra of LaCoO3 . Trial self-energies and the numerical value of the Luttinger-Ward functional are obtained by exact diagonalization of a CoO6 cluster. The VCA correctly predicts LaCoO3 as a paramagnetic insulator, and a gradual and relatively smooth increase in the occupation of high-spin Co3+ ions causes the temperature dependence of entropy and magnetic susceptibility. The single-particle spectral function agrees well with experiment; the experimentally observed temperature dependence of photoelectron spectra is reproduced satisfactorily. Remaining discrepancies with experiment highlight the importance of spin-orbit coupling and local lattice relaxation.

Asymmetric Suzuki-Miyaura coupling of heterocycles via Rhodium-catalysed allylic arylation of racemates

PubMed Central

Schäfer, Philipp; Palacin, Thomas; Sidera, Mireia; Fletcher, Stephen P.

2017-01-01

Using asymmetric catalysis to simultaneously form carbon–carbon bonds and generate single isomer products is strategically important. Suzuki-Miyaura cross-coupling is widely used in the academic and industrial sectors to synthesize drugs, agrochemicals and biologically active and advanced materials. However, widely applicable enantioselective Suzuki-Miyaura variations to provide 3D molecules remain elusive. Here we report a rhodium-catalysed asymmetric Suzuki-Miyaura reaction with important partners including aryls, vinyls, heteroaromatics and heterocycles. The method can be used to couple two heterocyclic species so the highly enantioenriched products have a wide array of cores. We show that pyridine boronic acids are unsuitable, but they can be halogen-modified at the 2-position to undergo reaction, and this halogen can then be removed or used to facilitate further reactions. The method is used to synthesize isoanabasine, preclamol, and niraparib—an anticancer agent in several clinical trials. We anticipate this method will be a useful tool in drug synthesis and discovery. PMID:28607510

Asymmetric Suzuki-Miyaura coupling of heterocycles via Rhodium-catalysed allylic arylation of racemates

NASA Astrophysics Data System (ADS)

Schäfer, Philipp; Palacin, Thomas; Sidera, Mireia; Fletcher, Stephen P.

2017-06-01

Using asymmetric catalysis to simultaneously form carbon-carbon bonds and generate single isomer products is strategically important. Suzuki-Miyaura cross-coupling is widely used in the academic and industrial sectors to synthesize drugs, agrochemicals and biologically active and advanced materials. However, widely applicable enantioselective Suzuki-Miyaura variations to provide 3D molecules remain elusive. Here we report a rhodium-catalysed asymmetric Suzuki-Miyaura reaction with important partners including aryls, vinyls, heteroaromatics and heterocycles. The method can be used to couple two heterocyclic species so the highly enantioenriched products have a wide array of cores. We show that pyridine boronic acids are unsuitable, but they can be halogen-modified at the 2-position to undergo reaction, and this halogen can then be removed or used to facilitate further reactions. The method is used to synthesize isoanabasine, preclamol, and niraparib--an anticancer agent in several clinical trials. We anticipate this method will be a useful tool in drug synthesis and discovery.

Exploring the feasibility and acceptability of couple-based psychosexual support following prostate cancer surgery: study protocol for a pilot randomised controlled trial

PubMed Central

2014-01-01

Background Men who undergo surgery for prostate cancer frequently experience significant side-effects including urinary and sexual dysfunction. These difficulties can lead to anxiety, depression and reduced quality of life. Many partners also experience psychological distress. An additional impact can be on the couple relationship, with changes to intimacy, and unmet psychosexual supportive needs in relation to sexual recovery and rehabilitation. The aim of this exploratory randomised controlled trial pilot study is to determine the feasibility and acceptability of a novel family-relational-psychosexual intervention to support intimacy and reduce distress among couples following prostate cancer surgery and to estimate the efficacy of this intervention. Methods/Design The intervention will comprise six sessions of psychosexual and relationship support delivered by experienced couple-support practitioners. Specialist training in delivering the intervention will be provided to practitioners and they will be guided by a detailed treatment manual based on systemic principles. Sixty-eight couples will be randomised to receive either the intervention or standard care (comprising usual follow-up hospital appointments). A pre-test, post-test design will be used to test the feasibility of the intervention (baseline, end of intervention and six-month follow-up) and its acceptability to couples and healthcare professionals (qualitative interviews). Both individual and relational outcome measures will assess sexual functioning, anxiety and depression, couple relationship, use of health services and erectile dysfunction medication/technologies. An economic analysis will estimate population costs of the intervention, compared to usual care, using simple modelling to evaluate the affordability of the intervention. Discussion Given the increasing incidence and survival of post-operative men with prostate cancer, it is timely and appropriate to determine the feasibility of a definitive trial through a pilot randomised controlled trial of a family-relational-psychosexual intervention for couples. The study will provide evidence about the components of a couple-based intervention, its acceptability to patients and healthcare professionals, and its influence on sexual and relational functioning. Data from this study will be used to calculate sample sizes required for any definitive trial. Trial registration ClinicalTrials.gov Identifier: NCT01842438. Registration date: 24 April 2013; Randomisation of first patient: 13 May 2013 PMID:24886676

Pilot testing a couples-focused intervention for mild cognitive impairment.

PubMed

Lu, Yvonne Yueh-Feng; Haase, Joan E; Weaver, Michael

2013-05-01

The purpose of this pilot was to evaluate the acceptability, feasibility, and potential benefits of the multicomponent, Daily Enhancement of Meaningful Activity (DEMA) intervention, which was tailored to help couples facing mild cognitive impairment (MCI) work together to meet goals, remain engaged in meaningful activities, and adapt to changes over time. Using a single-group design, 10 individuals with MCI and their family caregivers were recruited to participate in the DEMA intervention over 6 biweekly sessions. Data were collected pre-and at 1 week and 3 months postintervention completion rates indicated the program and study procedures were well accepted. Qualitative and quantitative finding indicated positive trends in meaningful activity performance and maintenance of health-related outcomes, as well as high program satisfaction. The DEMA intervention is potentially promising but needs further testing in a randomized clinical trial.

IVF with planned single-embryo transfer versus IUI with ovarian stimulation in couples with unexplained subfertility: an economic analysis.

PubMed

van Rumste, Minouche M E; Custers, Inge M; van Wely, Madelon; Koks, Carolien A; van Weering, Hans G I; Beckers, Nicole G M; Scheffer, Gabrielle J; Broekmans, Frank J M; Hompes, Peter G A; Mochtar, Monique H; van der Veen, Fulco; Mol, Ben W J

2014-03-01

Couples with unexplained subfertility are often treated with intrauterine insemination (IUI) with ovarian stimulation, which carries the risk of multiple pregnancies. An explorative randomized controlled trial was performed comparing one cycle of IVF with elective single-embryo transfer (eSET) versus three cycles of IUI-ovarian stimulation in couples with unexplained subfertility and a poor prognosis for natural conception, to assess the economic burden of the treatment modalities. The main outcome measures were ongoing pregnancy rates and costs. This study randomly assigned 58 couples to IVF-eSET and 58 couples to IUI-ovarian stimulation. The ongoing pregnancy rates were 24% in with IVF-eSET versus 21% with IUI-ovarian stimulation, with two and three multiple pregnancies, respectively. The mean cost per included couple was significantly different: €2781 with IVF-eSET and €1876 with IUI-ovarian stimulation (P<0.01). The additional costs per ongoing pregnancy were €2456 for IVF-eSET. In couples with unexplained subfertility, one cycle of IVF-eSET cost an additional €900 per couple compared with three cycles of IUI-ovarian stimulation, for no increase in ongoing pregnancy rates or decrease in multiple pregnancies. When IVF-eSET results in higher ongoing pregnancy rates, IVF would be the preferred treatment. Couples that have been trying to conceive unsuccessfully are often treated with intrauterine insemination (IUI) and medication to improve egg production (ovarian stimulation). This treatment carries the risk of multiple pregnancies like twins. We performed an explorative study among those couples that had a poor prognosis for natural conception. One cycle of IVF with transfer of one selected embryo (elective single-embryo transfer, eSET) was compared with three cycles of IUI-ovarian stimulation. The aim of this study was to assess the economic burden of both treatments. The Main outcome measures were number of good pregnancies above 12weeks and costs. We randomly assigned 58 couples to IVF-eSET and 58 couples to IUI-ovarian stimulation. The ongoing pregnancy rates were comparable: 24% with IVF-eSET versus 21% with IUI-ovarian stimulation. There were two multiple pregnancies with IVF-eSET and three multiple pregnancies with IUI-ovarian stimulation. The mean cost per included couple was significantly different, €2781 with IVF-eSET and €1876 with IUI-ovarian stimulation. The additional costs per ongoing pregnancy were €2456 for IVF-eSET. In couples with unexplained subfertility, one cycle of IVF-eSET costed an additional €900 per couple compared to three cycles of IUI-ovarian stimulation, for no increase in ongoing pregnancy rates or decrease in multiple pregnancies. We conclude that IUI-ovarian stimulation is the preferred treatment to start with. When IVF-eSET results in a higher ongoing pregnancy rate (>38%), IVF would be the preferred treatment. Copyright © 2013 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.

A Trade-Off Study Revealing Nested Timescales of Constraint

PubMed Central

Wijnants, M. L.; Cox, R. F. A.; Hasselman, F.; Bosman, A. M. T.; Van Orden, G.

2012-01-01

This study investigates human performance in a cyclic Fitts task at three different scales of observation, either in the presence (difficult condition) or in the absence (easy condition) of a speed–accuracy trade-off. At the fastest scale, the harmonicity of the back and forth movements, which reflects the dissipation of mechanical energy, was measured within the timeframe of single trials. At an intermediate scale, speed and accuracy measures were determined over a trial. The slowest scale pertains to the temporal structure of movement variability, which evolves over multiple trials. In the difficult condition, reliable correlations across each of the measures corroborated a coupling of nested scales of performance. Participants who predominantly emphasized the speed-side of the trade-off (despite the instruction to be both fast and accurate) produced more harmonic movements and clearer 1/f scaling in the produced movement time series, but were less accurate and produced more random variability in the produced movement amplitudes (vice versa for more accurate participants). This implied that speed–accuracy trade-off was accompanied by a trade-off between temporal and spatial streams of 1/f scaling, as confirmed by entropy measures. In the easy condition, however, no trade-offs nor couplings among scales of performance were observed. Together, these results suggest that 1/f scaling is more than just a byproduct of cognition. These findings rather support the claim that interaction-dominant dynamics constitute a coordinative basis for goal-directed behavior. PMID:22654760

Decreasing Divorce in Army Couples: Results from a Randomized Controlled Trial using PREP for Strong Bonds

PubMed Central

Stanley, Scott M.; Allen, Elizabeth S.; Markman, Howard J.; Rhoades, Galena K.; Prentice, Donnella L.

2010-01-01

Findings from a large, randomized controlled trial of couple education are presented in this brief report. Married Army couples were assigned to either PREP for Strong Bonds (n = 248) delivered by Army chaplains or to a no-treatment control group (n = 228). One year after the intervention, couples who received PREP for Strong Bonds had 1/3 the rate of divorce of the control group. Specifically, 6.20% of the control group divorced while 2.03% of the intervention group divorced. These findings suggest that couple education can reduce the risk of divorce, at least in the short run with military couples. PMID:20634994

Polarized and asymmetric emission of single colloidal nanoplatelets (Conference Presentation)

NASA Astrophysics Data System (ADS)

Feng, Fu; N'Guyen, Thu Loan; Nasilowski, Michel; Lethiec, Clotilde M.; Dubertret, Benoit; Coolen, Laurent; Maître, Agnès.

2017-02-01

Efficient coupling of nanoemitters to photonic or plasmonic structures requires the control of the orientation of the emitting dipoles. Nevertheless controlling the dipole orientation remains an experimental challenge. Many experiments rely on the realization of numerous samples, in order to be able to statistically get a well aligned dipole to realize an efficient coupling to a nanostructure. In order to avoid these statistical trials, the knowledge of the nature of the emitter and its orientation is crucial for a deterministical approach. We developed a method [1],[2] relying on the combination of polarimetric measurement and emission diagram which gives fine information both on the emitting dipolar transition involved and on the dipolar orientation We analyse by this method square and rectangle single colloidal CdSe/CdS nanoplatetelets. We demonstrate that their emission can be described by just by two orthogonal dipoles lying in the plane of the platelets. More surprisingly the emission of the square nanoplatelets is not polarised whereas the rectangle one is. We demonstrate that this polarized emission is due to the rectangular shape anisotropy by a dielectric effect. [1] C. Lethiec, et al, Three-dimensional orientation measurement of a single fluorescent nanoemitter by polarization analysis, Phys. Rev. X 4, 021037 (2014), [2] C. Lethiec et al, Polarimetry-based analysis of dipolar transitions of single colloidal CdSe/CdS dot-inrods, New Journal of Physics 16, 093014 (2014) [3] S. Ithurria et al, colloidal nanoplatelets with 2 dimensional electronic structure, Nature Materials 10, 936 (2011)

Preliminary experimental investigation of in vivo magnetic manipulation: results and potential application in hyperthermia.

PubMed

Grady, M S; Howard, M A; Molloy, J A; Ritter, R C; Quate, E G; Gillies, G T

1989-01-01

The first in vivo experiments in support of a new technique for delivering stereotaxic hyperthermia have been conducted at the Experimental Surgery Facility of the University of Virginia's Medical Center. We call this technique the "Video Tumor Fighter." In each of twelve trials a single, small permanent magnet or train of small permanent magnets was implanted on the brain surface of adult canine models. In three of the trials, this "seed" (typically 6-mm diameter X 6-mm long) was moved by magnetic manipulation to different locations within the brain. In two other trials, the seed moved along the interface between the brain and the inner vault of the skull. The noncontact magnetic manipulation was accomplished by coupling the permanently magnetized seed to the large dc magnetic field gradient created by a water-cooled coil surrounding the animal's head. The seed's motions were monitored with x-ray fluoroscopy; its rate of movement was found to be approximately 0.8 mm s-1. The forces required to produce these motions were on the order of 0.07 N. We document here the instrumentation used in these trials, describe the experimental procedures employed, and discuss the technical aspects of the results.

Learning robotic eye-arm-hand coordination from human demonstration: a coupled dynamical systems approach.

PubMed

Lukic, Luka; Santos-Victor, José; Billard, Aude

2014-04-01

We investigate the role of obstacle avoidance in visually guided reaching and grasping movements. We report on a human study in which subjects performed prehensile motion with obstacle avoidance where the position of the obstacle was systematically varied across trials. These experiments suggest that reaching with obstacle avoidance is organized in a sequential manner, where the obstacle acts as an intermediary target. Furthermore, we demonstrate that the notion of workspace travelled by the hand is embedded explicitly in a forward planning scheme, which is actively involved in detecting obstacles on the way when performing reaching. We find that the gaze proactively coordinates the pattern of eye-arm motion during obstacle avoidance. This study provides also a quantitative assessment of the coupling between the eye-arm-hand motion. We show that the coupling follows regular phase dependencies and is unaltered during obstacle avoidance. These observations provide a basis for the design of a computational model. Our controller extends the coupled dynamical systems framework and provides fast and synchronous control of the eyes, the arm and the hand within a single and compact framework, mimicking similar control system found in humans. We validate our model for visuomotor control of a humanoid robot.

Multiple linear regression to estimate time-frequency electrophysiological responses in single trials

PubMed Central

Hu, L.; Zhang, Z.G.; Mouraux, A.; Iannetti, G.D.

2015-01-01

Transient sensory, motor or cognitive event elicit not only phase-locked event-related potentials (ERPs) in the ongoing electroencephalogram (EEG), but also induce non-phase-locked modulations of ongoing EEG oscillations. These modulations can be detected when single-trial waveforms are analysed in the time-frequency domain, and consist in stimulus-induced decreases (event-related desynchronization, ERD) or increases (event-related synchronization, ERS) of synchrony in the activity of the underlying neuronal populations. ERD and ERS reflect changes in the parameters that control oscillations in neuronal networks and, depending on the frequency at which they occur, represent neuronal mechanisms involved in cortical activation, inhibition and binding. ERD and ERS are commonly estimated by averaging the time-frequency decomposition of single trials. However, their trial-to-trial variability that can reflect physiologically-important information is lost by across-trial averaging. Here, we aim to (1) develop novel approaches to explore single-trial parameters (including latency, frequency and magnitude) of ERP/ERD/ERS; (2) disclose the relationship between estimated single-trial parameters and other experimental factors (e.g., perceived intensity). We found that (1) stimulus-elicited ERP/ERD/ERS can be correctly separated using principal component analysis (PCA) decomposition with Varimax rotation on the single-trial time-frequency distributions; (2) time-frequency multiple linear regression with dispersion term (TF-MLRd) enhances the signal-to-noise ratio of ERP/ERD/ERS in single trials, and provides an unbiased estimation of their latency, frequency, and magnitude at single-trial level; (3) these estimates can be meaningfully correlated with each other and with other experimental factors at single-trial level (e.g., perceived stimulus intensity and ERP magnitude). The methods described in this article allow exploring fully non-phase-locked stimulus-induced cortical oscillations, obtaining single-trial estimate of response latency, frequency, and magnitude. This permits within-subject statistical comparisons, correlation with pre-stimulus features, and integration of simultaneously-recorded EEG and fMRI. PMID:25665966

A Couple-Based Communication Intervention for Hematopoietic Cell Transplantation Survivors and Their Caregiving Partners: Feasibility, Acceptability, and Change in Process Measures.

PubMed

Langer, Shelby L; Porter, Laura S; Romano, Joan M; Todd, Michael W; Lee, Stephanie J

2018-05-14

Hematopoietic cell transplantation (HCT) poses significant challenges for recipients and their caregiving partners. Couples may refrain from talking about treatment-related fears and concerns to minimize distress. This single-group, pre-post study examined feasibility and acceptability of an intervention designed to optimize communication between HCT patients and partners; it also assessed change in process measures. Couples met with a therapist 5 times to learn skills for disclosing illness-related thoughts and feelings and responding supportively to one another. The extent to which participants disclosed thoughts, feelings, and information during the session and felt supported was assessed at the close of each session. Forty of 89 eligible couples consented (45%). Thirty couples commenced intervention 1-month post-transplant; 26 of these completed all sessions (87%) and 27 completed follow-up (90%). Ratings of self-disclosure and feeling supported by one's partner increased linearly across intervention sessions among both patients and caregivers (all P ≥ .01). Ratings of satisfaction with the intervention were high. HCT couples can be recruited and retained for this intervention. They found it acceptable and were amenable to skills training. A randomized trial is needed to test efficacy and to identify moderators of treatment response. Copyright © 2018 The American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.

Locomotor-Respiratory Coupling in Wheelchair Racing Athletes: A Pilot Study.

PubMed

Perret, Claudio; Wenger, Martin; Leicht, Christof A; Goosey-Tolfrey, Victoria L

2016-01-01

In wheelchair racing, respiratory muscles of the rib cage are concomitantly involved in non-ventilatory functions during wheelchair propulsion. However, the relationship between locomotor-respiratory coupling (LRC: the ratio between push and breathing frequency), respiratory parameters and work efficiency is unknown. Therefore, the aim of the present study was to investigate the LRC in wheelchair racers over different race distances. Eight trained and experienced wheelchair racers completed three time-trials over the distances of 400, 800, and 5000 m on a training roller in randomized order. During the time trials, ventilatory and gas exchange variables as well as push frequency were continuously registered to determine possible LRC strategies. Four different coupling ratios were identified, namely 1:1; 2:1, 3:1 as well as a 1:1/2:1 alternating type, respectively. The 2:1 coupling was the most dominant type. The 1:1/2:1 alternating coupling type was found predominantly during the 400 m time-trial. Longer race distances tended to result in an increased coupling ratio (e.g., from 1:1 toward 2:1), and an increase in coupling ratio toward a more efficient respiration was found over the 5000 m distance. A significant correlation (r = 0.80, p < 0.05) between respiratory frequency and the respiratory equivalent for oxygen was found for the 400 m and the 800 m time-trials. These findings suggest that a higher coupling ratio indicates enhanced breathing work efficiency with a concomitant deeper and slower respiration during wheelchair racing. Thus, the selection of an appropriate LRC strategy may help to optimize wheelchair racing performance.

Single versus double embryo transfer: cost-effectiveness analysis alongside a randomized clinical trial.

PubMed

Fiddelers, Audrey A A; van Montfoort, Aafke P A; Dirksen, Carmen D; Dumoulin, John C M; Land, Jolande A; Dunselman, Gerard A J; Janssen, J Marij; Severens, Johan L; Evers, Johannes L H

2006-08-01

Twin pregnancies after IVF are still frequent and are considered high-risk pregnancies leading to high costs. Transferring one embryo can reduce the twin pregnancy rate. We compared cost-effectiveness of one fresh cycle elective single embryo transfer (eSET) versus one fresh cycle double embryo transfer (DET) in an unselected patient population. Patients starting their first IVF cycle were randomized between eSET and DET. Societal costs per couple were determined empirically, from hormonal stimulation up to 42 weeks after embryo transfer. An incremental cost-effectiveness ratio (ICER) was calculated, representing additional costs per successful pregnancy. Successful pregnancy rates were 20.8% for eSET and 39.6% for DET. Societal costs per couple were significantly lower after eSET (7334 euro) compared with DET (10,924 euro). The ICER of DET compared with eSET was 19,096 euro, meaning that each additional successful pregnancy in the DET group will cost 19,096 euro extra. One cycle eSET was less expensive, but also less effective compared to one cycle DET. It depends on the society's willingness to pay for one extra successful pregnancy, whether one cycle DET is preferred from a cost-effectiveness point of view.

Pilot Testing a Couples-focused Intervention for Mild Cognitive Impairment

PubMed Central

Lu, Yvonne Yueh-Feng; Haase, Joan E.; Weaver, Michael

2014-01-01

The purpose of this pilot study was to evaluate the acceptability, feasibility, and potential benefits of the multi-component Daily Enhancement of Meaningful Activity (DEMA) intervention, which was tailored to help couples facing mild cognitive impairment (MCI) work together to meet goals, remain engaged in meaningful activities, and adapt to changes over time. Using a single-group design, 10 persons with MCI and their family caregivers were recruited to receive DEMA over six bi-weekly sessions. Data were collected pre- and at one week and three months post-intervention. Consent, session, and questionnaire completion rates indicated the program and study procedures were well accepted. Qualitative and quantitative findings indicated positive trends in meaningful activity performance and maintenance of health-related outcomes, as well as high program satisfaction. The DEMA is a potentially promising intervention that will need further testing in a randomized clinical trial. PMID:23767062

Traditional Versus Integrative Behavioral Couple Therapy for Significantly and Chronically Distressed Married Couples.

ERIC Educational Resources Information Center

Christensen, Andrew; Atkins, David C.; Berns, Sara; Wheeler, Jennifer; Baucom, Donald H.; Simpson, Lorelei E.

2004-01-01

A randomized clinical trial compared the effects of traditional behavioral couple therapy (TBCT) and integrative behavioral couple therapy (IBCT) on 134 seriously and chronically distressed married couples, stratified into moderately and severely distressed groups. Couples in IBCT made steady improvements in satisfaction throughout the course of…

A Randomized Trial of Individual and Couple Behavioral Alcohol Treatment for Women

ERIC Educational Resources Information Center

Mccrady, Barbara S.; Epstein, Elizabeth E.; Cook, Sharon; Jensen, Noelle; Hildebrandt, Thomas

2009-01-01

Although alcohol use disorders (AUDs) adversely affect women, research on efficacious treatments for women is limited. In this randomized efficacy trial of 102 heterosexual women with AUDs, the authors compared alcohol behavioral couple therapy (ABCT) and alcohol behavioral individual therapy (ABIT) on percentage of days abstinent (PDA) and…

Enhanced photodegradation of pentachlorophenol by single and mixed nonionic and anionic surfactants using graphene-TiO₂ as catalyst.

PubMed

Zhang, Yaxin; He, Xin; Zeng, Guangming; Chen, Tan; Zhou, Zeyu; Wang, Hongtao; Lu, Wenjing

2015-11-01

The photodegradation of pentachlorophenol (PCP) in a surfactant-containing (single and mixed) complex system using graphene-TiO2 (GT) as catalyst was investigated. The objective was to better understand the behavior of surfactants in a GT catalysis system for its possible use in remediation technology of soil contaminated by hydrophobic organic compounds (HOCs). In a single-surfactant system, surfactant molecules aggregated on GT via hydrogen bonding and electrostatic force; nonideal mixing between nonionic and anionic surfactants rendered GT surface with mixed admicelles in a mixed surfactant system. Both effects helped incorporating PCP molecules into surfactant aggregates on catalyst surface. Hence, the targeted pollutants were rendered easily available to photo-yielded oxidative radicals, and photodegradation efficiency was significantly enhanced. Finally, real soil washing-photocatalysis trials proved that anionic-nonionic mixed surfactant soil washing coupled with graphene-TiO2 photocatalysis can be one promising technology for HOC-polluted soil remediation.

Characteristics of HIV-1 serodiscordant couples enrolled in a clinical trial of antiretroviral pre-exposure prophylaxis for HIV-1 prevention.

PubMed

Mujugira, Andrew; Baeten, Jared M; Donnell, Deborah; Ndase, Patrick; Mugo, Nelly R; Barnes, Linda; Campbell, James D; Wangisi, Jonathan; Tappero, Jordan W; Bukusi, Elizabeth; Cohen, Craig R; Katabira, Elly; Ronald, Allan; Tumwesigye, Elioda; Were, Edwin; Fife, Kenneth H; Kiarie, James; Farquhar, Carey; John-Stewart, Grace; Kidoguchi, Lara; Panteleeff, Dana; Krows, Meighan; Shah, Heena; Revall, Jennifer; Morrison, Susan; Ondrejcek, Lisa; Ingram, Charlotte; Coombs, Robert W; Lingappa, Jairam R; Celum, Connie

2011-01-01

Stable heterosexual HIV-1 serodiscordant couples in Africa have high HIV-1 transmission rates and are a critical population for evaluation of new HIV-1 prevention strategies. The Partners PrEP Study is a randomized, double-blind, placebo-controlled trial of tenofovir and emtricitabine-tenofovir pre-exposure prophylaxis to decrease HIV-1 acquisition within heterosexual HIV-1 serodiscordant couples. We describe the trial design and characteristics of the study cohort. HIV-1 serodiscordant couples, in which the HIV-1 infected partner did not meet national guidelines for initiation of antiretroviral therapy, were enrolled at 9 research sites in Kenya and Uganda. The HIV-1 susceptible partner was randomized to daily oral tenofovir, emtricitabine-tenofovir, or matching placebo with monthly follow-up for 24-36 months. From July 2008 to November 2010, 7920 HIV-1 serodiscordant couples were screened and 4758 enrolled. For 62% (2966/4758) of enrolled couples, the HIV-1 susceptible partner was male. Median age was 33 years for HIV-1 susceptible and HIV-1 infected partners [IQR (28-40) and (26-39) respectively]. Most couples (98%) were married, with a median duration of partnership of 7.0 years (IQR 3.0-14.0) and recent knowledge of their serodiscordant status [median 0.4 years (IQR 0.1-2.0)]. During the month prior to enrollment, couples reported a median of 4 sex acts (IQR 2-8); 27% reported unprotected sex and 14% of male and 1% of female HIV-1 susceptible partners reported sex with outside partners. Among HIV-1 infected partners, the median plasma HIV-1 level was 3.94 log(10) copies/mL (IQR 3.31-4.53) and median CD4 count was 496 cells/µL (IQR 375-662); the majority (64%) had WHO stage 1 HIV-1 disease. Couples at high risk of HIV-1 transmission were rapidly recruited into the Partners PrEP Study, the largest efficacy trial of oral PrEP. (ClinicalTrials.gov NCT00557245).

Can we identify subfertile couples that benefit from immediate in vitro fertilisation over intrauterine insemination?

PubMed

Tjon-Kon-Fat, Raïssa I; Tajik, Parvin; Custers, Inge M; Bossuyt, Patrick M M; van der Veen, Fulco; van Wely, Madelon; Mol, Ben W; Zafarmand, Mohammad H

2016-07-01

Available treatment options in couples with unexplained or mild male subfertility are intrauterine insemination with controlled ovarian hyperstimulation (IUI-COH) and in vitro fertilisation (IVF). IUI-COH is a less invasive treatment that is often used before proceeding with IVF. Yet as the IVF success rates might be higher and time to pregnancy shorter, expedited access to IVF might be the preferred option. To identify couples that could benefit from immediate IVF over IUI-COH, we assessed whether female age, duration of subfertility or prewash total motile count (TMC) can help to identify couples that would benefit from IVF over IUI-COH. We performed a secondary data-analysis of a multicentre open-label randomised controlled trial in three university and six teaching hospitals in the Netherlands. 116 couples with unexplained or mild male subfertility were randomised to one cycle of IVF with elective single embryo transfer with subsequent frozen-thawed embryo transfers or 3 cycles of IUI-COH. The primary outcome was an ongoing pregnancy within 4 months after randomisation. Our aim was to explore a possible differential effect of specific markers on the effectiveness of treatment. We chose to therefore assess female age, duration of subfertility and TMC as these have previously been identified as predictors. For each prognostic factor we developed a logistic regression model to predict ongoing pregnancy with that prognostic factor, treatment and a factor-by-treatment interaction term. Female age and duration of subfertility were not associated with better ongoing pregnancy chances after IVF compared to IUI-COH (p-value for interaction=0.65 and 0.26, respectively). Only when TMC was lower than 110 (×10(6)spermatozoa/mL), the probability of ongoing pregnancy was higher in women allocated to IVF (p-value for interaction=0.06). In couples with unexplained or mild male subfertility, a low TMC might lead to higher pregnancy rates after IVF than after IUI-COH. This finding needs to be validated in a larger trial before it can be applied in clinical practice. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Eye coding mechanisms in early human face event-related potentials.

PubMed

Rousselet, Guillaume A; Ince, Robin A A; van Rijsbergen, Nicola J; Schyns, Philippe G

2014-11-10

In humans, the N170 event-related potential (ERP) is an integrated measure of cortical activity that varies in amplitude and latency across trials. Researchers often conjecture that N170 variations reflect cortical mechanisms of stimulus coding for recognition. Here, to settle the conjecture and understand cortical information processing mechanisms, we unraveled the coding function of N170 latency and amplitude variations in possibly the simplest socially important natural visual task: face detection. On each experimental trial, 16 observers saw face and noise pictures sparsely sampled with small Gaussian apertures. Reverse-correlation methods coupled with information theory revealed that the presence of the eye specifically covaries with behavioral and neural measurements: the left eye strongly modulates reaction times and lateral electrodes represent mainly the presence of the contralateral eye during the rising part of the N170, with maximum sensitivity before the N170 peak. Furthermore, single-trial N170 latencies code more about the presence of the contralateral eye than N170 amplitudes and early latencies are associated with faster reaction times. The absence of these effects in control images that did not contain a face refutes alternative accounts based on retinal biases or allocation of attention to the eye location on the face. We conclude that the rising part of the N170, roughly 120-170 ms post-stimulus, is a critical time-window in human face processing mechanisms, reflecting predominantly, in a face detection task, the encoding of a single feature: the contralateral eye. © 2014 ARVO.

Do singles or couples live healthier lifestyles? Trends in Queensland between 2005-2014.

PubMed

Schoeppe, Stephanie; Vandelanotte, Corneel; Rebar, Amanda L; Hayman, Melanie; Duncan, Mitch J; Alley, Stephanie J

2018-01-01

To compare the frequency of and trends in healthy lifestyle factors between singles and couples. Cross-sectional data from annual surveys conducted from 2005-2014 were used. The pooled sample included 15,001 Australian adults (mean age: 52.9 years, 50% male, 74% couples) who participated in the annual Queensland Social Survey via computer-assisted telephone interviews. Relationship status was dichotomised into single and couple. Binary logistic regression was used to assess associations between relationship status, and the frequency of and trends in healthy lifestyle factors. Compared to singles, couples were significantly more likely to be a non-smoker (OR = 1.82), and meet recommendations for limited fast food (OR = 1.12), alcohol consumption (OR = 1.27) and fruit and vegetable intake (OR = 1.24). Fruit and vegetable intake was not significantly associated with relationship status after adjusting for the other healthy lifestyle factors. Conversely, couples were significantly less likely to be within a normal weight range (OR = 0.81). In both singles and couples, the trend data revealed significant declines in the rates of normal weight (singles: OR = 0.97, couples: OR = 0.97) and viewing TV for less than 14 hours per week (singles: OR = 0.85, couples: OR = 0.84), whilst non-smoking rates significantly increased (singles: OR = 1.12, couples: OR = 1.03). The BMI trend was no longer significant when adjusting for health behaviours. Further, in couples, rates of meeting recommendations for physical activity and fruit/vegetable consumption significantly decreased (OR = 0.97 and OR = 0.95, respectively), as did rates of eating no fast food (OR = 0.96). These trends were not significant when adjusting for the other healthy lifestyle factors. In singles, rates of meeting alcohol recommendations significantly increased (OR = 1.08). Health behaviour interventions are needed in both singles and couples, but relationship status needs to be considered in interventions targeting alcohol, fast food, smoking and BMI. Further research is needed to understand why health behaviours differ by relationship status in order to further improve interventions.

The Palliative Care in Heart Failure (PAL-HF) Trial: Rationale and Design

PubMed Central

Mentz, Robert J.; Tulsky, James A.; Granger, Bradi B.; Anstrom, Kevin J.; Adams, Patricia A.; Dodson, Gwen C.; Fiuzat, Mona; Johnson, Kimberly S.; Patel, Chetan B.; Steinhauser, Karen E.; Taylor, Donald H.; O’Connor, Christopher M.; Rogers, Joseph G.

2014-01-01

Background The progressive nature of heart failure (HF) coupled with high mortality and poor quality of life mandates greater attention to palliative care as a routine component of advanced HF management. Limited evidence exists from randomized, controlled trials supporting the use of interdisciplinary palliative care in HF. Methods The Palliative Care in Heart Failure trial (PAL-HF) is a prospective, controlled, unblinded, single-center study of an interdisciplinary palliative care intervention in 200 patients with advanced HF estimated to have a high likelihood of mortality or re-hospitalization in the ensuing 6 months. The 6-month PAL-HF intervention focuses on physical and psychosocial symptom relief, attention to spiritual concerns and advanced care planning. The primary endpoint is health-related quality of life measured by the Kansas City Cardiomyopathy Questionnaire and the Functional Assessment of Chronic Illness Therapy with Palliative Care Subscale score at 6 months. Secondary endpoints include changes in anxiety/depression, spiritual well-being, caregiver satisfaction, cost and resource utilization, and a composite of death, HF hospitalization and quality of life. Conclusions PAL-HF is a randomized, controlled clinical trial that will help evaluate the efficacy and cost-effectiveness of palliative care in advanced HF using a patient-centered outcome as well as clinical and economic endpoints. PMID:25440791

Single-trial dynamics of motor cortex and their applications to brain-machine interfaces

PubMed Central

Kao, Jonathan C.; Nuyujukian, Paul; Ryu, Stephen I.; Churchland, Mark M.; Cunningham, John P.; Shenoy, Krishna V.

2015-01-01

Increasing evidence suggests that neural population responses have their own internal drive, or dynamics, that describe how the neural population evolves through time. An important prediction of neural dynamical models is that previously observed neural activity is informative of noisy yet-to-be-observed activity on single-trials, and may thus have a denoising effect. To investigate this prediction, we built and characterized dynamical models of single-trial motor cortical activity. We find these models capture salient dynamical features of the neural population and are informative of future neural activity on single trials. To assess how neural dynamics may beneficially denoise single-trial neural activity, we incorporate neural dynamics into a brain–machine interface (BMI). In online experiments, we find that a neural dynamical BMI achieves substantially higher performance than its non-dynamical counterpart. These results provide evidence that neural dynamics beneficially inform the temporal evolution of neural activity on single trials and may directly impact the performance of BMIs. PMID:26220660

Single-trial laser-evoked potentials feature extraction for prediction of pain perception.

PubMed

Huang, Gan; Xiao, Ping; Hu, Li; Hung, Yeung Sam; Zhang, Zhiguo

2013-01-01

Pain is a highly subjective experience, and the availability of an objective assessment of pain perception would be of great importance for both basic and clinical applications. The objective of the present study is to develop a novel approach to extract pain-related features from single-trial laser-evoked potentials (LEPs) for classification of pain perception. The single-trial LEP feature extraction approach combines a spatial filtering using common spatial pattern (CSP) and a multiple linear regression (MLR). The CSP method is effective in separating laser-evoked EEG response from ongoing EEG activity, while MLR is capable of automatically estimating the amplitudes and latencies of N2 and P2 from single-trial LEP waveforms. The extracted single-trial LEP features are used in a Naïve Bayes classifier to classify different levels of pain perceived by the subjects. The experimental results show that the proposed single-trial LEP feature extraction approach can effectively extract pain-related LEP features for achieving high classification accuracy.

Single-arm phase II trial design under parametric cure models.

PubMed

Wu, Jianrong

2015-01-01

The current practice of designing single-arm phase II survival trials is limited under the exponential model. Trial design under the exponential model may not be appropriate when a portion of patients are cured. There is no literature available for designing single-arm phase II trials under the parametric cure model. In this paper, a test statistic is proposed, and a sample size formula is derived for designing single-arm phase II trials under a class of parametric cure models. Extensive simulations showed that the proposed test and sample size formula perform very well under different scenarios. Copyright © 2015 John Wiley & Sons, Ltd.

Couples HIV counselling and couple relationships in India, Georgia and the Dominican Republic.

PubMed

Tiendrebeogo, Thierry; Plazy, Melanie; Darak, Shrinivas; Miric, Marija; Perez-Then, Eddy; Butsashvili, Maia; Tchendjou, Patrice; Dabis, François; Orne-Gliemann, Joanna

2017-11-25

Couples HIV counseling and testing is essential for combination HIV prevention, but its uptake remains very low. We aimed to evaluate factors associated with couples HIV counseling uptake in India, Georgia and the Dominican Republic, as part of the ANRS 12127 Prenahtest intervention trial. Pregnant women ≥15 years, attending their first antenatal care (ANC) session between March and September 2009, self-reporting a stable partner, and having received couple-oriented post-test HIV counseling (trial intervention) were included. Individuals and couple characteristics associated with the acceptability of couples HIV counseling were assessed using multivariable logistic regression for each study site. Among 711 women included (232, 240 and 239 in the Dominican Republic, Georgia and India, respectively), the uptake of couples HIV counseling was 9.1% in the Dominican Republic, 13.8% in Georgia and 36.8% in India. The uptake of couples HIV counseling was associated with women having been accompanied by their partner to ANC, and never having used a condom with their partner in the Dominican Republic; with women having been accompanied by their partner to ANC in India; with women having a higher educational level than their partner and having ever discussed HIV with their partner in Georgia. Couple HIV counseling uptake was overall low. Strategies adapted to local socio-cultural contexts, aiming at improving women's education level, or tackling gender norms to facilitate the presence of men in reproductive health services, should be considered. ClinicalTrials.gov Identifier: NCT01494961 . Registered December 15, 2011. (Retrospectively registered).

Eban HIV/STD risk reduction intervention: conceptual basis and procedures.

PubMed

2008-09-01

To describe the Eban HIV/STD Risk Reduction Intervention being evaluated in the NIMH Multisite HIV/STD Prevention trial for heterosexual African American couples, including the integrated theoretical framework, the structure, core elements and procedures of the intervention, and how the content was shaped by culturally congruent concepts to address the needs of the study target population. The Eban HIV/STD Risk Reduction Intervention is designed to address multilevel individual-, interpersonal-, and community-level factors that contribute to HIV/STD transmission risk behaviors among heterosexual African American couples who are HIV serodiscordant. The Eban HIV/STD Risk Reduction Intervention employs a mixed modality, couple-based approach that is based on an integrated ecological framework incorporating social cognitive theory and uses an Afrocentric paradigm that is informed by previous evidence-based couples HIV prevention interventions. For this randomized controlled trial, African American serodiscordant couples were recruited from 4 urban sites (Atlanta, Los Angeles, New York, and Philadelphia) and were randomized to either the Eban HIV/STD Risk Reduction Intervention (treatment condition) or a Health Promotion Intervention that served as an attentional control condition. Both interventions had 4 individual couple sessions and 4 group sessions, but only the treatment condition was focused on reducing HIV/STD risk behaviors. Behavioral and biological data were collected at baseline, immediately after the intervention, and at 6 and 12 months. The theoretical framework, core elements, and content of each session are described and lessons learned from this intervention trial are discussed. An HIV prevention intervention combining couple and group sessions can be feasibly implemented with African American HIV-serodiscordant couples who remain at high risk of HIV/STD transmission. The lessons learned from the trial suggest that the participants responded very well to both the couple and the group sessions. Participant feedback suggests that the cultural congruence of the intervention and use of African American cofacilitators made them feel comfortable disclosing risky behaviors. Participant feedback also suggests that the intervention's couple-based focus on enhancing dyadic communication and decision-making skills was key to helping the couples work together to overcome barriers to using condoms. Participant and facilitator evaluations of the Eban Risk Reduction Intervention suggest that couples responded well to the Afrocentric content and mixed modalities of the intervention sessions. Couple sessions were optimal for enhancing interpersonal and microlevel factors, including communication, problem solving, and decision making.

Couple-Focused Prevention at the Transition to Parenthood, a Randomized Trial: Effects on Coparenting, Parenting, Family Violence, and Parent and Child Adjustment.

PubMed

Feinberg, Mark E; Jones, Damon E; Hostetler, Michelle L; Roettger, Michael E; Paul, Ian M; Ehrenthal, Deborah B

2016-08-01

The transition to parenthood is a stressful period for most parents as individuals and as couples, with variability in parent mental health and couple relationship functioning linked to children's long-term emotional, mental health, and academic outcomes. Few couple-focused prevention programs targeting this period have been shown to be effective. The purpose of this study was to test the short-term efficacy of a brief, universal, transition-to-parenthood intervention (Family Foundations) and report the results of this randomized trial at 10 months postpartum. This was a randomized controlled trial; 399 couples expecting their first child were randomly assigned to intervention or control conditions after pretest. Intervention couples received a manualized nine-session (five prenatal and four postnatal classes) psychoeducational program delivered in small groups. Intent-to-treat analyses indicated that intervention couples demonstrated better posttest levels than control couples on more than two thirds of measures of coparenting, parent mental health, parenting, child adjustment, and family violence. Program effects on family violence were particularly large. Of eight outcome variables that did not demonstrate main effects, seven showed moderated intervention impact; such that, intervention couples at higher levels of risk during pregnancy showed better outcomes than control couples at similar levels of risk. These findings replicate a prior smaller study of Family Foundations, indicating that the Family Foundations approach to supporting couples making the transition to parenthood can have broad impact for parents, family relationships, and children's adjustment. Program effects are consistent and benefit all families, with particularly notable effects for families at elevated prenatal risk.

[Topiramate in substance-related and addictive disorders].

PubMed

Cohen, Johan; Dervaux, Alain; Laqueille, Xavier

2014-09-01

Drug treatments used in substance use disorders are not effective in all patients. To assess the effectiveness of topiramate use in the treatment of substance use disorders. Medline database from January 1966 to December 2013, Cochrane database and clinicaltrials.gov. We used keywords topiramate, addiction, substance abuse, alcohol, tobacco, nicotine, cocaine, methamphetamine, opiate, heroin, benzodiazepine, cannabis, bulimia nervosa, binge eating disorder, gambling. All clinical trials were included. Animal trials, laboratory tests, reviews, answers to writers, case-reports, case series and publications unrelated to the topic were excluded. Twenty-eight articles investigating the efficacy of topiramate in substance use were included. In alcohol-related disorder, several trials and a meta-analysis showed a reduction of days of consumption. In a single-center trial on tobacco-related disorder, topiramate was not found effective in reducing the carbon monoxide expired. In cocaine-related disorder, one single-center trial showed a reduction of days of consumption and two single-center trials have found a trend in favour of topiramate. In alcohol and cocaine co-dependency, a single-center trial found a trend in favour of topiramate. In methamphetamine-related disorder, a multicenter trial found a trend in favour of topiramate. In bulimia nervosa, two single-center trials showed a reduction in binge eating and compensatory behaviours. In binge eating disorder, several trials showed a reduction of binge eating and weight. In gambling, one single-center trial did not show any significant results. There were no randomized controlled trials found in opioid-related disorder, benzodiazepines-related disorder, and cannabis-related disorder. Definition of abstinence and methods to assess the efficacy of topiramate differed between trials. The methodological quality of included trials was variable, especially with no double-blind procedure in eight trials. Topiramate showed interest mainly in alcoholism, binge eating disorder and bulimia nervosa. No definitive conclusions can be reached for other substance use disorders such as nicotine dependence, cocaine dependence, amphetamine dependence or cannabis dependence and for gambling. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Can we predict failure in couple therapy early enough to enhance outcome?

PubMed

Pepping, Christopher A; Halford, W Kim; Doss, Brian D

2015-02-01

Feedback to therapists based on systematic monitoring of individual therapy progress reliably enhances therapy outcome. An implicit assumption of therapy progress feedback is that clients unlikely to benefit from therapy can be detected early enough in the course of therapy for corrective action to be taken. To explore the possibility of using feedback of therapy progress to enhance couple therapy outcome, the current study tested whether weekly therapy progress could detect off-track clients early in couple therapy. In an effectiveness trial of couple therapy, 136 couples were monitored weekly on relationship satisfaction and an expert derived algorithm was used to attempt to predict eventual therapy outcome. As expected, the algorithm detected a significant proportion of couples who did not benefit from couple therapy at Session 3, but prediction was substantially improved at Session 4 so that eventual outcome was accurately predicted for 70% of couples, with little improvement of prediction thereafter. More sophisticated algorithms might enhance prediction accuracy, and a trial of the effects of therapy progress feedback on couple therapy outcome is needed. Copyright © 2015 Elsevier Ltd. All rights reserved.

Work life and mental well-being: single and coupled employed mothers in Southern Europe and Scandinavia.

PubMed

Bull, Torill

2009-09-01

Many European mothers, single and coupled, combine work outside the home and family life. The effects of this on their mental well-being may vary depending on the level of support available from the State's welfare system, since welfare may buffer working mothers from some of the stress that can arise from trying to manage significant responsibilities on the job and at home. Welfare may be especially important for single working mothers, for whom the burden of multiple roles may be even heavier. The present study assessed levels and predictors of well-being of single and coupled employed mothers in Greece, Portugal and Spain, where welfare support is relatively limited. Results were compared to a parallel study with data from Denmark, Norway and Sweden, where welfare support is relatively comprehensive. Coupled mothers in Scandinavia had significantly lower financial hardship, longer education, higher life satisfaction, more enriching jobs, practical support, financial support and social participation than coupled mothers in the Southern European sample. On the other hand, the Scandinavian coupled mothers had higher levels of work family conflict than coupled mothers in Southern Europe. Single mothers in Scandinavia, compared to single mothers in Southern Europe, had significantly longer education, higher life satisfaction and positive affect, more enriching jobs, confidant support, practical support, financial support and social participation. Level of job stress was the same for all mother groups. All groups differed significantly from each other in level of financial hardship, with Scandinavian coupled mothers being best off, followed by Scandinavian single mothers, Southern European coupled mothers, and Southern European single mothers. The regional differences suggest that single motherhood per se need not be a risk factor for poorer well-being, and that welfare policies may have a protective effect for the mental well-being of single mothers.

Evaluation of a demand-creation intervention for couples' HIV testing services among married or cohabiting individuals in Rakai, Uganda: a cluster-randomized intervention trial.

PubMed

Matovu, Joseph K B; Todd, Jim; Wanyenze, Rhoda K; Kairania, Robert; Serwadda, David; Wabwire-Mangen, Fred

2016-08-08

Uptake of couples' HIV counseling and testing (couples' HCT) services remains largely low in most settings. We report the effect of a demand-creation intervention trial on couples' HCT uptake among married or cohabiting individuals who had never received couples' HCT. This was a cluster-randomized intervention trial implemented in three study regions with differing HIV prevalence levels (range: 9-43 %) in Rakai district, southwestern Uganda, between February and September 2014. We randomly assigned six clusters (1:1) to receive the intervention or serve as the comparison arm using computer-generated random numbers. In the intervention clusters, individuals attended small group, couple and male-focused interactive sessions, reinforced with testimonies from 'expert couples', and received invitation coupons to test together with their partners at designated health facilities. In the comparison clusters, participants attended general adult health education sessions but received no invitation coupons. The primary outcome was couples' HCT uptake, measured 12 months post-baseline. Baseline data were collected between November 2013 and February 2014 while follow-up data were collected between March and April 2015. We conducted intention-to-treat analysis using a mixed effects Poisson regression model to assess for differences in couples' HCT uptake between the intervention and comparison clusters. Data analysis was conducted using STATA statistical software, version 14.1. Of 2135 married or cohabiting individuals interviewed at baseline, 42 % (n = 846) had ever received couples' HCT. Of those who had never received couples' HCT (n = 1,174), 697 were interviewed in the intervention clusters while 477 were interviewed in the comparison clusters. 73.6 % (n = 513) of those interviewed in the intervention and 82.6 % (n = 394) of those interviewed in the comparison cluster were interviewed at follow-up. Of those interviewed, 72.3 % (n = 371) in the intervention and 65.2 % (n = 257) in the comparison clusters received HCT. Couples' HCT uptake was higher in the intervention than in the comparison clusters (20.3 % versus 13.7 %; adjusted prevalence ratio (aPR) = 1.43, 95 % CI: 1.02, 2.01, P = 0.04). Our findings show that a small group, couple and male-focused, demand-creation intervention reinforced with testimonies from 'expert couples', improved uptake of couples' HCT in this rural setting. ClinicalTrials.gov, NCT02492061 . Date of registration: June 14, 2015.

Decoupled systems on trial: Eliminating bottlenecks to improve aquaponic processes.

PubMed

Monsees, Hendrik; Kloas, Werner; Wuertz, Sven

2017-01-01

In classical aquaponics (coupled aquaponic systems, 1-loop systems) the production of fish in recirculating aquaculture systems (RAS) and plants in hydroponics are combined in a single loop, entailing systemic compromises on the optimal production parameters (e.g. pH). Recently presented decoupled aquaponics (2-loop systems) have been awarded for eliminating major bottlenecks. In a pilot study, production in an innovative decoupled aquaponic system was compared with a coupled system and, as a control, a conventional RAS, assessing growth parameters of fish (FCR, SGR) and plants over an experimental period of 5 months. Soluble nutrients (NO3--N, NO2--N, NH4+-N, PO43-, K+, Ca2+, Mg2+, SO42-, Cl2- and Fe2+), elemental composition of plants, fish and sludge (N, P, K, Ca, Mg, Na, C), abiotic factors (temperature, pH, oxygen, and conductivity), fertilizer and water consumption were determined. Fruit yield was 36% higher in decoupled aquaponics and pH and fertilizer management was more effective, whereas fish production was comparable in both systems. The results of this pilot study clearly illustrate the main advantages of decoupled, two-loop aquaponics and demonstrate how bottlenecks commonly encountered in coupled aquaponics can be managed to promote application in aquaculture.

A frontal cortex event-related potential driven by the basal forebrain

PubMed Central

Nguyen, David P; Lin, Shih-Chieh

2014-01-01

Event-related potentials (ERPs) are widely used in both healthy and neuropsychiatric conditions as physiological indices of cognitive functions. Contrary to the common belief that cognitive ERPs are generated by local activity within the cerebral cortex, here we show that an attention-related ERP in the frontal cortex is correlated with, and likely generated by, subcortical inputs from the basal forebrain (BF). In rats performing an auditory oddball task, both the amplitude and timing of the frontal ERP were coupled with BF neuronal activity in single trials. The local field potentials (LFPs) associated with the frontal ERP, concentrated in deep cortical layers corresponding to the zone of BF input, were similarly coupled with BF activity and consistently triggered by BF electrical stimulation within 5–10 msec. These results highlight the important and previously unrecognized role of long-range subcortical inputs from the BF in the generation of cognitive ERPs. DOI: http://dx.doi.org/10.7554/eLife.02148.001 PMID:24714497

Two spatiotemporally distinct value systems shape reward-based learning in the human brain.

PubMed

Fouragnan, Elsa; Retzler, Chris; Mullinger, Karen; Philiastides, Marios G

2015-09-08

Avoiding repeated mistakes and learning to reinforce rewarding decisions is critical for human survival and adaptive actions. Yet, the neural underpinnings of the value systems that encode different decision-outcomes remain elusive. Here coupling single-trial electroencephalography with simultaneously acquired functional magnetic resonance imaging, we uncover the spatiotemporal dynamics of two separate but interacting value systems encoding decision-outcomes. Consistent with a role in regulating alertness and switching behaviours, an early system is activated only by negative outcomes and engages arousal-related and motor-preparatory brain structures. Consistent with a role in reward-based learning, a later system differentially suppresses or activates regions of the human reward network in response to negative and positive outcomes, respectively. Following negative outcomes, the early system interacts and downregulates the late system, through a thalamic interaction with the ventral striatum. Critically, the strength of this coupling predicts participants' switching behaviour and avoidance learning, directly implicating the thalamostriatal pathway in reward-based learning.

Singlet-paired coupled cluster theory for open shells

NASA Astrophysics Data System (ADS)

Gomez, John A.; Henderson, Thomas M.; Scuseria, Gustavo E.

2016-06-01

Restricted single-reference coupled cluster theory truncated to single and double excitations accurately describes weakly correlated systems, but often breaks down in the presence of static or strong correlation. Good coupled cluster energies in the presence of degeneracies can be obtained by using a symmetry-broken reference, such as unrestricted Hartree-Fock, but at the cost of good quantum numbers. A large body of work has shown that modifying the coupled cluster ansatz allows for the treatment of strong correlation within a single-reference, symmetry-adapted framework. The recently introduced singlet-paired coupled cluster doubles (CCD0) method is one such model, which recovers correct behavior for strong correlation without requiring symmetry breaking in the reference. Here, we extend singlet-paired coupled cluster for application to open shells via restricted open-shell singlet-paired coupled cluster singles and doubles (ROCCSD0). The ROCCSD0 approach retains the benefits of standard coupled cluster theory and recovers correct behavior for strongly correlated, open-shell systems using a spin-preserving ROHF reference.

Inversed Vernier effect based single-mode laser emission in coupled microdisks

PubMed Central

Li, Meng; Zhang, Nan; Wang, Kaiyang; Li, Jiankai; Xiao, Shumin; Song, Qinghai

2015-01-01

Recently, on-chip single-mode laser emissions in coupled microdisks have attracted considerable research attention due to their wide applications. While most of single-mode lasers in coupled microdisks or microrings have been qualitatively explained by either Vernier effect or inversed Vernier effect, none of them have been experimentally confirmed. Here, we studied the mechanism of single-mode laser operation in coupled microdisks. We found that the mode numbers had been significantly reduced to nearly single-mode within a large pumping power range from threshold to gain saturation. The detail laser spectra showed that the largest gain and the first lasing peak were mainly generated by one disk and the laser intensity was proportional to the wavelength detuning of two set of modes. The corresponding theoretical analysis showed that the experimental observations were dominated by internal coupling within one cavity, which was similar to the recently explored inversed Vernier effect in two coupled microrings. We believe our finding will be important for understanding the previous experimental findings and the development of on-chip single-mode laser. PMID:26330218

Efficient fiber-coupled single-photon source based on quantum dots in a photonic-crystal waveguide

PubMed Central

DAVEAU, RAPHAËL S.; BALRAM, KRISHNA C.; PREGNOLATO, TOMMASO; LIU, JIN; LEE, EUN H.; SONG, JIN D.; VERMA, VARUN; MIRIN, RICHARD; NAM, SAE WOO; MIDOLO, LEONARDO; STOBBE, SØREN; SRINIVASAN, KARTIK; LODAHL, PETER

2017-01-01

Many photonic quantum information processing applications would benefit from a high brightness, fiber-coupled source of triggered single photons. Here, we present a fiber-coupled photonic-crystal waveguide single-photon source relying on evanescent coupling of the light field from a tapered out-coupler to an optical fiber. A two-step approach is taken where the performance of the tapered out-coupler is recorded first on an independent device containing an on-chip reflector. Reflection measurements establish that the chip-to-fiber coupling efficiency exceeds 80 %. The detailed characterization of a high-efficiency photonic-crystal waveguide extended with a tapered out-coupling section is then performed. The corresponding overall single-photon source efficiency is 10.9 % ± 2.3 %, which quantifies the success probability to prepare an exciton in the quantum dot, couple it out as a photon in the waveguide, and subsequently transfer it to the fiber. The applied out-coupling method is robust, stable over time, and broadband over several tens of nanometers, which makes it a highly promising pathway to increase the efficiency and reliability of planar chip-based single-photon sources. PMID:28584859

A Randomized Controlled Trial of a Couple Relationship and Coparenting Program (Couple CARE for Parents) for High- and Low-Risk New Parents

ERIC Educational Resources Information Center

Petch, Jemima F.; Halford, W. Kim; Creedy, Debra K.; Gamble, Jenny

2012-01-01

Objective: This study evaluated the effectiveness of couple relationship education in assisting couples to sustain relationship functioning and parenting sensitivity, and whether benefits were moderated by risk of maladjustment in the transition to parenthood ("risk"). Method: Two hundred fifty couples expecting their first child were assessed on…

Project Eban: An HIV/STD Intervention for African American Couples

PubMed Central

2010-01-01

Objective To describe the Eban HIV/STD Risk Reduction Intervention being evaluated in the NIMH Multisite HIV/STD Prevention trial for heterosexual African American couples, including the integrated theoretical framework, the structure, core elements and procedures of the intervention and how the content was shaped by culturally congruent concepts to address the needs of the study target population. Design The Eban HIV/STD Risk Reduction Intervention is designed to address multilevel individual, interpersonal and community level factors that contribute to HIV/STD transmission risk behaviors among heterosexual African American couples who are HIV serodiscordant. Methods The Eban HIV/STD Risk Reduction Intervention employs a mixed modality, couples-based approach that is based on an integrated ecological framework incorporating social cognitive theory and uses an Afro-centric paradigm that is informed by previous evidence-based couples HIV prevention interventions. For this randomized controlled trial, African American serodiscordant couples were recruited from four urban sites (Atlanta, Los Angeles, New York and Philadelphia) and were randomized to either the Eban HIV/STD Risk Reduction Intervention (treatment condition) or a Health Promotion Intervention that served as an attentional control condition. Both interventions had 4 individual couple sessions and 4 group sessions, but only the treatment condition was focused on reducing HIV/STD risk behaviors. Behavioral and biological data were collected at baseline, immediately after the intervention, and at 6 and 12 months. The theoretical framework, core elements and content of each session are described and lessons learned from this intervention trial are discussed. Results An HIV prevention intervention combining couple and group sessions can be feasibly implemented with African American HIV serodiscordant couples who remain at high risk of HIV/STD transmission. The lessons learned from the trial suggest that the participants responded very well to both the couple and group sessions. Participant feedback suggests that the cultural congruence of the intervention and use of African American co-facilitators made them feel comfortable disclosing risky behaviors. Participant feedback also suggests that the intervention’s couples-based focus on enhancing dyadic communication and decision-making skills were key to helping the couples work together to overcome barriers to using condoms. Conclusion Participant and facilitator evaluations of the Eban Risk Reduction Intervention suggest that couples responded well to the Afro-centric content and mixed modalities of the intervention sessions. Couple sessions were optimal for enhancing interpersonal and microlevel factors, including communication, problem solving, and decision making. PMID:18724186

Utilisation of ART in single women and lesbian couples since the 2010 change in Victorian legislation.

PubMed

Fiske, Emily; Weston, Gareth

2014-10-01

Enactment of the Assisted Reproductive Treatment Act (Vic) 2008 in January 2010 allowed single persons and same sex couples in Victoria to access reproductive treatments. A retrospective cohort analysis of Monash IVF patients was conducted to identify trends in Assisted Reproductive Technology (ART) use amongst single women and lesbian couples after January 2010. A 102.8% increase in the utilisation of ART was observed amongst the single women group and a 248.8% increase in the lesbian couple population. © 2014 The Royal Australian and New Zealand College of Obstetricians and Gynaecologists.

Circuit-Host Coupling Induces Multifaceted Behavioral Modulations of a Gene Switch.

PubMed

Blanchard, Andrew E; Liao, Chen; Lu, Ting

2018-02-06

Quantitative modeling of gene circuits is fundamentally important to synthetic biology, as it offers the potential to transform circuit engineering from trial-and-error construction to rational design and, hence, facilitates the advance of the field. Currently, typical models regard gene circuits as isolated entities and focus only on the biochemical processes within the circuits. However, such a standard paradigm is getting challenged by increasing experimental evidence suggesting that circuits and their host are intimately connected, and their interactions can potentially impact circuit behaviors. Here we systematically examined the roles of circuit-host coupling in shaping circuit dynamics by using a self-activating gene switch as a model circuit. Through a combination of deterministic modeling, stochastic simulation, and Fokker-Planck equation formalism, we found that circuit-host coupling alters switch behaviors across multiple scales. At the single-cell level, it slows the switch dynamics in the high protein production regime and enlarges the difference between stable steady-state values. At the population level, it favors cells with low protein production through differential growth amplification. Together, the two-level coupling effects induce both quantitative and qualitative modulations of the switch, with the primary component of the effects determined by the circuit's architectural parameters. This study illustrates the complexity and importance of circuit-host coupling in modulating circuit behaviors, demonstrating the need for a new paradigm-integrated modeling of the circuit-host system-for quantitative understanding of engineered gene networks. Copyright © 2017 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Brain-behavioral adaptability predicts response to cognitive behavioral therapy for emotional disorders: A person-centered event-related potential study.

PubMed

Stange, Jonathan P; MacNamara, Annmarie; Kennedy, Amy E; Hajcak, Greg; Phan, K Luan; Klumpp, Heide

2017-06-23

Single-trial-level analyses afford the ability to link neural indices of elaborative attention (such as the late positive potential [LPP], an event-related potential) with downstream markers of attentional processing (such as reaction time [RT]). This approach can provide useful information about individual differences in information processing, such as the ability to adapt behavior based on attentional demands ("brain-behavioral adaptability"). Anxiety and depression are associated with maladaptive information processing implicating aberrant cognition-emotion interactions, but whether brain-behavioral adaptability predicts response to psychotherapy is not known. We used a novel person-centered, trial-level analysis approach to link neural indices of stimulus processing to behavioral responses and to predict treatment outcome. Thirty-nine patients with anxiety and/or depression received 12 weeks of cognitive behavioral therapy (CBT). Prior to treatment, patients performed a speeded reaction-time task involving briefly-presented pairs of aversive and neutral pictures while electroencephalography was recorded. Multilevel modeling demonstrated that larger LPPs predicted slower responses on subsequent trials, suggesting that increased attention to the task-irrelevant nature of pictures interfered with reaction time on subsequent trials. Whereas using LPP and RT averages did not distinguish CBT responders from nonresponders, in trial-level analyses individuals who demonstrated greater ability to benefit behaviorally (i.e., faster RT) from smaller LPPs on the previous trial (greater brain-behavioral adaptability) were more likely to respond to treatment and showed greater improvements in depressive symptoms. These results highlight the utility of trial-level analyses to elucidate variability in within-subjects, brain-behavioral attentional coupling in the context of emotion processing, in predicting response to CBT for emotional disorders. Copyright © 2017 Elsevier Ltd. All rights reserved.

Warp-averaging event-related potentials.

PubMed

Wang, K; Begleiter, H; Porjesz, B

2001-10-01

To align the repeated single trials of the event-related potential (ERP) in order to get an improved estimate of the ERP. A new implementation of the dynamic time warping is applied to compute a warp-average of the single trials. The trilinear modeling method is applied to filter the single trials prior to alignment. Alignment is based on normalized signals and their estimated derivatives. These features reduce the misalignment due to aligning the random alpha waves, explaining amplitude differences in latency differences, or the seemingly small amplitudes of some components. Simulations and applications to visually evoked potentials show significant improvement over some commonly used methods. The new implementation of the dynamic time warping can be used to align the major components (P1, N1, P2, N2, P3) of the repeated single trials. The average of the aligned single trials is an improved estimate of the ERP. This could lead to more accurate results in subsequent analysis.

Assisted reproduction in a cohort of same-sex male couples and single men.

PubMed

Grover, Stephanie A; Shmorgun, Ziva; Moskovtsev, Sergey I; Baratz, Ari; Librach, Clifford L

2013-08-01

To date, there is limited published data on same-sex male couples and single men using assisted reproduction treatment to build their families. The objective of this retrospective study was to better understand treatment considerations and outcomes for this population when using assisted reproduction treatment. A total of 37 same-sex male couples and eight single men (seven homosexual and one heterosexual) who attended the CReATe Fertility Centre for assisted reproduction services were studied. There was a 21-fold increase in the number of same-sex male couples and single men undergoing assisted reproduction treatment since 2003. The mean age was 46years (24-58). Twenty-eight couples (76%) chose to use spermatozoa from both partners to fertilize their donated oocytes. Most men (32 same-sex male couples and seven single men; 87%) obtained oocytes from an anonymous donor, whereas five couples and one single man (13%) had a known donor. Anonymous donors who were open to be contacted by the child after the age of 18 were selected by 67% of patients. Of all 25 deliveries, eight (32%) were sets of twins. All of the twins were half genetic siblings. Copyright © 2013 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.

Single-photon-driven high-order sideband transitions in an ultrastrongly coupled circuit-quantum-electrodynamics system

NASA Astrophysics Data System (ADS)

Chen, Zhen; Wang, Yimin; Li, Tiefu; Tian, Lin; Qiu, Yueyin; Inomata, Kunihiro; Yoshihara, Fumiki; Han, Siyuan; Nori, Franco; Tsai, J. S.; You, J. Q.

2017-07-01

We report the experimental observation of high-order sideband transitions at the single-photon level in a quantum circuit system of a flux qubit ultrastrongly coupled to a coplanar waveguide resonator. With the coupling strength reaching 10% of the resonator's fundamental frequency, we obtain clear signatures of higher order red-sideband and first-order blue-sideband transitions, which are mainly due to the ultrastrong Rabi coupling. Our observation advances the understanding of ultrastrongly coupled systems and paves the way to study high-order processes in the quantum Rabi model at the single-photon level.

A nanodiamond-tapered fiber system with high single-mode coupling efficiency.

PubMed

Schröder, Tim; Fujiwara, Masazumi; Noda, Tetsuya; Zhao, Hong-Quan; Benson, Oliver; Takeuchi, Shigeki

2012-05-07

We present a fiber-coupled diamond-based single photon system. Single nanodiamonds containing nitrogen vacancy defect centers are deposited on a tapered fiber of 273 nanometer in diameter providing a record-high number of 689,000 single photons per second from a defect center in a single-mode fiber. The system can be cooled to cryogenic temperatures and coupled evanescently to other nanophotonic structures, such as microresonators. The system is suitable for integrated quantum transmission experiments, two-photon interference, quantum-random-number generation and nano-magnetometry.

A coupled-cluster study of photodetachment cross sections of closed-shell anions

NASA Astrophysics Data System (ADS)

Cukras, Janusz; Decleva, Piero; Coriani, Sonia

2014-11-01

We investigate the performance of Stieltjes Imaging applied to Lanczos pseudo-spectra generated at the coupled cluster singles and doubles, coupled cluster singles and approximate iterative doubles and coupled cluster singles levels of theory in modeling the photodetachment cross sections of the closed shell anions H-, Li-, Na-, F-, Cl-, and OH-. The accurate description of double excitations is found to play a much more important role than in the case of photoionization of neutral species.

A coupled-cluster study of photodetachment cross sections of closed-shell anions.

PubMed

Cukras, Janusz; Decleva, Piero; Coriani, Sonia

2014-11-07

We investigate the performance of Stieltjes Imaging applied to Lanczos pseudo-spectra generated at the coupled cluster singles and doubles, coupled cluster singles and approximate iterative doubles and coupled cluster singles levels of theory in modeling the photodetachment cross sections of the closed shell anions H(-), Li(-), Na(-), F(-), Cl(-), and OH(-). The accurate description of double excitations is found to play a much more important role than in the case of photoionization of neutral species.

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

Gomez, John A.; Henderson, Thomas M.; Scuseria, Gustavo E.

Restricted single-reference coupled cluster theory truncated to single and double excitations accurately describes weakly correlated systems, but often breaks down in the presence of static or strong correlation. Good coupled cluster energies in the presence of degeneracies can be obtained by using a symmetry-broken reference, such as unrestricted Hartree-Fock, but at the cost of good quantum numbers. A large body of work has shown that modifying the coupled cluster ansatz allows for the treatment of strong correlation within a single-reference, symmetry-adapted framework. The recently introduced singlet-paired coupled cluster doubles (CCD0) method is one such model, which recovers correct behavior formore » strong correlation without requiring symmetry breaking in the reference. Here, we extend singlet-paired coupled cluster for application to open shells via restricted open-shell singlet-paired coupled cluster singles and doubles (ROCCSD0). The ROCCSD0 approach retains the benefits of standard coupled cluster theory and recovers correct behavior for strongly correlated, open-shell systems using a spin-preserving ROHF reference.« less

An automated and fast approach to detect single-trial visual evoked potentials with application to brain-computer interface.

PubMed

Tu, Yiheng; Hung, Yeung Sam; Hu, Li; Huang, Gan; Hu, Yong; Zhang, Zhiguo

2014-12-01

This study aims (1) to develop an automated and fast approach for detecting visual evoked potentials (VEPs) in single trials and (2) to apply the single-trial VEP detection approach in designing a real-time and high-performance brain-computer interface (BCI) system. The single-trial VEP detection approach uses common spatial pattern (CSP) as a spatial filter and wavelet filtering (WF) a temporal-spectral filter to jointly enhance the signal-to-noise ratio (SNR) of single-trial VEPs. The performance of the joint spatial-temporal-spectral filtering approach was assessed in a four-command VEP-based BCI system. The offline classification accuracy of the BCI system was significantly improved from 67.6±12.5% (raw data) to 97.3±2.1% (data filtered by CSP and WF). The proposed approach was successfully implemented in an online BCI system, where subjects could make 20 decisions in one minute with classification accuracy of 90%. The proposed single-trial detection approach is able to obtain robust and reliable VEP waveform in an automatic and fast way and it is applicable in VEP based online BCI systems. This approach provides a real-time and automated solution for single-trial detection of evoked potentials or event-related potentials (EPs/ERPs) in various paradigms, which could benefit many applications such as BCI and intraoperative monitoring. Copyright © 2014 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Reliability of Single-Leg Balance and Landing Tests in Rugby Union; Prospect of Using Postural Control to Monitor Fatigue

PubMed Central

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

Online Coupling of Flow-Field Flow Fractionation and Single Particle Inductively Coupled Plasma-Mass Spectrometry: Characterization of Nanoparticle Surface Coating Thickness and Aggregation State

EPA Science Inventory

Surface coating thickness and aggregation state have strong influence on the environmental fate, transport, and toxicity of engineered nanomaterials. In this study, flow-field flow fractionation coupled on-line with single particle inductively coupled plasma-mass spectrometry i...

Single-agent Taxane Versus Taxane-containing Combination Chemotherapy as Salvage Therapy for Advanced Urothelial Carcinoma.

PubMed

Sonpavde, Guru; Pond, Gregory R; Choueiri, Toni K; Mullane, Stephanie; Niegisch, Guenter; Albers, Peter; Necchi, Andrea; Di Lorenzo, Giuseppe; Buonerba, Carlo; Rozzi, Antonio; Matsumoto, Kazumasa; Lee, Jae-Lyun; Kitamura, Hiroshi; Kume, Haruki; Bellmunt, Joaquim

2016-04-01

Single-agent taxanes are commonly used as salvage systemic therapy for patients with advanced urothelial carcinoma (UC). To study the impact of combination chemotherapy delivering a taxane plus other chemotherapeutic agents compared with single-agent taxane as salvage therapy. Individual patient-level data from phase 2 trials of salvage systemic therapy were used. Trials evaluating either single agents (paclitaxel or docetaxel) or combination chemotherapy (taxane plus one other chemotherapeutic agent or more) following prior platinum-based therapy were used. Information regarding the known major baseline prognostic factors was required: time from prior chemotherapy, hemoglobin, performance status, albumin, and liver metastasis status. Cox proportional hazards regression was used to evaluate the association of prognostic factors and combination versus single-agent chemotherapy with overall survival (OS). Data were available from eight trials including 370 patients; two trials (n=109) evaluated single-agent chemotherapy with docetaxel (n=72) and cremophor-free paclitaxel (n=37), and six trials (n=261) evaluated combination chemotherapy with gemcitabine-paclitaxel (two trials, with n=99 and n=24), paclitaxel-cyclophosphamide (n=32), paclitaxel-ifosfamide-nedaplatin (n=45), docetaxel-ifosfamide-cisplatin (n=26), and paclitaxel-epirubicin (n=35). On multivariable analysis after adjustment for baseline prognostic factors, combination chemotherapy was independently and significantly associated with improved OS (hazard ratio: 0.60; 95% confidence interval, 0.45-0.82; p=0.001). The retrospective design of this analysis and the trial-eligible population were inherent limitations. Patients enrolled in trials of combination chemotherapy exhibited improved OS compared with patients enrolled in trials of single-agent chemotherapy as salvage therapy for advanced UC. Prospective randomized trials are required to validate a potential role for rational and tolerable combination chemotherapeutic regimens for the salvage therapy of advanced UC. This retrospective study suggests that a combination of chemotherapy agents may extend survival compared with single-agent chemotherapy in selected patients with metastatic urothelial cancer progressing after prior chemotherapy. Copyright © 2015 European Association of Urology. Published by Elsevier B.V. All rights reserved.

Photoionization cross section by Stieltjes imaging applied to coupled cluster Lanczos pseudo-spectra

NASA Astrophysics Data System (ADS)

Cukras, Janusz; Coriani, Sonia; Decleva, Piero; Christiansen, Ove; Norman, Patrick

2013-09-01

A recently implemented asymmetric Lanczos algorithm for computing (complex) linear response functions within the coupled cluster singles (CCS), coupled cluster singles and iterative approximate doubles (CC2), and coupled cluster singles and doubles (CCSD) is coupled to a Stieltjes imaging technique in order to describe the photoionization cross section of atoms and molecules, in the spirit of a similar procedure recently proposed by Averbukh and co-workers within the Algebraic Diagrammatic Construction approach. Pilot results are reported for the atoms He, Ne, and Ar and for the molecules H2, H2O, NH3, HF, CO, and CO2.

Photoionization cross section by Stieltjes imaging applied to coupled cluster Lanczos pseudo-spectra.

PubMed

Cukras, Janusz; Coriani, Sonia; Decleva, Piero; Christiansen, Ove; Norman, Patrick

2013-09-07

A recently implemented asymmetric Lanczos algorithm for computing (complex) linear response functions within the coupled cluster singles (CCS), coupled cluster singles and iterative approximate doubles (CC2), and coupled cluster singles and doubles (CCSD) is coupled to a Stieltjes imaging technique in order to describe the photoionization cross section of atoms and molecules, in the spirit of a similar procedure recently proposed by Averbukh and co-workers within the Algebraic Diagrammatic Construction approach. Pilot results are reported for the atoms He, Ne, and Ar and for the molecules H2, H2O, NH3, HF, CO, and CO2.

Evaluation of a Brief Marriage Intervention for Internal Behavioral Health Consultants in Primary Care

DTIC Science & Technology

2016-09-01

couples at risk for marital deterioration who would otherwise be unlikely to seek traditional couple counseling . The randomized trial is being...protocol to better assess (1) ability to involve couples who otherwise would not seek marriage counseling , and (2) whether participating in Marriage

European Marketing Authorizations Granted Based on a Single Pivotal Clinical Trial: The Rule or the Exception?

PubMed

Morant, Anne Vinther; Vestergaard, Henrik Tang

2018-07-01

A minimum of two positive, adequate, and well-controlled clinical trials has historically been the gold standard for providing substantial evidence to support regulatory approval of a new medicine. Nevertheless, the present analysis of European Marketing Authorizations granted between 2012 and 2016 showed that 45% of new active substances were approved based on a single pivotal clinical trial. For therapeutic areas such as oncology and cardiovascular diseases, approvals based on a single pivotal trial are the rule rather than the exception, whereas new medicines within the nervous system area were generally supported by two or more pivotal trials. While overall similar trends have been observed in the US, the recent US Food and Drug Administration approvals of nervous system medicines based on a single pivotal trial suggest that a case-by-case scientific evaluation of the totality of evidence is increasingly applied to facilitate faster access of new medicines to patients suffering from serious diseases. © 2017 American Society for Clinical Pharmacology and Therapeutics.

Dual-wavelength single-frequency laser emission in asymmetric coupled microdisks

PubMed Central

Wang, Haotian; Liu, Sheng; Chen, Lin; Shen, Deyuan; Wu, Xiang

2016-01-01

The gain and loss in a microcavity laser play an important role for the modulation of laser spectrum. We show that dual-wavelength single mode lasing can be achieved in an asymmetric coupled system consisted of two size-mismatched microdisks. The amount of eigenmodes in this coupled-microdisk system is reduced relying on the Vernier effect. Then a single mode is selected to lase by controlling the gain branching in the supermodes. The supermodes are formed by the coupling between different transverse whispering-gallery modes (WGMs). When the gain/loss status between the two mirodisks is changed through selectively pumping process, the modulated gain branching for various supermodes leads to the switchable single-frequency laser emission. The results obtained in this work will provide the further understand for the spectral modulation mechanism in the coupled microcavity laser system. PMID:27905506

Pregnancy Incidence and Correlates during the HVTN 503 Phambili HIV Vaccine Trial Conducted among South African Women

PubMed Central

Latka, Mary H.; Fielding, Katherine; Gray, Glenda E.; Bekker, Linda-Gail; Nchabeleng, Maphoshane; Mlisana, Koleka; Nielson, Tanya; Roux, Surita; Mkhize, Baningi; Mathebula, Matsontso; Naicker, Nivashnee; de Bruyn, Guy; Kublin, James; Churchyard, Gavin J.

2012-01-01

Background HIV prevention trials are increasingly being conducted in sub-Saharan Africa. Women at risk for HIV are also at risk of pregnancy. To maximize safety, women agree to avoid pregnancy during trials, yet pregnancies occur. Using data from the HVTN 503/“Phambili” vaccine trial, we report pregnancy incidence during and after the vaccination period and identify factors, measured at screening, associated with incident pregnancy. Methods To enrol in the trial, women agreed and were supported to avoid pregnancy until 1 month after their third and final vaccination (“vaccination period”), corresponding to the first 7 months of follow-up. Unsterilized women, pooled across study arms, were analyzed. Poisson regression compared pregnancy rates during and after the vaccination period. Cox proportional hazards regression identified associations with first pregnancy. Results Among 352 women (median age 23 yrs; median follow-up 1.5 yrs), pregnancy incidence was 9.6/100 women-years overall and 6.8/100 w-yrs and 11.3/100 w-yrs during and after the vaccination period, respectively [Rate Ratio = 0.60 (0.32–1.14), p = 0.10]. In multivariable analysis, pregnancy was reduced among women who: enrolled at sites providing contraception on-site [HR = 0.43, 95% CI (0.22–0.86)]; entered the trial as injectable contraceptive users [HR = 0.37 (0.21–0.67)] or as consistent condom users (trend) [HR = 0.54 (0.28–1.04)]. Compared with women with a single partner of HIV-unknown status, pregnancy rates were increased among women with: a single partner whose status was HIV-negative [HR = 2.34(1.16–4.73)] and; 2 partners both of HIV-unknown status [HR = 4.42(1.59–12.29)]. Women with 2 more of these risk factors: marijuana use, heavy drinking, or use of either during sex, had increased pregnancy incidence [HR = 2.66 (1.24–5.72)]. Conclusions It is possible to screen South African women for pregnancy risk at trial entry. Providing injectable contraception for free on-site and supporting consistent condom use may reduce incident pregnancy. Screening should determine the substance use, partnering, and HIV status of both members of the couple for both pregnancy and HIV prevention. Trial Registration SA National Health Research Database DOH-27-0207-1539; Clinicaltrials.gov NCT00413725 PMID:22532824

The palliative care in heart failure trial: rationale and design.

PubMed

Mentz, Robert J; Tulsky, James A; Granger, Bradi B; Anstrom, Kevin J; Adams, Patricia A; Dodson, Gwen C; Fiuzat, Mona; Johnson, Kimberly S; Patel, Chetan B; Steinhauser, Karen E; Taylor, Donald H; O'Connor, Christopher M; Rogers, Joseph G

2014-11-01

The progressive nature of heart failure (HF) coupled with high mortality and poor quality of life mandates greater attention to palliative care as a routine component of advanced HF management. Limited evidence exists from randomized, controlled trials supporting the use of interdisciplinary palliative care in HF. PAL-HF is a prospective, controlled, unblinded, single-center study of an interdisciplinary palliative care intervention in 200 patients with advanced HF estimated to have a high likelihood of mortality or rehospitalization in the ensuing 6 months. The 6-month PAL-HF intervention focuses on physical and psychosocial symptom relief, attention to spiritual concerns, and advanced care planning. The primary end point is health-related quality of life measured by the Kansas City Cardiomyopathy Questionnaire and the Functional Assessment of Chronic Illness Therapy with Palliative Care Subscale score at 6 months. Secondary end points include changes in anxiety/depression, spiritual well-being, caregiver satisfaction, cost and resource utilization, and a composite of death, HF hospitalization, and quality of life. PAL-HF is a randomized, controlled clinical trial that will help evaluate the efficacy and cost effectiveness of palliative care in advanced HF using a patient-centered outcome as well as clinical and economic end points. Copyright © 2014 Elsevier Inc. All rights reserved.

Knowing when not to swing: EEG evidence that enhanced perception-action coupling underlies baseball batter expertise.

PubMed

Muraskin, Jordan; Sherwin, Jason; Sajda, Paul

2015-12-01

Given a decision that requires less than half a second for evaluating the characteristics of the incoming pitch and generating a motor response, hitting a baseball potentially requires unique perception-action coupling to achieve high performance. We designed a rapid perceptual decision-making experiment modeled as a Go/No-Go task yet tailored to reflect a real scenario confronted by a baseball hitter. For groups of experts (Division I baseball players) and novices (non-players), we recorded electroencephalography (EEG) while they performed the task. We analyzed evoked EEG single-trial variability, contingent negative variation (CNV), and pre-stimulus alpha power with respect to the expert vs. novice groups. We found strong evidence for differences in inhibitory processes between the two groups, specifically differential activity in supplementary motor areas (SMA), indicative of enhanced inhibitory control in the expert (baseball player) group. We also found selective activity in the fusiform gyrus (FG) and orbital gyrus in the expert group, suggesting an enhanced perception-action coupling in baseball players that differentiates them from matched controls. In sum, our results show that EEG correlates of decision formation can be used to identify neural markers of high-performance athletes. Copyright © 2015 Elsevier Inc. All rights reserved.

Decoupled systems on trial: Eliminating bottlenecks to improve aquaponic processes

PubMed Central

Kloas, Werner; Wuertz, Sven

2017-01-01

In classical aquaponics (coupled aquaponic systems, 1-loop systems) the production of fish in recirculating aquaculture systems (RAS) and plants in hydroponics are combined in a single loop, entailing systemic compromises on the optimal production parameters (e.g. pH). Recently presented decoupled aquaponics (2-loop systems) have been awarded for eliminating major bottlenecks. In a pilot study, production in an innovative decoupled aquaponic system was compared with a coupled system and, as a control, a conventional RAS, assessing growth parameters of fish (FCR, SGR) and plants over an experimental period of 5 months. Soluble nutrients (NO3--N, NO2--N, NH4+-N, PO43-, K+, Ca2+, Mg2+, SO42-, Cl2- and Fe2+), elemental composition of plants, fish and sludge (N, P, K, Ca, Mg, Na, C), abiotic factors (temperature, pH, oxygen, and conductivity), fertilizer and water consumption were determined. Fruit yield was 36% higher in decoupled aquaponics and pH and fertilizer management was more effective, whereas fish production was comparable in both systems. The results of this pilot study clearly illustrate the main advantages of decoupled, two-loop aquaponics and demonstrate how bottlenecks commonly encountered in coupled aquaponics can be managed to promote application in aquaculture. PMID:28957357

Prediction of successful memory encoding based on single-trial rhinal and hippocampal phase information.

PubMed

Höhne, Marlene; Jahanbekam, Amirhossein; Bauckhage, Christian; Axmacher, Nikolai; Fell, Juergen

2016-10-01

Mediotemporal EEG characteristics are closely related to long-term memory formation. It has been reported that rhinal and hippocampal EEG measures reflecting the stability of phases across trials are better suited to distinguish subsequently remembered from forgotten trials than event-related potentials or amplitude-based measures. Theoretical models suggest that the phase of EEG oscillations reflects neural excitability and influences cellular plasticity. However, while previous studies have shown that the stability of phase values across trials is indeed a relevant predictor of subsequent memory performance, the effect of absolute single-trial phase values has been little explored. Here, we reanalyzed intracranial EEG recordings from the mediotemporal lobe of 27 epilepsy patients performing a continuous word recognition paradigm. Two-class classification using a support vector machine was performed to predict subsequently remembered vs. forgotten trials based on individually selected frequencies and time points. We demonstrate that it is possible to successfully predict single-trial memory formation in the majority of patients (23 out of 27) based on only three single-trial phase values given by a rhinal phase, a hippocampal phase, and a rhinal-hippocampal phase difference. Overall classification accuracy across all subjects was 69.2% choosing frequencies from the range between 0.5 and 50Hz and time points from the interval between -0.5s and 2s. For 19 patients, above chance prediction of subsequent memory was possible even when choosing only time points from the prestimulus interval (overall accuracy: 65.2%). Furthermore, prediction accuracies based on single-trial phase surpassed those based on single-trial power. Our results confirm the functional relevance of mediotemporal EEG phase for long-term memory operations and suggest that phase information may be utilized for memory enhancement applications based on deep brain stimulation. Copyright © 2016 Elsevier Inc. All rights reserved.

Search for anomalous top-quark couplings with the D0 detector.

PubMed

Abazov, V M; Abbott, B; Abolins, M; Acharya, B S; Adams, M; Adams, T; Aguilo, E; Ahsan, M; Alexeev, G D; Alkhazov, G; Alton, A; Alverson, G; Alves, G A; Anastasoaie, M; Ancu, L S; Andeen, T; Andrieu, B; Anzelc, M S; Aoki, M; Arnoud, Y; Arov, M; Arthaud, M; Askew, A; Asman, B; Assis Jesus, A C S; Atramentov, O; Avila, C; Backusmayes, J; Badaud, F; Bagby, L; Baldin, B; Bandurin, D V; Banerjee, P; Banerjee, S; Barberis, E; Barfuss, A-F; Bargassa, P; Baringer, P; Barreto, J; Bartlett, J F; Bassler, U; Bauer, D; Beale, S; Bean, A; Begalli, M; Begel, M; Belanger-Champagne, C; Bellantoni, L; Bellavance, A; Benitez, J A; Beri, S B; Bernardi, G; Bernhard, R; Bertram, I; Besançon, M; Beuselinck, R; Bezzubov, V A; Bhat, P C; Bhatnagar, V; Blazey, G; Blekman, F; Blessing, S; Bloom, K; Boehnlein, A; Boline, D; Bolton, T A; Boos, E E; Borissov, G; Bose, T; Brandt, A; Brock, R; Brooijmans, G; Bross, A; Brown, D; Bu, X B; Buchanan, N J; Buchholz, D; Buehler, M; Buescher, V; Bunichev, V; Burdin, S; Burnett, T H; Buszello, C P; Calfayan, P; Calpas, B; Calvet, S; Cammin, J; Carrasco-Lizarraga, M A; Carrera, E; Carvalho, W; Casey, B C K; Castilla-Valdez, H; Chakrabarti, S; Chakraborty, D; Chan, K M; Chandra, A; Cheu, E; Cho, D K; Choi, S; Choudhary, B; Christofek, L; Christoudias, T; Cihangir, S; Claes, D; Clutter, J; Cooke, M; Cooper, W E; Corcoran, M; Couderc, F; Cousinou, M-C; Crépé-Renaudin, S; Cuplov, V; Cutts, D; Cwiok, M; da Motta, H; Das, A; Davies, G; De, K; de Jong, S J; De La Cruz-Burelo, E; De Oliveira Martins, C; DeVaughan, K; Déliot, F; Demarteau, M; Demina, R; Denisov, D; Denisov, S P; Desai, S; Diehl, H T; Diesburg, M; Dominguez, A; Dorland, T; Dubey, A; Dudko, L V; Duflot, L; Dugad, S R; Duggan, D; Duperrin, A; Dutt, S; Dyer, J; Dyshkant, A; Eads, M; Edmunds, D; Ellison, J; Elvira, V D; Enari, Y; Eno, S; Ermolov, P; Escalier, M; Evans, H; Evdokimov, A; Evdokimov, V N; Ferapontov, A V; Ferbel, T; Fiedler, F; Filthaut, F; Fisher, W; Fisk, H E; Fortner, M; Fox, H; Fu, S; Fuess, S; Gadfort, T; Galea, C F; Garcia, C; Garcia-Bellido, A; Gavrilov, V; Gay, P; Geist, W; Geng, W; Gerber, C E; Gershtein, Y; Gillberg, D; Ginther, G; Gómez, B; Goussiou, A; Grannis, P D; Greenlee, H; Greenwood, Z D; Gregores, E M; Grenier, G; Gris, Ph; Grivaz, J-F; Grohsjean, A; Grünendahl, S; Grünewald, M W; Guo, F; Guo, J; Gutierrez, G; Gutierrez, P; Haas, A; Hadley, N J; Haefner, P; Hagopian, S; Haley, J; Hall, I; Hall, R E; Han, L; Harder, K; Harel, A; Hauptman, J M; Hays, J; Hebbeker, T; Hedin, D; Hegeman, J G; Heinson, A P; Heintz, U; Hensel, C; Herner, K; Hesketh, G; Hildreth, M D; Hirosky, R; Hoang, T; Hobbs, J D; Hoeneisen, B; Hohlfeld, M; Hossain, S; Houben, P; Hu, Y; Hubacek, Z; Huske, N; Hynek, V; Iashvili, I; Illingworth, R; Ito, A S; Jabeen, S; Jaffré, M; Jain, S; Jakobs, K; Jarvis, C; Jesik, R; Johns, K; Johnson, C; Johnson, M; Johnston, D; Jonckheere, A; Jonsson, P; Juste, A; Kajfasz, E; Karmanov, D; Kasper, P A; Katsanos, I; Kaushik, V; Kehoe, R; Kermiche, S; Khalatyan, N; Khanov, A; Kharchilava, A; Kharzheev, Y N; Khatidze, D; Kim, T J; Kirby, M H; Kirsch, M; Klima, B; Kohli, J M; Konrath, J-P; Kozelov, A V; Kraus, J; Kuhl, T; Kumar, A; Kupco, A; Kurca, T; Kuzmin, V A; Kvita, J; Lacroix, F; Lam, D; Lammers, S; Landsberg, G; Lebrun, P; Lee, W M; Leflat, A; Lellouch, J; Li, J; Li, L; Li, Q Z; Lietti, S M; Lim, J K; Lima, J G R; Lincoln, D; Linnemann, J; Lipaev, V V; Lipton, R; Liu, Y; Liu, Z; Lobodenko, A; Lokajicek, M; Love, P; Lubatti, H J; Luna-Garcia, R; Lyon, A L; Maciel, A K A; Mackin, D; Madaras, R J; Mättig, P; Magerkurth, A; Mal, P K; Malbouisson, H B; Malik, S; Malyshev, V L; Maravin, Y; Martin, B; McCarthy, R; Meijer, M M; Melnitchouk, A; Mendoza, L; Mercadante, P G; Merkin, M; Merritt, K W; Meyer, A; Meyer, J; Mitrevski, J; Mommsen, R K; Mondal, N K; Moore, R W; Moulik, T; Muanza, G S; Mulhearn, M; Mundal, O; Mundim, L; Nagy, E; Naimuddin, M; Narain, M; Neal, H A; Negret, J P; Neustroev, P; Nilsen, H; Nogima, H; Novaes, S F; Nunnemann, T; O'Neil, D C; Obrant, G; Ochando, C; Onoprienko, D; Oshima, N; Osman, N; Osta, J; Otec, R; Otero y Garzón, G J; Owen, M; Padilla, M; Padley, P; Pangilinan, M; Parashar, N; Park, S-J; Park, S K; Parsons, J; Partridge, R; Parua, N; Patwa, A; Pawloski, G; Penning, B; Perfilov, M; Peters, K; Peters, Y; Pétroff, P; Petteni, M; Piegaia, R; Piper, J; Pleier, M-A; Podesta-Lerma, P L M; Podstavkov, V M; Pogorelov, Y; Pol, M-E; Polozov, P; Pope, B G; Popov, A V; Potter, C; da Silva, W L Prado; Prosper, H B; Protopopescu, S; Qian, J; Quadt, A; Quinn, B; Rakitine, A; Rangel, M S; Ranjan, K; Ratoff, P N; Renkel, P; Rich, P; Rijssenbeek, M; Ripp-Baudot, I; Rizatdinova, F; Robinson, S; Rodrigues, R F; Rominsky, M; Royon, C; Rubinov, P; Ruchti, R; Safronov, G; Sajot, G; Sánchez-Hernández, A; Sanders, M P; Sanghi, B; Savage, G; Sawyer, L; Scanlon, T; Schaile, D; Schamberger, R D; Scheglov, Y; Schellman, H; Schliephake, T; Schlobohm, S; Schwanenberger, C; Schwienhorst, R; Sekaric, J; Severini, H; Shabalina, E; Shamim, M; Shary, V; Shchukin, A A; Shivpuri, R K; Siccardi, V; Simak, V; Sirotenko, V; Skubic, P; Slattery, P; Smirnov, D; Snow, G R; Snow, J; Snyder, S; Söldner-Rembold, S; Sonnenschein, L; Sopczak, A; Sosebee, M; Soustruznik, K; Spurlock, B; Stark, J; Stolin, V; Stoyanova, D A; Strandberg, J; Strandberg, S; Strang, M A; Strauss, E; Strauss, M; Ströhmer, R; Strom, D; Stutte, L; Sumowidagdo, S; Svoisky, P; Sznajder, A; Tanasijczuk, A; Taylor, W; Tiller, B; Tissandier, F; Titov, M; Tokmenin, V V; Torchiani, I; Tsybychev, D; Tuchming, B; Tully, C; Tuts, P M; Unalan, R; Uvarov, L; Uvarov, S; Uzunyan, S; Vachon, B; van den Berg, P J; Van Kooten, R; van Leeuwen, W M; Varelas, N; Varnes, E W; Vasilyev, I A; Verdier, P; Vertogradov, L S; Verzocchi, M; Vilanova, D; Villeneuve-Seguier, F; Vint, P; Vokac, P; Voutilainen, M; Wagner, R; Wahl, H D; Wang, M H L S; Warchol, J; Watts, G; Wayne, M; Weber, G; Weber, M; Welty-Rieger, L; Wenger, A; Wermes, N; Wetstein, M; White, A; Wicke, D; Williams, M R J; Wilson, G W; Wimpenny, S J; Wobisch, M; Wood, D R; Wyatt, T R; Xie, Y; Xu, C; Yacoob, S; Yamada, R; Yang, W-C; Yasuda, T; Yatsunenko, Y A; Ye, Z; Yin, H; Yip, K; Yoo, H D; Youn, S W; Yu, J; Zeitnitz, C; Zelitch, S; Zhao, T; Zhou, B; Zhu, J; Zielinski, M; Zieminska, D; Zivkovic, L; Zutshi, V; Zverev, E G

2009-03-06

Anomalous Wtb couplings modify the angular correlations of the top-quark decay products and change the single top-quark production cross section. We present limits on anomalous top-quark couplings by combining information from W boson helicity measurements in top-quark decays and anomalous coupling searches in the single top-quark final state. We set limits on right-handed vector couplings as well as left-handed and right-handed tensor couplings based on about 1 fb(-1) of data collected by the D0 experiment.

Optimization of GRIN lenses coupling system for twin-core fiber interconnection with single core fibers

NASA Astrophysics Data System (ADS)

Chen, Gongdai; Deng, Hongchang; Yuan, Libo

2018-07-01

We aim at a more compact, flexible, and simpler core-to-fiber coupling approach, optimal combinations of two graded refractive index (GRIN) lenses have been demonstrated for the interconnection between a twin-core single-mode fiber and two single-core single-mode fibers. The optimal two-lens combinations achieve an efficient core-to-fiber separating coupling and allow the fibers and lenses to coaxially assemble. Finally, axial deviations and transverse displacements of the components are discussed, and the latter increases the coupling loss more significantly. The gap length between the two lenses is designed to be fine-tuned to compensate for the transverse displacement, and the good linear compensation relationship contributes to the device manufacturing. This approach has potential applications in low coupling loss and low crosstalk devices without sophisticated alignment and adjustment, and enables the channel separating for multicore fibers.

Strong coupling of a single electron in silicon to a microwave photon

NASA Astrophysics Data System (ADS)

Mi, Xiao; Cady, Jeffrey; Zajac, David; Petta, Jason

We demonstrate a hybrid circuit quantum electrodynamics (cQED) architecture in which a single electron in a Si/SiGe double quantum dot is dipole-coupled to the electric field of microwave photons in a superconducting cavity. Vacuum Rabi splitting is observed in the cavity transmission when the transition energy of the single-electron charge qubit matches that of a cavity photon, demonstrating that our device is in the strong coupling regime. The achievement of strong coupling is largely facilitated by an exceptionally low charge decoherence rate of 5 MHz and paves the way toward a wide range of cQED experiments with quantum dots, such as non-local qubit interactions, strong spin-cavity coupling and single photon generation . Research sponsored by ARO Grant No. W911NF-15-1-0149, the Gordon and Betty Moore Foundation's EPiQS Initiative through Grant GBMF4535, and the NSF (DMR-1409556 and DMR-1420541).

Hybrid Circuit Quantum Electrodynamics: Coupling a Single Silicon Spin Qubit to a Photon

DTIC Science & Technology

2015-01-01

HYBRID CIRCUIT QUANTUM ELECTRODYNAMICS: COUPLING A SINGLE SILICON SPIN QUBIT TO A PHOTON PRINCETON UNIVERSITY JANUARY 2015 FINAL...SILICON SPIN QUBIT TO A PHOTON 5a. CONTRACT NUMBER FA8750-12-2-0296 5b. GRANT NUMBER N/A 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Jason R. Petta...architectures. 15. SUBJECT TERMS Quantum Computing, Quantum Hybrid Circuits, Quantum Electrodynamics, Coupling a Single Silicon Spin Qubit to a Photon

Fiber-Coupled Cavity-QED Source of Identical Single Photons

NASA Astrophysics Data System (ADS)

Snijders, H.; Frey, J. A.; Norman, J.; Post, V. P.; Gossard, A. C.; Bowers, J. E.; van Exter, M. P.; Löffler, W.; Bouwmeester, D.

2018-03-01

We present a fully fiber-coupled source of high-fidelity single photons. An (In,Ga)As semiconductor quantum dot is embedded in an optical Fabry-Perot microcavity with a robust design and rigidly attached single-mode fibers, which enables through-fiber cross-polarized resonant laser excitation and photon extraction. Even without spectral filtering, we observe that the incident coherent light pulses are transformed into a stream of single photons with high purity (97%) and indistinguishability (90%), which is measured at an in-fiber brightness of 5% with an excellent cavity-mode-to-fiber coupling efficiency of 85%. Our results pave the way for fully fiber-integrated photonic quantum networks. Furthermore, our method is equally applicable to fiber-coupled solid-state cavity-QED-based photonic quantum gates.

Photon antibunching from a single quantum-dot-microcavity system in the strong coupling regime.

PubMed

Press, David; Götzinger, Stephan; Reitzenstein, Stephan; Hofmann, Carolin; Löffler, Andreas; Kamp, Martin; Forchel, Alfred; Yamamoto, Yoshihisa

2007-03-16

We observe antibunching in the photons emitted from a strongly coupled single quantum dot and pillar microcavity in resonance. When the quantum dot was spectrally detuned from the cavity mode, the cavity emission remained antibunched, and also anticorrelated from the quantum dot emission. Resonant pumping of the selected quantum dot via an excited state enabled these observations by eliminating the background emitters that are usually coupled to the cavity. This device demonstrates an on-demand single-photon source operating in the strong coupling regime, with a Purcell factor of 61+/-7 and quantum efficiency of 97%.

Holograms for laser diode: Single mode optical fiber coupling

NASA Technical Reports Server (NTRS)

Fuhr, P. L.

1982-01-01

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

Somatosensory spatial attention modulates amplitudes, latencies, and latency jitter of laser-evoked brain potentials.

PubMed

Franz, Marcel; Nickel, Moritz M; Ritter, Alexander; Miltner, Wolfgang H R; Weiss, Thomas

2015-04-01

Several studies provided evidence that the amplitudes of laser-evoked potentials (LEPs) are modulated by attention. However, previous reports were based on across-trial averaging of LEP responses at the expense of losing information about intertrial variability related to attentional modulation. The aim of this study was to investigate the effects of somatosensory spatial attention on single-trial parameters (i.e., amplitudes, latencies, and latency jitter) of LEP components (N2 and P2). Twelve subjects participated in a sustained spatial attention paradigm while noxious laser stimuli (left hand) and noxious electrical stimuli (right hand) were sequentially delivered to the dorsum of the respective hand with nonnoxious air puffs randomly interspersed within the sequence of noxious stimuli. Participants were instructed to mentally count all stimuli (i.e., noxious and nonnoxious) applied to the attended location. Laser stimuli, presented to the attended hand (ALS), elicited larger single-trial amplitudes of the N2 component compared with unattended laser stimuli (ULS). In contrast, single-trial amplitudes of the P2 component were not significantly affected by spatial attention. Single-trial latencies of the N2 and P2 were significantly smaller for ALS vs. ULS. Additionally, the across-trial latency jitter of the N2 component was reduced for ALS. Conversely, the latency jitter of the P2 component was smaller for ULS compared with ALS. With the use of single-trial analysis, the study provided new insights into brain dynamics of LEPs related to spatial attention. Our results indicate that single-trial parameters of LEP components are differentially modulated by spatial attention. Copyright © 2015 the American Physiological Society.

Single-Trial Normalization for Event-Related Spectral Decomposition Reduces Sensitivity to Noisy Trials

PubMed Central

Grandchamp, Romain; Delorme, Arnaud

2011-01-01

In electroencephalography, the classical event-related potential model often proves to be a limited method to study complex brain dynamics. For this reason, spectral techniques adapted from signal processing such as event-related spectral perturbation (ERSP) – and its variant event-related synchronization and event-related desynchronization – have been used over the past 20 years. They represent average spectral changes in response to a stimulus. These spectral methods do not have strong consensus for comparing pre- and post-stimulus activity. When computing ERSP, pre-stimulus baseline removal is usually performed after averaging the spectral estimate of multiple trials. Correcting the baseline of each single-trial prior to averaging spectral estimates is an alternative baseline correction method. However, we show that this method leads to positively skewed post-stimulus ERSP values. We eventually present new single-trial-based ERSP baseline correction methods that perform trial normalization or centering prior to applying classical baseline correction methods. We show that single-trial correction methods minimize the contribution of artifactual data trials with high-amplitude spectral estimates and are robust to outliers when performing statistical inference testing. We then characterize these methods in terms of their time–frequency responses and behavior compared to classical ERSP methods. PMID:21994498

How attention influences perceptual decision making: Single-trial EEG correlates of drift-diffusion model parameters

PubMed Central

Nunez, Michael D.; Vandekerckhove, Joachim; Srinivasan, Ramesh

2016-01-01

Perceptual decision making can be accounted for by drift-diffusion models, a class of decision-making models that assume a stochastic accumulation of evidence on each trial. Fitting response time and accuracy to a drift-diffusion model produces evidence accumulation rate and non-decision time parameter estimates that reflect cognitive processes. Our goal is to elucidate the effect of attention on visual decision making. In this study, we show that measures of attention obtained from simultaneous EEG recordings can explain per-trial evidence accumulation rates and perceptual preprocessing times during a visual decision making task. Models assuming linear relationships between diffusion model parameters and EEG measures as external inputs were fit in a single step in a hierarchical Bayesian framework. The EEG measures were features of the evoked potential (EP) to the onset of a masking noise and the onset of a task-relevant signal stimulus. Single-trial evoked EEG responses, P200s to the onsets of visual noise and N200s to the onsets of visual signal, explain single-trial evidence accumulation and preprocessing times. Within-trial evidence accumulation variance was not found to be influenced by attention to the signal or noise. Single-trial measures of attention lead to better out-of-sample predictions of accuracy and correct reaction time distributions for individual subjects. PMID:28435173

How attention influences perceptual decision making: Single-trial EEG correlates of drift-diffusion model parameters.

PubMed

Nunez, Michael D; Vandekerckhove, Joachim; Srinivasan, Ramesh

2017-02-01

Perceptual decision making can be accounted for by drift-diffusion models, a class of decision-making models that assume a stochastic accumulation of evidence on each trial. Fitting response time and accuracy to a drift-diffusion model produces evidence accumulation rate and non-decision time parameter estimates that reflect cognitive processes. Our goal is to elucidate the effect of attention on visual decision making. In this study, we show that measures of attention obtained from simultaneous EEG recordings can explain per-trial evidence accumulation rates and perceptual preprocessing times during a visual decision making task. Models assuming linear relationships between diffusion model parameters and EEG measures as external inputs were fit in a single step in a hierarchical Bayesian framework. The EEG measures were features of the evoked potential (EP) to the onset of a masking noise and the onset of a task-relevant signal stimulus. Single-trial evoked EEG responses, P200s to the onsets of visual noise and N200s to the onsets of visual signal, explain single-trial evidence accumulation and preprocessing times. Within-trial evidence accumulation variance was not found to be influenced by attention to the signal or noise. Single-trial measures of attention lead to better out-of-sample predictions of accuracy and correct reaction time distributions for individual subjects.

Scanning gate imaging of two coupled quantum dots in single-walled carbon nanotubes.

PubMed

Zhou, Xin; Hedberg, James; Miyahara, Yoichi; Grutter, Peter; Ishibashi, Koji

2014-12-12

Two coupled single wall carbon nanotube quantum dots in a multiple quantum dot system were characterized by using a low temperature scanning gate microscopy (SGM) technique, at a temperature of 170 mK. The locations of single wall carbon nanotube quantum dots were identified by taking the conductance images of a single wall carbon nanotube contacted by two metallic electrodes. The single electron transport through single wall carbon nanotube multiple quantum dots has been observed by varying either the position or voltage bias of a conductive atomic force microscopy tip. Clear hexagonal patterns were observed in the region of the conductance images where only two sets of overlapping conductance rings are visible. The values of coupling capacitance over the total capacitance of the two dots, C(m)/C(1(2)) have been extracted to be 0.21 ∼ 0.27 and 0.23 ∼ 0.28, respectively. In addition, the interdot coupling (conductance peak splitting) has also been confirmed in both conductance image measurement and current-voltage curves. The results show that a SGM technique enables spectroscopic investigation of coupled quantum dots even in the presence of unexpected multiple quantum dots.

Coupled variational formulations of linear elasticity and the DPG methodology

NASA Astrophysics Data System (ADS)

Fuentes, Federico; Keith, Brendan; Demkowicz, Leszek; Le Tallec, Patrick

2017-11-01

This article presents a general approach akin to domain-decomposition methods to solve a single linear PDE, but where each subdomain of a partitioned domain is associated to a distinct variational formulation coming from a mutually well-posed family of broken variational formulations of the original PDE. It can be exploited to solve challenging problems in a variety of physical scenarios where stability or a particular mode of convergence is desired in a part of the domain. The linear elasticity equations are solved in this work, but the approach can be applied to other equations as well. The broken variational formulations, which are essentially extensions of more standard formulations, are characterized by the presence of mesh-dependent broken test spaces and interface trial variables at the boundaries of the elements of the mesh. This allows necessary information to be naturally transmitted between adjacent subdomains, resulting in coupled variational formulations which are then proved to be globally well-posed. They are solved numerically using the DPG methodology, which is especially crafted to produce stable discretizations of broken formulations. Finally, expected convergence rates are verified in two different and illustrative examples.

Surface 12 lead electrocardiogram recordings using smart phone technology.

PubMed

Baquero, Giselle A; Banchs, Javier E; Ahmed, Shameer; Naccarelli, Gerald V; Luck, Jerry C

2015-01-01

AliveCor ECG is an FDA approved ambulatory cardiac rhythm monitor that records a single channel (lead I) ECG rhythm strip using an iPhone. In the past few years, the use of smartphones and tablets with health related applications has significantly proliferated. In this initial feasibility trial, we attempted to reproduce the 12 lead ECG using the bipolar arrangement of the AliveCor monitor coupled to smart phone technology. We used the AliveCor heart monitor coupled with an iPhone cellular phone and the AliveECG application (APP) in 5 individuals. In our 5 individuals, recordings from both a standard 12 lead ECG and the AliveCor generated 12 lead ECG had the same interpretation. This study demonstrates the feasibility of creating a 12 lead ECG with a smart phone. The validity of the recordings would seem to suggest that this technology could become an important useful tool for clinical use. This new hand held smart phone 12 lead ECG recorder needs further development and validation. Copyright © 2015 Elsevier Inc. All rights reserved.

On-Chip Waveguide Coupling of a Layered Semiconductor Single-Photon Source.

PubMed

Tonndorf, Philipp; Del Pozo-Zamudio, Osvaldo; Gruhler, Nico; Kern, Johannes; Schmidt, Robert; Dmitriev, Alexander I; Bakhtinov, Anatoly P; Tartakovskii, Alexander I; Pernice, Wolfram; Michaelis de Vasconcellos, Steffen; Bratschitsch, Rudolf

2017-09-13

Fully integrated quantum technology based on photons is in the focus of current research, because of its immense potential concerning performance and scalability. Ideally, the single-photon sources, the processing units, and the photon detectors are all combined on a single chip. Impressive progress has been made for on-chip quantum circuits and on-chip single-photon detection. In contrast, nonclassical light is commonly coupled onto the photonic chip from the outside, because presently only few integrated single-photon sources exist. Here, we present waveguide-coupled single-photon emitters in the layered semiconductor gallium selenide as promising on-chip sources. GaSe crystals with a thickness below 100 nm are placed on Si 3 N 4 rib or slot waveguides, resulting in a modified mode structure efficient for light coupling. Using optical excitation from within the Si 3 N 4 waveguide, we find nonclassicality of generated photons routed on the photonic chip. Thus, our work provides an easy-to-implement and robust light source for integrated quantum technology.

Evaluating a multicomponent social behaviour change communication strategy to reduce intimate partner violence among married couples: study protocol for a cluster randomized trial in Nepal.

PubMed

Clark, Cari Jo; Spencer, Rachael A; Shrestha, Binita; Ferguson, Gemma; Oakes, J Michael; Gupta, Jhumka

2017-01-13

Intimate partner violence (IPV) is a significant public health issue that affects 1 in 3 women globally and a similarly large number of women in Nepal. Over the past decade, important policy and programmatic steps have been taken to address violence against women in Nepal. There remains a dearth of evidence on the effectiveness of primary violence prevention strategies. The Change Starts at Home study begins to fill this gap by utilizing a multi-component social behaviour change communication (SBCC) strategy involving a radio drama and community mobilization to shift attitudes, norms and behaviours that underpin IPV perpetration in Nepal. The study uses a concurrent mixed-methods design. The quantitative aspect of the evaluation is a pair-matched, repeated cross-sectional 2-armed, single-blinded cluster trial (RCT: N = 36 clusters, 1440 individuals), comparing a social behaviour change communication (SBCC) strategy to radio programming alone for its impact on physical and / or sexual IPV at the end of programming (12 months' post-baseline) and 6-months post the cessation of project activities (18-months post baseline). The qualitative aspects of the design include several longitudinal approaches to understand the impact of the intervention and to examine mechanisms of change including in-depth interviews with participants (N = 18 couples), and focus group discussions with community leaders (N = 3 groups), and family members of participants (N = 12 groups). Treatment effects will be estimated with generalized logistic mixed models specified to compare differences in primary outcome from baseline to 12-month follow-up, and baseline to 18-months follow-up in accordance with intention-to-treat principles. The study rigorously evaluates the effectiveness of a promising strategy to prevent IPV. The results of the trial will be immediately useful for governmental, nongovernmental, and donor funded programs targeting partner violence or social norms that underpin it. Findings of the study will also contribute to global knowledge on the effectiveness of media and community engagement as a primary prevention strategy for IPV. Trial was registered in clinicaltrials.gov, NCT02942433 , 10/13/2016, retrospectively registered.

The Effect of Emotional Focused Intervention on Spousal Emotional Abuse and Marital Satisfaction among Elderly Married Couples: A Randomized Controlled Trial.

PubMed

Hazrati, Maryam; Hamid, Tengku Aizan; Ibrahim, Rahimah; Hassan, Siti Aishah; Sharif, Farkhondeh; Bagheri, Zahra

2017-10-01

This study examined the impacts of an Emotional Focused Intervention on emotional abuse behaviors and marital satisfaction among the elderly married couples. This randomized controlled trial study was carried out in Shiraz-Iran, during September 2013-2014. The elderly couples were invited to join an emotional focused intervention, following the advertisement and announcement on bulletin boards in the elderly day clinic centers and all governmental primary health care centers. Then, 57 couples (114 participants) who were eligible for study were assigned in two groups by block randomization (29 in the experimental and 28 in the control group(.The couples in the experimental group received intervention twice a week for four weeks. Each session lasted 90 minutes. The control group didn't receive any intervention and the subjects were put in the waiting list. The outcome measures were evaluated by Multidimensional Measure of Emotional Abuse Questionnaire (MMEAQ) and Marital Satisfaction Questionnaire for Older People (MSQFOP). Repeated measurement ANOVA was used to detect any significant changes between groups in their mean scores of emotional abuse behaviors and marital satisfaction from pre- to post-test, and 3 months after the intervention. Analysis of data was performed using SPSS, version 19, and P≤0.05 was measured as significant. The mean duration of marriage was 39.56±9.64 years. In the experimental group, the abusive behaviors decreased significantly (P<0.001) at times 2 and 3 compared with time 1, and marital satisfaction improved significantly only at time 3 (P<0.001). These differences were not significant in the control group. Emotion-focused couple-based interventions are helpful in reducing the spousal emotional abuse and improving marital satisfaction in among the elderly couples. Trial Registration Number: 2013111715426N1.

A Randomized Clinical Trial to Determine Optimal Infertility Treatment in Older Couples: The Forty and Over Treatment Trial (FORT-T)

PubMed Central

Goldman, Marlene B.; Thornton, Kim L.; Ryley, David; Alper, Michael M.; Fung, June L.; Hornstein, Mark D.; Reindollar, Richard H.

2014-01-01

Objective To determine optimal infertility therapy in women at the end of their reproductive potential. Design Randomized clinical trial. Setting Academic medical centers and private infertility center in a state with mandated insurance coverage. Patients Couples with ≥ 6 months of unexplained infertility; female partner aged 38–42. Interventions Randomized to treatment with 2 cycles of clomiphene citrate (CC) and intrauterine insemination (IUI), follicle stimulating hormone (FSH)/IUI, or immediate IVF, followed by IVF if not pregnant. Main Outcome Measures Proportion with a clinically recognized pregnancy, number of treatment cycles, and time to conception after 2 treatment cycles and at the end of treatment. Results 154 couples were randomized to receive CC/IUI (N=51), FSH/IUI (N=52), or immediate IVF (N=51); 140 (90.9%) couples initiated treatment. Cumulative clinical pregnancy rates per couple after the first 2 cycles of CC/IUI, FSH/IUI, or immediate IVF were 21.6%, 17.3%, and 49.0%, respectively. After all treatment, 71.4% (110/154) of couples conceived a clinically recognized pregnancy and 46.1% delivered at least one live-born baby. 84.2% of all live born infants resulting from treatment were achieved from IVF. There were 36% fewer treatment cycles in the IVF arm compared to either COH/IUI arm and couples conceived a pregnancy leading to a live birth after fewer treatment cycles. Conclusions An RCT to compare treatment initiated with 2 cycles of COH/IUI to immediate IVF in older women with unexplained infertility demonstrated superior pregnancy rates with fewer treatment cycles in the immediate IVF group. PMID:24796764

Wide-field in vivo neocortical calcium dye imaging using a convection-enhanced loading technique combined with simultaneous multiwavelength imaging of voltage-sensitive dyes and hemodynamic signals

PubMed Central

Ma, Hongtao; Harris, Samuel; Rahmani, Redi; Lacefield, Clay O.; Zhao, Mingrui; Daniel, Andy G. S.; Zhou, Zhiping; Bruno, Randy M.; Berwick, Jason; Schwartz, Theodore H.

2014-01-01

Abstract. In vivo calcium imaging is an incredibly powerful technique that provides simultaneous information on fast neuronal events, such as action potentials and subthreshold synaptic activity, as well as slower events that occur in the glia and surrounding neuropil. Bulk-loading methods that involve multiple injections can be used for single-cell as well as wide-field imaging studies. However, multiple injections result in inhomogeneous loading as well as multiple sites of potential cortical injury. We used convection-enhanced delivery to create smooth, continuous loading of a large area of the cortical surface through a solitary injection site and demonstrated the efficacy of the technique using confocal microscopy imaging of single cells and physiological responses to single-trial events of spontaneous activity, somatosensory-evoked potentials, and epileptiform events. Combinations of calcium imaging with voltage-sensitive dye and intrinsic signal imaging demonstrate the utility of this technique in neurovascular coupling investigations. Convection-enhanced loading of calcium dyes may be a useful technique to advance the study of cortical processing when widespread loading of a wide-field imaging is required. PMID:25525611

Wide-field in vivo neocortical calcium dye imaging using a convection-enhanced loading technique combined with simultaneous multiwavelength imaging of voltage-sensitive dyes and hemodynamic signals.

PubMed

Ma, Hongtao; Harris, Samuel; Rahmani, Redi; Lacefield, Clay O; Zhao, Mingrui; Daniel, Andy G S; Zhou, Zhiping; Bruno, Randy M; Berwick, Jason; Schwartz, Theodore H

2014-07-24

In vivo calcium imaging is an incredibly powerful technique that provides simultaneous information on fast neuronal events, such as action potentials and subthreshold synaptic activity, as well as slower events that occur in the glia and surrounding neuropil. Bulk-loading methods that involve multiple injections can be used for single-cell as well as wide-field imaging studies. However, multiple injections result in inhomogeneous loading as well as multiple sites of potential cortical injury. We used convection-enhanced delivery to create smooth, continuous loading of a large area of the cortical surface through a solitary injection site and demonstrated the efficacy of the technique using confocal microscopy imaging of single cells and physiological responses to single-trial events of spontaneous activity, somatosensory-evoked potentials, and epileptiform events. Combinations of calcium imaging with voltage-sensitive dye and intrinsic signal imaging demonstrate the utility of this technique in neurovascular coupling investigations. Convection-enhanced loading of calcium dyes may be a useful technique to advance the study of cortical processing when widespread loading of a wide-field imaging is required.

A Randomized Controlled Trial of Relationship Education in the U.S. Army: 2-Year Outcomes

PubMed Central

Stanley, Scott M.; Rhoades, Galena K.; Loew, Benjamin A.; Allen, Elizabeth S.; Carter, Sarah; Osborne, Laura J.; Prentice, Donnella; Markman, Howard J.

2014-01-01

This study examined the effectiveness of an evidence-based, community-delivered adaptation of couple relationship education (CRE; specifically, PREP, The Prevention and Relationship Enhancement Program) delivered at two Army installations. The study is a randomized controlled trial with two years of follow-up, examining marital quality and stability. Sample composition was 662 married couples with a spouse in the U.S. Army. Analyses yielded no evidence of overall enduring intervention effects on relationship quality but couples assigned to intervention at the higher risk site were significantly less likely than controls to be divorced at the two-year follow-up (8.1% vs. 14.9%, p < .01). This effect was moderated by ethnic minority status. Specifically, the impact of the intervention on divorce was strongest for minority couples. The findings add to the literature on who may benefit most from CRE. PMID:25419027

Brief Report: Medication Sharing Is Rare Among African HIV-1 Serodiscordant Couples Enrolled in an Efficacy Trial of Oral Pre-exposure Prophylaxis (PrEP) for HIV-1 Prevention.

PubMed

Thomson, Kerry A; Haberer, Jessica E; Marzinke, Mark A; Mujugira, Andrew; Hendrix, Craig W; Celum, Connie; Ndase, Patrick; Ronald, Allan; Bangsberg, David R; Baeten, Jared M

2017-06-01

Sharing of pre-exposure prophylaxis (PrEP) medications is a concern for PrEP implementation. For HIV-1 serodiscordant couples, sharing may undermine the HIV-1 prevention benefit and also cause antiretroviral resistance if taken by HIV-1 infected partners. Within a PrEP efficacy trial among HIV-1 serodiscordant couples, we assessed the occurrence of PrEP sharing by self-report and plasma tenofovir concentrations in HIV-1 infected partners. PrEP sharing was self-reported at <0.01% of visits, and 0%-1.6% of randomly selected and 0% of purposively selected specimens from HIV-1 infected participants had detectable tenofovir concentrations (median: 66.5 ng/mL, range: 1.3-292 ng/mL). PrEP sharing within HIV-1 serodiscordant couples was extremely rare.

Cooling in the single-photon strong-coupling regime of cavity optomechanics

NASA Astrophysics Data System (ADS)

Nunnenkamp, A.; Børkje, K.; Girvin, S. M.

2012-05-01

In this Rapid Communication we discuss how red-sideband cooling is modified in the single-photon strong-coupling regime of cavity optomechanics where the radiation pressure of a single photon displaces the mechanical oscillator by more than its zero-point uncertainty. Using Fermi's golden rule we calculate the transition rates induced by the optical drive without linearizing the optomechanical interaction. In the resolved-sideband limit we find multiple-phonon cooling resonances for strong single-photon coupling that lead to nonthermal steady states including the possibility of phonon antibunching. Our study generalizes the standard linear cooling theory.

Reliability of Single-Leg Balance and Landing Tests in Rugby Union; Prospect of Using Postural Control to Monitor Fatigue.

PubMed

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.

A Phase I clinical trial of lodenafil carbonate, a new phosphodiesterase Type 5 (PDE5) inhibitor, in healthy male volunteers.

PubMed

Mendes, Gustavo D; dos Santos Filho, Hilton Oliveira; dos Santos Pereira, Alberto; Mendes, Fabiana D; Ilha, Jaime O; Alkharfy, Khalid M; De Nucci, Gilberto

2012-12-01

Lodenafil carbonate is a new phosphodiesterase Type 5 (PDE5) inhibitor used in treatment of erectile dysfunction. The present study was conducted to evaluate the safety, tolerability, and pharmacokinetics of lodenafil carbonate after administering ascending (1 - 100 mg) single oral doses to healthy male volunteers (n = 33). The study was an open label, dose-escalation, Phase I clinical trial involving the administration of single oral doses of lodenafil carbonate. Lodenafil carbonate was administered sequentially, escalating in single doses of 1 mg - 100 mg with a washout period of at least 1 week between each dose. The progression to the next dose was allowed after clinical and laboratory exams, Ambulatory Monitoring of Arterial Pressure (AMAP) without relevant clinical modifications and adverse events without clinical relevancy. Blood samples were collected at pre-dose, 0.25, 0.5, 0.75, 1, 1.25, 1.5, 1.75, 2, 2.5, 3, 3.5, 4, 4.5, 5, 6, 7, 8, 10, 12, 14, 16, 20 and 24 h post-dosing. Plasma samples for measurement of lodenafil carbonate and lodenafil were analyzed by liquid chromatography coupled to tandem mass spectrometry. No serious adverse events were observed, and none of the subjects discontinued the study due to intolerance. The AMAP measurements, clinical and laboratory exams and ECG revealed no significant changes even at higher doses. Lodenafil carbonate was not detected in any samples, indicating that it acts as a prodrug. The mean lodenafil pharmacokinetic parameters for tmax and t1/2 were 1.6 ( ± 0.4) h and 3.3 ( ± 1.1) h, respectively. This study demonstrated that lodenafil carbonate was well tolerated and showed a good safety profile in healthy male volunteers.

Low-loss and single-mode tapered hollow-core waveguides optically coupled with interband and quantum cascade lasers

NASA Astrophysics Data System (ADS)

Giglio, Marilena; Patimisco, Pietro; Sampaolo, Angelo; Kriesel, Jason M.; Tittel, Frank K.; Spagnolo, Vincenzo

2018-01-01

We report single-mode midinfrared laser beam delivery through a 50-cm-long tapered hollow-core waveguide (HCW) having bore diameter linearly increasing from 200 to 260 μm. We performed theoretical calculations to identify the best HCW-laser coupling conditions in terms of optical losses and single-mode fiber output. To validate our modeling, we coupled the HCW with an interband cascade laser and four quantum cascade lasers with their emission wavelengths spanning 3.5 to 7.8 μm, using focusing lenses with different focal lengths. With the best coupling conditions, we achieved single-mode output in the investigated 3.5 to 7.8 μm spectral range, with minimum transmission losses of 1.27 dB at 6.2 μm.

Foraging enrichment for stabled horses: effects on behaviour and selection.

PubMed

Goodwin, D; Davidson, H P B; Harris, P

2002-11-01

The restricted access to pasture experienced by many competition horses has been linked to the exhibition of stereotypic and redirected behaviour patterns. It has been suggested that racehorses provided with more than one source of forage are less likely to perform these patterns; however, the reasons for this are currently unclear. To investigate this in 4 replicated trials, up to 12 horses were introduced into each of 2 identical stables containing a single forage, or 6 forages for 5 min. To detect novelty effects, in the first and third trials the single forage was hay. In the second and fourth, it was the preferred forage from the preceding trial. Trials were videotaped and 12 mutually exclusive behaviour patterns compared. When hay was presented as the single forage (Trials 1 and 3), all recorded behaviour patterns were significantly different between stables; e.g. during Trial 3 in the 'Single' stable, horses looked over the stable door more frequently (P<0.001), moved for longer (P<0.001), foraged on straw bedding longer (P<0.001), and exhibited behaviour indicative of motivation to search for alternative resources (P<0.001) more frequently. When a previously preferred forage was presented as the single forage (Trials 2 and 4) behaviour was also significantly different between stables, e.g in Trial 4 horses looked out over the stable door more frequently (P<0.005) and foraged for longer in their straw bedding (P<0.005). Further study is required to determine whether these effects persist over longer periods. However, these trials indicate that enrichment of the stable environment through provision of multiple forages may have welfare benefits for horses, in reducing straw consumption and facilitating the expression of highly motivated foraging behaviour.

Effects of relationship education on couple communication and satisfaction: A randomized controlled trial with low-income couples.

PubMed

Williamson, Hannah C; Altman, Noemi; Hsueh, JoAnn; Bradbury, Thomas N

2016-02-01

Although preventive educational interventions for couples have been examined in more than 100 experimental studies, the value of this work is limited by reliance on economically advantaged populations and by an absence of data on proposed mediators and moderators. Data from the Supporting Healthy Marriage Project-a randomized, controlled trial of relationship education for couples living with low incomes-were therefore analyzed to test whether intervention effects on relationship satisfaction would be mediated by observational assessments of relationship communication and whether any such effects would be moderated by couples' pretreatment risk. Within the larger sample of Supporting Healthy Marriage Project couples randomized to a relationship education or no-treatment control condition, the present analyses focus on the 1,034 couples who provided (a) data on sociodemographic risk at baseline, (b) observational data on couple communication 12 months after randomization, and (c) reports of relationship satisfaction 30 months after randomization. Intervention couples reported higher satisfaction at 30 months than control couples, regardless of their level of pretreatment risk. Among higher risk couples, the intervention improved observed communication as well. Contrary to prediction, treatment effects on satisfaction were not mediated by improvements in communication, and improvements in communication did not translate into greater satisfaction. Relationship education programs produce small improvements in relationship satisfaction and communication, particularly for couples at elevated sociodemographic risk. The absence of behavioral effects on satisfaction indicates, however, that the mechanisms by which couples may benefit from relationship education are not yet well understood. (c) 2016 APA, all rights reserved).

Analysis and design of fiber-coupled high-power laser diode array

NASA Astrophysics Data System (ADS)

Zhou, Chongxi; Liu, Yinhui; Xie, Weimin; Du, Chunlei

2003-11-01

A conclusion that a single conventional optical system could not realize fiber coupled high-power laser diode array is drawn based on the BPP of laser beam. According to the parameters of coupled fiber, a method to couple LDA beams into a single multi-mode fiber including beams collimating, shaping, focusing and coupling is present. The divergence angles after collimating are calculated and analyzed; the shape equation of the collimating micro-lenses array is deprived. The focusing lens is designed. A fiber coupled LDA result with the core diameter of 800 um and numeric aperture of 0.37 is gotten.

Effects of Coping-Oriented Couples Therapy on Depression: A Randomized Clinical Trial

ERIC Educational Resources Information Center

Bodenmann, Guy; Plancherel, Bernard; Beach, Steven R. H.; Widmer, Kathrin; Gabriel, Barbara; Meuwly, Nathalie; Charvoz, Linda; Hautzinger, Martin; Schramm, Elisabeth

2008-01-01

The aim of this study was to evaluate the effectiveness of treating depression with coping-oriented couples therapy (COCT) as compared with cognitive-behavioral therapy (CBT; A. T. Beck, C. Ward, & M. Mendelson, 1961) and interpersonal psychotherapy (IPT; M. M. Weissman, J. C. Markowitz, & G. L. Klerman, 2000). Sixty couples, including 1…

Cognitive-Behavioral Couple Therapies: Review of the Evidence for the Treatment of Relationship Distress, Psychopathology, and Chronic Health Conditions.

PubMed

Fischer, Melanie S; Baucom, Donald H; Cohen, Matthew J

2016-09-01

Cognitive-behavioral couple therapy (CBCT) is an approach to assisting couples that has strong empirical support for alleviating relationship distress. This paper provides a review of the empirical status of CBCT along with behavioral couple therapy (BCT), as well as the evidence for recent applications of CBCT principles to couple-based interventions for individual psychopathology and medical conditions. Several meta-analyses and major reviews have confirmed the efficacy of BCT and CBCT across trials in the United States, Europe, and Australia, and there is little evidence to support differential effectiveness of various forms of couple therapy derived from behavioral principles. A much smaller number of effectiveness studies have shown that successful implementation in community settings is possible, although effect sizes tend to be somewhat lower than those evidenced in randomized controlled trials. Adapted for individual problems, cognitive-behavioral couple-based interventions appear to be at least as effective as individual cognitive behavioral therapy (CBT) across a variety of psychological disorders, and often more effective, especially when partners are substantially involved in treatment. In addition, couple-based interventions tend to have the unique added benefit of improving relationship functioning. Findings on couple-based interventions for medical conditions are more varied and more complex to interpret given the greater range of target outcomes (psychological, relational, and medical variables). © 2016 Family Process Institute.

Comparison of Critical Power and W' Derived From 2 or 3 Maximal Tests.

PubMed

Simpson, Len Parker; Kordi, Mehdi

2017-07-01

Typically, accessing the asymptote (critical power; CP) and curvature constant (W') parameters of the hyperbolic power-duration relationship requires multiple constant-power exhaustive-exercise trials spread over several visits. However, more recently single-visit protocols and personal power meters have been used. This study investigated the practicality of using a 2-trial, single-visit protocol in providing reliable CP and W' estimates. Eight trained cyclists underwent 3- and 12-min maximal-exercise trials in a single session to derive (2-trial) CP and W' estimates. On a separate occasion a 5-min trial was performed, providing a 3rd trial to calculate (3-trial) CP and W'. There were no differences in CP (283 ± 66 vs 282 ± 65 W) or W' (18.72 ± 6.21 vs 18.27 ± 6.29 kJ) obtained from either the 2-trial or 3-trial method, respectively. After 2 familiarization sessions (completing a 3- and a 12-min trial on both occasions), both CP and W' remained reliable over additional separate measurements. The current study demonstrates that after 2 familiarization sessions, reliable CP and W' parameters can be obtained from trained cyclists using only 2 maximal-exercise trials. These results offer practitioners a practical, time-efficient solution for incorporating power-duration testing into applied athlete support.

Single-Trial Regression Elucidates the Role of Prefrontal Theta Oscillations in Response Conflict

PubMed Central

Cohen, Michael X; Cavanagh, James F.

2011-01-01

In most cognitive neuroscience experiments there are many behavioral and experimental dynamics, and many indices of brain activity, that vary from trial to trial. For example, in studies of response conflict, conflict is usually treated as a binary variable (i.e., response conflict exists or does not in any given trial), whereas some evidence and intuition suggests that conflict may vary in intensity from trial to trial. Here we demonstrate that single-trial multiple regression of time–frequency electrophysiological activity reveals neural mechanisms of cognitive control that are not apparent in cross-trial averages. We also introduce a novel extension to oscillation phase coherence and synchronization analyses, based on “weighted” phase modulation, that has advantages over standard coherence measures in terms of linking electrophysiological dynamics to trial-varying behavior and experimental variables. After replicating previous response conflict findings using trial-averaged data, we extend these findings using single-trial analytic methods to provide novel evidence for the role of medial frontal–lateral prefrontal theta-band synchronization in conflict-induced response time dynamics, including a role for lateral prefrontal theta-band activity in biasing response times according to perceptual conflict. Given that these methods shed new light on the prefrontal mechanisms of response conflict, they are also likely to be useful for investigating other neurocognitive processes. PMID:21713190

An extension of the standard model with a single coupling parameter

NASA Astrophysics Data System (ADS)

Atance, Mario; Cortés, José Luis; Irastorza, Igor G.

1997-02-01

We show that it is possible to find an extension of the matter content of the standard model with a unification of gauge and Yukawa couplings reproducing their known values. The perturbative renormalizability of the model with a single coupling and the requirement to accommodate the known properties of the standard model fix the masses and couplings of the additional particles. The implications on the parameters of the standard model are discussed.

Robot-assisted single-site compared with laparoscopic single-incision cholecystectomy for benign gallbladder disease: protocol for a randomized controlled trial.

PubMed

Grochola, Lukasz Filip; Soll, Christopher; Zehnder, Adrian; Wyss, Roland; Herzog, Pascal; Breitenstein, Stefan

2017-02-09

Recent advances in robotic technology suggest that the utilization of the da Vinci Single-Site™ platform for cholecystectomy is safe, feasible and results in a shorter learning curve compared to conventional single-incision laparoscopic cholecystectomy. Moreover, the robot-assisted technology has been shown to reduce the surgeon's stress load compared to standard single-incision laparoscopy in an experimental setup, suggesting an important advantage of the da Vinci platform. However, the above-mentioned observations are based solely on case series, case reports and experimental data, as high-quality clinical trials to demonstrate the benefits of the da Vinci Single-Site™ cholecystectomy have not been performed to date. This study addresses the question whether robot-assisted Single-Site™ cholecystectomy provides significant benefits over single-incision laparoscopic cholecystectomy in terms of surgeon's stress load, while matching the standards of the conventional single-incision approach with regard to peri- and postoperative outcomes. It is designed as a single centre, single-blinded randomized controlled trial, which compares both surgical approaches with the primary endpoint surgeon's physical and mental stress load at the time of surgery. In addition, the study aims to assess secondary endpoints such as operating time, conversion rates, additional trocar placement, intra-operative blood loss, length of hospital stay, costs of procedure, health-related quality of life, cosmesis and complications. Patients as well as ward staff are blinded until the 1 st postoperative year. Sample size calculation based on the results of a previously published experimental setup utilizing an estimated effect size of surgeon's comfort of 0.8 (power of 0.8, alpha-error level of 0.05, error margin of 10-15%) resulted in a number of 30 randomized patients per arm. The study is the first randomized controlled trial that compares the da Vinci Single Site™ platform to conventional laparoscopic approaches in cholecystectomy, one of the most frequently performed operations in general surgery. This trial is registered at clinicaltrials.gov (trial number: NCT02485392 ). Registered February 19, 2015.

Tunneling of coupled methyl quantum rotors in 4-methylpyridine: Single rotor potential versus coupling interaction

NASA Astrophysics Data System (ADS)

Khazaei, Somayeh; Sebastiani, Daniel

2017-11-01

We study the influence of rotational coupling between a pair of methyl rotators on the tunneling spectrum in condensed phase. Two interacting adjacent methyl groups are simulated within a coupled-pair model composed of static rotational potential created by the chemical environment and the interaction potential between two methyl groups. We solve the two-dimensional time-independent Schrödinger equation analytically by expanding the wave functions on the basis set of two independent free-rotor functions. We investigate three scenarios which differ with respect to the relative strength of single-rotor and coupling potential. For each scenario, we illustrate the dependence of the energy level scheme on the coupling strength. It is found that the main determinant of splitting energy levels tends to be a function of the ratio of strengths of coupling and single-rotor potential. The tunnel splitting caused by coupling is maximized for the coupled rotors in which their total hindering potential is relatively shallow. Such a weakly hindered methyl rotational potential is predicted for 4-methylpyridine at low temperature. The experimental observation of multiple tunneling peaks arising from a single type of methyl group in 4-methylpyridine in the inelastic neutron scattering spectrum is widely attributed to the rotor-rotor coupling. In this regard, using a set of first-principles calculations combined with the nudged elastic band method, we investigate the rotational potential energy surface (PES) of the coaxial pairs of rotors in 4-methylpyridine. A Numerov-type method is used to numerically solve the two-dimensional time-independent Schrödinger equation for the calculated 2D-density functional theory profile. Our computed energy levels reproduce the observed tunneling transitions well. Moreover, the calculated density distribution of the three methyl protons resembles the experimental nuclear densities obtained from the Fourier difference method. By mapping the calculated first-principles PES on the model, it is confirmed that the hindering potential in 4-methylpyridine consists of proportionally shallow single-rotor potential to coupling interaction.

Tunneling of coupled methyl quantum rotors in 4-methylpyridine: Single rotor potential versus coupling interaction.

PubMed

Khazaei, Somayeh; Sebastiani, Daniel

2017-11-21

We study the influence of rotational coupling between a pair of methyl rotators on the tunneling spectrum in condensed phase. Two interacting adjacent methyl groups are simulated within a coupled-pair model composed of static rotational potential created by the chemical environment and the interaction potential between two methyl groups. We solve the two-dimensional time-independent Schrödinger equation analytically by expanding the wave functions on the basis set of two independent free-rotor functions. We investigate three scenarios which differ with respect to the relative strength of single-rotor and coupling potential. For each scenario, we illustrate the dependence of the energy level scheme on the coupling strength. It is found that the main determinant of splitting energy levels tends to be a function of the ratio of strengths of coupling and single-rotor potential. The tunnel splitting caused by coupling is maximized for the coupled rotors in which their total hindering potential is relatively shallow. Such a weakly hindered methyl rotational potential is predicted for 4-methylpyridine at low temperature. The experimental observation of multiple tunneling peaks arising from a single type of methyl group in 4-methylpyridine in the inelastic neutron scattering spectrum is widely attributed to the rotor-rotor coupling. In this regard, using a set of first-principles calculations combined with the nudged elastic band method, we investigate the rotational potential energy surface (PES) of the coaxial pairs of rotors in 4-methylpyridine. A Numerov-type method is used to numerically solve the two-dimensional time-independent Schrödinger equation for the calculated 2D-density functional theory profile. Our computed energy levels reproduce the observed tunneling transitions well. Moreover, the calculated density distribution of the three methyl protons resembles the experimental nuclear densities obtained from the Fourier difference method. By mapping the calculated first-principles PES on the model, it is confirmed that the hindering potential in 4-methylpyridine consists of proportionally shallow single-rotor potential to coupling interaction.

Single-trial detection of visual evoked potentials by common spatial patterns and wavelet filtering for brain-computer interface.

PubMed

Tu, Yiheng; Huang, Gan; Hung, Yeung Sam; Hu, Li; Hu, Yong; Zhang, Zhiguo

2013-01-01

Event-related potentials (ERPs) are widely used in brain-computer interface (BCI) systems as input signals conveying a subject's intention. A fast and reliable single-trial ERP detection method can be used to develop a BCI system with both high speed and high accuracy. However, most of single-trial ERP detection methods are developed for offline EEG analysis and thus have a high computational complexity and need manual operations. Therefore, they are not applicable to practical BCI systems, which require a low-complexity and automatic ERP detection method. This work presents a joint spatial-time-frequency filter that combines common spatial patterns (CSP) and wavelet filtering (WF) for improving the signal-to-noise (SNR) of visual evoked potentials (VEP), which can lead to a single-trial ERP-based BCI.

The Impact of Reporting a Prior Penicillin Allergy on the Treatment of Methicillin-Sensitive Staphylococcus aureus Bacteremia

PubMed Central

Shenoy, Erica S.; Huang, Mingshu; Kuhlen, James L.; Ware, Winston A.; Parker, Robert A.; Walensky, Rochelle P.

2016-01-01

Background Methicillin-sensitive Staphylococcus aureus (MSSA) bacteremia is a morbid infection with mortality benefit from receipt of parenteral β-lactam therapy. A substantial portion of MSSA bacteremia patients report penicillin allergy, but infrequently have true allergy. Objective To determine the frequency and predictors of optimal and adequate therapy in patients with MSSA bacteremia. Design Retrospective cohort. Participants Adult inpatients with MSSA bacteremia, January 2009 through October 2013. Main Measures The primary measure was a trial of optimal therapy (OT), defined as ≥3 inpatient days or discharge on any first-line agents (nafcillin, oxacillin, cefazolin, or penicillin G, if susceptible). The secondary measure was completion of adequate therapy (AT), defined as ≥10 inpatient days or discharge on an agent appropriate for MSSA bacteremia. Data were electronically gathered with key variables manually validated through chart review. Log-binomial regression models were used to determine the frequency and predictors of outcomes. Key Results Of 456 patients, 346 (76%) received a trial of OT. Patients reporting penicillin allergy (13%) were less likely to receive OT trial than those without penicillin allergy (47% vs. 80%, p <0.001). Adjusting for other factors, penicillin allergy was the largest negative predictor of OT trial (RR 0.64 [0.49, 0.83]). Infectious Disease (ID) consultation was the largest positive predictor of OT trial across all patients (RR 1.34 [1.14, 1.57]). Allergy/Immunology consultation was the single most important predictor of OT trial among patients reporting penicillin allergy (RR 2.33 [1.44, 3.77]). Of 440 patients, 391 (89%) completed AT, with ID consultation the largest positive predictor of the outcome (RR 1.28 [1.15, 1.43]). Conclusions Nearly 25% of patients with MSSA bacteremia did not receive OT trial and about 10% did not receive AT completion. Reported penicillin allergy reduced, and ID consult increased, the likelihood of OT. Allergy evaluation, coupled with ID consultation, may improve outcomes in MSSA bacteremic patients. PMID:27438379

The Impact of Reporting a Prior Penicillin Allergy on the Treatment of Methicillin-Sensitive Staphylococcus aureus Bacteremia.

PubMed

Blumenthal, Kimberly G; Shenoy, Erica S; Huang, Mingshu; Kuhlen, James L; Ware, Winston A; Parker, Robert A; Walensky, Rochelle P

2016-01-01

Methicillin-sensitive Staphylococcus aureus (MSSA) bacteremia is a morbid infection with mortality benefit from receipt of parenteral β-lactam therapy. A substantial portion of MSSA bacteremia patients report penicillin allergy, but infrequently have true allergy. To determine the frequency and predictors of optimal and adequate therapy in patients with MSSA bacteremia. Retrospective cohort. Adult inpatients with MSSA bacteremia, January 2009 through October 2013. The primary measure was a trial of optimal therapy (OT), defined as ≥3 inpatient days or discharge on any first-line agents (nafcillin, oxacillin, cefazolin, or penicillin G, if susceptible). The secondary measure was completion of adequate therapy (AT), defined as ≥10 inpatient days or discharge on an agent appropriate for MSSA bacteremia. Data were electronically gathered with key variables manually validated through chart review. Log-binomial regression models were used to determine the frequency and predictors of outcomes. Of 456 patients, 346 (76%) received a trial of OT. Patients reporting penicillin allergy (13%) were less likely to receive OT trial than those without penicillin allergy (47% vs. 80%, p <0.001). Adjusting for other factors, penicillin allergy was the largest negative predictor of OT trial (RR 0.64 [0.49, 0.83]). Infectious Disease (ID) consultation was the largest positive predictor of OT trial across all patients (RR 1.34 [1.14, 1.57]). Allergy/Immunology consultation was the single most important predictor of OT trial among patients reporting penicillin allergy (RR 2.33 [1.44, 3.77]). Of 440 patients, 391 (89%) completed AT, with ID consultation the largest positive predictor of the outcome (RR 1.28 [1.15, 1.43]). Nearly 25% of patients with MSSA bacteremia did not receive OT trial and about 10% did not receive AT completion. Reported penicillin allergy reduced, and ID consult increased, the likelihood of OT. Allergy evaluation, coupled with ID consultation, may improve outcomes in MSSA bacteremic patients.

The Effects of Test Trial and Processing Level on Immediate and Delayed Retention.

PubMed

Chang, Sau Hou

2017-03-01

The purpose of the present study was to investigate the effects of test trial and processing level on immediate and delayed retention. A 2 × 2 × 2 mixed ANOVAs was used with two between-subject factors of test trial (single test, repeated test) and processing level (shallow, deep), and one within-subject factor of final recall (immediate, delayed). Seventy-six college students were randomly assigned first to the single test (studied the stimulus words three times and took one free-recall test) and the repeated test trials (studied the stimulus words once and took three consecutive free-recall tests), and then to the shallow processing level (asked whether each stimulus word was presented in capital letter or in small letter) and the deep processing level (whether each stimulus word belonged to a particular category) to study forty stimulus words. The immediate test was administered five minutes after the trials, whereas the delayed test was administered one week later. Results showed that single test trial recalled more words than repeated test trial in immediate final free-recall test, participants in deep processing performed better than those in shallow processing in both immediate and delayed retention. However, the dominance of single test trial and deep processing did not happen in delayed retention. Additional study trials did not further enhance the delayed retention of words encoded in deep processing, but did enhance the delayed retention of words encoded in shallow processing.

The Effects of Test Trial and Processing Level on Immediate and Delayed Retention

PubMed Central

Chang, Sau Hou

2017-01-01

The purpose of the present study was to investigate the effects of test trial and processing level on immediate and delayed retention. A 2 × 2 × 2 mixed ANOVAs was used with two between-subject factors of test trial (single test, repeated test) and processing level (shallow, deep), and one within-subject factor of final recall (immediate, delayed). Seventy-six college students were randomly assigned first to the single test (studied the stimulus words three times and took one free-recall test) and the repeated test trials (studied the stimulus words once and took three consecutive free-recall tests), and then to the shallow processing level (asked whether each stimulus word was presented in capital letter or in small letter) and the deep processing level (whether each stimulus word belonged to a particular category) to study forty stimulus words. The immediate test was administered five minutes after the trials, whereas the delayed test was administered one week later. Results showed that single test trial recalled more words than repeated test trial in immediate final free-recall test, participants in deep processing performed better than those in shallow processing in both immediate and delayed retention. However, the dominance of single test trial and deep processing did not happen in delayed retention. Additional study trials did not further enhance the delayed retention of words encoded in deep processing, but did enhance the delayed retention of words encoded in shallow processing. PMID:28344679

Recruitment strategies in two Reproductive Medicine Network infertility trials

PubMed Central

Usadi, Rebecca S.; Diamond, Michael P.; Legro, Richard S.; Schlaff, William D.; Hansen, Karl R.; Casson, Peter; Christman, Gregory; Bates, G. Wright; Baker, Valerie; Seungdamrong, Aimee; Rosen, Mitchell P.; Lucidi, Scott; Thomas, Tracey; Huang, Hao; Santoro, Nanette; Eisenberg, Esther; Zhang, Heping; Alvero, Ruben

2016-01-01

Background Recruitment of individuals into clinical trials is a critical step in completing studies. Reports examining the effectiveness of different recruitment strategies, and specifically in infertile couples, are limited. Methods We investigated recruitment methods used in two NIH sponsored trials, Pregnancy in Polycystic Ovary Syndrome (PPCOS II) and Assessment of Multiple Intrauterine Gestations from Ovarian Stimulation (AMIGOS), and examined which strategies yielded the greatest number of participants completing the trials. Results 3683 couples were eligible for screening. 1650 participants were randomized and 1339 completed the trials. 750 women were randomized in PPCOS II; 212 of the participants who completed the trial were referred by physicians. Participants recruited from radio ads (84/750) and the internet (81/750) resulted in similar rates of trial completion in PPCOS II. 900 participants were randomized in AMIGOS. 440 participants who completed the trial were referred to the study by physicians. The next most successful method in AMIGOS was use of the internet, achieving 78 completed participants. Radio ads proved the most successful strategy in both trials for participants who earned <$50,000 annually. Radio ads were most successful in enrolling white patients in PPCOS II and black patients in AMIGOS. Seven ancillary Clinical Research Scientist Training (CREST) sites enrolled 324 of the participants who completed the trials. Conclusions Physician referral was the most successful recruitment strategy. Radio ads and the internet were the next most successful strategies, particularly for women of limited income. Ancillary clinical sites were important for overall recruitment. PMID:26386293

Recruitment strategies in two reproductive medicine network infertility trials.

PubMed

Usadi, Rebecca S; Diamond, Michael P; Legro, Richard S; Schlaff, William D; Hansen, Karl R; Casson, Peter; Christman, Gregory; Wright Bates, G; Baker, Valerie; Seungdamrong, Aimee; Rosen, Mitchell P; Lucidi, Scott; Thomas, Tracey; Huang, Hao; Santoro, Nanette; Eisenberg, Esther; Zhang, Heping; Alvero, Ruben

2015-11-01

Recruitment of individuals into clinical trials is a critical step in completing studies. Reports examining the effectiveness of different recruitment strategies, and specifically in infertile couples, are limited. We investigated recruitment methods used in two NIH sponsored trials, Pregnancy in Polycystic Ovary Syndrome (PPCOS II) and Assessment of Multiple Intrauterine Gestations from Ovarian Stimulation (AMIGOS), and examined which strategies yielded the greatest number of participants completing the trials. 3683 couples were eligible for screening. 1650 participants were randomized and 1339 completed the trials. 750 women were randomized in PPCOS II; 212 of the participants who completed the trial were referred by physicians. Participants recruited from radio ads (84/750) and the internet (81/750) resulted in similar rates of trial completion in PPCOS II. 900 participants were randomized in AMIGOS. 440 participants who completed the trial were referred to the study by physicians. The next most successful method in AMIGOS was the use of the internet, achieving 78 completed participants. Radio ads proved the most successful strategy in both trials for participants who earned <$50,000 annually. Radio ads were most successful in enrolling white patients in PPCOS II and black patients in AMIGOS. Seven ancillary Clinical Research Scientist Training (CREST) sites enrolled 324 of the participants who completed the trials. Physician referral was the most successful recruitment strategy. Radio ads and the internet were the next most successful strategies, particularly for women of limited income. Ancillary clinical sites were important for overall recruitment. Copyright © 2015 Elsevier Inc. All rights reserved.

Multistabilities and symmetry-broken one-color and two-color states in closely coupled single-mode lasers.

PubMed

Clerkin, Eoin; O'Brien, Stephen; Amann, Andreas

2014-03-01

We theoretically investigate the dynamics of two mutually coupled, identical single-mode semi-conductor lasers. For small separation and large coupling between the lasers, symmetry-broken one-color states are shown to be stable. In this case the light outputs of the lasers have significantly different intensities while at the same time the lasers are locked to a single common frequency. For intermediate coupling we observe stable symmetry-broken two-color states, where both lasers lase simultaneously at two optical frequencies which are separated by up to 150 GHz. Using a five-dimensional model, we identify the bifurcation structure which is responsible for the appearance of symmetric and symmetry-broken one-color and two-color states. Several of these states give rise to multistabilities and therefore allow for the design of all-optical memory elements on the basis of two coupled single-mode lasers. The switching performance of selected designs of optical memory elements is studied numerically.

Multistabilities and symmetry-broken one-color and two-color states in closely coupled single-mode lasers

NASA Astrophysics Data System (ADS)

Clerkin, Eoin; O'Brien, Stephen; Amann, Andreas

2014-03-01

We theoretically investigate the dynamics of two mutually coupled, identical single-mode semi-conductor lasers. For small separation and large coupling between the lasers, symmetry-broken one-color states are shown to be stable. In this case the light outputs of the lasers have significantly different intensities while at the same time the lasers are locked to a single common frequency. For intermediate coupling we observe stable symmetry-broken two-color states, where both lasers lase simultaneously at two optical frequencies which are separated by up to 150 GHz. Using a five-dimensional model, we identify the bifurcation structure which is responsible for the appearance of symmetric and symmetry-broken one-color and two-color states. Several of these states give rise to multistabilities and therefore allow for the design of all-optical memory elements on the basis of two coupled single-mode lasers. The switching performance of selected designs of optical memory elements is studied numerically.

Single treatments that have lasting effects: some thoughts on the antidepressant effects of ketamine and botulinum toxin and the anxiolytic effect of psilocybin.

PubMed

Young, Simon N

2013-03-01

Recent clinical trials suggest that 3 single biological treatments have effects that persist. Based on research showing that the muscles involved in facial expressions can feed back to influence mood, a single trial diminishing glabella frown lines with botulinum toxin demonstrated a significant antidepressant effect for 16 weeks. Based primarily on research with animal models of depression suggesting that glutamate may be involved in depression, the N-methyl-D-aspartate antagonist ketamine has been tested in several trials. A single dose decreased depression for up to a week. The reported effects of the use of mushrooms containing psilocybin by a number of cultures around the world has stimulated several trials showing beneficial effects of a single dose of psilocybin for over a year in healthy people, and for up to 3 months in patients with anxiety disorders who have advanced cancer. This article discusses these studies, their rationale, their possible mechanisms of action, the future clinical research required to establish these therapies and the basic research required to optimize single treatments that have lasting effects.

Rod electrical coupling is controlled by a circadian clock and dopamine in mouse retina

PubMed Central

Jin, Nan Ge; Chuang, Alice Z; Masson, Philippe J; Ribelayga, Christophe P

2015-01-01

Key points Rod photoreceptors play a key role in vision in dim light; in the mammalian retina, although rods are anatomically connected or coupled by gap junctions, a type of electrical synapse, the functional importance and regulation of rod coupling has remained elusive. We have developed a new technique in the mouse: perforated patch-clamp recording of rod inner segments in isolated intact retinae maintained by superfusion. We find that rod electrical coupling is controlled by a circadian clock and dopamine, and is weak during the day and stronger at night. The results also indicate that the signal-to-noise ratio for a dim light response is increased at night because of coupling. Our observations will provide a framework for understanding the daily variations in human vision as well as the basis of specific retinal malfunctions. Abstract Rod single-photon responses are critical for vision in dim light. Electrical coupling via gap junction channels shapes the light response properties of vertebrate photoreceptors, but the regulation of rod coupling and its impact on the single-photon response have remained unclear. To directly address these questions, we developed a perforated patch-clamp recording technique and recorded from single rod inner segments in isolated intact neural mouse retinae, maintained by superfusion. Experiments were conducted at different times of the day or under constant environmental conditions, at different times across the circadian cycle. We show that rod electrical coupling is regulated by a circadian clock and dopamine, so that coupling is weak during the day and strong at night. Altogether, patch-clamp recordings of single-photon responses in mouse rods, tracer coupling, receptive field measurements and pharmacological manipulations of gap junction and dopamine receptor activity provide compelling evidence that rod coupling is modulated in a circadian manner. These data are consistent with computer modelling. At night, single-photon responses are smaller due to coupling, but the signal-to-noise ratio for a dim (multiphoton) light response is increased at night because of signal averaging between coupled rods. PMID:25616058

Duration of treatment for asymptomatic bacteriuria during pregnancy.

PubMed

Villar, J; Lydon-Rochelle, M T; Gülmezoglu, A M; Roganti, A

2000-01-01

A Cochrane systematic review has shown that drug treatment of asymptomatic bacteriuria in pregnant women substantially decreases the risk of pyelonephritis and reduces the risk of preterm delivery. However, it is not clear whether single dose therapy is as effective as longer conventional antibiotic treatment. The objective of this review was to assess the effects of different durations of treatment for asymptomatic bacteriuria in pregnancy. We searched the Cochrane Pregnancy and Childbirth Group trials register, the Cochrane Controlled Trials Register and the reference lists of articles. Randomised and quasi-randomised trials comparing antimicrobial therapeutic regimens that differed in duration (particularly comparing single dose with longer duration regimens) in pregnant women diagnosed with asymptomatic bacteriuria. Trial quality was assessed and data were extracted independently by the reviewers. Eight studies involving over 400 women were included. All were comparisons of single dose treatment with four to seven day treatments. The trials were generally of poor quality. No difference in 'no-cure' rate was detected between single dose and short course (4-7 day) treatment for asymptomatic bacteriuria in pregnant women (relative risk 1.13, 95% confidence interval 0.82 to 1.54) as well as in the recurrent asymptomtic bacteriuria (relative risk 1.08, 95% confidence interval 0.70 to 1.66). However these results showed significant heterogeneity. No differences were detected for preterm births and pyelonephritis although sample size of trials was small. Longer duration treatment was associated with an increase in reports of adverse effects (relative risk 0.53, 95% confidence interval 0.31 to 0.91). There is not enough evidence to evaluate whether single dose or longer duration doses are more effective in treating asymptomatic bacteriuria in pregnant women. Because single dose has lower cost and increases compliance, this comparison should be explored in a properly sized randomized controlled trial.

Sharing the trousers: gender roles and relationships in an HIV-prevention trial in Zimbabwe.

PubMed

Montgomery, Elizabeth T; Chidanyika, Agnes; Chipato, Tsungai; van der Straten, Ariane

2012-01-01

Male and female gender roles and inequalities are important in contributing to the disproportionate burden of HIV experienced by women in sub-Saharan Africa. Within the context of an HIV prevention trial, we aimed to describe and understand male partner influence on women's use of HIV-prevention methods. Our presumption was not that regressive gender norms prevailed - rather, that a wide range of gendered attitudes and dynamics would be expressed among couples. Data from 16 focus groups with Zimbabwean female trial participants and their male partners and 4 in-depth couples interviews were collected, and form the basis of the analysis. Findings offer descriptions of how couples have adapted techniques for negotiating modern household economies and sexual decision-making in a manner that both preserves traditional gender roles, while accommodating women's entrance into new domains such as the workforce or an HIV-prevention trial. Women's agency to introduce novel female-initiated-method use into her intimate relationships is described. Men and women's accounts of method introduction and use suggest different perceptions about the locus of sexual decision making. The study provides unique insight into a gendered context that is dynamic yet sensitive to change, which in turn can provide useful information to more appropriately guide HIV-prevention activities in this setting.

Controlling single-photon transport in an optical waveguide coupled to an optomechanical cavity with a Λ-type three-level atom

NASA Astrophysics Data System (ADS)

Zhang, Yu-Qing; Zhu, Zhong-Hua; Peng, Zhao-Hui; Jiang, Chun-Lei; Chai, Yi-Feng; Hai, Lian; Tan, Lei

2018-06-01

We theoretically study the single-photon transport along a one-dimensional optical waveguide coupled to an optomechanical cavity containing a Λ-type three-level atom. Our numerical results show that the transmission spectra of the incident photon can be well controlled by such a hybrid atom-optomechanical system. The effects of the optomechanical coupling strength, the classical laser beam applied to the atom, atom-cavity detuning, and atomic dissipation on the single-photon transport properties are analyzed. It is of particular interest that an analogous double electromagnetically induced transparency emerges in the single-photon transmission spectra.

Single-photon transport through a waveguide coupling to a quadratic optomechanical system

NASA Astrophysics Data System (ADS)

Qiao, Lei

2017-07-01

We study the coherent transport of a single photon, which propagates in a one-dimensional waveguide and is scattered by a quadratic optomechanical system. Our approach, which is based on the Lippmann-Schwinger equation, gives an analytical solution to describe the single-photon transmission and reflection properties. We analyze the transport spectra and find they are not only related to the optomechanical system's energy-level structure, but also dependent on the optomechanical system's inherent parameters. For the existence of atomic degrees of freedom, we get a Rabi-splitting-like or an electromagnetically induced transparency (EIT)-like spectrum, depending on the atom-cavity coupling strength. Here, we focus on the single-photon strong-coupling regime so that single-quantum effects could be seen.

Sensitive and specific radioimmunoassay for fialuridine: initial assessment of pharmacokinetics after single oral doses to healthy volunteers.

PubMed Central

Bowsher, R R; Compton, J A; Kirkwood, J A; Place, G D; Jones, C D; Mabry, T E; Hyslop, D L; Hatcher, B L; DeSante, K A

1994-01-01

Fialuridine (FIAU) is a halogen-substituted analog of thymidine that was undergoing clinical investigation as a drug for the treatment of chronic hepatitis B viral infection. However, clinical trials of FIAU were terminated after adverse events occurred following chronic oral administration. Prior to the termination of clinical trials, a sensitive assay was needed for the measurement of FIAU because of the anticipated low dose administered to patients. We therefore undertook the development of a radioimmunoassay (RIA). A specific antiserum was raised in rabbits following immunization with a 5'-O-hemisuccinate analog of FIAU coupled to keyhole limpet hemocyanin. Radiolabeled FIAU was synthesized by a destannylation procedure by using sodium [125I]iodide. We developed a competitive-binding procedure and used precipitation with polyethylene glycol as the method for separating the bound and free forms of FIAU. The RIA is sensitive (0.2 ng/ml), specific (negligible interference from known metabolites and endogenous nucleosides), and reproducible (interassay coefficients of variation range from 5 to 19.7% for serum controls). We used the RIA to assess the pharmacokinetics of FIAU in healthy adult volunteers following administration of a single 5-mg oral dose. The sensitivity of the RIA permitted the detection of a prolonged elimination phase for FIAU in healthy volunteers and dogs, with mean elimination half-lives of 29.3 and 35.3 h, respectively. We conclude the RIA is a valid method for the quantification of FIAU in biological fluids. PMID:7811032

Ayurvedic management of pulmonary tuberculosis: A systematic review.

PubMed

Samal, Janmejaya

2016-01-01

Tuberculosis (TB) is a global public health crisis. 25% of world's TB cases are found in India. Ayurveda, an ancient medical science may offer some solution to this problem. Hence, a systematic review was carried out to assess the role of Ayurveda for the management of TB. A systematic review was carried out using published literature obtained through "PubMed" until April 2015. The key words used for literature search include "Ayurveda, role and TB." It was observed that a couple of single and compound drugs have been used for the management of TB. However, none of the studies could reflect the true anti-TB activities of any drug, both single and compound. Two of the studies revealed in vitro anti-TB properties of some herbs which can potentially be brought into the realm of a clinical trial to test their efficacy in a human subject. Most of these Ayurvedic therapeutic preparations studied in different clinical settings primarily reflected their adjunct properties for the management of TB. These studies revealed that Ayurvedic therapeutics was able to reduce associated symptoms and the adverse drug effects of ATDs (anti-TB drugs). Furthermore, some of the preparations showed potential hepato-protective properties that can be simultaneously administered with ATDs. Distressingly research on the role of Ayurveda in the management of TB is very scanty and mostly limited to adjunct or supportive therapy. Being a global public health crisis, it is highly recommended to carry out clinical trials on TB patients using Ayurvedic drugs and therapeutic regimens.

Strain Coupling of a Nitrogen-Vacancy Center Spin to a Diamond Mechanical Oscillator

NASA Astrophysics Data System (ADS)

Teissier, J.; Barfuss, A.; Appel, P.; Neu, E.; Maletinsky, P.

2014-07-01

We report on single electronic spins coupled to the motion of mechanical resonators by a novel mechanism based on crystal strain. Our device consists of single-crystal diamond cantilevers with embedded nitrogen-vacancy center spins. Using optically detected electron spin resonance, we determine the unknown spin-strain coupling constants and demonstrate that our system resides well within the resolved sideband regime. We realize coupling strengths exceeding 10 MHz under mechanical driving and show that our system has the potential to reach strong coupling. Our novel hybrid system forms a resource for future experiments on spin-based cantilever cooling and coherent spin-oscillator coupling.

Analysis and visualization of single-trial event-related potentials

NASA Technical Reports Server (NTRS)

Jung, T. P.; Makeig, S.; Westerfield, M.; Townsend, J.; Courchesne, E.; Sejnowski, T. J.

2001-01-01

In this study, a linear decomposition technique, independent component analysis (ICA), is applied to single-trial multichannel EEG data from event-related potential (ERP) experiments. Spatial filters derived by ICA blindly separate the input data into a sum of temporally independent and spatially fixed components arising from distinct or overlapping brain or extra-brain sources. Both the data and their decomposition are displayed using a new visualization tool, the "ERP image," that can clearly characterize single-trial variations in the amplitudes and latencies of evoked responses, particularly when sorted by a relevant behavioral or physiological variable. These tools were used to analyze data from a visual selective attention experiment on 28 control subjects plus 22 neurological patients whose EEG records were heavily contaminated with blink and other eye-movement artifacts. Results show that ICA can separate artifactual, stimulus-locked, response-locked, and non-event-related background EEG activities into separate components, a taxonomy not obtained from conventional signal averaging approaches. This method allows: (1) removal of pervasive artifacts of all types from single-trial EEG records, (2) identification and segregation of stimulus- and response-locked EEG components, (3) examination of differences in single-trial responses, and (4) separation of temporally distinct but spatially overlapping EEG oscillatory activities with distinct relationships to task events. The proposed methods also allow the interaction between ERPs and the ongoing EEG to be investigated directly. We studied the between-subject component stability of ICA decomposition of single-trial EEG epochs by clustering components with similar scalp maps and activation power spectra. Components accounting for blinks, eye movements, temporal muscle activity, event-related potentials, and event-modulated alpha activities were largely replicated across subjects. Applying ICA and ERP image visualization to the analysis of sets of single trials from event-related EEG (or MEG) experiments can increase the information available from ERP (or ERF) data. Copyright 2001 Wiley-Liss, Inc.

In-situ coupling between kinase activities and protein dynamics within single focal adhesions

NASA Astrophysics Data System (ADS)

Wu, Yiqian; Zhang, Kaiwen; Seong, Jihye; Fan, Jason; Chien, Shu; Wang, Yingxiao; Lu, Shaoying

2016-07-01

The dynamic activation of oncogenic kinases and regulation of focal adhesions (FAs) are crucial molecular events modulating cell adhesion in cancer metastasis. However, it remains unclear how these events are temporally coordinated at single FA sites. Therefore, we targeted fluorescence resonance energy transfer (FRET)-based biosensors toward subcellular FAs to report local molecular events during cancer cell adhesion. Employing single FA tracking and cross-correlation analysis, we quantified the dynamic coupling characteristics between biochemical kinase activities and structural FA within single FAs. We show that kinase activations and FA assembly are strongly and sequentially correlated, with the concurrent FA assembly and Src activation leading focal adhesion kinase (FAK) activation by 42.6 ± 12.6 sec. Strikingly, the temporal coupling between kinase activation and individual FA assembly reflects the fate of FAs at later stages. The FAs with a tight coupling tend to grow and mature, while the less coupled FAs likely disassemble. During FA disassembly, however, kinase activations lead the disassembly, with FAK being activated earlier than Src. Therefore, by integrating subcellularly targeted FRET biosensors and computational analysis, our study reveals intricate interplays between Src and FAK in regulating the dynamic life of single FAs in cancer cells.

Single-visit or multiple-visit root canal treatment: systematic review, meta-analysis and trial sequential analysis

PubMed Central

Schwendicke, Falk; Göstemeyer, Gerd

2017-01-01

Objectives Single-visit root canal treatment has some advantages over conventional multivisit treatment, but might increase the risk of complications. We systematically evaluated the risk of complications after single-visit or multiple-visit root canal treatment using meta-analysis and trial-sequential analysis. Data Controlled trials comparing single-visit versus multiple-visit root canal treatment of permanent teeth were included. Trials needed to assess the risk of long-term complications (pain, infection, new/persisting/increasing periapical lesions ≥1 year after treatment), short-term pain or flare-up (acute exacerbation of initiation or continuation of root canal treatment). Sources Electronic databases (PubMed, EMBASE, Cochrane Central) were screened, random-effects meta-analyses performed and trial-sequential analysis used to control for risk of random errors. Evidence was graded according to GRADE. Study selection 29 trials (4341 patients) were included, all but 6 showing high risk of bias. Based on 10 trials (1257 teeth), risk of complications was not significantly different in single-visit versus multiple-visit treatment (risk ratio (RR) 1.00 (95% CI 0.75 to 1.35); weak evidence). Based on 20 studies (3008 teeth), risk of pain did not significantly differ between treatments (RR 0.99 (95% CI 0.76 to 1.30); moderate evidence). Risk of flare-up was recorded by 8 studies (1110 teeth) and was significantly higher after single-visit versus multiple-visit treatment (RR 2.13 (95% CI 1.16 to 3.89); very weak evidence). Trial-sequential analysis revealed that firm evidence for benefit, harm or futility was not reached for any of the outcomes. Conclusions There is insufficient evidence to rule out whether important differences between both strategies exist. Clinical significance Dentists can provide root canal treatment in 1 or multiple visits. Given the possibly increased risk of flare-ups, multiple-visit treatment might be preferred for certain teeth (eg, those with periapical lesions). PMID:28148534

Duration of treatment for asymptomatic bacteriuria during pregnancy.

PubMed

Widmer, Mariana; Gülmezoglu, A Metin; Mignini, Luciano; Roganti, Ariel

2011-12-07

A Cochrane systematic review has shown that drug treatment of asymptomatic bacteriuria in pregnant women substantially decreases the risk of pyelonephritis and reduces the risk of preterm delivery. However, it is not clear whether single-dose therapy is as effective as longer conventional antibiotic treatment. To assess the effects of different durations of treatment for asymptomatic bacteriuria in pregnancy. We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 August 2011) and reference lists of identified articles. Randomized and quasi-randomized trials comparing antimicrobial therapeutic regimens that differed in duration (particularly comparing single dose with longer duration regimens) in pregnant women diagnosed with asymptomatic bacteriuria. We assessed trial quality and extracted data independently. We included 13 studies, involving 1622 women. All were comparisons of single-dose treatment with four- to seven-day treatments. The trials were generally of limited quality. The 'no cure rate' for asymptomatic bacteriuria in pregnant women was slightly higher for the single-dose than for the short-course treatment; however, these results were not statistically significant and showed heterogeneity. When comparing the trials that used the same antibiotic in both treatment and control groups with the trials that used different antibiotics in both groups, the 'no cure rate' risk ratio was similar. There was no statistically significant difference in the recurrence of asymptomatic bacteriuria rate between treatment and control groups. Slight differences were detected for preterm births and pyelonephritis although, apart from one trial, the sample size of the trials was inadequate. Single-dose treatment was associated with a decrease in reports of 'any side-effects' . Single-dose regimen of antibiotics may be less effective than the seven-day regimen. Women with asymptomatic bacteriuria in pregnancy should be treated by the standard regimen of antibiotics until more data become available testing seven-day compared with three- or five-day regimens.

Adherence in single-parent households in a long-term asthma clinical trial.

PubMed

Spicher, Mary; Bollers, Nancy; Chinn, Tamara; Hall, Anita; Plunkett, Anne; Rodgers, Denise; Sundström, D A; Wilson, Laura

2012-01-01

Adherence of participants in a long-term clinical trial is necessary to assure validity of findings. This article examines adherence differences between single-parent and two-parent families in the Childhood Asthma Management Program (CAMP). Adherence was defined as the percentage of completed daily diary cards and scheduled study visits during the course of the trial. Logistic regression and ordinal logistic regression analyses were used. Children from single-parent families had a lower percentage of completed diary cards (72% vs. 84%) than two-parent families. Single-parent families were also more likely to reschedule visits (62% vs. 45%) and miss more clinic visits (23% vs. 17%) than two-parent families. Suggestions are given for study coordinators to assist participants in completing a long-term clinical trial. Many suggestions may be adapted for nurses in inpatient or outpatient settings for assisting parents of patients with chronic diseases.

Cognitive workload modulation through degraded visual stimuli: a single-trial EEG study

NASA Astrophysics Data System (ADS)

Yu, K.; Prasad, I.; Mir, H.; Thakor, N.; Al-Nashash, H.

2015-08-01

Objective. Our experiments explored the effect of visual stimuli degradation on cognitive workload. Approach. We investigated the subjective assessment, event-related potentials (ERPs) as well as electroencephalogram (EEG) as measures of cognitive workload. Main results. These experiments confirm that degradation of visual stimuli increases cognitive workload as assessed by subjective NASA task load index and confirmed by the observed P300 amplitude attenuation. Furthermore, the single-trial multi-level classification using features extracted from ERPs and EEG is found to be promising. Specifically, the adopted single-trial oscillatory EEG/ERP detection method achieved an average accuracy of 85% for discriminating 4 workload levels. Additionally, we found from the spatial patterns obtained from EEG signals that the frontal parts carry information that can be used for differentiating workload levels. Significance. Our results show that visual stimuli can modulate cognitive workload, and the modulation can be measured by the single trial EEG/ERP detection method.

EEG source reconstruction reveals frontal-parietal dynamics of spatial conflict processing.

PubMed

Cohen, Michael X; Ridderinkhof, K Richard

2013-01-01

Cognitive control requires the suppression of distracting information in order to focus on task-relevant information. We applied EEG source reconstruction via time-frequency linear constrained minimum variance beamforming to help elucidate the neural mechanisms involved in spatial conflict processing. Human subjects performed a Simon task, in which conflict was induced by incongruence between spatial location and response hand. We found an early (∼200 ms post-stimulus) conflict modulation in stimulus-contralateral parietal gamma (30-50 Hz), followed by a later alpha-band (8-12 Hz) conflict modulation, suggesting an early detection of spatial conflict and inhibition of spatial location processing. Inter-regional connectivity analyses assessed via cross-frequency coupling of theta (4-8 Hz), alpha, and gamma power revealed conflict-induced shifts in cortical network interactions: Congruent trials (relative to incongruent trials) had stronger coupling between frontal theta and stimulus-contrahemifield parietal alpha/gamma power, whereas incongruent trials had increased theta coupling between medial frontal and lateral frontal regions. These findings shed new light into the large-scale network dynamics of spatial conflict processing, and how those networks are shaped by oscillatory interactions.

Tapered waveguides for guided wave optics.

PubMed

Campbell, J C

1979-03-15

Strip waveguides having half-paraboloid shaped tapers that permit efficient fiber to waveguide coupling have been fabricated by Ag ion exchange in soda-lime glass. A reduction in the input coupling loss has been accomplished by tailoring the diffusion to provide a gradual transition from a single-mode waveguide to a multimode waveguide having cross-sectional dimensions comparable to the core diameter of a single-mode fiber. Waveguides without tapers exhibit an attenuation of 1.0 dB/cm and an input coupling loss of 0.6 dB. The additional loss introduced by the tapered region is 0.5 dB. By way of contrast, an input coupling loss of 2.4 dB is obtained by coupling directly to a single-mode waveguide, indicating a net improvement of 1.3 dB for the tapered waveguides.

Transverse single-mode edge-emitting lasers based on coupled waveguides.

PubMed

Gordeev, Nikita Yu; Payusov, Alexey S; Shernyakov, Yuri M; Mintairov, Sergey A; Kalyuzhnyy, Nikolay A; Kulagina, Marina M; Maximov, Mikhail V

2015-05-01

We report on the transverse single-mode emission from InGaAs/GaAs quantum well edge-emitting lasers with broadened waveguide. The lasers are based on coupled large optical cavity (CLOC) structures where high-order vertical modes of the broad active waveguide are suppressed due to their resonant tunneling into a coupled single-mode passive waveguide. The CLOC lasers have shown stable Gaussian-shaped vertical far-field profiles with a reduced divergence of ∼22° FWHM (full width at half-maximum) in CW (continuous-wave) operation.

Dual-color single-mode lasing in axially coupled organic nanowire resonators

PubMed Central

Zhang, Chunhuan; Zou, Chang-Ling; Dong, Haiyun; Yan, Yongli; Yao, Jiannian; Zhao, Yong Sheng

2017-01-01

Miniaturized lasers with multicolor output and high spectral purity are of crucial importance for yielding more compact and more versatile photonic devices. However, multicolor lasers usually operate in multimode, which largely restricts their practical applications due to the lack of an effective mode selection mechanism that is simultaneously applicable to multiple wavebands. We propose a mutual mode selection strategy to realize dual-color single-mode lasing in axially coupled cavities constructed from two distinct organic self-assembled single-crystal nanowires. The unique mode selection mechanism in the heterogeneously coupled nanowires was elucidated experimentally and theoretically. With each individual nanowire functioning as both the laser source and the mode filter for the other nanowire, dual-color single-mode lasing was successfully achieved in the axially coupled heterogeneous nanowire resonators. Furthermore, the heterogeneously coupled resonators provided multiple nanoscale output ports for delivering coherent signals with different colors, which could greatly contribute to increasing the integration level of functional photonic devices. These results advance the fundamental understanding of the lasing modulation in coupled cavity systems and offer a promising route to building multifunctional nanoscale lasers for high-level practical photonic integrations. PMID:28785731

Personalized ovarian stimulation for assisted reproductive technology: study design considerations to move from hype to added value for patients.

PubMed

Mol, Ben W; Bossuyt, Patrick M; Sunkara, Sesh K; Garcia Velasco, Juan A; Venetis, Christos; Sakkas, Denny; Lundin, Kersti; Simón, Carlos; Taylor, Hugh S; Wan, Robert; Longobardi, Salvatore; Cottell, Evelyn; D'Hooghe, Thomas

2018-06-01

Although most medical treatments are designed for the average patient with a one-size-fits-all-approach, they may not benefit all. Better understanding of the function of genes, proteins, and metabolite, and of personal and environmental factors has led to a call for personalized medicine. Personalized reproductive medicine is still in its infancy, without clear guidance on treatment aspects that could be personalized and on trial design to evaluate personalized treatment effect and benefit-harm balance. While the rationale for a personalized approach often relies on retrospective analyses of large observational studies or real-world data, solid evidence of superiority of a personalized approach will come from randomized trials comparing outcomes and safety between a personalized and one-size-fits-all strategy. A more efficient, targeted randomized trial design may recruit only patients or couples for which the personalized approach would differ from the previous, standard approach. Multiple monocenter studies using the same study protocol (allowing future meta-analysis) might reduce the major center effect associated with multicenter studies. In certain cases, single-arm observational studies can generate the necessary evidence for a personalized approach. This review describes each of the main segments of patient care in assisted reproductive technologies treatment, addressing which aspects could be personalized, emphasizing current evidence and relevant study design. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

Comparison of coherently coupled multi-cavity and quantum dot embedded single cavity systems.

PubMed

Kocaman, Serdar; Sayan, Gönül Turhan

2016-12-12

Temporal group delays originating from the optical analogue to electromagnetically induced transparency (EIT) are compared in two systems. Similar transmission characteristics are observed between a coherently coupled high-Q multi-cavity array and a single quantum dot (QD) embedded cavity in the weak coupling regime. However, theoretically generated group delay values for the multi-cavity case are around two times higher. Both configurations allow direct scalability for chip-scale optical pulse trapping and coupled-cavity quantum electrodynamics (QED).

Selectivity of N170 for visual words in the right hemisphere: Evidence from single-trial analysis.

PubMed

Yang, Hang; Zhao, Jing; Gaspar, Carl M; Chen, Wei; Tan, Yufei; Weng, Xuchu

2017-08-01

Neuroimaging and neuropsychological studies have identified the involvement of the right posterior region in the processing of visual words. Interestingly, in contrast, ERP studies of the N170 typically demonstrate selectivity for words more strikingly over the left hemisphere. Why is right hemisphere selectivity for words during the N170 epoch typically not observed, despite the clear involvement of this region in word processing? One possibility is that amplitude differences measured on averaged ERPs in previous studies may have been obscured by variation in peak latency across trials. This study examined this possibility by using single-trial analysis. Results show that words evoked greater single-trial N170s than control stimuli in the right hemisphere. Additionally, we observed larger trial-to-trial variability on N170 peak latency for words as compared to control stimuli over the right hemisphere. Results demonstrate that, in contrast to much of the prior literature, the N170 can be selective to words over the right hemisphere. This discrepancy is explained in terms of variability in trial-to-trial peak latency for responses to words over the right hemisphere. © 2017 Society for Psychophysiological Research.

Signatures of single-photon interaction between two quantum dots located in different cavities of a weakly coupled double microdisk structure

NASA Astrophysics Data System (ADS)

Seyfferle, S.; Hargart, F.; Jetter, M.; Hu, E.; Michler, P.

2018-01-01

We report on the radiative interaction of two single quantum dots (QDs) each in a separate InP/GaInP-based microdisk cavity via resonant whispering gallery modes. The investigations are based on as-fabricated coupled disk modes. We apply optical spectroscopy involving a 4 f setup, as well as mode-selective real-space imaging and photoluminescence mapping to discern single QDs coupled to a resonant microdisk mode. Excitation of one disk of the double cavity structure and detecting photoluminescence from the other yields proof of single-photon emission of a QD excited by incoherent energy transfer from one disk to the other via a mode in the weak-coupling regime. Finally, we present evidence of photons emitted by a QD in one disk that are transferred to the other disk by a resonant mode and are subsequently resonantly scattered by another QD.

Single-use instruments, cutting blocks, and trials increase efficiency in the operating room during total knee arthroplasty: a prospective comparison of navigated and non-navigated cases.

PubMed

Mont, Michael A; McElroy, Mark J; Johnson, Aaron J; Pivec, Robert

2013-08-01

The purpose of this prospective controlled trial was to determine if efficiency increases could be achieved in non-navigated and navigated total knee arthroplasties by replacing traditional saws, cutting blocks, and trials with specialized saws and single-use cutting blocks and trials. Various timing metrics during total knee arthroplasty, including operating room preparation times and specific intra-operative times, were measured in 400 procedures performed by eight different surgeons at 6 institutions. Efficiency increases were the result of statistically significant reductions in combined instrument setup and cleanup times as well as in adjusted surgical episode times in navigated total knee arthroplasties. Single-use instruments show promising benefits, but adequate patient follow-up is needed to confirm safety and efficacy before they can be widely adopted. Nevertheless, the authors believe that the use of single-use instruments, cutting guides, and trial implants for total knee arthroplasty will play an increasing role in improving operating room efficiency. Copyright © 2013 Elsevier Inc. All rights reserved.

Spontaneous Fluctuations in Sensory Processing Predict Within-Subject Reaction Time Variability.

PubMed

Ribeiro, Maria J; Paiva, Joana S; Castelo-Branco, Miguel

2016-01-01

When engaged in a repetitive task our performance fluctuates from trial-to-trial. In particular, inter-trial reaction time variability has been the subject of considerable research. It has been claimed to be a strong biomarker of attention deficits, increases with frontal dysfunction, and predicts age-related cognitive decline. Thus, rather than being just a consequence of noise in the system, it appears to be under the control of a mechanism that breaks down under certain pathological conditions. Although the underlying mechanism is still an open question, consensual hypotheses are emerging regarding the neural correlates of reaction time inter-trial intra-individual variability. Sensory processing, in particular, has been shown to covary with reaction time, yet the spatio-temporal profile of the moment-to-moment variability in sensory processing is still poorly characterized. The goal of this study was to characterize the intra-individual variability in the time course of single-trial visual evoked potentials and its relationship with inter-trial reaction time variability. For this, we chose to take advantage of the high temporal resolution of the electroencephalogram (EEG) acquired while participants were engaged in a 2-choice reaction time task. We studied the link between single trial event-related potentials (ERPs) and reaction time using two different analyses: (1) time point by time point correlation analyses thereby identifying time windows of interest; and (2) correlation analyses between single trial measures of peak latency and amplitude and reaction time. To improve extraction of single trial ERP measures related with activation of the visual cortex, we used an independent component analysis (ICA) procedure. Our ERP analysis revealed a relationship between the N1 visual evoked potential and reaction time. The earliest time point presenting a significant correlation of its respective amplitude with reaction time occurred 175 ms after stimulus onset, just after the onset of the N1 peak. Interestingly, single trial N1 latency correlated significantly with reaction time, while N1 amplitude did not. In conclusion, our findings suggest that inter-trial variability in the timing of extrastriate visual processing contributes to reaction time variability.

Spontaneous Fluctuations in Sensory Processing Predict Within-Subject Reaction Time Variability

PubMed Central

Ribeiro, Maria J.; Paiva, Joana S.; Castelo-Branco, Miguel

2016-01-01

When engaged in a repetitive task our performance fluctuates from trial-to-trial. In particular, inter-trial reaction time variability has been the subject of considerable research. It has been claimed to be a strong biomarker of attention deficits, increases with frontal dysfunction, and predicts age-related cognitive decline. Thus, rather than being just a consequence of noise in the system, it appears to be under the control of a mechanism that breaks down under certain pathological conditions. Although the underlying mechanism is still an open question, consensual hypotheses are emerging regarding the neural correlates of reaction time inter-trial intra-individual variability. Sensory processing, in particular, has been shown to covary with reaction time, yet the spatio-temporal profile of the moment-to-moment variability in sensory processing is still poorly characterized. The goal of this study was to characterize the intra-individual variability in the time course of single-trial visual evoked potentials and its relationship with inter-trial reaction time variability. For this, we chose to take advantage of the high temporal resolution of the electroencephalogram (EEG) acquired while participants were engaged in a 2-choice reaction time task. We studied the link between single trial event-related potentials (ERPs) and reaction time using two different analyses: (1) time point by time point correlation analyses thereby identifying time windows of interest; and (2) correlation analyses between single trial measures of peak latency and amplitude and reaction time. To improve extraction of single trial ERP measures related with activation of the visual cortex, we used an independent component analysis (ICA) procedure. Our ERP analysis revealed a relationship between the N1 visual evoked potential and reaction time. The earliest time point presenting a significant correlation of its respective amplitude with reaction time occurred 175 ms after stimulus onset, just after the onset of the N1 peak. Interestingly, single trial N1 latency correlated significantly with reaction time, while N1 amplitude did not. In conclusion, our findings suggest that inter-trial variability in the timing of extrastriate visual processing contributes to reaction time variability. PMID:27242470

Tapered fiber coupling of single photons emitted by a deterministically positioned single nitrogen vacancy center

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

Liebermeister, Lars, E-mail: lars.liebermeister@physik.uni-muenchen.de; Petersen, Fabian; Münchow, Asmus v.

2014-01-20

A diamond nano-crystal hosting a single nitrogen vacancy (NV) center is optically selected with a confocal scanning microscope and positioned deterministically onto the subwavelength-diameter waist of a tapered optical fiber (TOF) with the help of an atomic force microscope. Based on this nano-manipulation technique, we experimentally demonstrate the evanescent coupling of single fluorescence photons emitted by a single NV-center to the guided mode of the TOF. By comparing photon count rates of the fiber-guided and the free-space modes and with the help of numerical finite-difference time domain simulations, we determine a lower and upper bound for the coupling efficiency ofmore » (9.5 ± 0.6)% and (10.4 ± 0.7)%, respectively. Our results are a promising starting point for future integration of single photon sources into photonic quantum networks and applications in quantum information science.« less

Patients' preferences for selection of endpoints in cardiovascular clinical trials.

PubMed

Chow, Robert D; Wankhedkar, Kashmira P; Mete, Mihriye

2014-01-01

To reduce the duration and overall costs of cardiovascular trials, use of the combined endpoints in trial design has become commonplace. Though this methodology may serve the needs of investigators and trial sponsors, the preferences of patients or potential trial subjects in the trial design process has not been studied. To determine the preferences of patients in the design of cardiovascular trials. Participants were surveyed in a pilot study regarding preferences among various single endpoints commonly used in cardiovascular trials, preference for single vs. composite endpoints, and the likelihood of compliance with a heart medication if patients similar to them participated in the trial design process. One hundred adult English-speaking patients, 38% male, from a primary care ambulatory practice located in an urban setting. Among single endpoints, participants rated heart attack as significantly more important than death from other causes (4.53 vs. 3.69, p=0.004) on a scale of 1-6. Death from heart disease was rated as significantly more important than chest pain (4.73 vs. 2.47, p<0.001), angioplasty/PCI/CABG (4.73 vs. 2.43, p<0.001), and stroke (4.73 vs. 2.43, p<0.001). Participants also expressed a slight preference for combined endpoints over single endpoint (43% vs. 57%), incorporation of the opinions of the study patient population into the design of trials (48% vs. 41% for researchers), and a greater likelihood of medication compliance if patient preferences were considered during trial design (67% indicated a significant to major effect). Patients are able to make judgments and express preferences regarding trial design. They prefer that the opinions of the study population rather than the general population be incorporated into the design of the study. This novel approach to study design would not only incorporate patient preferences into medical decision making, but it also has the potential to improve compliance with cardiovascular medications.

Does a strategy to promote shared decision-making reduce medical practice variation in the choice of either single or double embryo transfer after in vitro fertilisation? A secondary analysis of a randomised controlled trial.

PubMed

Brabers, Anne E M; van Dijk, Liset; Groenewegen, Peter P; van Peperstraten, Arno M; de Jong, Judith D

2016-05-06

The hypothesis that shared decision-making (SDM) reduces medical practice variations is increasingly common, but no evidence is available. We aimed to elaborate further on this, and to perform a first exploratory analysis to examine this hypothesis. This analysis, based on a limited data set, examined how SDM is associated with variation in the choice of single embryo transfer (SET) or double embryo transfer (DET) after in vitro fertilisation (IVF). We examined variation between and within hospitals. A secondary analysis of a randomised controlled trial. 5 hospitals in the Netherlands. 222 couples (woman aged <40 years) on a waiting list for a first IVF cycle, who could choose between SET and DET (ie, ≥2 embryos available). SDM via a multifaceted strategy aimed to empower couples in deciding how many embryos should be transferred. The strategy consisted of decision aid, support of IVF nurse and the offer of reimbursement for an extra treatment cycle. Control group received standard IVF care. Difference in variation due to SDM in the choice of SET or DET, both between and within hospitals. There was large variation in the choice of SET or DET between hospitals in the control group. Lower variation between hospitals was observed in the group with SDM. Within most hospitals, variation in the choice of SET or DET appeared to increase due to SDM. Variation particularly increased in hospitals where mainly DET was chosen in the control group. Although based on a limited data set, our study gives a first insight that including patients' preferences through SDM results in less variation between hospitals, and indicates another pattern of variation within hospitals. Variation that results from patient preferences could be potentially named the informed patient rate. Our results provide the starting point for further research. NCT00315029; Post-results. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Single treatments that have lasting effects: some thoughts on the antidepressant effects of ketamine and botulinum toxin and the anxiolytic effect of psilocybin

PubMed Central

Young, Simon N.

2013-01-01

Recent clinical trials suggest that 3 single biological treatments have effects that persist. Based on research showing that the muscles involved in facial expressions can feed back to influence mood, a single trial diminishing glabella frown lines with botulinum toxin demonstrated a significant antidepressant effect for 16 weeks. Based primarily on research with animal models of depression suggesting that glutamate may be involved in depression, the N-methyl-d-aspartate antagonist ketamine has been tested in several trials. A single dose decreased depression for up to a week. The reported effects of the use of mushrooms containing psilocybin by a number of cultures around the world has stimulated several trials showing beneficial effects of a single dose of psilocybin for over a year in healthy people, and for up to 3 months in patients with anxiety disorders who have advanced cancer. This article discusses these studies, their rationale, their possible mechanisms of action, the future clinical research required to establish these therapies and the basic research required to optimize single treatments that have lasting effects. PMID:23171696

Polarization preserving single mode fiber optic coupler

NASA Technical Reports Server (NTRS)

Nelson, M. D.; Goss, W. C.

1982-01-01

A technique is described for fabrication of etched single mode fiber optical waveguide couplers which preserve the polarization state to within 0.0001. The coupling ratio is tunable over a broad range (0-9 percent) during fabrication. Back-coupling is less than 0.001, insertion loss is less than 1.5 dB, and coupling ratio thermal coefficient is about 1 percent per degree C.

Waveguide-Coupled Superconducting Nanowire Single-Photon Detectors

NASA Technical Reports Server (NTRS)

Beyer, Andrew D.; Briggs, Ryan M.; Marsili, Francesco; Cohen, Justin D.; Meenehan, Sean M.; Painter, Oskar J.; Shaw, Matthew D.

2015-01-01

We have demonstrated WSi-based superconducting nanowire single-photon detectors coupled to SiNx waveguides with integrated ring resonators. This photonics platform enables the implementation of robust and efficient photon-counting detectors with fine spectral resolution near 1550 nm.

A pilot randomized controlled trial of the feasibility of a self-directed coping skills intervention for couples facing prostate cancer: Rationale and design

PubMed Central

2012-01-01

Background Although it is known both patients’ and partners’ reactions to a prostate cancer diagnosis include fear, uncertainty, anxiety and depression with patients’ partners’ reactions mutually determining how they cope with and adjust to the illness, few psychosocial interventions target couples. Those that are available tend to be led by highly trained professionals, limiting their accessibility and long-term sustainability. In addition, it is recognised that patients who might benefit from conventional face-to-face psychosocial interventions do not access these, either by preference or because of geographical or mobility barriers. Self-directed interventions can overcome some of these limitations and have been shown to contribute to patient well-being. This study will examine the feasibility of a self-directed, coping skills intervention for couples affected by cancer, called Coping-Together, and begin to explore its potential impact on couples’ illness adjustment. The pilot version of Coping-Together includes a series of four booklets, a DVD, and a relaxation audio CD. Methods/design In this double-blind, two-group, parallel, randomized controlled trial, 70 couples will be recruited within 4 months of a prostate cancer diagnosis through urology private practices and randomized to: 1) Coping-Together or 2) a minimal ethical care condition. Minimal ethical care condition couples will be mailed information booklets available at the Cancer Council New South Wales and a brochure for the Cancer Council Helpline. The primary outcome (anxiety) and additional secondary outcomes (distress, depression, dyadic adjustment, quality of life, illness or caregiving appraisal, self-efficacy, and dyadic and individual coping) will be assessed at baseline (before receiving study material) and 2 months post-baseline. Intention-to-treat and per protocol analysis will be conducted. Discussion As partners’ distress rates exceed not only population norms, but also those reported by patients themselves, it is imperative that coping skills interventions target the couple as a unit and enhance both partners’ ability to overcome cancer challenges. This pilot study will examine the feasibility and potential efficacy of Coping-Together in optimising couples’ illness adjustment. This is one of the first feasibility studies to test this innovative coping intervention, which in turn will contribute to the larger literature advocating for psychosocial care of couples affected by prostate cancer. Trial registration Australian New Zealand Clinical Trials Registry ACTRN12611000438954 PMID:23013404

Investigating User Identification in Remote Patient Monitoring Devices.

PubMed

Ondiege, Brian; Clarke, Malcolm

2017-09-13

With the increase in the number of people having a chronic disease, there is an increase in households having more than a single person suffering from the same chronic illness. One problem of monitoring such patients in their own home is that current devices have a limitation in the number of people who can use a single device. This study investigates the use of Near Field Communication (NFC) for identification in a multi-user environment. A mixed-method qualitative and quantitative approach was adopted, including focus groups, observations and a field trial. Data were collected in three phases. In Phase 1, five focus groups were conducted with patients to determine their beliefs, concerns and issues with using identification in remote patient monitoring devices. In Phase 2, participants were given a blood pressure monitor modified to include an NFC reader to enable identification. The modified device was given to patients living as a couple in the same household and both suffering from hypertension. Both patients used the device for a period of two weeks to observe their acceptance of the technology and determine their experience of usage. A total of 40 (20 couples) patients participated in the trial. Non-adherence to the full monitoring regimen was low and was mainly due to usability issues or commitments taking them away from the home and thus unable to take readings. After the trial period participants were invited to discuss their experiences with the technology in a focus group discussion (Phase 3), a total of five focus groups were conducted. Focus group discussions with the patients revealed that most participants liked using the system and were not apprehensive towards Healthcare Information Technology (HIT). The participants also had suggestions for improvements that could be made to the modified blood pressure monitor (such as, rechargeable in place batteries, integrate the components, easier to use cuff, and increased sensitivity of the NFC reader) that might improve the overall experience of the proposed technology and its acceptance. The study proposes a new framework, the Senior Patient Technology Acceptance Model (SPTAM) that offers an understanding of the needs of the elderly towards technology use and the factors that influence its acceptance. SPTAM emphasises that involving the patient in the early stages of development can lead to a more user-centred technology and help in identifying any underlying issues at an early stage, thus avoiding adding features which patients do not need. The findings from this empirical research can be used as recommendations to improve current RPM devices, save the NHS costs, inform standardization groups.

Investigating User Identification in Remote Patient Monitoring Devices

PubMed Central

Clarke, Malcolm

2017-01-01

With the increase in the number of people having a chronic disease, there is an increase in households having more than a single person suffering from the same chronic illness. One problem of monitoring such patients in their own home is that current devices have a limitation in the number of people who can use a single device. This study investigates the use of Near Field Communication (NFC) for identification in a multi-user environment. Methods: A mixed-method qualitative and quantitative approach was adopted, including focus groups, observations and a field trial. Data were collected in three phases. In Phase 1, five focus groups were conducted with patients to determine their beliefs, concerns and issues with using identification in remote patient monitoring devices. In Phase 2, participants were given a blood pressure monitor modified to include an NFC reader to enable identification. The modified device was given to patients living as a couple in the same household and both suffering from hypertension. Both patients used the device for a period of two weeks to observe their acceptance of the technology and determine their experience of usage. A total of 40 (20 couples) patients participated in the trial. Non-adherence to the full monitoring regimen was low and was mainly due to usability issues or commitments taking them away from the home and thus unable to take readings. After the trial period participants were invited to discuss their experiences with the technology in a focus group discussion (Phase 3), a total of five focus groups were conducted. Focus group discussions with the patients revealed that most participants liked using the system and were not apprehensive towards Healthcare Information Technology (HIT). The participants also had suggestions for improvements that could be made to the modified blood pressure monitor (such as, rechargeable in place batteries, integrate the components, easier to use cuff, and increased sensitivity of the NFC reader) that might improve the overall experience of the proposed technology and its acceptance. Conclusion: The study proposes a new framework, the Senior Patient Technology Acceptance Model (SPTAM) that offers an understanding of the needs of the elderly towards technology use and the factors that influence its acceptance. SPTAM emphasises that involving the patient in the early stages of development can lead to a more user-centred technology and help in identifying any underlying issues at an early stage, thus avoiding adding features which patients do not need. The findings from this empirical research can be used as recommendations to improve current RPM devices, save the NHS costs, inform standardization groups. PMID:28952556

Vowel Imagery Decoding toward Silent Speech BCI Using Extreme Learning Machine with Electroencephalogram

PubMed Central

Kim, Jongin; Park, Hyeong-jun

2016-01-01

The purpose of this study is to classify EEG data on imagined speech in a single trial. We recorded EEG data while five subjects imagined different vowels, /a/, /e/, /i/, /o/, and /u/. We divided each single trial dataset into thirty segments and extracted features (mean, variance, standard deviation, and skewness) from all segments. To reduce the dimension of the feature vector, we applied a feature selection algorithm based on the sparse regression model. These features were classified using a support vector machine with a radial basis function kernel, an extreme learning machine, and two variants of an extreme learning machine with different kernels. Because each single trial consisted of thirty segments, our algorithm decided the label of the single trial by selecting the most frequent output among the outputs of the thirty segments. As a result, we observed that the extreme learning machine and its variants achieved better classification rates than the support vector machine with a radial basis function kernel and linear discrimination analysis. Thus, our results suggested that EEG responses to imagined speech could be successfully classified in a single trial using an extreme learning machine with a radial basis function and linear kernel. This study with classification of imagined speech might contribute to the development of silent speech BCI systems. PMID:28097128

Cognitive Existential Couple Therapy for newly diagnosed prostate cancer patients and their partners: a descriptive pilot study.

PubMed

Collins, Anna L; Love, Anthony W; Bloch, Sidney; Street, Annette F; Duchesne, Gillian M; Dunai, Judy; Couper, Jeremy W

2013-02-01

This paper aims to describe 'Cognitive Existential Couple Therapy' (CECT), a novel couples-based intervention for men with early stage prostate cancer (PCa) and their partners, and to report preliminary findings from a pilot study that investigated the acceptability and feasibility of the intervention and the measures to be used in a subsequent randomised controlled trial. A manualised CECT programme was delivered to 12 couples facing a diagnosis of PCa within the previous 12 months by psychiatrists and clinical psychologists. Participants completed measures of psychological distress, marital function and coping pattern before and after CECT. Semi-structured interviews were conducted with nine couples shortly after the completion of CECT. The application of CECT was both feasible and acceptable as indicated by favourable participant compliance (10 of the 12 couples attended all six designated sessions), completion of measures before and after CECT and participation in semi-structured interviews by nine couples. Preliminary results included reduced levels of avoidance and hyperarousal after the programme, with this effect stronger in partners than in patients. Interviews demonstrated that couples valued the therapist's contribution to their overall care. Previous research suggests that a couple-focused psychological intervention is desirable in the context of early stage PCa. This pilot study has established that CECT is acceptable, feasible and valued by couples facing a recent PCa diagnosis and demonstrates a potential for reduced psychological distress following CECT. A randomised controlled trial is currently being undertaken to validate the efficacy of this novel approach. Copyright © 2011 John Wiley & Sons, Ltd.

Probing the Higgs self coupling via single Higgs production at the LHC

DOE PAGES

Degrassi, G.; Giardino, P. P.; Maltoni, F.; ...

2016-12-16

Here, we propose a method to determine the trilinear Higgs self coupling that is alternative to the direct measurement of Higgs pair production total cross sections and differential distributions. Furthermore, the method relies on the effects that electroweak loops featuring an anomalous trilinear coupling would imprint on single Higgs production at the LHC. We first calculate these contributions to all the phenomenologically relevant Higgs production (ggF, VBF, WH, ZH, tmore » $$\\bar{t}$$ ) and decay (γγ,WW*/ZZ*→ 4f, b$$\\bar{b}$$,ττ) modes at the LHC and then estimate the sensitivity to the trilinear coupling via a one-parameter fit to the single Higgs measurements at the LHC 8 TeV. We also found that the bounds on the self coupling are already competitive with those from Higgs pair production and will be further improved in the current and next LHC runs.« less

The Challenges to Coupling Dynamic Geospatial Models

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

Goldstein, N

2006-06-23

Many applications of modeling spatial dynamic systems focus on a single system and a single process, ignoring the geographic and systemic context of the processes being modeled. A solution to this problem is the coupled modeling of spatial dynamic systems. Coupled modeling is challenging for both technical reasons, as well as conceptual reasons. This paper explores the benefits and challenges to coupling or linking spatial dynamic models, from loose coupling, where information transfer between models is done by hand, to tight coupling, where two (or more) models are merged as one. To illustrate the challenges, a coupled model of Urbanizationmore » and Wildfire Risk is presented. This model, called Vesta, was applied to the Santa Barbara, California region (using real geospatial data), where Urbanization and Wildfires occur and recur, respectively. The preliminary results of the model coupling illustrate that coupled modeling can lead to insight into the consequences of processes acting on their own.« less

The Effect of Emotional Focused Intervention on Spousal Emotional Abuse and Marital Satisfaction among Elderly Married Couples: A Randomized Controlled Trial

PubMed Central

Hazrati, Maryam; Hamid, Tengku Aizan; Ibrahim, Rahimah; Hassan, Siti Aishah; Sharif, Farkhondeh; Bagheri, Zahra

2017-01-01

ABSTRACT Background: This study examined the impacts of an Emotional Focused Intervention on emotional abuse behaviors and marital satisfaction among the elderly married couples. Methods: This randomized controlled trial study was carried out in Shiraz-Iran, during September 2013-2014. The elderly couples were invited to join an emotional focused intervention, following the advertisement and announcement on bulletin boards in the elderly day clinic centers and all governmental primary health care centers. Then, 57 couples (114 participants) who were eligible for study were assigned in two groups by block randomization (29 in the experimental and 28 in the control group(.The couples in the experimental group received intervention twice a week for four weeks. Each session lasted 90 minutes. The control group didn’t receive any intervention and the subjects were put in the waiting list. The outcome measures were evaluated by Multidimensional Measure of Emotional Abuse Questionnaire (MMEAQ) and Marital Satisfaction Questionnaire for Older People (MSQFOP). Repeated measurement ANOVA was used to detect any significant changes between groups in their mean scores of emotional abuse behaviors and marital satisfaction from pre- to post-test, and 3 months after the intervention. Analysis of data was performed using SPSS, version 19, and P≤0.05 was measured as significant. Results: The mean duration of marriage was 39.56±9.64 years. In the experimental group, the abusive behaviors decreased significantly (P<0.001) at times 2 and 3 compared with time 1, and marital satisfaction improved significantly only at time 3 (P<0.001). These differences were not significant in the control group. Conclusion: Emotion-focused couple-based interventions are helpful in reducing the spousal emotional abuse and improving marital satisfaction in among the elderly couples. Trial Registration Number: 2013111715426N1 PMID:29043279

Couple and Family Interventions in Health Problems

ERIC Educational Resources Information Center

Shields, Cleveland G.; Finley, Michelle A.; Chawla, Neelu

2012-01-01

Intervention research for couples and families managing chronic health problems is in an early developmental stage. We reviewed randomized clinical trials of family interventions for common neurological diseases, cardiovascular diseases, cancer, and diabetes, which is similar to the content of previous reviews discussed later. One overriding theme…

Interactive weekly mobile phone text messaging plus motivational interviewing in promotion of breastfeeding among women living with HIV in South Africa: study protocol for a randomized controlled trial.

PubMed

Zunza, Moleen; Cotton, Mark F; Mbuagbaw, Lawrence; Lester, Richard; Thabane, Lehana

2017-07-17

South Africa recently phased out access to free formula milk in the public sector in support of breastfeeding for women living with HIV. Few women living with HIV in South Africa choose breastfeeding and among those who do, many stop breastfeeding early. We sought to explore the feasibility of using mobile phone text messaging coupled with motivational interviewing to enhance adherence to breastfeeding practices. A randomized, parallel group, single-center pilot trial. Electronic sequence generation and random allocation will be done centrally. Women of low socioeconomic status, from Cape Town, South Africa will be randomly assigned within 24 h of giving birth at a primary healthcare clinic to a structured weekly text message plus motivational interviewing and usual standard of care, using a permutation of different block sizes. Criteria for feasibility success will include: five participants recruited per week (over 12 weeks), about 75% of all eligible participants consent for study participation, complete evaluation of outcomes in at least 70% of all recruited participants, breastfeeding adherence rates of at least 70% in the intervention group, six months after delivery. Participants will be evaluated soon after giving birth and post-delivery at weeks 2, 6, 10, and 24. Primary analysis will follow the "intention-to-treat" principle. Sub-group analysis will be used to assess sub-group effects. This pilot trial will evaluate the feasibility of conducting a larger trial on communication and support approaches to improve adherence to breastfeeding by HIV-infected women. Text messaging and motivational interviewing are simple interventions which may allow participants to access personalized adherence advice and support. ClinicalTrials.gov: NCT02949713 . Registered on 26 October 2016; Pan African Clinical Trial Registry PACTR201611001855404 . Registered on 8 November 2016.

Controlling the angular radiation of single emitters using dielectric patch nanoantennas

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

Yang, Yuanqing; Li, Qiang; Qiu, Min, E-mail: minqiu@zju.edu.cn

2015-07-20

Dielectric nanoantennas have generated much interest in recent years owing to their low loss and optically induced electric and magnetic resonances. In this paper, we investigate the coupling between a single emitter and dielectric patch nanoantennas. For the coupled system involving non-spherical structures, analytical Mie theory is no longer applicable. A semi-analytical model is proposed instead to interpret the coupling mechanism and the radiation characteristics of the system. Based on the presented model, we demonstrate that the angular emission of the single emitter can be not only enhanced but also rotated using the dielectric patch nanoantennas.

Single-agent tenofovir versus combination emtricitabine plus tenofovir for pre-exposure prophylaxis for HIV-1 acquisition: an update of data from a randomised, double-blind, phase 3 trial.

PubMed

Baeten, Jared M; Donnell, Deborah; Mugo, Nelly R; Ndase, Patrick; Thomas, Katherine K; Campbell, James D; Wangisi, Jonathan; Tappero, Jordan W; Bukusi, Elizabeth A; Cohen, Craig R; Katabira, Elly; Ronald, Allan; Tumwesigye, Elioda; Were, Edwin; Fife, Kenneth H; Kiarie, James; Farquhar, Carey; John-Stewart, Grace; Kidoguchi, Lara; Coombs, Robert W; Hendrix, Craig; Marzinke, Mark A; Frenkel, Lisa; Haberer, Jessica E; Bangsberg, David; Celum, Connie

2014-11-01

Antiretroviral pre-exposure prophylaxis (PrEP), with daily oral tenofovir disoproxil fumarate or tenofovir disoproxil fumarate in combination with emtricitabine, has been shown to be efficacious for HIV-1 prevention. Although the use of more than one antiretroviral agent is essential for effective HIV-1 treatment, more than one agent might not be required for effective prophylaxis. We assessed the efficacy of single-agent tenofovir disoproxil fumarate relative to combination emtricitabine plus tenofovir disoproxil fumarate as PrEP. We did a randomised, double-blind, placebo-controlled three-group phase 3 trial of daily oral tenofovir disoproxil fumarate and emtricitabine plus tenofovir disoproxil fumarate PrEP in HIV-1 uninfected individuals in heterosexual HIV-1 serodiscordant couples from Kenya and Uganda. After an interim review, the trial's placebo group was discontinued and thereafter the active groups were continued, and participants initially randomly assigned to placebo were offered rerandomisation in a 1:1 ratio to tenofovir disoproxil fumarate or emtricitabine plus tenofovir disoproxil fumarate as PrEP. The primary endpoints were HIV-1 seroconversion and safety. This trial is registered with ClinicalTrials.gov, number NCT00557245. 4410 (99·6%) of 4427 couples received tenofovir disoproxil fumarate or emtricitabine plus tenofovir disoproxil fumarate and were followed up for HIV-1 acquisition. Of 52 incident HIV-1 infections, 31 occurred in individuals assigned tenofovir disoproxil fumarate (incidence 0·71 cases per 100 person-years) and 21 were in those assigned emtricitabine plus tenofovir disoproxil fumarate (0·48 cases per 100 person-years); HIV-1 incidence in the placebo group until discontinuation was two cases per 100 person-years. HIV-1 prevention efficacy with emtricitabine plus tenofovir disoproxil fumarate was not significantly different from that of tenofovir disoproxil fumarate alone (hazard ratio [HR] 0·67, 95% CI 0·39-1·17; p=0·16). Detection of tenofovir in plasma samples, compared with no detection and as measured in seroconverters and a subset of non-seroconverters, was associated with an 85% relative risk reduction in HIV-1 acquisition for the tenofovir disoproxil fumarate group (HR 0·15, 95% CI 0·06-0·37; p<0·0001) and 93% for the emtricitabine plus tenofovir disoproxil fumarate group (0·07, 0·02-0·23; p<0·0001). No significant differences were noted in the frequency of deaths, serious adverse events, or serum creatinine and phosphorus abnormalities between the two groups. These results do not rule out the potential for a slight difference in HIV-1 protection with tenofovir disoproxil fumarate compared with emtricitabine plus tenofovir disoproxil fumarate, but show that once-daily oral tenofovir disoproxil fumarate or emtricitabine plus tenofovir disoproxil fumarate regimens both provide high protection against HIV-1 acquisition in heterosexual men and women. Bill & Melinda Gates Foundation and US National Institutes of Health. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effects of Computer-Aided Interlimb Force Coupling Training on Paretic Hand and Arm Motor Control following Chronic Stroke: A Randomized Controlled Trial

PubMed Central

Lin, Chueh-Ho; Chou, Li-Wei; Luo, Hong-Ji; Tsai, Po-Yi; Lieu, Fu-Kong; Chiang, Shang-Lin; Sung, Wen-Hsu

2015-01-01

Objective We investigated the training effects of interlimb force coupling training on paretic upper extremity outcomes in patients with chronic stroke and analyzed the relationship between motor recovery of the paretic hand, arm and functional performances on paretic upper limb. Design A randomized controlled trial with outcome assessment at baseline and after 4 weeks of intervention. Setting Taipei Veterans General Hospital, National Yang-Ming University. Participants Thirty-three subjects with chronic stroke were recruited and randomly assigned to training (n = 16) and control groups (n = 17). Interventions The computer-aided interlimb force coupling training task with visual feedback included different grip force generation methods on both hands. Main Outcome Measures The Barthel Index (BI), the upper extremity motor control Fugl-Meyer Assessment (FMA-UE), the Motor Assessment Score (MAS), and the Wolf Motor Function Test (WMFT). All assessments were executed by a blinded evaluator, and data management and statistical analysis were also conducted by a blinded researcher. Results The training group demonstrated greater improvement on the FMA-UE (p<.001), WMFT (p<.001), MAS (p = .004) and BI (p = .037) than the control group after 4 weeks of intervention. In addition, a moderate correlation was found between the improvement of scores for hand scales of the FMA and other portions of the FMA UE (r = .528, p = .018) or MAS (r = .596, p = .015) in the training group. Conclusion Computer-aided interlimb force coupling training improves the motor recovery of a paretic hand, and facilitates motor control and enhances functional performance in the paretic upper extremity of people with chronic stroke. Trial Registration ClinicalTrials.gov NCT02247674. PMID:26193492

Coupled-resonator waveguide perfect transport single-photon by interatomic dipole-dipole interaction

NASA Astrophysics Data System (ADS)

Yan, Guo-an; Lu, Hua; Qiao, Hao-xue; Chen, Ai-xi; Wu, Wan-qing

2018-06-01

We theoretically investigate single-photon coherent transport in a one-dimensional coupled-resonator waveguide coupled to two quantum emitters with dipole-dipole interactions. The numerical simulations demonstrate that the transmission spectrum of the photon depends on the two atoms dipole-dipole interactions and the photon-atom couplings. The dipole-dipole interactions may change the dip positions in the spectra and the coupling strength may broaden the frequency band width in the transmission spectrum. We further demonstrate that the typical transmission spectra split into two dips due to the dipole-dipole interactions. This phenomenon may be used to manufacture new quantum waveguide devices.

Embedding the dynamics of a single delay system into a feed-forward ring.

PubMed

Klinshov, Vladimir; Shchapin, Dmitry; Yanchuk, Serhiy; Wolfrum, Matthias; D'Huys, Otti; Nekorkin, Vladimir

2017-10-01

We investigate the relation between the dynamics of a single oscillator with delayed self-feedback and a feed-forward ring of such oscillators, where each unit is coupled to its next neighbor in the same way as in the self-feedback case. We show that periodic solutions of the delayed oscillator give rise to families of rotating waves with different wave numbers in the corresponding ring. In particular, if for the single oscillator the periodic solution is resonant to the delay, it can be embedded into a ring with instantaneous couplings. We discover several cases where the stability of a periodic solution for the single unit can be related to the stability of the corresponding rotating wave in the ring. As a specific example, we demonstrate how the complex bifurcation scenario of simultaneously emerging multijittering solutions can be transferred from a single oscillator with delayed pulse feedback to multijittering rotating waves in a sufficiently large ring of oscillators with instantaneous pulse coupling. Finally, we present an experimental realization of this dynamical phenomenon in a system of coupled electronic circuits of FitzHugh-Nagumo type.

A randomized waitlist-controlled trial of culturally sensitive relationship education for male same-sex couples.

PubMed

Whitton, Sarah W; Weitbrecht, Eliza M; Kuryluk, Amanda D; Hutsell, David W

2016-09-01

Relationship education, effective in improving relationship quality among different-sex couples, represents a promising and nonstigmatizing approach to promoting the health and stability of same-sex couples. A new culturally sensitive relationship education program was developed specifically for male same-sex couples, which includes adaptations of evidence-based strategies to build core relationship skills (e.g., communication skills training) and newly developed content to address unique challenges faced by this group (e.g., discrimination; low social support). A small randomized waitlist-control trial (N = 20 couples) was conducted to evaluate the program. To assess program efficacy, dyadic longitudinal data (collected at pre- and postprogram and 3-month follow-up) were analyzed using multilevel models that accounted for nonindependence in data from indistinguishable dyads. Results indicated significant program effects in comparison to waitlist controls on couple constructive and destructive communication, perceived stress, and relationship satisfaction. Gains in each of these areas were maintained at 3-month follow-up. Although there was no evidence of within-person program effects on social support, satisfaction, or relationship instability immediately postprogram, all 3 showed within-person improvements by follow-up. Ratings of program satisfaction were high. In summary, study findings support the feasibility, acceptability, and initial efficacy of the program and highlight the potential value of culturally sensitive adaptations of relationship education for same-sex couples. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Coupling losses between standard single-mode fibers and rectangular waveguides for integrated optics.

PubMed

Lierstuen, L O; Sudbø, A S

1995-02-20

The butt-coupling loss between different tapered rectangular waveguides and a standard single-mode optical fiber has been calculated. Losses as low as 0.16 dB can be reached for waveguides with a refractive-index contrast in the range of 0.5% to 1.96%. The fabrication tolerances are such that practical devices with coupling losses below 0.25 dB are feasible.

Single-molecule strong coupling at room temperature in plasmonic nanocavities

NASA Astrophysics Data System (ADS)

Chikkaraddy, Rohit; de Nijs, Bart; Benz, Felix; Barrow, Steven J.; Scherman, Oren A.; Rosta, Edina; Demetriadou, Angela; Fox, Peter; Hess, Ortwin; Baumberg, Jeremy J.

2016-07-01

Photon emitters placed in an optical cavity experience an environment that changes how they are coupled to the surrounding light field. In the weak-coupling regime, the extraction of light from the emitter is enhanced. But more profound effects emerge when single-emitter strong coupling occurs: mixed states are produced that are part light, part matter, forming building blocks for quantum information systems and for ultralow-power switches and lasers. Such cavity quantum electrodynamics has until now been the preserve of low temperatures and complicated fabrication methods, compromising its use. Here, by scaling the cavity volume to less than 40 cubic nanometres and using host-guest chemistry to align one to ten protectively isolated methylene-blue molecules, we reach the strong-coupling regime at room temperature and in ambient conditions. Dispersion curves from more than 50 such plasmonic nanocavities display characteristic light-matter mixing, with Rabi frequencies of 300 millielectronvolts for ten methylene-blue molecules, decreasing to 90 millielectronvolts for single molecules—matching quantitative models. Statistical analysis of vibrational spectroscopy time series and dark-field scattering spectra provides evidence of single-molecule strong coupling. This dressing of molecules with light can modify photochemistry, opening up the exploration of complex natural processes such as photosynthesis and the possibility of manipulating chemical bonds.

Evidence for single-dose protection by the bivalent HPV vaccine-Review of the Costa Rica HPV vaccine trial and future research studies.

PubMed

Kreimer, Aimée R; Herrero, Rolando; Sampson, Joshua N; Porras, Carolina; Lowy, Douglas R; Schiller, John T; Schiffman, Mark; Rodriguez, Ana Cecilia; Chanock, Stephen; Jimenez, Silvia; Schussler, John; Gail, Mitchell H; Safaeian, Mahboobeh; Kemp, Troy J; Cortes, Bernal; Pinto, Ligia A; Hildesheim, Allan; Gonzalez, Paula

2018-01-20

The Costa Rica Vaccine Trial (CVT), a phase III randomized clinical trial, provided the initial data that one dose of the HPV vaccine could provide durable protection against HPV infection. Although the study design was to administer all participants three doses of HPV or control vaccine, 20% of women did not receive the three-dose regimens, mostly due to involuntary reasons unrelated to vaccination. In 2011, we reported that a single dose of the bivalent HPV vaccine could be as efficacious as three doses of the vaccine using the endpoint of persistent HPV infection accumulated over the first four years of the trial; findings independently confirmed in the GSK-sponsored PATRICIA trial. Antibody levels after one dose, although lower than levels elicited by three doses, were 9-times higher than levels elicited by natural infection. Importantly, levels remained essentially constant over at least seven years, suggesting that the observed protection provided by a single dose might be durable. Much work has been done to assure these non-randomized findings are valid. Yet, the group of recipients who received one dose of the bivalent HPV vaccine in the CVT and PATRICIA trials was small and not randomly selected nor blinded to the number of doses received. The next phase of research is to conduct a formal randomized, controlled trial to evaluate the protection afforded by a single dose of HPV vaccine. Complementary studies are in progress to bridge our findings to other populations, and to further document the long-term durability of antibody response following a single dose. Published by Elsevier Ltd.

How I treat and manage strokes in sickle cell disease

PubMed Central

Kassim, Adetola A.; Galadanci, Najibah A.; Pruthi, Sumit

2015-01-01

Neurologic complications are a major cause of morbidity and mortality in sickle cell disease (SCD). In children with sickle cell anemia, routine use of transcranial Doppler screening, coupled with regular blood transfusion therapy, has decreased the prevalence of overt stroke from ∼11% to 1%. Limited evidence is available to guide acute and chronic management of individuals with SCD and strokes. Current management strategies are based primarily on single arm clinical trials and observational studies, coupled with principles of neurology and hematology. Initial management of a focal neurologic deficit includes evaluation by a multidisciplinary team (a hematologist, neurologist, neuroradiologist, and transfusion medicine specialist); prompt neuro-imaging and an initial blood transfusion (simple followed immediately by an exchange transfusion or only exchange transfusion) is recommended if the hemoglobin is >4 gm/dL and <10 gm/dL. Standard therapy for secondary prevention of strokes and silent cerebral infarcts includes regular blood transfusion therapy and in selected cases, hematopoietic stem cell transplantation. A critical component of the medical care following an infarct is cognitive and physical rehabilitation. We will discuss our strategy of acute and long-term management of strokes in SCD. PMID:25824688

Bimetallic catalysis for C–C and C–X coupling reactions

PubMed Central

Pye, Dominic R.

2017-01-01

Bimetallic catalysis represents an alternative paradigm for coupling chemistry that complements the more traditional single-site catalysis approach. In this perspective, recent advances in bimetallic systems for catalytic C–C and C–X coupling reactions are reviewed. Behavior which complements that of established single-site catalysts is highlighted. Two major reaction classes are covered. First, generation of catalytic amounts of organometallic species of e.g. Cu, Au, or Ni capable of transmetallation to a Pd co-catalyst (or other traditional cross-coupling catalyst) has allowed important new C–C coupling technologies to emerge. Second, catalytic transformations involving binuclear bond-breaking and/or bond-forming steps, in some cases involving metal–metal bonds, represent a frontier area for C–C and C–X coupling processes.

Single photon sources with single semiconductor quantum dots

NASA Astrophysics Data System (ADS)

Shan, Guang-Cun; Yin, Zhang-Qi; Shek, Chan Hung; Huang, Wei

2014-04-01

In this contribution, we briefly recall the basic concepts of quantum optics and properties of semiconductor quantum dot (QD) which are necessary to the understanding of the physics of single-photon generation with single QDs. Firstly, we address the theory of quantum emitter-cavity system, the fluorescence and optical properties of semiconductor QDs, and the photon statistics as well as optical properties of the QDs. We then review the localization of single semiconductor QDs in quantum confined optical microcavity systems to achieve their overall optical properties and performances in terms of strong coupling regime, efficiency, directionality, and polarization control. Furthermore, we will discuss the recent progress on the fabrication of single photon sources, and various approaches for embedding single QDs into microcavities or photonic crystal nanocavities and show how to extend the wavelength range. We focus in particular on new generations of electrically driven QD single photon source leading to high repetition rates, strong coupling regime, and high collection efficiencies at elevated temperature operation. Besides, new developments of room temperature single photon emission in the strong coupling regime are reviewed. The generation of indistinguishable photons and remaining challenges for practical single-photon sources are also discussed.

Acute effects of a single exercise class on appetite, energy intake and mood. Is there a time of day effect?

PubMed

Maraki, M; Tsofliou, F; Pitsiladis, Y P; Malkova, D; Mutrie, N; Higgins, S

2005-12-01

This study aimed to investigate the acute effects of a single exercise class on appetite sensations, energy intake and mood, and to determine if there was a time of day effect. Twelve healthy, young, normal weight females, who were non-regular exercisers, participated in four trials: morning control, morning exercise, evening control and evening exercise. Exercise trials were a one-hour class of aerobic and muscle conditioning exercise of varying intensities, to music. Control trials were a one-hour rest. Ratings of perceived exertion were significantly greater during the warm-up and muscle conditioning parts of the morning exercise trial compared to those of the evening exercise trial. Although both exercise trials, compared to control trials, produced an increase in appetite sensations, they did not alter energy intake and produced a decrease in 'relative' energy intake. In relation to mood, both exercise trials increased positive affect and decreased negative affect. These results suggest that a single exercise class, representative of that offered by many sports centres, regardless of whether it is performed in the morning or evening produces a short-term negative energy balance and improves mood in normal weight women. However, when this type of exercise was performed in the morning it was perceived to require more effort.

Research design considerations for single-dose analgesic clinical trials in acute pain: IMMPACT recommendations.

PubMed

Cooper, Stephen A; Desjardins, Paul J; Turk, Dennis C; Dworkin, Robert H; Katz, Nathaniel P; Kehlet, Henrik; Ballantyne, Jane C; Burke, Laurie B; Carragee, Eugene; Cowan, Penney; Croll, Scott; Dionne, Raymond A; Farrar, John T; Gilron, Ian; Gordon, Debra B; Iyengar, Smriti; Jay, Gary W; Kalso, Eija A; Kerns, Robert D; McDermott, Michael P; Raja, Srinivasa N; Rappaport, Bob A; Rauschkolb, Christine; Royal, Mike A; Segerdahl, Märta; Stauffer, Joseph W; Todd, Knox H; Vanhove, Geertrui F; Wallace, Mark S; West, Christine; White, Richard E; Wu, Christopher

2016-02-01

This article summarizes the results of a meeting convened by the Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials (IMMPACT) on key considerations and best practices governing the design of acute pain clinical trials. We discuss the role of early phase clinical trials, including pharmacokinetic-pharmacodynamic (PK-PD) trials, and the value of including both placebo and active standards of comparison in acute pain trials. This article focuses on single-dose and short-duration trials with emphasis on the perioperative and study design factors that influence assay sensitivity. Recommendations are presented on assessment measures, study designs, and operational factors. Although most of the methodological advances have come from studies of postoperative pain after dental impaction, bunionectomy, and other surgeries, the design considerations discussed are applicable to many other acute pain studies conducted in different settings.

Client Narratives about Experiences with a Multicouple Treatment Program for Intimate Partner Violence

ERIC Educational Resources Information Center

Todahl, Jeff; Linville, Deanna; Tuttle Shamblin, Abby F.; Ball, David

2012-01-01

A handful of clinical trials have concluded that conjoint couples treatment for intimate partner violence is safe and at least as effective as conventional batterer intervention programs, yet very few researchers have explored couples' perspectives on conjoint treatment. Using qualitative narrative analysis methodology, the researchers conducted…

Design of 150W, 105-μm, 0.22NA, fiber coupled laser diode module by ZEMAX

NASA Astrophysics Data System (ADS)

Qi, Yunfei; Zhao, Pengfei; Chen, Qing; Wu, Yulong; Chen, Yongqi; Zou, Yonggang; Lin, Xuechun

2016-10-01

We represent a design of a high brightness, fiber coupled diode laser module based on 16 single emitters at 915nm. The module can produce more than 150 Watts output power from a standard fiber with core diameter of 105μm and numerical aperture (NA) of 0.22. To achieve a high power and high brightness laser beam, the spatial beam combination and polarization beam combination are used to combine output of 16 single emitters into a single beam, and then an aspheric lens is used to couple the combined beam into an optical fiber. The simulation show that the total coupling efficiency is more than 95% and the highest brightness is estimated to be 11MW/ (cm2*sr).

Adiabatic regularization of the power spectrum in nonminimally coupled general single-field inflation

NASA Astrophysics Data System (ADS)

Alinea, Allan L.; Kubota, Takahiro

2018-03-01

We perform adiabatic regularization of power spectrum in nonminimally coupled general single-field inflation with varying speed of sound. The subtraction is performed within the framework of earlier study by Urakawa and Starobinsky dealing with the canonical inflation. Inspired by Fakir and Unruh's model on nonminimally coupled chaotic inflation, we find upon imposing near scale-invariant condition, that the subtraction term exponentially decays with the number of e -folds. As in the result for the canonical inflation, the regularized power spectrum tends to the "bare" power spectrum as the Universe expands during (and even after) inflation. This work justifies the use of the "bare" power spectrum in standard calculation in the most general context of slow-roll single-field inflation involving nonminimal coupling and varying speed of sound.

Parabolic dish collectors - A solar option

NASA Astrophysics Data System (ADS)

Truscello, V. C.

1981-05-01

A description is given of several parabolic-dish high temperature solar thermal systems currently undergoing performance trials. A single parabolic dish has the potential for generating 20 to 30 kW of electricity with fluid temperatures from 300 to 1650 C. Each dish is a complete power-producing unit, and may function either independently or as part of a group of linked modules. The two dish designs under consideration are of 11 and 12 meter diameters, yielding receiver operating temperatures of 925 and 815 C, respectively. The receiver designs described include (1) an organic working fluid (toluene) Rankine cycle engine; (2) a Brayton open cycle unit incorporating a hybrid combustion chamber and nozzle and a shaft-coupled permanent magnet alternator; and (3) a modified Stirling cycle device originally designed for automotive use. Also considered are thermal buffer energy storage and thermochemical transport and storage.

Single-visit or multiple-visit root canal treatment: systematic review, meta-analysis and trial sequential analysis.

PubMed

Schwendicke, Falk; Göstemeyer, Gerd

2017-02-01

Single-visit root canal treatment has some advantages over conventional multivisit treatment, but might increase the risk of complications. We systematically evaluated the risk of complications after single-visit or multiple-visit root canal treatment using meta-analysis and trial-sequential analysis. Controlled trials comparing single-visit versus multiple-visit root canal treatment of permanent teeth were included. Trials needed to assess the risk of long-term complications (pain, infection, new/persisting/increasing periapical lesions ≥1 year after treatment), short-term pain or flare-up (acute exacerbation of initiation or continuation of root canal treatment). Electronic databases (PubMed, EMBASE, Cochrane Central) were screened, random-effects meta-analyses performed and trial-sequential analysis used to control for risk of random errors. Evidence was graded according to GRADE. 29 trials (4341 patients) were included, all but 6 showing high risk of bias. Based on 10 trials (1257 teeth), risk of complications was not significantly different in single-visit versus multiple-visit treatment (risk ratio (RR) 1.00 (95% CI 0.75 to 1.35); weak evidence). Based on 20 studies (3008 teeth), risk of pain did not significantly differ between treatments (RR 0.99 (95% CI 0.76 to 1.30); moderate evidence). Risk of flare-up was recorded by 8 studies (1110 teeth) and was significantly higher after single-visit versus multiple-visit treatment (RR 2.13 (95% CI 1.16 to 3.89); very weak evidence). Trial-sequential analysis revealed that firm evidence for benefit, harm or futility was not reached for any of the outcomes. There is insufficient evidence to rule out whether important differences between both strategies exist. Dentists can provide root canal treatment in 1 or multiple visits. Given the possibly increased risk of flare-ups, multiple-visit treatment might be preferred for certain teeth (eg, those with periapical lesions). Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Grand average ERP-image plotting and statistics: A method for comparing variability in event-related single-trial EEG activities across subjects and conditions

PubMed Central

Delorme, Arnaud; Miyakoshi, Makoto; Jung, Tzyy-Ping; Makeig, Scott

2014-01-01

With the advent of modern computing methods, modeling trial-to-trial variability in biophysical recordings including electroencephalography (EEG) has become of increasingly interest. Yet no widely used method exists for comparing variability in ordered collections of single-trial data epochs across conditions and subjects. We have developed a method based on an ERP-image visualization tool in which potential, spectral power, or some other measure at each time point in a set of event-related single-trial data epochs are represented as color coded horizontal lines that are then stacked to form a 2-D colored image. Moving-window smoothing across trial epochs can make otherwise hidden event-related features in the data more perceptible. Stacking trials in different orders, for example ordered by subject reaction time, by context-related information such as inter-stimulus interval, or some other characteristic of the data (e.g., latency-window mean power or phase of some EEG source) can reveal aspects of the multifold complexities of trial-to-trial EEG data variability. This study demonstrates new methods for computing and visualizing grand ERP-image plots across subjects and for performing robust statistical testing on the resulting images. These methods have been implemented and made freely available in the EEGLAB signal-processing environment that we maintain and distribute. PMID:25447029

[Enhanced prenatal HIV couple oriented counselling session and couple communication about HIV (ANRS 12127 Prenahtest Trial)].

PubMed

Plazy, M; Orne-Gliemann, J; Balestre, E; Miric, M; Darak, S; Butsashvili, M; Tchendjou, P; Dabis, F; Desgrées du Loû, A

2013-08-01

The Prenahtest study investigated the efficacy of a couple-oriented HIV counselling session (COC) in encouraging couple HIV counselling and testing, and improving intra-couple communication about sexual and reproductive health. We report here on the effect of COC on intra-couple communication about HIV. Within this 4-country trial (India, Georgia, Dominican Republic and Cameroon), 484 to 491 pregnant women per site were recruited and individually randomized to receive either the COC intervention, enhanced counselling with role playing, or standard post-test HIV counselling. Women were interviewed at recruitment, before HIV testing (T0), and 2 to 8 weeks after post-test HIV counselling (T1). Four dichotomous variables documented intra-couple communication about HIV at T1: 1) discussion about HIV, 2) discussion about condom use, 3) suggesting HIV testing and 4) suggesting couple HIV counselling to the partner. An intra-couple HIV communication index was created: low degree of communication ("yes" response to zero or one of the four variables), intermediate degree of communication ("yes" to two or three variables) or high degree of communication ("yes" to the four variables). To estimate the impact of COC on the intra-couple HIV communication index, multivariable logistic regressions were conducted. One thousand six hundred and seven women were included in the analysis of whom 54 (3.4%) were HIV-infected (49 in Cameroon). In the four countries, the counselling group was associated with intra-couple HIV communication (P≤0.03): women allocated to the COC group were significantly more likely to report high or intermediate degrees of intra-couple communication about HIV (versus low degree of communication) than women allocated to standard counselling. COC improved short-term communication about HIV within couples in different sociocultural contexts, a positive finding for a couple approach to HIV prevention. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Novel spot size converter for coupling standard single mode fibers to SOI waveguides

NASA Astrophysics Data System (ADS)

Sisto, Marco Michele; Fisette, Bruno; Paultre, Jacques-Edmond; Paquet, Alex; Desroches, Yan

2016-03-01

We have designed and numerically simulated a novel spot size converter for coupling standard single mode fibers with 10.4μm mode field diameter to 500nm × 220nm SOI waveguides. Simulations based on the eigenmode expansion method show a coupling loss of 0.4dB at 1550nm for the TE mode at perfect alignment. The alignment tolerance on the plane normal to the fiber axis is evaluated at +/-2.2μm for <=1dB excess loss, which is comparable to the alignment tolerance between two butt-coupled standard single mode fibers. The converter is based on a cross-like arrangement of SiOxNy waveguides immersed in a 12μm-thick SiO2 cladding region deposited on top of the SOI chip. The waveguides are designed to collectively support a single degenerate mode for TE and TM polarizations. This guided mode features a large overlap to the LP01 mode of standard telecom fibers. Along the spot size converter length (450μm), the mode is first gradually confined in a single SiOxNy waveguide by tapering its width. Then, the mode is adiabatically coupled to a SOI waveguide underneath the structure through a SOI inverted taper. The shapes of SiOxNy and SOI tapers are optimized to minimize coupling loss and structure length, and to ensure adiabatic mode evolution along the structure, thus improving the design robustness to fabrication process errors. A tolerance analysis based on conservative microfabrication capabilities suggests that coupling loss penalty from fabrication errors can be maintained below 0.3dB. The proposed spot size converter is fully compliant to industry standard microfabrication processes available at INO.

EEG Source Reconstruction Reveals Frontal-Parietal Dynamics of Spatial Conflict Processing

PubMed Central

Cohen, Michael X; Ridderinkhof, K. Richard

2013-01-01

Cognitive control requires the suppression of distracting information in order to focus on task-relevant information. We applied EEG source reconstruction via time-frequency linear constrained minimum variance beamforming to help elucidate the neural mechanisms involved in spatial conflict processing. Human subjects performed a Simon task, in which conflict was induced by incongruence between spatial location and response hand. We found an early (∼200 ms post-stimulus) conflict modulation in stimulus-contralateral parietal gamma (30–50 Hz), followed by a later alpha-band (8–12 Hz) conflict modulation, suggesting an early detection of spatial conflict and inhibition of spatial location processing. Inter-regional connectivity analyses assessed via cross-frequency coupling of theta (4–8 Hz), alpha, and gamma power revealed conflict-induced shifts in cortical network interactions: Congruent trials (relative to incongruent trials) had stronger coupling between frontal theta and stimulus-contrahemifield parietal alpha/gamma power, whereas incongruent trials had increased theta coupling between medial frontal and lateral frontal regions. These findings shed new light into the large-scale network dynamics of spatial conflict processing, and how those networks are shaped by oscillatory interactions. PMID:23451201

Cortical theta wanes for language.

PubMed

Hermes, Dora; Miller, Kai J; Vansteensel, Mariska J; Edwards, Erik; Ferrier, Cyrille H; Bleichner, Martin G; van Rijen, Peter C; Aarnoutse, Erik J; Ramsey, Nick F

2014-01-15

The role of low frequency oscillations in language areas is not yet understood. Using ECoG in six human subjects, we studied whether different language regions show prominent power changes in a specific rhythm, in similar manner as the alpha rhythm shows the most prominent power changes in visual areas. Broca's area and temporal language areas were localized in individual subjects using fMRI. In these areas, the theta rhythm showed the most pronounced power changes and theta power decreased significantly during verb generation. To better understand the role of this language-related theta decrease, we then studied the interaction between low frequencies and local neuronal activity reflected in high frequencies. Amplitude-amplitude correlations showed that theta power correlated negatively with high frequency activity, specifically across verb generation trials. Phase-amplitude coupling showed that during control trials, high frequency power was coupled to theta phase, but this coupling decreased significantly during verb generation trials. These results suggest a dynamic interaction between the neuronal mechanisms underlying the theta rhythm and local neuronal activity in language areas. As visual areas show a pronounced alpha rhythm that may reflect pulsed inhibition, language regions show a pronounced theta rhythm with highly similar features. © 2013.

A research protocol for a pilot randomized controlled trial designed to examine the feasibility of a couple-based mind-body intervention for patients with metastatic lung cancer and their partners.

PubMed

Milbury, Kathrin; Tsao, Anne S; Liao, Zhongxing; Owns, April; Engle, Rosalinda; Gonzalez, Edrea A; Bruera, Eduardo; Cohen, Lorenzo

2018-01-01

Given the generally incurable nature of metastatic non-small cell lung cancer (mNSCLC), patients and their romantic partners are at risk for existential/spiritual distress. Although a handful of dyadic psychosocial interventions for lung cancer patients and their caregivers exist, none of them target spiritual well-being. Informed by the mindfulness-based intervention literature and our pilot work in couples affected by lung cancer, we developed a brief couple-based mind-body (CBMB) intervention. The primary aim of this research protocol is to determine the feasibility of implementing the CBMB intervention versus an active control (AC) or wait list control (WLC) group in patients with mNSCLC and their partners using a randomized controlled trial design. Seventy-five patients with mNSCLC receiving treatment and their partners are randomized to the CBMB intervention, an AC or a WLC group. Those in the CBMB intervention and AC groups receive four intervention sessions of 60 min each over 4 weeks and complete weekly homework assignments. The first session is delivered in person, and the remaining sessions are delivered via videoconference. The dyads in the AC group discuss cancer-related and personal growth concerns with the interventionist but are not taught coping skills. Patients and partners in all groups complete baseline assessments of quality of life (QOL) prior to randomization. Follow-up assessments are performed 4 weeks and then again 3 months later. The primary outcome is feasibility (i.e., ≥ 30% of eligible couples consent, ≥ 70% of enrolled couples are retained, and ≥ 50% of all CBMB and AC sessions are attended). We will also perform primarily descriptive analyses of the self-reported outcomes (e.g., spiritual well-being and psychological distress) and explore potential intervention mediators (i.e., compassion, communication, mindfulness, and closeness) to inform a larger, future trial. This trial will provide important information regarding the feasibility of a behavioral intervention in a vulnerable yet understudied population using videoconferencing and descriptive data regarding spiritual well-being and other indices of QOL in both mNSCLC patients and their partners. ClinicalTrials.gov NCT02596490.

Affective Synchrony in Dual- and Single-Smoker Couples: Further Evidence of “Symptom-System Fit”?

PubMed Central

ROHRBAUGH, MICHAEL J.; SHOHAM, VARDA; BUTLER, EMILYA.; HASLER, BRANT P.; BERMAN, JEFFREY S.

2009-01-01

Couples in which one or both partners smoked despite one of them having a heart or lung problem discussed a health-related disagreement before and during a period of laboratory smoking. Immediately afterwards, the partners in these 25 couples used independent joysticks to recall their continuous emotional experience during the interaction while watching themselves on video. A couple-level index of affective synchrony, reflecting correlated moment-to-moment change in the two partners’ joystick ratings, tended to increase from baseline to smoking for 9 dual-smoker couples but decrease for 16 single-smoker couples. Results suggest that coregulation of shared emotional experience could be a factor in smoking persistence, particularly when both partners in a couple smoke. Relationship-focused interventions addressing this fit between symptom and system may help smokers achieve stable cessation. PMID:19378645

High-fidelity gates towards a scalable superconducting quantum processor

NASA Astrophysics Data System (ADS)

Chow, Jerry M.; Corcoles, Antonio D.; Gambetta, Jay M.; Rigetti, Chad; Johnson, Blake R.; Smolin, John A.; Merkel, Seth; Poletto, Stefano; Rozen, Jim; Rothwell, Mary Beth; Keefe, George A.; Ketchen, Mark B.; Steffen, Matthias

2012-02-01

We experimentally explore the implementation of high-fidelity gates on multiple superconducting qubits coupled to multiple resonators. Having demonstrated all-microwave single and two qubit gates with fidelities > 90% on multi-qubit single-resonator systems, we expand the application to qubits across two resonators and investigate qubit coupling in this circuit. The coupled qubit-resonators are building blocks towards two-dimensional lattice networks for the application of surface code quantum error correction algorithms.

A two-locus global DNA barcode for land plants: the coding rbcL gene complements the non-coding trnH-psbA spacer region.

PubMed

Kress, W John; Erickson, David L

2007-06-06

A useful DNA barcode requires sufficient sequence variation to distinguish between species and ease of application across a broad range of taxa. Discovery of a DNA barcode for land plants has been limited by intrinsically lower rates of sequence evolution in plant genomes than that observed in animals. This low rate has complicated the trade-off in finding a locus that is universal and readily sequenced and has sufficiently high sequence divergence at the species-level. Here, a global plant DNA barcode system is evaluated by comparing universal application and degree of sequence divergence for nine putative barcode loci, including coding and non-coding regions, singly and in pairs across a phylogenetically diverse set of 48 genera (two species per genus). No single locus could discriminate among species in a pair in more than 79% of genera, whereas discrimination increased to nearly 88% when the non-coding trnH-psbA spacer was paired with one of three coding loci, including rbcL. In silico trials were conducted in which DNA sequences from GenBank were used to further evaluate the discriminatory power of a subset of these loci. These trials supported the earlier observation that trnH-psbA coupled with rbcL can correctly identify and discriminate among related species. A combination of the non-coding trnH-psbA spacer region and a portion of the coding rbcL gene is recommended as a two-locus global land plant barcode that provides the necessary universality and species discrimination.

Mode coupling in hybrid square-rectangular lasers for single mode operation

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

Ma, Xiu-Wen; Huang, Yong-Zhen, E-mail: yzhuang@semi.ac.cn; Yang, Yue-De

Mode coupling between a square microcavity and a Fabry-Pérot (FP) cavity is proposed and demonstrated for realizing single mode lasers. The modulations of the mode Q factor as simulation results are observed and single mode operation is obtained with a side mode suppression ratio of 46 dB and a single mode fiber coupling loss of 3.2 dB for an AlGaInAs/InP hybrid laser as a 300-μm-length and 1.5-μm-wide FP cavity connected to a vertex of a 10-μm-side square microcavity. Furthermore, tunable single mode operation is demonstrated with a continuous wavelength tuning range over 10 nm. The simple hybrid structure may shed light on practicalmore » applications of whispering-gallery mode microcavities in large-scale photonic integrated circuits and optical communication and interconnection.« less

Single, double or multiple-injection techniques for non-ultrasound guided axillary brachial plexus block in adults undergoing surgery of the lower arm.

PubMed

Chin, Ki Jinn; Alakkad, Husni; Cubillos, Javier E

2013-08-08

Regional anaesthesia comprising axillary block of the brachial plexus is a common anaesthetic technique for distal upper limb surgery. This is an update of a review first published in 2006 and updated in 2011. To compare the relative effects (benefits and harms) of three injection techniques (single, double and multiple) of axillary block of the brachial plexus for distal upper extremity surgery. We considered these effects primarily in terms of anaesthetic effectiveness; the complication rate (neurological and vascular); and pain and discomfort caused by performance of the block. We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library), MEDLINE, EMBASE and reference lists of trials. We contacted trial authors. The date of the last search was March 2013 (updated from March 2011). We included randomized controlled trials that compared double with single-injection techniques, multiple with single-injection techniques, or multiple with double-injection techniques for axillary block in adults undergoing surgery of the distal upper limb. We excluded trials using ultrasound-guided techniques. Independent study selection, risk of bias assessment and data extraction were performed by at least two investigators. We undertook meta-analysis. The 21 included trials involved a total of 2148 participants who received regional anaesthesia for hand, wrist, forearm or elbow surgery. Risk of bias assessment indicated that trial design and conduct were generally adequate; the most common areas of weakness were in blinding and allocation concealment.Eight trials comparing double versus single injections showed a statistically significant decrease in primary anaesthesia failure (risk ratio (RR 0.51), 95% confidence interval (CI) 0.30 to 0.85). Subgroup analysis by method of nerve location showed that the effect size was greater when neurostimulation was used rather than the transarterial technique.Eight trials comparing multiple with single injections showed a statistically significant decrease in primary anaesthesia failure (RR 0.25, 95% CI 0.14 to 0.44) and of incomplete motor block (RR 0.61, 95% CI 0.39 to 0.96) in the multiple injection group.Eleven trials comparing multiple with double injections showed a statistically significant decrease in primary anaesthesia failure (RR 0.28, 95% CI 0.20 to 0.40) and of incomplete motor block (RR 0.55, 95% CI 0.36 to 0.85) in the multiple injection group.Tourniquet pain was significantly reduced with multiple injections compared with double injections (RR 0.53, 95% CI 0.33 to 0.84). Otherwise there were no statistically significant differences between groups in any of the three comparisons on secondary analgesia failure, complications and patient discomfort. The time for block performance was significantly shorter for single and double injections compared with multiple injections. This review provides evidence that multiple-injection techniques using nerve stimulation for axillary plexus block produce more effective anaesthesia than either double or single-injection techniques. However, there was insufficient evidence for a significant difference in other outcomes, including safety.

Numerical aperture limits on efficient ball lens coupling of laser diodes to single-mode fibers with defocus to balance spherical aberration

NASA Technical Reports Server (NTRS)

Wilson, R. Gale

1994-01-01

The potential capabilities and limitations of single ball lenses for coupling laser diode radiation to single-mode optical fibers have been analyzed; parameters important to optical communications were specifically considered. These parameters included coupling efficiency, effective numerical apertures, lens radius, lens refractive index, wavelength, magnification in imaging the laser diode on the fiber, and defocus to counterbalance spherical aberration of the lens. Limiting numerical apertures in object and image space were determined under the constraint that the lens perform to the Rayleigh criterion of 0.25-wavelength (Strehl ratio = 0.80). The spherical aberration-defocus balance to provide an optical path difference of 0.25 wavelength units was shown to define a constant coupling efficiency (i.e., 0.56). The relative numerical aperture capabilities of the ball lens were determined for a set of wavelengths and associated fiber-core diameters of particular interest for single-mode fiber-optic communication. The results support general continuing efforts in the optical fiber communications industry to improve coupling links within such systems with emphasis on manufacturing simplicity, system packaging flexibility, relaxation of assembly alignment tolerances, cost reduction of opto-electronic components and long term reliability and stability.

Coupling of small, low-loss hexapole mode with photonic crystal slab waveguide mode.

PubMed

Kim, Guk-Hyun; Lee, Yong-Hee; Shinya, Akihiko; Notomi, Masaya

2004-12-27

Coupling characteristics between the single-cell hexapole mode and the triangular-lattice photonic crystal slab waveguide mode is studied by the finite-difference time-domain method. The single-cell hexapole mode has a high quality factor (Q) of 3.3Chi106 and a small modal volume of 1.18(lambda/n)3. Based on the symmetry, three representative types of coupling geometries (shoulder-couple, butt-couple and side-couple structures) are selected and tested. The coupling efficiency shows strong dependence on the transverse overlap of the cavity mode and the waveguide mode over the region of the waveguide. The shoulder-couple structure shows best coupling characteristics among three tested structures. For example, two shouldercouple waveguides and a hexapole cavity result in a high performance resonant-tunneling-filter with Q of 9.7Chi105 and transmittance of 0.48. In the side-couple structure, the coupling strength is much weaker than that of the shoulder-couple structure because of the poor spatial overlap between the mode profiles. In the direct-couple structure, the energy transfer from the cavity to the waveguide is prohibited because of the symmetry mismatch and no coupling is observed.

Coherent interaction of single molecules and plasmonic nanowires

NASA Astrophysics Data System (ADS)

Gerhardt, Ilja; Grotz, Bernhard; Siyushev, Petr; Wrachtrup, Jörg

2017-09-01

Quantum plasmonics opens the option to integrate complex quantum optical circuitry onto chip scale devices. In the past, often external light sources were used and nonclassical light was coupled in and out of plasmonic structures, such as hole arrays or waveguide structures. Another option to launch single plasmonic excitations is the coupling of single emitters in the direct proximity of, e.g., a silver or gold nanostructure. Here, we present our attempts to integrate the research of single emitters with wet-chemically grown silver nanowires. The emitters of choice are single organic dye molecules under cryogenic conditions, which are known to act as high-brightness and extremely narrow-band single photon sources. Another advantage is their high optical nonlinearity, such that they might mediate photon-photon interactions on the nanoscale. We report on the coupling of a single molecule fluorescence emission through the wire over the length of several wavelengths. The transmission of coherently emitted photons is proven by an extinction type experiment. As for influencing the spectral properties of a single emitter, we are able to show a remote change of the line-width of a single terrylene molecule, which is in close proximity to the nanowire.

Coupling Single-Mode Fiber to Uniform and Symmetrically Tapered Thin-Film Waveguide Structures Using Gadolinium Gallium Garnet

NASA Technical Reports Server (NTRS)

Gadi, Jagannath; Yalamanchili, Raj; Shahid, Mohammad

1995-01-01

The need for high efficiency components has grown significantly due to the expanding role of fiber optic communications for various applications. Integrated optics is in a state of metamorphosis and there are many problems awaiting solutions. One of the main problems being the lack of a simple and efficient method of coupling single-mode fibers to thin-film devices for integrated optics. In this paper, optical coupling between a single-mode fiber and a uniform and tapered thin-film waveguide is theoretically modeled and analyzed. A novel tapered structure presented in this paper is shown to produce perfect match for power transfer.

Single photon detection in a waveguide-coupled Ge-on-Si lateral avalanche photodiode.

PubMed

Martinez, Nicholas J D; Gehl, Michael; Derose, Christopher T; Starbuck, Andrew L; Pomerene, Andrew T; Lentine, Anthony L; Trotter, Douglas C; Davids, Paul S

2017-07-10

We examine gated-Geiger mode operation of an integrated waveguide-coupled Ge-on-Si lateral avalanche photodiode (APD) and demonstrate single photon detection at low dark count for this mode of operation. Our integrated waveguide-coupled APD is fabricated using a selective epitaxial Ge-on-Si growth process resulting in a separate absorption and charge multiplication (SACM) design compatible with our silicon photonics platform. Single photon detection efficiency and dark count rate is measured as a function of temperature in order to understand and optimize performance characteristics in this device. We report single photon detection of 5.27% at 1310 nm and a dark count rate of 534 kHz at 80 K for a Ge-on-Si single photon avalanche diode. Dark count rate is the lowest for a Ge-on-Si single photon detector in this range of temperatures while maintaining competitive detection efficiency. A jitter of 105 ps was measured for this device.

Two semiconductor ring lasers coupled by a single-waveguide for optical memory operation

NASA Astrophysics Data System (ADS)

Van der Sande, Guy; Coomans, Werner; Gelens, Lendert

2014-05-01

Semiconductor ring lasers are semiconductor lasers where the laser cavity consists of a ring-shaped waveguide. SRLs are highly integrable and scalable, making them ideal candidates for key components in photonic integrated circuits. SRLs can generate light in two counterpropagating directions between which bistability has been demonstrated. Hence, information can be coded into the emission direction. This bistable operation allows SRLs to be used in systems for all-optical switching and as all-optical memories. For the demonstration of fast optical flip-flop operation, Hill et al. [Nature 432, 206 (2004)] fabricated two SRLs coupled by a single waveguide, rather than a solitary SRL. Nevertheless, the literature shows that a single SRL can also function perfectly as an all-optical memory. In our recent paper [W. Coomans et al., Phys. Rev. A 88, 033813, (2013)], we have raised the question whether coupling two SRLs to realize a single optical memory has any advantage over using a solitary SRL, taking into account the obvious disadvantage of a doubled footprint and power consumption. To provide the answer, we have presented in that paper a numerical study of the dynamical behavior of semiconductor ring lasers coupled by a single bus waveguide, both when weakly coupled and when strongly coupled. We have provided a detailed analysis of the multistable landscape in the coupled system, analyzed the stability of all solutions and related the internal dynamics in the individual lasers to the field effectively measured at the output of the waveguide. We have shown which coupling phases generally promote instabilities and therefore need to be avoided in the design. Regarding all-optical memory operation, we have demonstrated that there is no real advantage for bistable memory operation compared to using a solitary SRL. An increased power suppression ratio has been found to be mainly due to the destructive interference of the SRL fields at the low power port. Also, multistability between several modal configurations has been shown to remain unavoidable.

Sensitivity subgroup analysis based on single-center vs. multi-center trial status when interpreting meta-analyses pooled estimates: the logical way forward.

PubMed

Alexander, Paul E; Bonner, Ashley J; Agarwal, Arnav; Li, Shelly-Anne; Hariharan, Abishek; Izhar, Zain; Bhatnagar, Neera; Alba, Carolina; Akl, Elie A; Fei, Yutong; Guyatt, Gordon H; Beyene, Joseph

2016-06-01

Prior studies regarding whether single-center trial estimates are larger than multi-center are equivocal. We examined the extent to which single-center trials yield systematically larger effects than multi-center trials. We searched the 119 core clinical journals and the Cochrane Database of Systematic Reviews for meta-analyses (MAs) of randomized controlled trials (RCTs) published during 2012. In this meta-epidemiologic study, for binary variables, we computed the pooled ratio of ORs (RORs), and for continuous outcomes mean difference in standardized mean differences (SMDs), we conducted weighted random-effects meta-regression and random-effects MA modeling. Our primary analyses were restricted to MAs that included at least five RCTs and in which at least 25% of the studies used each of single trial center (SC) and more trial center (MC) designs. We identified 81 MAs for the odds ratio (OR) and 43 for the SMD outcome measures. Based on our analytic plan, our primary analysis (core) is based on 25 MAs/241 RCTs (binary outcome) and 18 MAs/173 RCTs (continuous outcome). Based on the core analysis, we found no difference in magnitude of effect between SC and MC for binary outcomes [RORs: 1.02; 95% confidence interval (CI): 0.83, 1.24; I(2) 20.2%]. Effect sizes were systematically larger for SC than MC for the continuous outcome measure (mean difference in SMDs: -0.13; 95% CI: -0.21, -0.05; I(2) 0%). Our results do not support prior findings of larger effects in SC than MC trials addressing binary outcomes but show a very similar small increase in effect in SC than MC trials addressing continuous outcomes. Authors of systematic reviews would be wise to include all trials irrespective of SC vs. MC design and address SC vs. MC status as a possible explanation of heterogeneity (and consider sensitivity analyses). Copyright © 2015 Elsevier Inc. All rights reserved.

Theoretical Studies of Microstrip Antennas : Volume I, General Design Techniques and Analyses of Single and Coupled Elements

DOT National Transportation Integrated Search

1979-09-01

Volume 1 of Theoretical Studies of Microstrip Antennas deals with general techniques and analyses of single and coupled radiating elements. Specifically, we review and then employ an important equivalence theorem that allows a pair of vector potentia...

Comparison of different Kalman filter approaches in deriving time varying connectivity from EEG data.

PubMed

Ghumare, Eshwar; Schrooten, Maarten; Vandenberghe, Rik; Dupont, Patrick

2015-08-01

Kalman filter approaches are widely applied to derive time varying effective connectivity from electroencephalographic (EEG) data. For multi-trial data, a classical Kalman filter (CKF) designed for the estimation of single trial data, can be implemented by trial-averaging the data or by averaging single trial estimates. A general linear Kalman filter (GLKF) provides an extension for multi-trial data. In this work, we studied the performance of the different Kalman filtering approaches for different values of signal-to-noise ratio (SNR), number of trials and number of EEG channels. We used a simulated model from which we calculated scalp recordings. From these recordings, we estimated cortical sources. Multivariate autoregressive model parameters and partial directed coherence was calculated for these estimated sources and compared with the ground-truth. The results showed an overall superior performance of GLKF except for low levels of SNR and number of trials.

Semiconductor ring lasers coupled by a single waveguide

NASA Astrophysics Data System (ADS)

Coomans, W.; Gelens, L.; Van der Sande, G.; Mezosi, G.; Sorel, M.; Danckaert, J.; Verschaffelt, G.

2012-06-01

We experimentally and theoretically study the characteristics of semiconductor ring lasers bidirectionally coupled by a single bus waveguide. This configuration has, e.g., been suggested for use as an optical memory and as an optical neural network motif. The main results are that the coupling can destabilize the state in which both rings lase in the same direction, and it brings to life a state with equal powers at both outputs. These are both undesirable for optical memory operation. Although the coupling between the rings is bidirectional, the destabilization occurs due to behavior similar to an optically injected laser system.

Optical signatures of coupled quantum dots.

PubMed

Stinaff, E A; Scheibner, M; Bracker, A S; Ponomarev, I V; Korenev, V L; Ware, M E; Doty, M F; Reinecke, T L; Gammon, D

2006-02-03

An asymmetric pair of coupled InAs quantum dots is tuned into resonance by applying an electric field so that a single hole forms a coherent molecular wave function. The optical spectrum shows a rich pattern of level anticrossings and crossings that can be understood as a superposition of charge and spin configurations of the two dots. Coulomb interactions shift the molecular resonance of the optically excited state (charged exciton) with respect to the ground state (single charge), enabling light-induced coupling of the quantum dots. This result demonstrates the possibility of optically coupling quantum dots for application in quantum information processing.

Optical Signatures of Coupled Quantum Dots

NASA Astrophysics Data System (ADS)

Stinaff, E. A.; Scheibner, M.; Bracker, A. S.; Ponomarev, I. V.; Korenev, V. L.; Ware, M. E.; Doty, M. F.; Reinecke, T. L.; Gammon, D.

2006-02-01

An asymmetric pair of coupled InAs quantum dots is tuned into resonance by applying an electric field so that a single hole forms a coherent molecular wave function. The optical spectrum shows a rich pattern of level anticrossings and crossings that can be understood as a superposition of charge and spin configurations of the two dots. Coulomb interactions shift the molecular resonance of the optically excited state (charged exciton) with respect to the ground state (single charge), enabling light-induced coupling of the quantum dots. This result demonstrates the possibility of optically coupling quantum dots for application in quantum information processing.

Antenna-Coupled Superconducting Tunnel Junctions with Single-Electron Transistor Readout for Detection of Sub-mm Radiation

NASA Technical Reports Server (NTRS)

Stevenson, T. R.; Hsieh, W.-T.; Li, M. J.; Stahle, C. M.; Wollack, E. J.; Schoelkopf, R. J.; Teufel, J.; Krebs, Carolyn (Technical Monitor)

2002-01-01

Antenna-coupled superconducting tunnel junction detectors have the potential for photon-counting sensitivity at sub-mm wavelengths. The device consists of an antenna structure to couple radiation into a small superconducting volume and cause quasiparticle excitations, and a single-electron transistor to measure currents through tunnel junction contacts to the absorber volume. We will describe optimization of device parameters, and recent results on fabrication techniques for producing devices with high yield for detector arrays. We will also present modeling of expected saturation power levels, antenna coupling, and rf multiplexing schemes.

Improving the Amazonian Hydrologic Cycle in a Coupled Land-Atmosphere, Single Column Model

NASA Astrophysics Data System (ADS)

Harper, A. B.; Denning, S.; Baker, I.; Prihodko, L.; Branson, M.

2006-12-01

We have coupled a land-surface model, the Simple Biosphere Model (SiB3), to a single column of the Colorado State University General Circulation Model (CSU-GCM) in the Amazon River Basin. This is a preliminary step in the broader goal of improved simulation of Basin-wide hydrology. A previous version of the coupled model (SiB2) showed drought and catastrophic dieback of the Amazon rain forest. SiB3 includes updated soil hydrology and root physiology. Our test area for the coupled single column model is near Santarem, Brazil, where measurements from the km 83 flux tower in the Tapajos National Forest can be used to evaluate model output. The model was run for 2001 using NCEP2 Reanalysis as driver data. Preliminary results show that the updated biosphere model coupled to the GCM produces improved simulations of the seasonal cycle of surface water balance and precipitation. Comparisons of the diurnal and seasonal cycles of surface fluxes are also being made.

Fano-Agarwal couplings and non-rotating wave approximation in single-photon timed Dicke subradiance

NASA Astrophysics Data System (ADS)

Mirza, Imran M.; Begzjav, Tuguldur

2016-04-01

Recently a new class of single-photon timed Dicke (TD) subradiant states has been introduced with possible applications in single-photon-based quantum information storage and on demand ultrafast retrieval (Scully M. O., Phys. Rev. Lett., 115 (2015) 243602). However, the influence of any kind of virtual processes on the decay of these new kind of subradiant states has been left as an open question. In the present paper, we focus on this problem in detail. In particular, we investigate how pure Fano-Agarwal couplings and other virtual processes arising from non-rotating wave approximation impact the decay of otherwise sub- and superradiant states. In addition to the overall virtual couplings among all TD states, we also focus on the dominant role played by the couplings between specific TD states.

Field Telemetry of Blade-rotor Coupled Torsional Vibration at Matuura Power Station Number 1 Unit

NASA Technical Reports Server (NTRS)

Isii, Kuniyoshi; Murakami, Hideaki; Otawara, Yasuhiko; Okabe, Akira

1991-01-01

The quasi-modal reduction technique and finite element model (FEM) were used to construct an analytical model for the blade-rotor coupled torsional vibration of a steam turbine generator of the Matuura Power Station. A single rotor test was executed in order to evaluate umbrella vibration characteristics. Based on the single rotor test results and the quasi-modal procedure, the total rotor system was analyzed to predict coupled torsional frequencies. Finally, field measurement of the vibration of the last stage buckets was made, which confirmed that the double synchronous resonance was 124.2 Hz, meaning that the machine can be safely operated. The measured eigen values are very close to the predicted value. The single rotor test and this analytical procedure thus proved to be a valid technique to estimate coupled torsional vibration.

Coupling of individual quantum emitters to channel plasmons.

PubMed

Bermúdez-Ureña, Esteban; Gonzalez-Ballestero, Carlos; Geiselmann, Michael; Marty, Renaud; Radko, Ilya P; Holmgaard, Tobias; Alaverdyan, Yury; Moreno, Esteban; García-Vidal, Francisco J; Bozhevolnyi, Sergey I; Quidant, Romain

2015-08-07

Efficient light-matter interaction lies at the heart of many emerging technologies that seek on-chip integration of solid-state photonic systems. Plasmonic waveguides, which guide the radiation in the form of strongly confined surface plasmon-polariton modes, represent a promising solution to manipulate single photons in coplanar architectures with unprecedented small footprints. Here we demonstrate coupling of the emission from a single quantum emitter to the channel plasmon polaritons supported by a V-groove plasmonic waveguide. Extensive theoretical simulations enable us to determine the position and orientation of the quantum emitter for optimum coupling. Concomitantly with these predictions, we demonstrate experimentally that 42% of a single nitrogen-vacancy centre emission efficiently couples into the supported modes of the V-groove. This work paves the way towards practical realization of efficient and long distance transfer of energy for integrated solid-state quantum systems.

All-fiber bandpass filter based on asymmetrical modes exciting and coupling

NASA Astrophysics Data System (ADS)

Zhang, Qiang; Zhu, Tao; Shi, Leilei; Liu, Min

2013-01-01

A low cost all-fiber bandpass filter is demonstrated by fabricating an asymmetric long-period fiber grating (LPFG) in an off-set splicing fiber structure of two single mode fibers in this paper. The main principle of the filter is that the asymmetric LPFG written by single-side CO2 laser irradiation is used to couple the asymmetric cladding modes excited by the offset-coupling of the splicing point between the single mode fiber and the grating, and the left core mode of the splicing point cannot be coupled to the right fiber core, hence the interference effect is avoided. So the bandpass characteristics in the transmission spectrum are achieved. The designed filter exhibits a pass band at a central wavelength of 1565.0 nm with a full-width at half-maximum bandwidth of 12.3 nm.

Home-Based HIV Testing and Counseling for Male Couples (Project Nexus): A Protocol for a Randomized Controlled Trial.

PubMed

Stephenson, Rob; Freeland, Ryan; Sullivan, Stephen P; Riley, Erin; Johnson, Brent A; Mitchell, Jason; McFarland, Deborah; Sullivan, Patrick S

2017-05-30

HIV prevalence remains high among men who have sex with men (MSM) in the United States, yet the majority of research has focused on MSM as individuals, not as dyads, and has discussed HIV risks primarily in the context of casual sex. Nexus is an online prevention program that combines home-based HIV testing and couples HIV testing and counseling (CHTC). It allows partners in dyadic MSM relationships to receive HIV testing and care in the comfort of their designated residence, via video-based chat. By using video-based technologies (eg, VSee video chat), male couples receive counseling and support from a remote online counselor, while testing for HIV at home. This randomized control trial (RCT) aims to examine the effects of video-based counseling combined with home-based HIV testing on couples' management of HIV risk, formation and adherence to explicit sexual agreements, and sexual risk-taking. The research implements a prospective RCT of 400 online-recruited male couples: 200 self-reported concordant-negative couples and 200 self-reported discordant couples. Couples in the control arm will receive one or two home-based HIV self-testing kits and will be asked to report their results via the study's website. Couples in the experimental arm will receive one or two home-based HIV self-testing kits and will conduct these tests together under the facilitation of a remotely located counselor during a prescheduled VSee-based video CHTC session. Study assessments are taken at baseline, as well as at 3- and 6-month follow-up sessions. Project Nexus was launched in April 2016 and is ongoing. To date, 219 eligible couples have been enrolled and randomized. Combining home-based HIV testing with video-based counseling creates an opportunity to expand CHTC to male couples who (1) live outside metro areas, (2) live in rural areas without access to testing services or LGBTQ resources, or (3) feel that current clinic-based testing is not for them (eg, due to fears of discrimination associated with HIV and/or sexuality). ClinicalTrials.gov NCT02335138; https://clinicaltrials.gov/ct2/show/NCT02335138 (Archived by WebCite at http://www.webcitation.org/6qHxtNIdW). ©Rob Stephenson, Ryan Freeland, Stephen P Sullivan, Erin Riley, Brent A Johnson, Jason Mitchell, Deborah McFarland, Patrick S Sullivan. Originally published in JMIR Research Protocols (http://www.researchprotocols.org), 30.05.2017.

National Institute of Mental Health Multisite Eban HIV/STD Prevention Intervention for African American HIV Serodiscordant Couples: a cluster randomized trial.

PubMed

El-Bassel, Nabila; Jemmott, John B; Landis, J Richard; Pequegnat, Willo; Wingood, Gina M; Wyatt, Gail E; Bellamy, Scarlett L

2010-09-27

Human immunodeficiency virus (HIV) has disproportionately affected African Americans. Couple-level interventions may be a promising intervention strategy. To determine if a behavioral intervention can reduce HIV/sexually transmitted disease (STD) risk behaviors among African American HIV serodiscordant couples, a cluster randomized controlled trial (Eban) was conducted in Atlanta, Georgia; Los Angeles, California; New York, New York; and Philadelphia, Pennsylvania; with African American HIV serodiscordant heterosexual couples who were eligible if both partners were at least 18 years old and reported unprotected intercourse in the previous 90 days and awareness of each other's serostatus. One thousand seventy participants were enrolled (mean age, 43 years; 40% of male participants were HIV positive). Couples were randomized to 1 of 2 interventions: couple-focused Eban HIV/STD risk-reduction intervention or attention-matched individual-focused health promotion comparison. The primary outcomes were the proportion of condom-protected intercourse acts and cumulative incidence of STDs (chlamydia, gonorrhea, or trichomonas). Data were collected preintervention and postintervention, and at 6- and 12-month follow-ups. Data were analyzed for 535 randomized couples: 260 in the intervention group and 275 in the comparison group; 81.9% were retained at the 12-month follow-up. Generalized estimating equation analyses revealed that the proportion of condom-protected intercourse acts was larger among couples in the intervention group (0.77) than in the comparison group (0.47; risk ratio, 1.24; 95% confidence interval [CI], 1.09 to 1.41; P = .006) when adjusted for the baseline criterion measure. The adjusted percentage of couples using condoms consistently was higher in the intervention group (63%) than in the comparison group (48%; risk ratio, 1.45; 95% CI, 1.24 to 1.70; P < .001). The adjusted mean number of (log)unprotected intercourse acts was lower in the intervention group than in the comparison group (mean difference, -1.52; 95% CI, -2.07 to -0.98; P < .001). The cumulative STD incidence over the 12-month follow-up did not differ between couples in the intervention and comparison groups. The overall HIV seroconversion at the 12-month follow-up was 5 (2 in the intervention group, 3 in the comparison group) of 535 individuals, which translates to 935 per 100,000 population. To our knowledge, this is the first randomized controlled intervention trial to report significant reductions in HIV/STD risk behaviors among African American HIV serodiscordant couples. clinicaltrials.gov Identifier: NCT00644163.

Prediction of Response to Treatment in a Randomized Clinical Trial of Couple Therapy: A 2-Year Follow-Up

ERIC Educational Resources Information Center

Baucom, Brian R.; Atkins, David C.; Simpson, Lorelei E.; Christensen, Andrew

2009-01-01

Many studies have examined pretreatment predictors of immediate posttreatment outcome, but few studies have examined prediction of long-term treatment response to couple therapies. Four groups of predictors (demographic, intrapersonal, communication, and other interpersonal) and 2 moderators (pretreatment severity and type of therapy) were…

Is IVF-served two different ways-more cost-effective than IUI with controlled ovarian hyperstimulation?

PubMed

Tjon-Kon-Fat, R I; Bensdorp, A J; Bossuyt, P M M; Koks, C; Oosterhuis, G J E; Hoek, A; Hompes, P; Broekmans, F J; Verhoeve, H R; de Bruin, J P; van Golde, R; Repping, S; Cohlen, B J; Lambers, M D A; van Bommel, P F; Slappendel, E; Perquin, D; Smeenk, J; Pelinck, M J; Gianotten, J; Hoozemans, D A; Maas, J W M; Groen, H; Eijkemans, M J C; van der Veen, F; Mol, B W J; van Wely, M

2015-10-01

What is the cost-effectiveness of in vitro fertilization (IVF) with conventional ovarian stimulation, single embryo transfer (SET) and subsequent cryocycles or IVF in a modified natural cycle (MNC) compared with intrauterine insemination with controlled ovarian hyperstimulation (IUI-COH) as a first-line treatment in couples with unexplained subfertility and an unfavourable prognosis on natural conception?. Both IVF strategies are significantly more expensive when compared with IUI-COH, without being significantly more effective. In the comparison between IVF-MNC and IUI-COH, the latter is the dominant strategy. Whether IVF-SET is cost-effective depends on society's willingness to pay for an additional healthy child. IUI-COH and IVF, either after conventional ovarian stimulation or in a MNC, are used as first-line treatments for couples with unexplained or mild male subfertility. As IUI-COH is less invasive, this treatment is usually offered before proceeding to IVF. Yet, as conventional IVF with SET may lead to higher pregnancy rates in fewer cycles for a lower multiple pregnancy rate, some have argued to start with IVF instead of IUI-COH. In addition, IVF in the MNC is considered to be a more patient friendly and less costly form of IVF. We performed a cost-effectiveness analysis alongside a randomized noninferiority trial. Between January 2009 and February 2012, 602 couples with unexplained infertility and a poor prognosis on natural conception were allocated to three cycles of IVF-SET including frozen embryo transfers, six cycles of IVF-MNC or six cycles of IUI-COH. These couples were followed until 12 months after randomization. We collected data on resource use related to treatment, medication and pregnancy from the case report forms. We calculated unit costs from various sources. For each of the three strategies, we calculated the mean costs and effectiveness. Incremental cost-effectiveness ratios (ICER) were calculated for IVF-SET compared with IUI-COH and for IVF-MNC compared with IUI-COH. Nonparametric bootstrap resampling was used to investigate the effect of uncertainty in our estimates. There were 104 healthy children (52%) born in the IVF-SET group, 83 (43%) the IVF-MNC group and 97 (47%) in the IUI-COH group. The mean costs per couple were €7187 for IVF-SET, €8206 for IVF-MNC and €5070 for IUI-COH. Compared with IUI-COH, the costs for IVF-SET and IVF-MNC were significantly higher (mean differences €2117; 95% CI: €1544-€2657 and €3136, 95% CI: €2519-€3754, respectively).The ICER for IVF-SET compared with IUI-COH was €43 375 for the birth of an additional healthy child. In the comparison of IVF-MNC to IUI-COH, the latter was the dominant strategy, i.e. more effective at lower costs. We only report on direct health care costs. The present analysis is limited to 12 months. Since we found no evidence in support of offering IVF as a first-line strategy in couples with unexplained and mild subfertility, IUI-COH should remain the treatment of first choice. The study was supported by a grant from ZonMw, the Netherlands Organization for Health Research and Development, (120620027) and a grant from Zorgverzekeraars Nederland, the Netherlands' association of health care insurers (09-003). Current Controlled Trials ISRCTN52843371; Nederlands Trial Register NTR939. © The Author 2015. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Laterally Coupled Distributed-Feedback GaSb-Based Diode Lasers for Atmospheric Gas Detection at 2 Microns

NASA Technical Reports Server (NTRS)

Briggs, Ryan M.; Frez, Clifford; Ksendzov, Alexander; Franz, Kale J.; Bagheri, Mahmood; Forouhar, Siamak

2012-01-01

We demonstrate single-mode laterally coupled distributed-feedback diode lasers at 2.05 microns employing low-loss etched gratings. Single-facet CW output exceeds 50 mW near room temperature with linewidth below 1 MHz over 10-ms observation times

Project FOOTPRINT: Substation modeling and simulations for E1 pulses

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

Nelson, Scott D.; Larson, D. J.; Kirkendall, B. A.

This report includes a presentation with an: Introduction to CW coupling; Introduction to single-pulse coupling; Description of E1 waveforms; Structures in a substation yard --articulated (as part of the substation's defined electrical functionality)--unarticulated (not as part of the substation's defined electrical functionality); Coupling --electrical coupling (capacitive coupling) --magnetic coupling (inductive coupling); Connectivity to long-line transmission lines; Control infrastructure; Summary; and References.

Study of gain-coupled distributed feedback laser based on high order surface gain-coupled gratings

NASA Astrophysics Data System (ADS)

Gao, Feng; Qin, Li; Chen, Yongyi; Jia, Peng; Chen, Chao; Cheng, LiWen; Chen, Hong; Liang, Lei; Zeng, Yugang; Zhang, Xing; Wu, Hao; Ning, Yongqiang; Wang, Lijun

2018-03-01

Single-longitudinal-mode, gain-coupled distributed feedback (DFB) lasers based on high order surface gain-coupled gratings are achieved. Periodic surface metal p-contacts with insulated grooves realize gain-coupled mechanism. To enhance gain contrast in the quantum wells without the introduction of effective index-coupled effect, groove length and depth were well designed. Our devices provided a single longitudinal mode with the maximum CW output power up to 48.8 mW/facet at 971.31 nm at 250 mA without facet coating, 3dB linewidth (<3.2 pm) and SMSR (>39 dB). Optical bistable characteristic was observed with a threshold current difference. Experimentally, devices with different cavity lengths were contrasted on power-current and spectrum characteristics. Due to easy fabrication technique and stable performance, it provides a method of fabricating practical gain-coupled distributed feedback lasers for commercial applications.

A highly sensitive search strategy for clinical trials in Literatura Latino Americana e do Caribe em Ciências da Saúde (LILACS) was developed.

PubMed

Manríquez, Juan J

2008-04-01

Systematic reviews should include as many articles as possible. However, many systematic reviews use only databases with high English language content as sources of trials. Literatura Latino Americana e do Caribe em Ciências da Saúde (LILACS) is an underused source of trials, and there is not a validated strategy for searching clinical trials to be used in this database. The objective of this study was to develop a sensitive search strategy for clinical trials in LILACS. An analytical survey was performed. Several single and multiple-term search strategies were tested for their ability to retrieve clinical trials in LILACS. Sensitivity, specificity, and accuracy of each single and multiple-term strategy were calculated using the results of a hand-search of 44 Chilean journals as gold standard. After combining the most sensitive, specific, and accurate single and multiple-term search strategy, a strategy with a sensitivity of 97.75% (95% confidence interval [CI]=95.98-99.53) and a specificity of 61.85 (95% CI=61.19-62.51) was obtained. LILACS is a source of trials that could improve systematic reviews. A new highly sensitive search strategy for clinical trials in LILACS has been developed. It is hoped this search strategy will improve and increase the utilization of LILACS in future systematic reviews.

Factors associated with HCV risk practices in methadone-maintained patients: the importance of considering the couple in prevention interventions.

PubMed

Roux, Perrine; Lions, Caroline; Michel, Laurent; Mora, Marion; Daulouède, Jean-Pierre; Marcellin, Fabienne; Spire, Bruno; Morel, Alain; Carrieri, Patrizia M

2014-09-10

One important public health issue associated with opioid use today is the risk of hepatitis C (HCV) infection. Although methadone maintenance may help to decrease HCV-related risk practices, HCV risk behaviors persist and are strongly associated with specific substance use patterns, mental status and social context. The ANRS-Methaville study gave us the opportunity to better disentangle the different relationships between these various factors and HCV risk practices. The ANRS-Methaville multisite randomized trial was designed to assess the feasibility of initiating methadone in primary care by comparing it with methadone initiation in specialized centers. This study recruited 195 participants initiating methadone maintenance and followed up for 12 months. Longitudinal data from this trial was used to acquire a greater understanding of HCV risk practices and their pattern of correlates in this population. We selected 176 patients who had data on HCV risk practices at M0 and M12, accounting for 312 visits. HCV risk practices were defined as follows: sharing needles or syringes, sharing drug paraphernalia, getting a tattoo or having a piercing in a non-professional context, sharing toiletry items. To identify factors associated with HCV risk practices, we performed a mixed logistic regression analysis. HCV risk practices were reported by 19% and 15% of participants at baseline and M12, respectively. After adjustment for age, cocaine use and alcohol dependence as well as suicidal risk, living in a couple with a non-drug user and in a couple with a drug user were both independent predictors of HCV risk practices (OR[CI95%] = 4.16 [1.42-12.12]; OR[CI95%] = 9.85 [3.13-31.06], respectively). Identifying individuals at risk of HCV transmission during methadone treatment such as stimulant users, alcohol dependent individuals, and those at suicidal risk is necessary to optimize response to treatment. Innovative prevention approaches tailored to couples are also urgently needed and could decrease HCV-risk in this population. The trial is registered with the French Agency of Pharmaceutical Products (ANSM) under the number 2008-A0277-48, the European Union Drug Regulating Authorities Clinical Trials. Number Eudract 2008-001338-28, the ClinicalTrials.gov Identifier: NCT00657397 and the International Standard Randomised Controlled Trial Number Register ISRCTN31125511.

Factors associated with HCV risk practices in methadone-maintained patients: the importance of considering the couple in prevention interventions

PubMed Central

2014-01-01

Background One important public health issue associated with opioid use today is the risk of hepatitis C (HCV) infection. Although methadone maintenance may help to decrease HCV-related risk practices, HCV risk behaviors persist and are strongly associated with specific substance use patterns, mental status and social context. The ANRS-Methaville study gave us the opportunity to better disentangle the different relationships between these various factors and HCV risk practices. Methods The ANRS-Methaville multisite randomized trial was designed to assess the feasibility of initiating methadone in primary care by comparing it with methadone initiation in specialized centers. This study recruited 195 participants initiating methadone maintenance and followed up for 12 months. Longitudinal data from this trial was used to acquire a greater understanding of HCV risk practices and their pattern of correlates in this population. We selected 176 patients who had data on HCV risk practices at M0 and M12, accounting for 312 visits. HCV risk practices were defined as follows: sharing needles or syringes, sharing drug paraphernalia, getting a tattoo or having a piercing in a non-professional context, sharing toiletry items. To identify factors associated with HCV risk practices, we performed a mixed logistic regression analysis. Results HCV risk practices were reported by 19% and 15% of participants at baseline and M12, respectively. After adjustment for age, cocaine use and alcohol dependence as well as suicidal risk, living in a couple with a non-drug user and in a couple with a drug user were both independent predictors of HCV risk practices (OR[CI95%] = 4.16 [1.42-12.12]; OR[CI95%] = 9.85 [3.13-31.06], respectively). Conclusions Identifying individuals at risk of HCV transmission during methadone treatment such as stimulant users, alcohol dependent individuals, and those at suicidal risk is necessary to optimize response to treatment. Innovative prevention approaches tailored to couples are also urgently needed and could decrease HCV-risk in this population. The trial is registered with the French Agency of Pharmaceutical Products (ANSM) under the number 2008-A0277-48, the European Union Drug Regulating Authorities Clinical Trials. Number Eudract 2008-001338-28, the ClinicalTrials.gov Identifier: NCT00657397 and the International Standard Randomised Controlled Trial Number Register ISRCTN31125511. PMID:25209306

Impact of long-term contraceptive promotion on incident pregnancy: a randomized controlled trial among HIV-positive couples in Lusaka, Zambia.

PubMed

Wall, Kristin M; Vwalika, Bellington; Haddad, Lisa; Khu, Naw H; Vwalika, Cheswa; Kilembe, William; Chomba, Elwyn; Stephenson, Rob; Kleinbaum, David; Nizam, Azhar; Brill, Ilene; Tichacek, Amanda; Allen, Susan

2013-05-01

To evaluate the impact of family planning promotion on incident pregnancy in a combined effort to address Prongs 1 and 2 of prevention of mother-to-child transmission of HIV. We conducted a factorial randomized controlled trial of 2 video-based interventions. "Methods" and "Motivational" messages promoted long-term contraceptive use among 1060 couples with HIV in Lusaka, Zambia. Among couples not using contraception before randomization (n = 782), the video interventions had no impact on incident pregnancy. Among baseline contraceptive users, viewing the "Methods video" which focused on the intrauterine device and contraceptive implant was associated with a significantly lower pregnancy incidence [hazard ratio (HR) = 0.38; 95% confidence interval (CI): 0.19 to 0.75] relative to those viewing control and/or motivational videos. The effect was strongest in concordant positive couples (HR = 0.22; 95% CI: 0.08 to 0.58) and couples with HIV-positive women (HR = 0.23; 95% CI: 0.09 to 0.55). The "Methods video" intervention was previously shown to increase uptake of long-acting contraception and to prompt a shift from daily oral contraceptives to quarterly injectables and long-acting methods such as the intrauterine device and implant. Follow-up confirms sustained intervention impact on pregnancy incidence among baseline contraceptive users, in particular couples with HIV-positive women. Further work is needed to identify effective interventions to promote long-acting contraception among couples who have not yet adopted modern methods.

Trial latencies estimation of event-related potentials in EEG by means of genetic algorithms

NASA Astrophysics Data System (ADS)

Da Pelo, P.; De Tommaso, M.; Monaco, A.; Stramaglia, S.; Bellotti, R.; Tangaro, S.

2018-04-01

Objective. Event-related potentials (ERPs) are usually obtained by averaging thus neglecting the trial-to-trial latency variability in cognitive electroencephalography (EEG) responses. As a consequence the shape and the peak amplitude of the averaged ERP are smeared and reduced, respectively, when the single-trial latencies show a relevant variability. To date, the majority of the methodologies for single-trial latencies inference are iterative schemes providing suboptimal solutions, the most commonly used being the Woody’s algorithm. Approach. In this study, a global approach is developed by introducing a fitness function whose global maximum corresponds to the set of latencies which renders the trial signals most aligned as possible. A suitable genetic algorithm has been implemented to solve the optimization problem, characterized by new genetic operators tailored to the present problem. Main results. The results, on simulated trials, showed that the proposed algorithm performs better than Woody’s algorithm in all conditions, at the cost of an increased computational complexity (justified by the improved quality of the solution). Application of the proposed approach on real data trials, resulted in an increased correlation between latencies and reaction times w.r.t. the output from RIDE method. Significance. The above mentioned results on simulated and real data indicate that the proposed method, providing a better estimate of single-trial latencies, will open the way to more accurate study of neural responses as well as to the issue of relating the variability of latencies to the proper cognitive and behavioural correlates.

Genomic Selection in Multi-environment Crop Trials.

PubMed

Oakey, Helena; Cullis, Brian; Thompson, Robin; Comadran, Jordi; Halpin, Claire; Waugh, Robbie

2016-05-03

Genomic selection in crop breeding introduces modeling challenges not found in animal studies. These include the need to accommodate replicate plants for each line, consider spatial variation in field trials, address line by environment interactions, and capture nonadditive effects. Here, we propose a flexible single-stage genomic selection approach that resolves these issues. Our linear mixed model incorporates spatial variation through environment-specific terms, and also randomization-based design terms. It considers marker, and marker by environment interactions using ridge regression best linear unbiased prediction to extend genomic selection to multiple environments. Since the approach uses the raw data from line replicates, the line genetic variation is partitioned into marker and nonmarker residual genetic variation (i.e., additive and nonadditive effects). This results in a more precise estimate of marker genetic effects. Using barley height data from trials, in 2 different years, of up to 477 cultivars, we demonstrate that our new genomic selection model improves predictions compared to current models. Analyzing single trials revealed improvements in predictive ability of up to 5.7%. For the multiple environment trial (MET) model, combining both year trials improved predictive ability up to 11.4% compared to a single environment analysis. Benefits were significant even when fewer markers were used. Compared to a single-year standard model run with 3490 markers, our partitioned MET model achieved the same predictive ability using between 500 and 1000 markers depending on the trial. Our approach can be used to increase accuracy and confidence in the selection of the best lines for breeding and/or, to reduce costs by using fewer markers. Copyright © 2016 Oakey et al.

Laser-diode-pumped 1319-nm monolithic non-planar ring single-frequency laser

NASA Astrophysics Data System (ADS)

Wang, Qing; Gao, Chunqing; Zhao, Yan; Yang, Suhui; Wei, Guanghui; 2, Dongmei Hong

2003-10-01

Single-frequency 1319-nm laser was obtained by using a laser-diode-pumped monolithic Nd:YAG crystal with a non-planar ring oscillator (NPRO). When the NPRO laser was pumped by an 800-?m fiber coupled laser diode, the output power of the single-frequency 1319-nm laser was 220 mW, and the slope efficiency was 16%. With a 100-1m fiber coupled diode laser pumped, 99-mW single-frequency 1319-nm laser was obtained with a slope efficiency of 29%.

Multiple Component Event-Related Potential (mcERP) Estimation

NASA Technical Reports Server (NTRS)

Knuth, K. H.; Clanton, S. T.; Shah, A. S.; Truccolo, W. A.; Ding, M.; Bressler, S. L.; Trejo, L. J.; Schroeder, C. E.; Clancy, Daniel (Technical Monitor)

2002-01-01

We show how model-based estimation of the neural sources responsible for transient neuroelectric signals can be improved by the analysis of single trial data. Previously, we showed that a multiple component event-related potential (mcERP) algorithm can extract the responses of individual sources from recordings of a mixture of multiple, possibly interacting, neural ensembles. McERP also estimated single-trial amplitudes and onset latencies, thus allowing more accurate estimation of ongoing neural activity during an experimental trial. The mcERP algorithm is related to informax independent component analysis (ICA); however, the underlying signal model is more physiologically realistic in that a component is modeled as a stereotypic waveshape varying both in amplitude and onset latency from trial to trial. The result is a model that reflects quantities of interest to the neuroscientist. Here we demonstrate that the mcERP algorithm provides more accurate results than more traditional methods such as factor analysis and the more recent ICA. Whereas factor analysis assumes the sources are orthogonal and ICA assumes the sources are statistically independent, the mcERP algorithm makes no such assumptions thus allowing investigators to examine interactions among components by estimating the properties of single-trial responses.

Fixed-dose combinations of drugs versus single-drug formulations for treating pulmonary tuberculosis

PubMed Central

Gallardo, Carmen R; Rigau Comas, David; Valderrama Rodríguez, Angélica; Roqué i Figuls, Marta; Parker, Lucy Anne; Caylà, Joan; Bonfill Cosp, Xavier

2016-01-01

Background People who are newly diagnosed with pulmonary tuberculosis (TB) typically receive a standard first-line treatment regimen that consists of two months of isoniazid, rifampicin, pyrazinamide, and ethambutol followed by four months of isoniazid and rifampicin. Fixed-dose combinations (FDCs) of these drugs are widely recommended. Objectives To compare the efficacy, safety, and acceptability of anti-tuberculosis regimens given as fixed-dose combinations compared to single-drug formulations for treating people with newly diagnosed pulmonary tuberculosis. Search methods We searched the Cochrane Infectious Disease Group Specialized Register; the Cochrane Central Register of Controlled Trials (CENTRAL, published in the Cochrane Library, Issue 11 2015); MEDLINE (1966 to 20 November 2015); EMBASE (1980 to 20 November 2015); LILACS (1982 to 20 November 2015); the metaRegister of Controlled Trials; and the World Health Organization International Clinical Trials Registry Platform (WHO ICTRP), without language restrictions, up to 20 November 2015. Selection criteria Randomized controlled trials that compared the use of FDCs with single-drug formulations in adults (aged 15 years or more) newly diagnosed with pulmonary TB. Data collection and analysis Two review authors independently assessed studies for inclusion, and assessed the risk of bias and extracted data from the included trials. We used risk ratios (RRs) for dichotomous data and mean differences (MDs) for continuous data with 95% confidence intervals (CIs). We attempted to assess the effect of treatment for time-to-event measures with hazard ratios and their 95% CIs. We used the Cochrane 'Risk of bias' assessment tool to determine the risk of bias in included trials. We used the fixed-effect model when there was little heterogeneity and the random-effects model with moderate heterogeneity. We used an I² statistic value of 75% or greater to denote significant heterogeneity, in which case we did not perform a meta-analysis. We assessed the quality of evidence using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. Main results We included 13 randomized controlled trials (RCTs) in the review, which enrolled 5824 participants. Trials were published between 1987 and 2015 and included participants in treatment with newly diagnosed pulmonary TB in countries with high TB prevalence. Only two trials reported the HIV status of included participants. Overall there is little or no difference detected between FDCs and single-drug formulations for most outcomes reported. We did not detect a difference in treatment failure between FDCs compared with single-drug formulations (RR 1.28, 95% CI 0.82 to 2.00; 3606 participants, seven trials, moderate quality evidence). Relapse may be more frequent in people treated with FDCs compared to single-drug formulations, although the confidence interval (CI) includes no difference (RR 1.28, 95% CI 1.00 to 1.64; 3621 participants, 10 trials, low quality evidence). We did not detect any difference in death between fixed-dose and single-drug formulation groups (RR 0.96, 95% CI 0.67 to 1.39; 4800 participants, 11 trials, moderate quality evidence). When we compared FDCs with single-drug formulations we found little or no difference for sputum smear or culture conversion at the end of treatment (RR 0.99, 95% CI 0.96 to 1.02; 2319 participants, seven trials, high quality evidence), for serious adverse events (RR 1.45, 95% CI 0.90 to 2.33; 3388 participants, six trials, moderate quality evidence), and for adverse events that led to discontinuation of therapy (RR 0.96, 95% CI 0.56 to 1.66; 5530 participants, 13 trials, low quality evidence). We conducted a sensitivity analysis excluding studies at high risk of bias and this did not alter the review findings. Authors' conclusions Fixed-dose combinations and single-drug formulations probably have similar effects for treating people with newly diagnosed pulmonary TB. PLAIN LANGUAGE SUMMARY Fixed-dose combinations for treating pulmonary tuberculosis What are fixed-dose combinations and how might they improve care of people with tuberculosis Tuberculosis (TB) is an important health problem, especially in developing countries. The treatment for pulmonary TB in new patients includes four oral medicines taken for six months, sometimes as fixed-dose combinations (FDCs) that are combined in one tablet, or taken separately as single-drug formulations. The World Health Organization recommends prescribers use fixed-dose combinations to reduce the number of tablets that people take. On the supply side, this might reduce prescribing errors and improve drug supply efficiency; on the patient's side, FDCS simplify treatment and improve adherence. We conducted a review to assess the efficacy, safety, and acceptability of FDCs compared with single-drug formulations for treating people with newly diagnosed pulmonary TB. What the research says We searched for relevant trials up to 20 November 2015, and included 13 randomized controlled trials that enrolled 5824 people. Trials were published between 1987 and 2015 and included participants in treatment with newly diagnosed pulmonary TB in countries with high TB prevalence. Only two trials reported the HIV status of included participants. There is probably little or no difference in FDCs compared to single-drug formulations for treatment failure (moderate quality evidence); relapse may be more frequent (low quality evidence); and the number of deaths were similar (moderate quality evidence). There is little or no difference in sputum smear or culture conversion (high quality evidence), and no difference was shown for serious adverse events (moderate quality evidence) or adverse events that led to discontinuation of therapy (low quality evidence). Authors' conclusions We concluded that fixed-dose combinations have similar efficacy to single-drug formulations for treating people with newly diagnosed pulmonary TB. PMID:27186634

Effects of Recent Exposure to a Conditioned Stimulus on Extinction of Pavlovian Fear Conditioning

ERIC Educational Resources Information Center

Chan, Wan Yee Macy; Leung, Hiu T.; Westbrook, R. Frederick; McNally, Gavan P.

2010-01-01

In six experiments we studied the effects of a single re-exposure to a conditioned stimulus (CS; "retrieval trial") prior to extinction training (extinction-reconsolidation boundary) on the development of and recovery from fear extinction. A single retrieval trial prior to extinction training significantly augmented the renewal and reinstatement…

Neural Prediction of Multidimensional Decisions in Monkey Superior Colliculus

NASA Astrophysics Data System (ADS)

Hasegawa, Ryohei P.; Hasegawa, Yukako T.; Segraves, Mark A.

To examine the function of the superior colliculus (SC) in decision-making processes and the application of its single trial activity for “neural mind reading,” we recorded from SC deep layers while two monkeys performed oculomotor go/no-go tasks. We have recently focused on monitoring single trial activities in single SC neurons, and designed a virtual decision function (VDF) to provide a good estimation of single-dimensional decisions (go/no-go decisions for a cue presented at a specific visual field, a response field of each neuron). In this study, we used two VDFs for multidimensional decisions (go/no-go decisions at two cue locations) with the ensemble activity which was simultaneously recorded from a small group (4 to 6) of neurons at both sides of the SC. VDFs predicted cue locations as well as go/no-go decisions. These results suggest that monitoring of ensemble SC activity had sufficient capacity to predict multidimensional decisions on a trial-by-trial basis, which is an ideal candidate to serve for cognitive brain-machine interfaces (BMI) such as two-dimensional word spellers.

Evaluation of a physical activity intervention for new parents: protocol paper for a randomized trial.

PubMed

Quinlan, Alison; Rhodes, Ryan E; Beauchamp, Mark R; Symons Downs, Danielle; Warburton, Darren E R; Blanchard, Chris M

2017-11-09

Identifying critical life transitions in people's physical activity behaviors may illuminate the most opportune intervention apertures for chronic disease prevention. A substantive evidence base now indicates that parenthood is one of these critical transition points for physical activity decline. This study will examine whether a brief theory-based intervention can prevent a decline in physical activity among new parents over 6 months following intervention. This study protocol represents the first dyad-based physical activity initiative in the parenthood literature involving both mothers and fathers; prior research has focused on only mothers or only fathers (albeit limited), and has shown only short-term changes in physical activity. This study will be investigating whether a theory-based physical activity intervention can maintain or improve moderate to vigorous intensity physical activity measured via accelerometry of new parents over a 6 month period following intervention compared to a control group. This study is a 6-month longitudinal randomized controlled trial. Parents are measured at baseline (2 months postpartum) with two assessment points at 6 weeks (3.5 months postpartum) and 3 months (5 months postpartum) and a final follow-up assessment at 6 months (8 months postpartum). The content of the theory-based intervention was derived from the results of our prior longitudinal trial of new parents using an adapted theory of planned behavior framework to predict changes in physical activity. A total of 152 couples have been recruited to date. Sixteen couples dropped out after baseline and a total of 88 couples have completed their 6-month measures. If the intervention proves successful, couple-based physical activity promotion efforts among parents could be a promising avenue to pursue to help mitigate the declines of physical activity levels during parenthood. These findings could inform public health materials and practitioners. This trial has been registered with the Clinical Trials Registry maintained by the National Library of Medicine at the National Institutes of Health on April 19, 2014. The registration ID is NCT02290808 .

Single-photon driven high-order sideband transitions in an ultrastrongly coupled circuit quantum electrodynamics system

NASA Astrophysics Data System (ADS)

Li, Tiefu; Chen, Zhen; Wang, Yimin; Tian, Lin; Qiu, Yueyin; Inomata, Kunihiro; Yoshihara, Fumiki; Han, Siyuan; Nori, Franco; Tsai, Jaw-Shen; You, J. Q.

We report the experimental observation of high-order sideband transitions at the single-photon level in a quantum circuit system of a flux qubit ultrastrongly coupled to a coplanar waveguide resonator. With the coupling strength reaching 10 % of the resonator's fundamental frequency, we obtain clear signatures of higher-order red- and first-order blue-sideband transitions. These transitions are owing to the ultrastrong Rabi coupling, instead of the driving power. Our observation advances the understanding of ultrastrongly-coupled systems and paves the way to study high-order processes in the quantum Rabi model. This work is supported by the National Basic Research Program of China and the National Natural Science Foundation of China.

Precise single-qubit control of the reflection phase of a photon mediated by a strongly-coupled ancilla–cavity system

NASA Astrophysics Data System (ADS)

Motzoi, F.; Mølmer, K.

2018-05-01

We propose to use the interaction between a single qubit atom and a surrounding ensemble of three level atoms to control the phase of light reflected by an optical cavity. Our scheme employs an ensemble dark resonance that is perturbed by the qubit atom to yield a single-atom single photon gate. We show here that off-resonant excitation towards Rydberg states with strong dipolar interactions offers experimentally-viable regimes of operations with low errors (in the 10‑3 range) as required for fault-tolerant optical-photon, gate-based quantum computation. We also propose and analyze an implementation within microwave circuit-QED, where a strongly-coupled ancilla superconducting qubit can be used in the place of the atomic ensemble to provide high-fidelity coupling to microwave photons.

Generation and transfer of single photons on a photonic crystal chip.

PubMed

Englund, Dirk; Faraon, Andrei; Zhang, Bingyang; Yamamoto, Yoshihisa; Vucković, Jelena

2007-04-30

We present a basic building block of a quantum network consisting of a quantum dot coupled to a source cavity, which in turn is coupled to a target cavity via a waveguide. The single photon emission from the high-Q/V source cavity is characterized by twelve-fold spontaneous emission (SE) rate enhancement, SE coupling efficiency beta ~ 0.98 into the source cavity mode, and mean wavepacket indistinguishability of ~67%. Single photons are efficiently transferred into the target cavity via the waveguide, with a target/source field intensity ratio of 0.12 +/- 0.01. This system shows great promise as a building block of future on-chip quantum information processing systems.

Two-qubit gates and coupling with low-impedance flux qubits

NASA Astrophysics Data System (ADS)

Chow, Jerry; Corcoles, Antonio; Rigetti, Chad; Rozen, Jim; Keefe, George; Rothwell, Mary-Beth; Rohrs, John; Borstelmann, Mark; Divincenzo, David; Ketchen, Mark; Steffen, Matthias

2011-03-01

We experimentally demonstrate the coupling of two low-impedance flux qubits mediated via a transmission line resonator. We explore the viability of experimental coupling protocols which involve selective microwave driving on the qubits independently as well as fast frequency tuning through on-chip flux-bias. Pulse-shaping techniques for single-qubit and two-qubit gates are employed for reducing unwanted leakage and phase errors. A joint readout through the transmission line resonator is used for characterizing single-qubit and two-qubit states.

Optical bistability in a single-sided cavity coupled to a quantum channel

NASA Astrophysics Data System (ADS)

Payravi, M.; Solookinejad, Gh; Jabbari, M.; Nafar, M.; Ahmadi Sangachin, E.

2018-06-01

In this paper, we discuss the long wavelength optical reflection and bistable behavior of an InGaN/GaN quantum dot nanostructure coupled to a single-sided cavity. It is found that due to the presence of a strong coupling field, the reflection coefficient can be controlled at long wavelength, which is essential for adjusting the threshold of reflected optical bistability. Moreover, the phase shift features of the reflection pulse inside an electromagnetically induced transparency window are also discussed.

Ground state transitions in vertically coupled N-layer single electron quantum dots

NASA Astrophysics Data System (ADS)

Xie, Wenfang; Wang, Anmei

2003-12-01

A method is proposed to exactly diagonalize the Hamiltonian of a N-layer quantum dot containing a single electron in each dot in arbitrary magnetic fields. For N=4, the energy spectra of the dot are calculated as a function of the applied magnetic field. We find discontinuous ground-state energy transitions induced by an external magnetic field in the case of strong coupling. However, in the case of weak coupling, such a transition does not occur and the angular momentum remains zero.

Experimental demonstration of single-mode fiber coupling over relatively strong turbulence with adaptive optics.

PubMed

Chen, Mo; Liu, Chao; Xian, Hao

2015-10-10

High-speed free-space optical communication systems using fiber-optic components can greatly improve the stability of the system and simplify the structure. However, propagation through atmospheric turbulence degrades the spatial coherence of the signal beam and limits the single-mode fiber (SMF) coupling efficiency. In this paper, we analyze the influence of the atmospheric turbulence on the SMF coupling efficiency over various turbulences. The results show that the SMF coupling efficiency drops from 81% without phase distortion to 10% when phase root mean square value equals 0.3λ. The simulations of SMF coupling with adaptive optics (AO) indicate that it is inevitable to compensate the high-order aberrations for SMF coupling over relatively strong turbulence. The SMF coupling efficiency experiments, using an AO system with a 137-element deformable mirror and a Hartmann-Shack wavefront sensor, obtain average coupling efficiency increasing from 1.3% in open loop to 46.1% in closed loop under a relatively strong turbulence, D/r₀=15.1.

Retention of the "first-trial effect" in gait-slip among community-living older adults.

PubMed

Liu, Xuan; Bhatt, Tanvi; Wang, Shuaijie; Yang, Feng; Pai, Yi-Chung Clive

2017-02-01

"First-trial effect" characterizes the rapid adaptive behavior that changes the performance outcome (from fall to non-fall) after merely a single exposure to postural disturbance. The purpose of this study was to investigate how long the first-trial effect could last. Seventy-five (≥ 65 years) community-dwelling older adults, who were protected by an overhead full body harness system, were retested for a single slip 6-12 months after their initial exposure to a single gait-slip. Subjects' body kinematics that was used to compute their proactive (feedforward) and reactive (feedback) control of stability was recorded by an eight-camera motion analysis system. We found the laboratory falls of subjects on their retest slip were significantly lower than that on the novel initial slip, and the reactive stability of these subjects was also significantly improved. However, the proactive stability of subjects remains unchanged between their initial slip and retest slip. The fall rates and stability control had no difference among the 6-, 9-, and 12-month retest groups, which indicated a maximum retention on 12 months after a single slip in the laboratory. These results highlighted the importance of the "first-trial effect" and suggested that perturbation training is effective for fall prevention, with lower trial doses for a long period (up to 1 year). Therefore, single slip training might benefit those older adults who could not tolerate larger doses in reality.

Frontal Theta Links Prediction Errors to Behavioral Adaptation in Reinforcement Learning

PubMed Central

Cavanagh, James F.; Frank, Michael J.; Klein, Theresa J.; Allen, John J.B.

2009-01-01

Investigations into action monitoring have consistently detailed a fronto-central voltage deflection in the Event-Related Potential (ERP) following the presentation of negatively valenced feedback, sometimes termed the Feedback Related Negativity (FRN). The FRN has been proposed to reflect a neural response to prediction errors during reinforcement learning, yet the single trial relationship between neural activity and the quanta of expectation violation remains untested. Although ERP methods are not well suited to single trial analyses, the FRN has been associated with theta band oscillatory perturbations in the medial prefrontal cortex. Medio-frontal theta oscillations have been previously associated with expectation violation and behavioral adaptation and are well suited to single trial analysis. Here, we recorded EEG activity during a probabilistic reinforcement learning task and fit the performance data to an abstract computational model (Q-learning) for calculation of single-trial reward prediction errors. Single-trial theta oscillatory activities following feedback were investigated within the context of expectation (prediction error) and adaptation (subsequent reaction time change). Results indicate that interactive medial and lateral frontal theta activities reflect the degree of negative and positive reward prediction error in the service of behavioral adaptation. These different brain areas use prediction error calculations for different behavioral adaptations: with medial frontal theta reflecting the utilization of prediction errors for reaction time slowing (specifically following errors), but lateral frontal theta reflecting prediction errors leading to working memory-related reaction time speeding for the correct choice. PMID:19969093

Characterizing Oscillatory Bursts in Single-Trial EEG Data

NASA Technical Reports Server (NTRS)

Knuth, K. H.; Shah, A. S.; Lakatos, P.; Schroeder, C. E.

2004-01-01

Oscillatory bursts in numerous bands ranging from low (theta) to high frequencies (e.g., gamma) undoubtedly play an important role in cortical dynamics. Largely because of the inadequacy of existing analytic techniques. however, oscillatory bursts and their role in cortical processing remains poorly understood. To study oscillatory bursts effectively one must be able to isolate them and characterize them in the single trial. We describe a series of straightforward analysis techniques that produce useful indices of burst characteristics. First, stimulus-evoked responses are estimated using Differentially Variable Component Analysis (dVCA), and are subtracted from the single-trial. The single-trial characteristics of the evoked responses are stored to identify possible correlations with burst activity. Time-frequency (T-F), or wavelet, analyses are then applied to the single trial residuals. While T-F plots have been used in recent studies to identify and isolate bursts, we go further by fitting each burst in the T-F plot with a two-dimensional Gaussian. This provides a set of burst characteristics, such as, center time. burst duration, center frequency. frequency dispersion. and amplitude, all of which contribute to the accurate characterization of the individual burst. The burst phase can also be estimated. Burst characteristics can be quantified with several standard techniques (e.g.. histogramming and clustering), as well as Bayesian techniques (e.g., blocking) to allow a more parametric description analysis of the characteristics of oscillatory bursts, and the relationships of specific parameters to cortical excitability and stimulus integration.

Kernel PLS Estimation of Single-trial Event-related Potentials

NASA Technical Reports Server (NTRS)

Rosipal, Roman; Trejo, Leonard J.

2004-01-01

Nonlinear kernel partial least squaes (KPLS) regressior, is a novel smoothing approach to nonparametric regression curve fitting. We have developed a KPLS approach to the estimation of single-trial event related potentials (ERPs). For improved accuracy of estimation, we also developed a local KPLS method for situations in which there exists prior knowledge about the approximate latency of individual ERP components. To assess the utility of the KPLS approach, we compared non-local KPLS and local KPLS smoothing with other nonparametric signal processing and smoothing methods. In particular, we examined wavelet denoising, smoothing splines, and localized smoothing splines. We applied these methods to the estimation of simulated mixtures of human ERPs and ongoing electroencephalogram (EEG) activity using a dipole simulator (BESA). In this scenario we considered ongoing EEG to represent spatially and temporally correlated noise added to the ERPs. This simulation provided a reasonable but simplified model of real-world ERP measurements. For estimation of the simulated single-trial ERPs, local KPLS provided a level of accuracy that was comparable with or better than the other methods. We also applied the local KPLS method to the estimation of human ERPs recorded in an experiment on co,onitive fatigue. For these data, the local KPLS method provided a clear improvement in visualization of single-trial ERPs as well as their averages. The local KPLS method may serve as a new alternative to the estimation of single-trial ERPs and improvement of ERP averages.

Mandibular single-implant overdentures: a review with surgical and prosthodontic perspectives of a novel approach.

PubMed

Alsabeeha, Nabeel; Payne, Alan G T; De Silva, Rohana K; Swain, Michael V

2009-04-01

To review the literature on mandibular single-implant overdentures (opposing complete maxillary dentures), and present surgical and prosthodontic perspectives of a novel approach for this treatment option. An electronic search through the databases of Pubmed, Embase and Medline using the linked key words 'mandibular single implant overdentures' was performed. The search was limited to English language articles published up to August 2008. Hand searches through articles retrieved from the electronic search, peer-reviewed journals and recent conference proceedings were also conducted. A limited number of reports were identified on mandibular single-implant overdentures (opposing maxillary complete dentures). They comprised of case-series reports, short-term prospective trials and current randomized-controlled clinical trials. Different loading protocols with different implant systems have been used, but always with regular diameter implants. Specific anatomical and vascular dangers of the mandibular midline symphysis are identified including a novel surgical approach using a currently available short, wide diameter tapered implant. In addition, the prosthodontic rationale for using a larger attachment system (incorporating a platform switch) for mandibular single-implant overdentures is described. The review reveals that there is a lack of published randomized clinical trials using mandibular single-implant overdentures, opposing maxillary complete dentures. Without the evidence from randomized clinical trials, routine use of this novel approach cannot be recommended, compared with using regular diameter implants and matching attachment systems.

Health behaviour change interventions for couples: A systematic review.

PubMed

Arden-Close, Emily; McGrath, Nuala

2017-05-01

Partners are a significant influence on individuals' health, and concordance in health behaviours increases over time in couples. Several theories suggest that couple-focused interventions for health behaviour change may therefore be more effective than individual interventions. A systematic review of health behaviour change interventions for couples was conducted. Systematic search methods identified randomized controlled trials (RCTs) and non-randomized interventions of health behaviour change for couples with at least one member at risk of a chronic physical illness, published from 1990-2014. We identified 14 studies, targeting the following health behaviours: cancer prevention (6), obesity (1), diet (2), smoking in pregnancy (2), physical activity (1) and multiple health behaviours (2). In four out of seven trials couple-focused interventions were more effective than usual care. Of four RCTs comparing a couple-focused intervention to an individual intervention, two found that the couple-focused intervention was more effective. The studies were heterogeneous, and included participants at risk of a variety of illnesses. In many cases the intervention was compared to usual care for an individual or an individual-focused intervention, which meant the impact of the couplebased content could not be isolated. Three arm studies could determine whether any added benefits of couple-focused interventions are due to adding the partner or specific content of couple-focused interventions. Statement of contribution What is already known on this subject? Health behaviours and health behaviour change are more often concordant across couples than between individuals in the general population. Couple-focused interventions for chronic conditions are more effective than individual interventions or usual care (Martire, Schulz, Helgeson, Small, & Saghafi, ). What does this study add? Identified studies targeted a variety of health behaviours, with few studies in any one area. Further assessment of the effectiveness of couple-focused versus individual interventions for those at risk is needed. Three-arm study designs are needed to determine benefits of targeting couples versus couple-focused intervention content. © 2017 The Authors. British Journal of Health Psychology published by John Wiley & Sons Ltd on behalf of the British Psychological Society.

Efficacy of umbilical cord cleansing with a single application of 4% chlorhexidine for the prevention of newborn infections in Uganda: study protocol for a randomized controlled trial.

PubMed

Nankabirwa, Victoria; Tylleskär, Thorkild; Tumuhamye, Josephine; Tumwine, James K; Ndeezi, Grace; Martines, José C; Sommerfelt, Halvor

2017-07-12

Yearly, nearly all the estimated worldwide 2.7 million neonatal deaths occur in low- and middle-income countries. Infections, including those affecting the umbilical cord (omphalitis), are a significant factor in approximately a third of these deaths. In fact, the odds of all-cause mortality are 46% higher among neonates with omphalitis than in those without. Five large randomized controlled trials in Asia and Sub-Saharan Africa (SSA) have examined the effect of multiple cord stump applications with 4% chlorhexidine (CHX) for at least 7 days on the risk of omphalitis and neonatal death. These studies, all community-based, show that multiple CHX applications reduced the risk of omphalitis. Of these trials, only one study from South Asia (the Bangladeshi study) and none from Africa examined the effect of a single application of CHX as soon as possible after birth. In this Bangladeshi trial, CHX led to a reduction in the risk of mild-moderate omphalitis and neonatal death. It is important, in an African setting, to explore the effect of a single application among health-facility births. A single application is programmatically much simpler to implement than daily applications for 7 days. Therefore, our study compares umbilical cord cleansing with a single application of 4% CHX at birth with dry cord care among Ugandan babies born in health facilities, on the risk of omphalitis and severe neonatal illness. The CHX study is a facility-based, individually randomized controlled trial that will be conducted among 4760 newborns in Uganda. The primary outcomes are severe illness and omphalitis during the neonatal period. Analysis will be by intention-to-treat. This study will provide novel evidence, from a Sub-Saharan African setting, of the effect of umbilical cord cleansing with a single application of 4% CHX at birth and identify modifiable risk factors for omphalitis. ClinicalTrials.gov, identifier: NCT02606565 . Registered on 12 November 2015.

Design of 20 W fiber-coupled green laser diode by Zemax

NASA Astrophysics Data System (ADS)

Qi, Yunfei; Zhao, Pengfei; Wu, Yulong; Chen, Yongqi; Zou, Yonggang

2017-09-01

We represent a design of a 20 W, fiber-coupled diode laser module based on 26 single emitters at 520 nm. The module can produce more than 20 W output power from a standard fiber with core diameter of 400 μm and numerical aperture (NA) of 0.22. To achieve a 20 W laser beam, the spatial beam combination and polarization beam combination by polarization beam splitter are used to combine output of 26 single emitters into a single beam, and then an aspheric lens is used to couple the combined beam into an optical fiber. The simulation shows that the total coupling efficiency is more than 95%. Project supported by the National Key R& D Program of China (No. 2016YFB0402105), the Key Deployment Program of the Chinese Academy of Sciences (No. KGZD-SW-T01-2), and the National Natural Science Foundation of China (No. 61404135).

Quantum Stirling heat engine and refrigerator with single and coupled spin systems

NASA Astrophysics Data System (ADS)

Huang, Xiao-Li; Niu, Xin-Ya; Xiu, Xiao-Ming; Yi, Xue-Xi

2014-02-01

We study the reversible quantum Stirling cycle with a single spin or two coupled spins as the working substance. With the single spin as the working substance, we find that under certain conditions the reversed cycle of a heat engine is NOT a refrigerator, this feature holds true for a Stirling heat engine with an ion trapped in a shallow potential as its working substance. The efficiency of quantum Stirling heat engine can be higher than the efficiency of the Carnot engine, but the performance coefficient of the quantum Stirling refrigerator is always lower than its classical counterpart. With two coupled spins as the working substance, we find that a heat engine can turn to a refrigerator due to the increasing of the coupling constant, this can be explained by the properties of the isothermal line in the magnetic field-entropy plane.

Crosstalk error correction through dynamical decoupling of single-qubit gates in capacitively coupled singlet-triplet semiconductor spin qubits

NASA Astrophysics Data System (ADS)

Buterakos, Donovan; Throckmorton, Robert E.; Das Sarma, S.

2018-01-01

In addition to magnetic field and electric charge noise adversely affecting spin-qubit operations, performing single-qubit gates on one of multiple coupled singlet-triplet qubits presents a new challenge: crosstalk, which is inevitable (and must be minimized) in any multiqubit quantum computing architecture. We develop a set of dynamically corrected pulse sequences that are designed to cancel the effects of both types of noise (i.e., field and charge) as well as crosstalk to leading order, and provide parameters for these corrected sequences for all 24 of the single-qubit Clifford gates. We then provide an estimate of the error as a function of the noise and capacitive coupling to compare the fidelity of our corrected gates to their uncorrected versions. Dynamical error correction protocols presented in this work are important for the next generation of singlet-triplet qubit devices where coupling among many qubits will become relevant.

Promoting a positive transition to parenthood: a randomized clinical trial of couple relationship education.

PubMed

Halford, W Kim; Petch, Jemima; Creedy, Debra K

2010-03-01

The transition to parenthood is often associated with a decline in couple relationship adjustment. Couples (n = 71) expecting their first child were randomly assigned to either: (a) Becoming a Parent (BAP), a maternal parenting education program; or (b) Couple CARE for Parents (CCP), a couple relationship and parenting education program. Couples were assessed pre-intervention (last trimester of pregnancy), post-intervention (5 months postpartum), and follow-up (12 months postpartum). Relative to BAP, CCP reduced negative couple communication from pre- to post-intervention, and prevented erosion of relationship adjustment and self-regulation in women but not men from pre-intervention to follow-up. Mean parenting stress reflected positive adjustment to parenthood with no differences between BAP and CCP. CCP shows promise as a brief program that can enhance couple communication and women's adjustment to parenthood.

Efficient coupling of starlight into single mode photonics using Adaptive Injection (AI)

NASA Astrophysics Data System (ADS)

Norris, Barnaby; Cvetojevic, Nick; Gross, Simon; Arriola, Alexander; Tuthill, Peter; Lawrence, Jon; Richards, Samuel; Goodwin, Michael; Zheng, Jessica

2016-08-01

Using single-mode fibres in astronomy enables revolutionary techniques including single-mode interferometry and spectroscopy. However, injection of seeing-limited starlight into single mode photonics is extremely difficult. One solution is Adaptive Injection (AI). The telescope pupil is segmented into a number of smaller subapertures each with size r0, such that seeing can be approximated as a single tip / tilt / piston term for each subaperture, and then injected into a separate fibre via a facet of a segmented MEMS deformable mirror. The injection problem is then reduced to a set of individual tip tilt loops, resulting in high overall coupling efficiency.

Three-terminal graphene single-electron transistor fabricated using feedback-controlled electroburning

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

Puczkarski, Paweł; Gehring, Pascal, E-mail: pascal.gehring@materials.ox.ac.uk; Lau, Chit S.

2015-09-28

We report room-temperature Coulomb blockade in a single layer graphene three-terminal single-electron transistor fabricated using feedback-controlled electroburning. The small separation between the side gate electrode and the graphene quantum dot results in a gate coupling up to 3 times larger compared to the value found for the back gate electrode. This allows for an effective tuning between the conductive and Coulomb blocked state using a small side gate voltage of about 1 V. The technique can potentially be used in the future to fabricate all-graphene based room temperature single-electron transistors or three terminal single molecule transistors with enhanced gate coupling.

Unified model for the electromechanical coupling factor of orthorhombic piezoelectric rectangular bar with arbitrary aspect ratio

NASA Astrophysics Data System (ADS)

Rouffaud, R.; Levassort, F.; Hladky-Hennion, A.-C.

2017-02-01

Piezoelectric Single Crystals (PSC) are increasingly used in the manufacture of ultrasonic transducers and in particular for linear arrays or single element transducers. Among these PSCs, according to their microstructure and poled direction, some exhibit a mm2 symmetry. The analytical expression of the electromechanical coupling coefficient for a vibration mode along the poling direction for piezoelectric rectangular bar resonator is established. It is based on the mode coupling theory and fundamental energy ratio definition of electromechanical coupling coefficients. This unified formula for mm2 symmetry class material is obtained as a function of an aspect ratio (G) where the two extreme cases correspond to a thin plate (with a vibration mode characterized by the thickness coupling factor, kt) and a thin bar (characterized by k33'). To optimize the k33' value related to the thin bar design, a rotation of the crystallogaphic axis in the plane orthogonal to the poling direction is done to choose the highest value for PIN-PMN-PT single crystal. Finally, finite element calculations are performed to deduce resonance frequencies and coupling coefficients in a large range of G value to confirm developed analytical relations.

Single Versus Multiple Events Error Potential Detection in a BCI-Controlled Car Game With Continuous and Discrete Feedback.

PubMed

Kreilinger, Alex; Hiebel, Hannah; Müller-Putz, Gernot R

2016-03-01

This work aimed to find and evaluate a new method for detecting errors in continuous brain-computer interface (BCI) applications. Instead of classifying errors on a single-trial basis, the new method was based on multiple events (MEs) analysis to increase the accuracy of error detection. In a BCI-driven car game, based on motor imagery (MI), discrete events were triggered whenever subjects collided with coins and/or barriers. Coins counted as correct events, whereas barriers were errors. This new method, termed ME method, combined and averaged the classification results of single events (SEs) and determined the correctness of MI trials, which consisted of event sequences instead of SEs. The benefit of this method was evaluated in an offline simulation. In an online experiment, the new method was used to detect erroneous MI trials. Such MI trials were discarded and could be repeated by the users. We found that, even with low SE error potential (ErrP) detection rates, feasible accuracies can be achieved when combining MEs to distinguish erroneous from correct MI trials. Online, all subjects reached higher scores with error detection than without, at the cost of longer times needed for completing the game. Findings suggest that ErrP detection may become a reliable tool for monitoring continuous states in BCI applications when combining MEs. This paper demonstrates a novel technique for detecting errors in online continuous BCI applications, which yields promising results even with low single-trial detection rates.

Field trials of 100G and beyond: an operator's point of view

NASA Astrophysics Data System (ADS)

Vorbeck, S.; Schneiders, M.; Weiershausen, W.; Mayer, H.; Schippel, A.; Wagner, P.; Ehrhardt, A.; Braun, R.; Breuer, D.; Drafz, U.; Fritzsche, D.

2011-01-01

In this article we present a summary of the latest 100 Gbps field trials in the network of Deutsche Telekom AG with industry partners. We cover a brown field approach as alien wavelength on existing systems, a green field high speed overlay network approach and a high speed interface router-router coupling.

Removal of BCG artifacts using a non-Kirchhoffian overcomplete representation.

PubMed

Dyrholm, Mads; Goldman, Robin; Sajda, Paul; Brown, Truman R

2009-02-01

We present a nonlinear unmixing approach for extracting the ballistocardiogram (BCG) from EEG recorded in an MR scanner during simultaneous acquisition of functional MRI (fMRI). First, an overcomplete basis is identified in the EEG based on a custom multipath EEG electrode cap. Next, the overcomplete basis is used to infer non-Kirchhoffian latent variables that are not consistent with a conservative electric field. Neural activity is strictly Kirchhoffian while the BCG artifact is not, and the representation can hence be used to remove the artifacts from the data in a way that does not attenuate the neural signals needed for optimal single-trial classification performance. We compare our method to more standard methods for BCG removal, namely independent component analysis and optimal basis sets, by looking at single-trial classification performance for an auditory oddball experiment. We show that our overcomplete representation method for removing BCG artifacts results in better single-trial classification performance compared to the conventional approaches, indicating that the derived neural activity in this representation retains the complex information in the trial-to-trial variability.

The non-planar single-frequency ring laser with variable output coupling

NASA Astrophysics Data System (ADS)

Wu, Ke-ying; Yang, Su-hui; Wei, Guang-hui

2002-03-01

We put forward a novel non-planar single-frequency ring laser, which consists of a corner cube prism and a specially cut Porro prism made by Nd:YAG crystal. The relative angle between the corner cube and the Porro prism could be adjusted to control the output coupling of the laser resonator and the polarization-state of the output laser. A 1.06 μm single-frequency laser with 1 W output has been obtained.

Statement of Facts for 1980 City-Wide Mock Trial Competitions. Albert Banks and Virginia Smallwood, for Herself and on Behalf of Her Minor Son, Dwayne Jones, Plaintiffs v. Potomac Properties, Inc., Thomas R. Baldwin, and Victoria Reese, Defendants. No. MT-80.

ERIC Educational Resources Information Center

National Inst. for Citizen Education in the Law, Washington, DC.

Prepared by the District of Columbia Street Law Project for its ninth annual city-wide mock trial competition, this instructional handout provides the material for a civil trial over housing discrimination. The plaintiffs are an unmarried couple with a disabled child whose application to live at Waterfront Gardens, a property owned by Potomac…

A MISO-ARX-Based Method for Single-Trial Evoked Potential Extraction.

PubMed

Yu, Nannan; Wu, Lingling; Zou, Dexuan; Chen, Ying; Lu, Hanbing

2017-01-01

In this paper, we propose a novel method for solving the single-trial evoked potential (EP) estimation problem. In this method, the single-trial EP is considered as a complex containing many components, which may originate from different functional brain sites; these components can be distinguished according to their respective latencies and amplitudes and are extracted simultaneously by multiple-input single-output autoregressive modeling with exogenous input (MISO-ARX). The extraction process is performed in three stages: first, we use a reference EP as a template and decompose it into a set of components, which serve as subtemplates for the remaining steps. Then, a dictionary is constructed with these subtemplates, and EPs are preliminarily extracted by sparse coding in order to roughly estimate the latency of each component. Finally, the single-trial measurement is parametrically modeled by MISO-ARX while characterizing spontaneous electroencephalographic activity as an autoregression model driven by white noise and with each component of the EP modeled by autoregressive-moving-average filtering of the subtemplates. Once optimized, all components of the EP can be extracted. Compared with ARX, our method has greater tracking capabilities of specific components of the EP complex as each component is modeled individually in MISO-ARX. We provide exhaustive experimental results to show the effectiveness and feasibility of our method.

Combining features from ERP components in single-trial EEG for discriminating four-category visual objects.

PubMed

Wang, Changming; Xiong, Shi; Hu, Xiaoping; Yao, Li; Zhang, Jiacai

2012-10-01

Categorization of images containing visual objects can be successfully recognized using single-trial electroencephalograph (EEG) measured when subjects view images. Previous studies have shown that task-related information contained in event-related potential (ERP) components could discriminate two or three categories of object images. In this study, we investigated whether four categories of objects (human faces, buildings, cats and cars) could be mutually discriminated using single-trial EEG data. Here, the EEG waveforms acquired while subjects were viewing four categories of object images were segmented into several ERP components (P1, N1, P2a and P2b), and then Fisher linear discriminant analysis (Fisher-LDA) was used to classify EEG features extracted from ERP components. Firstly, we compared the classification results using features from single ERP components, and identified that the N1 component achieved the highest classification accuracies. Secondly, we discriminated four categories of objects using combining features from multiple ERP components, and showed that combination of ERP components improved four-category classification accuracies by utilizing the complementarity of discriminative information in ERP components. These findings confirmed that four categories of object images could be discriminated with single-trial EEG and could direct us to select effective EEG features for classifying visual objects.

Fast Purcell-enhanced single photon source in 1,550-nm telecom band from a resonant quantum dot-cavity coupling

PubMed Central

Birowosuto, Muhammad Danang; Sumikura, Hisashi; Matsuo, Shinji; Taniyama, Hideaki; van Veldhoven, Peter J.; Nötzel, Richard; Notomi, Masaya

2012-01-01

High-bit-rate nanocavity-based single photon sources in the 1,550-nm telecom band are challenges facing the development of fibre-based long-haul quantum communication networks. Here we report a very fast single photon source in the 1,550-nm telecom band, which is achieved by a large Purcell enhancement that results from the coupling of a single InAs quantum dot and an InP photonic crystal nanocavity. At a resonance, the spontaneous emission rate was enhanced by a factor of 5 resulting a record fast emission lifetime of 0.2 ns at 1,550 nm. We also demonstrate that this emission exhibits an enhanced anti-bunching dip. This is the first realization of nanocavity-enhanced single photon emitters in the 1,550-nm telecom band. This coupled quantum dot cavity system in the telecom band thus provides a bright high-bit-rate non-classical single photon source that offers appealing novel opportunities for the development of a long-haul quantum telecommunication system via optical fibres. PMID:22432053

Fast Purcell-enhanced single photon source in 1,550-nm telecom band from a resonant quantum dot-cavity coupling.

PubMed

Birowosuto, Muhammad Danang; Sumikura, Hisashi; Matsuo, Shinji; Taniyama, Hideaki; van Veldhoven, Peter J; Nötzel, Richard; Notomi, Masaya

2012-01-01

High-bit-rate nanocavity-based single photon sources in the 1,550-nm telecom band are challenges facing the development of fibre-based long-haul quantum communication networks. Here we report a very fast single photon source in the 1,550-nm telecom band, which is achieved by a large Purcell enhancement that results from the coupling of a single InAs quantum dot and an InP photonic crystal nanocavity. At a resonance, the spontaneous emission rate was enhanced by a factor of 5 resulting a record fast emission lifetime of 0.2 ns at 1,550 nm. We also demonstrate that this emission exhibits an enhanced anti-bunching dip. This is the first realization of nanocavity-enhanced single photon emitters in the 1,550-nm telecom band. This coupled quantum dot cavity system in the telecom band thus provides a bright high-bit-rate non-classical single photon source that offers appealing novel opportunities for the development of a long-haul quantum telecommunication system via optical fibres.

Modulation of localized solutions in a system of two coupled nonlinear Schrödinger equations.

PubMed

Cardoso, W B; Avelar, A T; Bazeia, D

2012-08-01

In this work we study localized solutions of a system of two coupled nonlinear Schrödinger equations, with the linear (potential) and nonlinear coefficients engendering spatial and temporal dependencies. Similarity transformations are used to convert the nonautonomous coupled equations into autonomous ones and we use the trial orbit method to help us solving them, presenting solutions in a general way. Numerical experiments are then used to verify the stability of the localized solutions.

Effect of resource constraints on intersimilar coupled networks.

PubMed

Shai, S; Dobson, S

2012-12-01

Most real-world networks do not live in isolation but are often coupled together within a larger system. Recent studies have shown that intersimilarity between coupled networks increases the connectivity of the overall system. However, unlike connected nodes in a single network, coupled nodes often share resources, like time, energy, and memory, which can impede flow processes through contention when intersimilarly coupled. We study a model of a constrained susceptible-infected-recovered (SIR) process on a system consisting of two random networks sharing the same set of nodes, where nodes are limited to interact with (and therefore infect) a maximum number of neighbors at each epidemic time step. We obtain that, in agreement with previous studies, when no limit exists (regular SIR model), positively correlated (intersimilar) coupling results in a lower epidemic threshold than negatively correlated (interdissimilar) coupling. However, in the case of the constrained SIR model, the obtained epidemic threshold is lower with negatively correlated coupling. The latter finding differentiates our work from previous studies and provides another step towards revealing the qualitative differences between single and coupled networks.

Effect of resource constraints on intersimilar coupled networks

NASA Astrophysics Data System (ADS)

Shai, S.; Dobson, S.

2012-12-01

Most real-world networks do not live in isolation but are often coupled together within a larger system. Recent studies have shown that intersimilarity between coupled networks increases the connectivity of the overall system. However, unlike connected nodes in a single network, coupled nodes often share resources, like time, energy, and memory, which can impede flow processes through contention when intersimilarly coupled. We study a model of a constrained susceptible-infected-recovered (SIR) process on a system consisting of two random networks sharing the same set of nodes, where nodes are limited to interact with (and therefore infect) a maximum number of neighbors at each epidemic time step. We obtain that, in agreement with previous studies, when no limit exists (regular SIR model), positively correlated (intersimilar) coupling results in a lower epidemic threshold than negatively correlated (interdissimilar) coupling. However, in the case of the constrained SIR model, the obtained epidemic threshold is lower with negatively correlated coupling. The latter finding differentiates our work from previous studies and provides another step towards revealing the qualitative differences between single and coupled networks.

Single vs two implant-retained overdentures for edentulous mandibles: a systematic review.

PubMed

Alqutaibi, Ahmed Yaseen; Esposito, Marco; Algabri, Radwan; Alfahad, Adnan; Kaddah, Amal; Farouk, Mohammed; Alsourori, Ali

To compare prosthesis and implant failure, patient satisfaction, prosthetic complications and peri-implant marginal bone loss of mandibular overdentures (IOD) supported by a single or two implants. Manual and electronic database (PubMed and Cochrane) searches were performed to identify randomised controlled trials, without language restriction, comparing single vs two implant supported mandibular overdentures. Two investigators extracted data independently. The Cochrane tool was used for assessing the quality of included studies. Meta-analyses were performed for the included RCTs. Six publications corresponding to four RCTs were identified. Three RCTs (corresponding to five publications) were included and one trial was excluded. Follow-ups in function were 1, 3 and 5 years after loading. All included studies were considered to be at a high risk of bias. The pooled result revealed more prosthesis failures at overdentures supported by two implants at 1 year (three trials) (P = 0.02; Risk Difference: -0.12, 95% CI: -0.22, -0.02), however, there were non-significant differences at 3 years (two trials) (P = 0.22; Risk Difference: -0.32, 95% CI: -0.83, 0.19) and at 5 years (one trial) (P = 0.95; Risk Difference: 0.01, 95% CI: -0.22, 0.24). Regarding implant failures, there were more implant losses in overdentures supported by two implants at 1 year (three trials) (P = 0.02; Risk Difference: -0.12, 95% CI: -0.22, -0.02) and at 5 years (one trial) (P = 0.95; Risk Difference: -0.15, 95% CI: -0.28, -0.02), however, there were non-significant difference at 3 years (two trials) (P = 0.2; Risk Difference: -0.33, 95% CI: -0.84, 0.18). After 5 years in function, meta-analyses revealed that there were non-significant differences regarding overall prosthetic complications when mandibular overdentures supported by a single implant were compared with overdentures supported by two implants (P = 0.43; RD: 0.04, 95% CI: -0.06, 0.15). Mandibular overdentures retained by a single implant have comparable results to those retained by two implants. However, this should be interpreted with caution as all the included studies were considered at a high risk of bias.

Associative Interference and Recognition Memory.

ERIC Educational Resources Information Center

Underwood, Benton J.; And Others

Three experiments tested the generality of the conclusion that associative unlearning is minimal in the A-B, A-D paradigm. In Experiment 1, single-trial study of A-D, following single-trial study of A-B, did not produce retroactive inhibition in the recognition of A-B. In Experiment 2, A-B was acquired by associative matching. The interpolated…

A coupled cluster theory with iterative inclusion of triple excitations and associated equation of motion formulation for excitation energy and ionization potential

NASA Astrophysics Data System (ADS)

Maitra, Rahul; Akinaga, Yoshinobu; Nakajima, Takahito

2017-08-01

A single reference coupled cluster theory that is capable of including the effect of connected triple excitations has been developed and implemented. This is achieved by regrouping the terms appearing in perturbation theory and parametrizing through two different sets of exponential operators: while one of the exponentials, involving general substitution operators, annihilates the ground state but has a non-vanishing effect when it acts on the excited determinant, the other is the regular single and double excitation operator in the sense of conventional coupled cluster theory, which acts on the Hartree-Fock ground state. The two sets of operators are solved as coupled non-linear equations in an iterative manner without significant increase in computational cost than the conventional coupled cluster theory with singles and doubles excitations. A number of physically motivated and computationally advantageous sufficiency conditions are invoked to arrive at the working equations and have been applied to determine the ground state energies of a number of small prototypical systems having weak multi-reference character. With the knowledge of the correlated ground state, we have reconstructed the triple excitation operator and have performed equation of motion with coupled cluster singles, doubles, and triples to obtain the ionization potential and excitation energies of these molecules as well. Our results suggest that this is quite a reasonable scheme to capture the effect of connected triple excitations as long as the ground state remains weakly multi-reference.

Are multiple-trial experiments appropriate for eyewitness identification studies? Accuracy, choosing, and confidence across trials.

PubMed

Mansour, J K; Beaudry, J L; Lindsay, R C L

2017-12-01

Eyewitness identification experiments typically involve a single trial: A participant views an event and subsequently makes a lineup decision. As compared to this single-trial paradigm, multiple-trial designs are more efficient, but significantly reduce ecological validity and may affect the strategies that participants use to make lineup decisions. We examined the effects of a number of forensically relevant variables (i.e., memory strength, type of disguise, degree of disguise, and lineup type) on eyewitness accuracy, choosing, and confidence across 12 target-present and 12 target-absent lineup trials (N = 349; 8,376 lineup decisions). The rates of correct rejections and choosing (across both target-present and target-absent lineups) did not vary across the 24 trials, as reflected by main effects or interactions with trial number. Trial number had a significant but trivial quadratic effect on correct identifications (OR = 0.99) and interacted significantly, but again trivially, with disguise type (OR = 1.00). Trial number did not significantly influence participants' confidence in correct identifications, confidence in correct rejections, or confidence in target-absent selections. Thus, multiple-trial designs appear to have minimal effects on eyewitness accuracy, choosing, and confidence. Researchers should thus consider using multiple-trial designs for conducting eyewitness identification experiments.

Generation of “Virtual” Control Groups for Single Arm Prostate Cancer Adjuvant Trials

PubMed Central

Koziol, James A.; Chen, Xin; Xia, Xiao-Qin; Wang, Yipeng; Skarecky, Douglas; Sutton, Manuel; Sawyers, Anne; Ruckle, Herbert; Carpenter, Philip M.; Wang-Rodriguez, Jessica; Jiang, Jun; Deng, Mingsen; Pan, Cong; Zhu, Jian-guo; McLaren, Christine E.; Gurley, Michael J.; Lee, Chung; McClelland, Michael; Ahlering, Thomas; Kattan, Michael W.; Mercola, Dan

2014-01-01

It is difficult to construct a control group for trials of adjuvant therapy (Rx) of prostate cancer after radical prostatectomy (RP) due to ethical issues and patient acceptance. We utilized 8 curve-fitting models to estimate the time to 60%, 65%, … 95% chance of progression free survival (PFS) based on the data derived from Kattan post-RP nomogram. The 8 models were systematically applied to a training set of 153 post-RP cases without adjuvant Rx to develop 8 subsets of cases (reference case sets) whose observed PFS times were most accurately predicted by each model. To prepare a virtual control group for a single-arm adjuvant Rx trial, we first select the optimal model for the trial cases based on the minimum weighted Euclidean distance between the trial case set and the reference case set in terms of clinical features, and then compare the virtual PFS times calculated by the optimum model with the observed PFSs of the trial cases by the logrank test. The method was validated using an independent dataset of 155 post-RP patients without adjuvant Rx. We then applied the method to patients on a Phase II trial of adjuvant chemo-hormonal Rx post RP, which indicated that the adjuvant Rx is highly effective in prolonging PFS after RP in patients at high risk for prostate cancer recurrence. The method can accurately generate control groups for single-arm, post-RP adjuvant Rx trials for prostate cancer, facilitating development of new therapeutic strategies. PMID:24465467

Generation of "virtual" control groups for single arm prostate cancer adjuvant trials.

PubMed

Jia, Zhenyu; Lilly, Michael B; Koziol, James A; Chen, Xin; Xia, Xiao-Qin; Wang, Yipeng; Skarecky, Douglas; Sutton, Manuel; Sawyers, Anne; Ruckle, Herbert; Carpenter, Philip M; Wang-Rodriguez, Jessica; Jiang, Jun; Deng, Mingsen; Pan, Cong; Zhu, Jian-Guo; McLaren, Christine E; Gurley, Michael J; Lee, Chung; McClelland, Michael; Ahlering, Thomas; Kattan, Michael W; Mercola, Dan

2014-01-01

It is difficult to construct a control group for trials of adjuvant therapy (Rx) of prostate cancer after radical prostatectomy (RP) due to ethical issues and patient acceptance. We utilized 8 curve-fitting models to estimate the time to 60%, 65%, … 95% chance of progression free survival (PFS) based on the data derived from Kattan post-RP nomogram. The 8 models were systematically applied to a training set of 153 post-RP cases without adjuvant Rx to develop 8 subsets of cases (reference case sets) whose observed PFS times were most accurately predicted by each model. To prepare a virtual control group for a single-arm adjuvant Rx trial, we first select the optimal model for the trial cases based on the minimum weighted Euclidean distance between the trial case set and the reference case set in terms of clinical features, and then compare the virtual PFS times calculated by the optimum model with the observed PFSs of the trial cases by the logrank test. The method was validated using an independent dataset of 155 post-RP patients without adjuvant Rx. We then applied the method to patients on a Phase II trial of adjuvant chemo-hormonal Rx post RP, which indicated that the adjuvant Rx is highly effective in prolonging PFS after RP in patients at high risk for prostate cancer recurrence. The method can accurately generate control groups for single-arm, post-RP adjuvant Rx trials for prostate cancer, facilitating development of new therapeutic strategies.

Effects of Gait Self-Efficacy and Lower-Extremity Physical Function on Dual-Task Performance in Older Adults

PubMed Central

Banducci, Sarah E.; Daugherty, Ana M.; Fanning, Jason; Awick, Elizabeth A.; Porter, Gwenndolyn C.; Burzynska, Agnieszka; Shen, Sa; Kramer, Arthur F.; McAuley, Edward

2017-01-01

Objectives. Despite evidence of self-efficacy and physical function's influences on functional limitations in older adults, few studies have examined relationships in the context of complex, real-world tasks. The present study tested the roles of self-efficacy and physical function in predicting older adults' street-crossing performance in single- and dual-task simulations. Methods. Lower-extremity physical function, gait self-efficacy, and street-crossing success ratio were assessed in 195 older adults (60–79 years old) at baseline of a randomized exercise trial. During the street-crossing task, participants walked on a self-propelled treadmill in a virtual reality environment. Participants crossed the street without distraction (single-task trials) and conversed on a cell phone (dual-task trials). Structural equation modeling was used to test hypothesized associations independent of demographic and clinical covariates. Results. Street-crossing performance was better on single-task trials when compared with dual-task trials. Direct effects of self-efficacy and physical function on success ratio were observed in dual-task trials only. The total effect of self-efficacy was significant in both conditions. The indirect path through physical function was evident in the dual-task condition only. Conclusion. Physical function can predict older adults' performance on high fidelity simulations of complex, real-world tasks. Perceptions of function (i.e., self-efficacy) may play an even greater role. The trial is registered with United States National Institutes of Health ClinicalTrials.gov (ID: NCT01472744; Fit & Active Seniors Trial). PMID:28255557

Fluorescence enhancement and strong-coupling in faceted plasmonic nanocavities

NASA Astrophysics Data System (ADS)

Kongsuwan, Nuttawut; Demetriadou, Angela; Chikkaraddy, Rohit; Baumberg, Jeremy J.; Hess, Ortwin

2018-06-01

Emission properties of a quantum emitter can be significantly modified inside nanometre-sized gaps between two plasmonic nanostructures. This forms a nanoscopic optical cavity which allows single-molecule detection and single-molecule strong-coupling at room temperature. However, plasmonic resonances of a plasmonic nanocavity are highly sensitive to the exact gap morphology. In this article, we shed light on the effect of gap morphology on the plasmonic resonances of a faceted nanoparticle-on-mirror (NPoM) nanocavity and their interaction with quantum emitters. We find that with increasing facet width the NPoM nanocavity provides weaker field enhancement and thus less coupling strength to a single quantum emitter since the effective mode volume increases with the facet width. However, if multiple emitters are present, a faceted NPoM nanocavity is capable of accommodating a larger number of emitters, and hence the overall coupling strength is larger due to the collective and coherent energy exchange from all the emitters. Our findings pave the way to more efficient designs of nanocavities for room-temperature light-matter strong-coupling, thus providing a big step forward to a non-cryogenic platform for quantum technologies.

Silicon-based highly-efficient fiber-to-waveguide coupler for high index contrast systems

NASA Astrophysics Data System (ADS)

Nguyen, Victor; Montalbo, Trisha; Manolatou, Christina; Agarwal, Anu; Hong, Ching-yin; Yasaitis, John; Kimerling, L. C.; Michel, Jurgen

2006-02-01

A coupler to efficiently transfer broadband light from a single-mode optical fiber to a single-mode high-index contrast waveguide has been fabricated on a silicon substrate. We utilized a novel coupling scheme, with a vertically asymmetric design consisting of a stepwise parabolic graded index profile combined with a horizontal taper, to simultaneously confine light in both directions. Coupling efficiency has been measured as a function of the device dimensions. The optimal coupling efficiency is achieved for structures whose length equals the focal distance of the graded index and whose input width is close to the mode field diameter of the fiber. The fabricated structure is compact, robust and highly efficient, with an insertion loss of 2.2dB at 1550nm. The coupler exhibits less than 1dB variation in coupling efficiency in the measured spectral range from 1520nmto1620nm. The lowest insertion loss of 1.9dB is measured at 1540nm. The coupler design offers highly efficient coupling for single mode waveguides of core indices up to 2.2.

Assessment of bilayer silicene to probe as quantum spin and valley Hall effect

NASA Astrophysics Data System (ADS)

Rehman, Majeed Ur; Qiao, Zhenhua

2018-02-01

Silicene takes precedence over graphene due to its buckling type structure and strong spin orbit coupling. Motivated by these properties, we study the silicene bilayer in the presence of applied perpendicular electric field and intrinsic spin orbit coupling to probe as quantum spin/valley Hall effect. Using analytical approach, we calculate the spin Chern-number of bilayer silicene and then compare it with monolayer silicene. We reveal that bilayer silicene hosts double spin Chern-number as compared to single layer silicene and therefore accordingly has twice as many edge states in contrast to single layer silicene. In addition, we investigate the combined effect of intrinsic spin orbit coupling and the external electric field, we find that bilayer silicene, likewise single layer silicene, goes through a phase transitions from a quantum spin Hall state to a quantum valley Hall state when the strength of the applied electric field exceeds the intrinsic spin orbit coupling strength. We believe that the results and outcomes obtained for bilayer silicene are experimentally more accessible as compared to bilayer graphene, because of strong SO coupling in bilayer silicene.

Mate-choice copying in single and coupled women: the influence of mate acceptance and mate rejection decisions of other women.

PubMed

Deng, Yan; Zheng, Yong

2015-01-26

Studies of humans and non-human animals indicate that females tend to change the likelihood of choosing a potential mate based on the decisions of other females; this is known as mate-choice copying. In a sample of both single and coupled women, we examined the influence of other women's (model) mate-choice decisions, including mate acceptance and mate rejection, on participants' attractiveness ratings of men (target) and willingness of mate selection. We also examined whether different types of relationships between the target men and the model women affected mate-choice copying. We found that both the single and coupled women showed mate-choice copying, but their response patterns differed. The significant effects for single women were dependent on a decrease in attractiveness ratings when they perceived the models' mate rejection. However, the significant findings for coupled women relied on an increase in attractiveness ratings when they observed the models' mate acceptance. Furthermore, the relationship status between the target men and the model women affected the magnitude of mate-choice copying effects for the single women. Specifically, they showed less mate-choice copying when the targets and models were in a committed romantic relationship than when in a temporary relationship.

Mode selection and tuning of single-frequency short-cavity VECSELs

DOE PAGES

Serkland, Darwin K.; So, Haley M.; Peake, Gregory M.; ...

2018-03-05

Here, we report on mode selection and tuning properties of vertical-external-cavity surface-emitting lasers (VECSELs) containing coupled semiconductor and external cavities of total length less than 1 mm. Our goal is to create narrowlinewidth (<1MHz) single-frequency VECSELs that operate near 850 nm on a single longitudinal cavity resonance and tune versus temperature without mode hops. We have designed, fabricated, and measured VECSELs with external-cavity lengths ranging from 25 to 800 μm. Lastly, we compare simulated and measured coupled-cavity mode frequencies and discuss criteria for single mode selection.

A methodology for assessing the effect of correlations among muscle synergy activations on task-discriminating information.

PubMed

Delis, Ioannis; Berret, Bastien; Pozzo, Thierry; Panzeri, Stefano

2013-01-01

Muscle synergies have been hypothesized to be the building blocks used by the central nervous system to generate movement. According to this hypothesis, the accomplishment of various motor tasks relies on the ability of the motor system to recruit a small set of synergies on a single-trial basis and combine them in a task-dependent manner. It is conceivable that this requires a fine tuning of the trial-to-trial relationships between the synergy activations. Here we develop an analytical methodology to address the nature and functional role of trial-to-trial correlations between synergy activations, which is designed to help to better understand how these correlations may contribute to generating appropriate motor behavior. The algorithm we propose first divides correlations between muscle synergies into types (noise correlations, quantifying the trial-to-trial covariations of synergy activations at fixed task, and signal correlations, quantifying the similarity of task tuning of the trial-averaged activation coefficients of different synergies), and then uses single-trial methods (task-decoding and information theory) to quantify their overall effect on the task-discriminating information carried by muscle synergy activations. We apply the method to both synchronous and time-varying synergies and exemplify it on electromyographic data recorded during performance of reaching movements in different directions. Our method reveals the robust presence of information-enhancing patterns of signal and noise correlations among pairs of synchronous synergies, and shows that they enhance by 9-15% (depending on the set of tasks) the task-discriminating information provided by the synergy decompositions. We suggest that the proposed methodology could be useful for assessing whether single-trial activations of one synergy depend on activations of other synergies and quantifying the effect of such dependences on the task-to-task differences in muscle activation patterns.

A randomized trial of a minimal intervention for sexual concerns after cancer: a comparison of self-help and professionally delivered modalities.

PubMed

Perz, Janette; Ussher, Jane M

2015-09-09

Information and discussion of sexual changes with a health professional is a high priority for many cancer patients in order to assist with sexual changes and ensure that sexual intimacy does not cease post-cancer. The PLISSIT model is widely recommended as a framework for providing sexual information and support, allowing for the discussion of sexual changes at various levels of increasing intensity. The aim of the present study is to evaluate the early stages of the PLISSIT model by examining the relative efficacy of written information provision about cancer related sexual changes, and information provision accompanied by a single session of counselling, for people with cancer and their partners, across a range of cancer types. Eighty-eight people with cancer and 53 partners across a range of sexual and non-sexual cancers, took part in a randomised trial which adopted mixed method analysis to examine changes in psychological wellbeing, quality of life, relationship satisfaction and communication, and sexual functioning, following written information provision about cancer related sexual changes (self-help condition; SH), or written information accompanied by a single session of counselling (health professional condition; HP). Ratings of the usefulness and efficacy of the SH and HP interventions, collected through analysis of Likert scales, open ended survey items and interviews, indicated that both conditions were found to be useful and efficacious by the majority of participants, serving to increase awareness of sexuality, improve couple communication about sex, and help in the management of sexual changes, through the exploration of non-coital sexual practices. In contrast, the quantitative analysis of standardized instruments found no significant improvements in psychological wellbeing, quality of life, relationship satisfaction and communication, or sexual functioning. There were significant reductions in self-silencing in the HP condition, and a trend towards increases in sexual satisfaction across both conditions. These results offer support for the early stages of the PLISSIT model, in terms of normalization and increased awareness of sexual changes after cancer, increased couple communication about sexual changes, and legitimation of exploration of a range of non-coital sexual practices and intimacy. However, more complex and intensive interventions are needed to address sexual functioning and psychological wellbeing. The findings provide support for the proposition that providing permission to discuss sexuality should be the core feature underpinning all stages of interventions designed to provide sexuality information and support for people with cancer and their partners, and also demonstrate the potential importance of limited information and specific suggestions. This study was registered in the Australian New Zealand Clinical Trials Registry. ( ACTRN12615000399594 ) on 29 April 2015.

Single dental implant retained mandibular complete dentures – influence of the loading protocol: study protocol for a randomized controlled trial

PubMed Central

2014-01-01

Background Over the years, there has been a strong consensus in dentistry that at least two implants are required to retain a complete mandibular denture. It has been shown in several clinical trials that one single median implant can retain a mandibular overdenture sufficiently well for up to 5 years without implant failures, when delayed loading was used. However, other trials have reported conflicting results with in part considerable failure rates when immediate loading was applied. Therefore it is the purpose of the current randomized clinical trial to test the hypothesis that immediate loading of a single mandibular midline implant with an overdenture will result in a comparable clinical outcome as using the standard protocol of delayed loading. Methods/design This prospective nine-center randomized controlled clinical trial is still ongoing. The final patient will complete the trial in 2016. In total, 180 edentulous patients between 60 and 89 years with sufficient complete dentures will receive one median implant in the edentulous mandible, which will retain the existing complete denture using a ball attachment. Loading of the median implant is either immediately after implant placement (experimental group) or delayed by 3 months of submerged healing at second-stage surgery (control group). Follow-up of patients will be performed for 24 months after implant loading. The primary outcome measure is non-inferiority of implant success rate of the experimental group compared to the control group. The secondary outcome measures encompass clinical, technical and subjective variables. The study was funded by the Deutsche Forschungsgemeinschaft (German research foundation, KE 477/8-1). Discussion This multi-center clinical trial will give information on the ability of a single median implant to retain a complete mandibular denture when immediately loaded. If viable, this treatment option will strongly improve everyday dental practice. Trial registration The trial has been registered at Deutsches Register Klinischer Studien (German register of clinical trials) under DRKS-ID: DRKS00003730 since 23 August 2012. (http://www.germanctr.de). PMID:24884848

Development and Application of Single-Referenced Perturbation and Coupled-Cluster Theories for Excited Electronic States

NASA Technical Reports Server (NTRS)

Lee, Timothy J.; Langhoff, Stephen R. (Technical Monitor)

1997-01-01

Recent work on the development of single-reference perturbation theories for the study of excited electronic states will be discussed. The utility of these methods will be demonstrated by comparison to linear-response coupled-cluster excitation energies. Results for some halogen molecules of interest in stratospheric chemistry will be presented.

Strong exciton-photon coupling in organic single crystal microcavity with high molecular orientation

NASA Astrophysics Data System (ADS)

Goto, Kaname; Yamashita, Kenichi; Yanagi, Hisao; Yamao, Takeshi; Hotta, Shu

2016-08-01

Strong exciton-photon coupling has been observed in a highly oriented organic single crystal microcavity. This microcavity consists of a thiophene/phenylene co-oligomer (TPCO) single crystal laminated on a high-reflection distributed Bragg reflector. In the TPCO crystal, molecular transition dipole was strongly polarized along a certain horizontal directions with respect to the main crystal plane. This dipole polarization causes significantly large anisotropies in the exciton transition and optical constants. Especially the anisotropic exciton transition was found to provide the strong enhancement in the coupling with the cavity mode, which was demonstrated by a Rabi splitting energy as large as ˜100 meV even in the "half-vertical cavity surface emitting lasing" microcavity structure.

Super-Poissonian statistics of photon emission from single CdSe-CdS core-shell nanocrystals coupled to metal nanostructures.

PubMed

Park, Young-Shin; Ghosh, Yagnaseni; Chen, Yongfen; Piryatinski, Andrei; Xu, Ping; Mack, Nathan H; Wang, Hsing-Lin; Klimov, Victor I; Hollingsworth, Jennifer A; Htoon, Han

2013-03-15

We demonstrate that photon antibunching observed for individual nanocrystal quantum dots (NQDs) can be transformed into photon bunching characterized by super-Poissonian statistics when they are coupled to metal nanostructures (MNs). This observation indicates that, while the quantum yield of a biexciton (Q(2X)) is lower than that of a single exciton (Q(1X)) in freestanding NQDs, Q(2X) becomes greater than Q(1X) in NQDs coupled to MNs. This unique phenomenon is attributed to metal-induced quenching with a rate that scales more slowly with exciton multiplicity than the radiative decay rate and dominates over other nonradiative decay channels for both single excitons and biexcitons.

Coupling a single nitrogen-vacancy center with a superconducting qubit via the electro-optic effect

NASA Astrophysics Data System (ADS)

Li, Chang-Hao; Li, Peng-Bo

2018-05-01

We propose an efficient scheme for transferring quantum states and generating entangled states between two qubits of different nature. The hybrid system consists of a single nitrogen-vacancy (NV) center and a superconducting (SC) qubit, which couple to an optical cavity and a microwave resonator, respectively. Meanwhile, the optical cavity and the microwave resonator are coupled via the electro-optic effect. By adjusting the relative parameters, we can achieve high-fidelity quantum state transfer as well as highly entangled states between the NV center and the SC qubit. This protocol is within the reach of currently available techniques, and may provide interesting applications in quantum communication and computation with single NV centers and SC qubits.

Surface acoustic wave regulated single photon emission from a coupled quantum dot–nanocavity system

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

Weiß, M.; Kapfinger, S.; Wixforth, A.

2016-07-18

A coupled quantum dot–nanocavity system in the weak coupling regime of cavity-quantumelectrodynamics is dynamically tuned in and out of resonance by the coherent elastic field of a f{sub SAW} ≃ 800 MHz surface acoustic wave. When the system is brought to resonance by the sound wave, light-matter interaction is strongly increased by the Purcell effect. This leads to a precisely timed single photon emission as confirmed by the second order photon correlation function, g{sup (2)}. All relevant frequencies of our experiment are faithfully identified in the Fourier transform of g{sup (2)}, demonstrating high fidelity regulation of the stream of single photonsmore » emitted by the system.« less

Single Cell Fluorescence Imaging Using Metal Plasmon-Coupled Probe

PubMed Central

Zhang, Jian; Fu, Yi; Lakowicz, Joseph R.

2009-01-01

This work constitutes the first fluorescent imaging of cells using metal plasmon-coupled probes (PCPs) at single cell resolution. N-(2-Mercapto-propionyl)glycine-coated silver nanoparticles were synthesized by reduction of silver nitrate using sodium borohyride and then succinimidylated via ligand exchange. Alexa Fluor 647-labeled concanavalin A (con A) was chemically bound to the silver particles to make the fluorescent metal plasmon-coupled probes. The fluorescence images were collected using a scanning confocal microscopy. The fluorescence intensity was observed to enhance 7-fold when binding the labeled con A on a single silver particle. PCPs were conjugated on HEK 293 A cells. Imaging results demonstrate that cells labeled by PCPs were 20-fold brighter than those by free labeled con A. PMID:17375898

Low-energy electron-impact single ionization of helium

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

Colgan, J.; Pindzola, M. S.; Childers, G.

2006-04-15

A study is made of low-energy electron-impact single ionization of ground-state helium. The time-dependent close-coupling method is used to calculate total integral, single differential, double differential, and triple differential ionization cross sections for impact electron energies ranging from 32 to 45 eV. For all quantities, the calculated cross sections are found to be in very good agreement with experiment, and for the triple differential cross sections, good agreement is also found with calculations made using the convergent close-coupling technique.

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

Serkland, Darwin K.; So, Haley M.; Peake, Gregory M.

Here, we report on mode selection and tuning properties of vertical-external-cavity surface-emitting lasers (VECSELs) containing coupled semiconductor and external cavities of total length less than 1 mm. Our goal is to create narrowlinewidth (<1MHz) single-frequency VECSELs that operate near 850 nm on a single longitudinal cavity resonance and tune versus temperature without mode hops. We have designed, fabricated, and measured VECSELs with external-cavity lengths ranging from 25 to 800 μm. Lastly, we compare simulated and measured coupled-cavity mode frequencies and discuss criteria for single mode selection.

Effect of counseling on quality of marital relationship of infertile couples: a randomized, controlled trial (RCT) study.

PubMed

Vizheh, Maryam; Pakgohar, Minoo; Babaei, Gholamreza; Ramezanzadeh, Fatemeh

2013-03-01

Infertility is a major cause of marital problems and sexual dissatisfaction. This study was conducted to determine the effects of counseling on infertile couple's marital relationship and sexual satisfaction. This study was performed as a randomized controlled trial (RCT) in which 100 infertile couples (200 participants) who visited Reproductive Health Research Center Tehran, Iran were randomly assigned into two groups: intervention (n = 50 couples, 50 wives and 50 husbands) and control (n = 50 couples, 50 wives and 50 husbands). Intervention was defined as three counseling sessions per week, each lasting 60-90 min. Counseling in the intervention group was conducted separately for each couple. Demographic characteristics and marital and sexual satisfaction were investigated using three questionnaires through interviews. The outcomes, including changes in marital satisfaction and sexual satisfaction, were compared between the two groups 3 months later. Based on the data collected 3 months after the intervention period, the mean scores of marital and sexual satisfaction in intervention and control groups for wives were 49.62 ± 11.09 versus 54.97 ± 12.64 (P = 0.036) and 36.00 ± 8.37 versus 40.04 ± 7.69 (P = 0.019), respectively. Respective scores for husbands were 45.48 ± 9.55 versus 50.08 ± 11.43 (P = 0.042) and 33.37 ± 7.09 versus 36.63 ± 6.52 (P = 0.025), respectively. It should be noted that higher scores in questionnaires inspecting marital and sexual satisfaction indicate lower satisfaction. Infertility counseling improves marital and sexual satisfaction in infertile couples.

Coupling a single electron spin to a microwave resonator: Part I: controlling transverse and longitudinal couplings

NASA Astrophysics Data System (ADS)

Lachance-Quirion, Dany; Beaudoin, Félix; Camirand Lemyre, Julien; Coish, William A.; Pioro-Ladrière, Michel

Novel quantum technologies can be combined within hybrid systems to benefit from the complementary capabilities of individual components. For example, microwave-frequency superconducting resonators are ideally suited to perform qubit readout and to mediate two-qubit gates, while spin qubits offer long coherence times and high-fidelity single-qubit gates. In this talk, we consider strong coupling between a microwave resonator and an electron-spin qubit in a double quantum dot due to an inhomogeneous magnetic field generated by a nearby nanomagnet.. Considering realistic parameters, we estimate spin-resonator couplings of order 1 MHz. Further, we show that the position of the double dot relative to the nanomagnet allows us to select between purely longitudinal and transverse couplings. While the transverse coupling may be used for quantum state transfer between the spin qubit and the resonator, the longitudinal coupling could be used in a new qubit readout scheme recently introduced for superconducting qubits.

Espresso Coffee for the Treatment of Somnolence in Parkinson’s Disease: Results of n-of-1 Trials

PubMed Central

Ferreira, Joaquim J.; Mestre, Tiago; Guedes, Leonor Correia; Coelho, Miguel; Rosa, Mário M.; Santos, Ana T.; Barra, Márcio; Sampaio, Cristina; Rascol, Olivier

2016-01-01

There is limited information available concerning the treatment of daytime somnolence associated with Parkinson’s disease (PD); the most frequently applied therapeutic strategies include decreasing the dose of dopamine agonists or adding potential wake-promoting agents. There is recent data from a placebo-controlled trial concluding on a non-significant trend in favor of caffeine. We aimed to evaluate the efficacy of espresso-coffee in the treatment of daytime somnolence in PD. To evaluate the efficacy of espresso-coffee in the treatment of daytime somnolence in PD, we have conducted multiple single-patient (n-of-1) clinical trials comparing regular espresso coffee to decaffeinated coffee in PD patients presenting moderate to severe daytime somnolence defined as an Epworth Sleepiness Scale score >9. Each single-patient (n-of-1) trial included a sequence of three crossovers (two treatment periods separated by two days of washout). Four patients were included in the studies and three completed the three pairs of treatment periods. In two of the four patients, espresso coffee was considered beneficial. This study concludes that multiple single patient trials are feasible in PD and suggests that espresso-coffee may have a beneficial effect on daytime somnolence in some patients. These results cannot be generalized beyond the patients included in these trials. PMID:27014181

Effects of underwater turbulence on laser beam propagation and coupling into single-mode optical fiber.

PubMed

Hanson, Frank; Lasher, Mark

2010-06-01

We characterize and compare the effects of turbulence on underwater laser propagation with theory. Measurements of the coupling efficiency of the focused beam into a single-mode fiber are reported. A simple tip-tilt control system, based on the position of the image centroid in the focal plane, was shown to maintain good coupling efficiency for a beam radius equal to the transverse coherence length, r(0). These results are relevant to high bandwidth communication technology that requires good spatial mode quality.

Single-trial extraction of cognitive evoked potentials by combination of third-order correlation and wavelet denoising.

PubMed

Zhang, Z; Tian, X

2005-01-01

The application of a recently proposed denoising implementation for obtaining cognitive evoked potentials (CEPs) at the single-trial level is shown. The aim of this investigation is to develop the technique of extracting CEPs by combining both the third-order correlation and the wavelet denoising methods. First, the noisy CEPs was passed through a finite impulse response filter whose impulse response is matched with the shape of the noise-free signal. It was shown that it is possible to estimate the filter impulse response on basis of a select third-order correlation slice (TOCS) of the input noisy CEPs. Second, the output from the third-order correlation filter is decomposed with bi-orthogonal splines at 5 levels. The CEPs is reconstructed by wavelet final approximation a5. We study its performance in simulated data as well as in cognitive evoked potentials of normal rat and Alzheimer's disease (AD) model rat. For the simulated data, the method gives a significantly better reconstruction of the single-trial cognitive evoked potentials responses in comparison with the simulated data. Moreover, with this approach we obtain a significantly better estimation of the amplitudes and latencies of the simulated CEPs. For the real data, the method clearly improves the visualization of single-trial CEPs. This allows the calculation of better averages as well as the study of systematic or unsystematic variations between trials.

Method for enhancing single-trial P300 detection by introducing the complexity degree of image information in rapid serial visual presentation tasks

PubMed Central

Lin, Zhimin; Zeng, Ying; Tong, Li; Zhang, Hangming; Zhang, Chi

2017-01-01

The application of electroencephalogram (EEG) generated by human viewing images is a new thrust in image retrieval technology. A P300 component in the EEG is induced when the subjects see their point of interest in a target image under the rapid serial visual presentation (RSVP) experimental paradigm. We detected the single-trial P300 component to determine whether a subject was interested in an image. In practice, the latency and amplitude of the P300 component may vary in relation to different experimental parameters, such as target probability and stimulus semantics. Thus, we proposed a novel method, Target Recognition using Image Complexity Priori (TRICP) algorithm, in which the image information is introduced in the calculation of the interest score in the RSVP paradigm. The method combines information from the image and EEG to enhance the accuracy of single-trial P300 detection on the basis of traditional single-trial P300 detection algorithm. We defined an image complexity parameter based on the features of the different layers of a convolution neural network (CNN). We used the TRICP algorithm to compute for the complexity of an image to quantify the effect of different complexity images on the P300 components and training specialty classifier according to the image complexity. We compared TRICP with the HDCA algorithm. Results show that TRICP is significantly higher than the HDCA algorithm (Wilcoxon Sign Rank Test, p<0.05). Thus, the proposed method can be used in other and visual task-related single-trial event-related potential detection. PMID:29283998

Mixed response and time-to-event endpoints for multistage single-arm phase II design.

PubMed

Lai, Xin; Zee, Benny Chung-Ying

2015-06-04

The objective of phase II cancer clinical trials is to determine if a treatment has sufficient activity to warrant further study. The efficiency of a conventional phase II trial design has been the object of considerable debate, particularly when the study regimen is characteristically cytostatic. At the time of development of a phase II cancer trial, we accumulated clinical experience regarding the time to progression (TTP) for similar classes of drugs and for standard therapy. By considering the time to event (TTE) in addition to the tumor response endpoint, a mixed-endpoint phase II design may increase the efficiency and ability of selecting promising cytotoxic and cytostatic agents for further development. We proposed a single-arm phase II trial design by extending the Zee multinomial method to fully use mixed endpoints with tumor response and the TTE. In this design, the dependence between the probability of response and the TTE outcome is modeled through a Gaussian copula. Given the type I and type II errors and the hypothesis as defined by the response rate (RR) and median TTE, such as median TTP, the decision rules for a two-stage phase II trial design can be generated. We demonstrated through simulation that the proposed design has a smaller expected sample size and higher early stopping probability under the null hypothesis than designs based on a single-response endpoint or a single TTE endpoint. The proposed design is more efficient for screening new cytotoxic or cytostatic agents and less likely to miss an effective agent than the alternative single-arm design.

Thinking outside the Randomized Controlled Trials Experimental Box: Strategies for Enhancing Credibility and Social Justice

ERIC Educational Resources Information Center

Hesse-Biber, Sharlene

2013-01-01

Some evaluators employ randomized controlled trials (RCTs) as the gold standard of evidence-based practice (EBP). Critics of RCT designs argue that RCTs do not include the complexity of program participants' experiences or clinical expertise, and couple this with criticisms that it is difficult to transfer RCT findings from the laboratory to…

Strong coupling between adenine nucleobases in DNA single strands revealed by circular dichroism using synchrotron radiation

NASA Astrophysics Data System (ADS)

Kadhane, Umesh; Holm, Anne I. S.; Hoffmann, Søren Vrønning; Nielsen, Steen Brøndsted

2008-02-01

Circular dichroism (CD) experiments on DNA single strands (dAn) at the ASTRID synchrotron radiation facility reveal that eight adenine (A) bases electronically couple upon 190nm excitation. After n=8 , the CD signal increases linearly with n with a slope equal to the sum of the coupling terms. Nearest neighbor interactions account for only 24% of the CD signal whereas electronic communication is limited to nearest neighbors for two other exciton bands observed at 218 and 251nm (i.e., dimer excited states). Electronic coupling between bases in DNA is important for nonradiative deexcitation of electronically excited states since the hazardous energy is spread over a larger spatial region.

Antiferromagnetic exchange coupling measurements on single Co clusters

NASA Astrophysics Data System (ADS)

Wernsdorfer, W.; Leroy, D.; Portemont, C.; Brenac, A.; Morel, R.; Notin, L.; Mailly, D.

2009-03-01

We report on single-cluster measurements of the angular dependence of the low-temperature ferromagnetic core magnetization switching field in exchange-coupled Co/CoO core-shell clusters (4 nm) using a micro-bridge DC superconducting quantum interference device (μ-SQUID). It is observed that the coupling with the antiferromagnetic shell induces modification in the switching field for clusters with intrinsic uniaxial anisotropy depending on the direction of the magnetic field applied during the cooling. Using a modified Stoner-Wohlfarth model, it is shown that the core interacts with two weakly coupled and asymmetrical antiferromagnetic sublattices. Ref.: C. Portemont, R. Morel, W. Wernsdorfer, D. Mailly, A. Brenac, and L. Notin, Phys. Rev. B 78, 144415 (2008)

Photoionization of Li2

NASA Astrophysics Data System (ADS)

Li, Y.; Pindzola, M. S.; Ballance, C. P.; Colgan, J.

2014-05-01

Single and double photoionization cross sections for Li2 are calculated using a time-dependent close-coupling method. The correlation between the outer two electrons of Li2 is obtained by relaxation of the close-coupled equations in imaginary time. Propagation of the close-coupled equations in real time yields single and double photoionization cross sections for Li2. The two active electron cross sections are compared with one active electron distorted-wave and close-coupling results for both Li and Li2. This work was supported in part by grants from NSF and US DoE. Computational work was carried out at NERSC in Oakland, California, NICS in Knoxville, Tennessee, and OLCF in Oak Ridge, Tennessee.

Single-mode fibers to single-mode waveguides coupling with minimum Fresnel back-reflection

NASA Astrophysics Data System (ADS)

Sneh, Anat; Ruschin, Shlomo; Marom, Emanuel

1991-04-01

Slantly polished fibers and waveguides coupling as a means for achieving both low optical power reflection and efficient power transmission is proposed. Return losses exceeding -70 dB can be obtained in fiber-to-Lithium Niobate waveguides operating at ) = 0.633 jm and ) = 1.3 pm by polishing the fiber at an angle of 6°. A phase matching condition between the propagation constants ,8 and the polishing angles in the fiber and the waveguide: fl(fiber)sincx(fiber) = fl(waveguide)sina(waveguide) must be fulifiled in order to enable efficient power coupling. Polishing angle tolerances of approximately lO are allowed for a maximum of 1 dB decrease in the coupling efficiency.

Spin-orbit splitted excited states using explicitly-correlated equation-of-motion coupled-cluster singles and doubles eigenvectors

NASA Astrophysics Data System (ADS)

Bokhan, Denis; Trubnikov, Dmitrii N.; Perera, Ajith; Bartlett, Rodney J.

2018-04-01

An explicitly-correlated method of calculation of excited states with spin-orbit couplings, has been formulated and implemented. Developed approach utilizes left and right eigenvectors of equation-of-motion coupled-cluster model, which is based on the linearly approximated explicitly correlated coupled-cluster singles and doubles [CCSD(F12)] method. The spin-orbit interactions are introduced by using the spin-orbit mean field (SOMF) approximation of the Breit-Pauli Hamiltonian. Numerical tests for several atoms and molecules show good agreement between explicitly-correlated results and the corresponding values, calculated in complete basis set limit (CBS); the highly-accurate excitation energies can be obtained already at triple- ζ level.

Strong coupling of a single electron in silicon to a microwave photon

NASA Astrophysics Data System (ADS)

Mi, X.; Cady, J. V.; Zajac, D. M.; Deelman, P. W.; Petta, J. R.

2017-01-01

Silicon is vital to the computing industry because of the high quality of its native oxide and well-established doping technologies. Isotopic purification has enabled quantum coherence times on the order of seconds, thereby placing silicon at the forefront of efforts to create a solid-state quantum processor. We demonstrate strong coupling of a single electron in a silicon double quantum dot to the photonic field of a microwave cavity, as shown by the observation of vacuum Rabi splitting. Strong coupling of a quantum dot electron to a cavity photon would allow for long-range qubit coupling and the long-range entanglement of electrons in semiconductor quantum dots.

Studies on low-loss coupling of non-node anti-resonant hollow-core fiber and tapered fiber

NASA Astrophysics Data System (ADS)

Zhang, Naiqian; Wang, Zefeng; Liu, Wenbo; Xi, Xiaoming

2017-10-01

Up to now, near almost optical fiber gas lasers employ/adopt the scheme of free-space coupling, which increases the difficulty to adjust the optical path, and has poor stability. All-fiber structure fiber-gas lasers are important development directions in the future. We established the numerical model of SMF-28 type tapered single-mode fiber and non-node hollow-core fiber. When the SMF-28 type single-mode fiber has a waist diameter of 40μm when the light source is LP01 fundamental mode with 1550nm wavelength, the mode field diameter is the largest. Meanwhile, we simulated that the equivalent mode field diameter of non-node anti-resonant hollow-core fiber is about 75μm at the same 1550nm wavelength light source. Then, we use different waist diameters of SMF-28 type tapered fibers injected to the non-node anti-resonant hollow-core fiber in simulation and experiments. In the scheme of the single-ended low-loss coupling, the simulation results indicate that the best waist diameter of tapered fiber is 40μm, and the calculated maximum coupling efficiency is 83.55%. Meanwhile, the experimental result of maximum coupling efficiency is 80.74% when the best waist diameter of tapered fiber is also 40μm. As for the double-ended low-loss coupling, the calculated maximum coupling efficiency is near 83.38%.

A Two-Locus Global DNA Barcode for Land Plants: The Coding rbcL Gene Complements the Non-Coding trnH-psbA Spacer Region

PubMed Central

Kress, W. John; Erickson, David L.

2007-01-01

Background A useful DNA barcode requires sufficient sequence variation to distinguish between species and ease of application across a broad range of taxa. Discovery of a DNA barcode for land plants has been limited by intrinsically lower rates of sequence evolution in plant genomes than that observed in animals. This low rate has complicated the trade-off in finding a locus that is universal and readily sequenced and has sufficiently high sequence divergence at the species-level. Methodology/Principal Findings Here, a global plant DNA barcode system is evaluated by comparing universal application and degree of sequence divergence for nine putative barcode loci, including coding and non-coding regions, singly and in pairs across a phylogenetically diverse set of 48 genera (two species per genus). No single locus could discriminate among species in a pair in more than 79% of genera, whereas discrimination increased to nearly 88% when the non-coding trnH-psbA spacer was paired with one of three coding loci, including rbcL. In silico trials were conducted in which DNA sequences from GenBank were used to further evaluate the discriminatory power of a subset of these loci. These trials supported the earlier observation that trnH-psbA coupled with rbcL can correctly identify and discriminate among related species. Conclusions/Significance A combination of the non-coding trnH-psbA spacer region and a portion of the coding rbcL gene is recommended as a two-locus global land plant barcode that provides the necessary universality and species discrimination. PMID:17551588

How Do Children Coordinate Simultaneous Upper and Lower Extremity Tasks? The Development of Dual Motor Task Coordination.

ERIC Educational Resources Information Center

Getchell, Nancy; Whitall, Jill

2003-01-01

Compared coupling characteristics of clapping simultaneous with walking or galloping, consistency across trials, and phasing variability among 4-, 6-, 8-, and 10-year-olds. Found that for walk/clap tasks, children adopted adult-like coupling patterns by age 8 and with the same consistency by age 10. Across age, children became less variable in…

Effects of a Health Behavior Change Model-Based HIV/STI Prevention Intervention on Condom Use among Heterosexual Couples: A Randomized Trial

ERIC Educational Resources Information Center

Harvey, S. Marie; Kraft, Joan Marie; West, Stephen G.; Taylor, Aaron B.; Pappas-DeLuca, Katina A.; Beckman, Linda J.

2009-01-01

This study examines an intervention for heterosexual couples to prevent human immunodeficiency virus/sexually transmitted infections. It also evaluates the effect of the intervention, which is based on current models of health behavior change, on intermediate outcomes (individual and relationship factors) and consistency of condom use. Eligible…

Vaxchora: A Single-Dose Oral Cholera Vaccine.

PubMed

Cabrera, Adriana; Lepage, Jayne E; Sullivan, Karyn M; Seed, Sheila M

2017-07-01

To review trials evaluating the efficacy and safety of Vaxchora, a reformulated, single-dose, oral, lyophilized Vibrio cholerae CVD 103-HgR vaccine for the prevention of travel-related cholera caused by V cholerae serogroup O1. A literature search was conducted using MEDLINE (1946 to January week 3, 2017) and EMBASE (1996 to 2017 week 3). Keywords included oral cholera vaccine, single-dose, Vaxchora, and CVD 103-HgR. Limits included human, clinical trials published in English since 2010. ClinicalTrials.gov was used as a source for unpublished data. Additional data sources were obtained through bibliographic review of selected articles. Studies that addressed the safety and efficacy of Vaxchora, the reformulated, single-dose oral CVD 103-HgR cholera vaccine, were selected for analysis. Approval of Vaxchora, was based on efficacy of the vaccine in human trials demonstrating 90.3% protection among those challenged with V cholerae 10 days after vaccination and in immunogenicity studies with 90% systemic vibriocidal antibody conversion at 6 months after a single-dose of vaccine. Tolerability was acceptable, with the most common adverse effects reported to be fatigue, headache, and abdominal pain. Vaxchora is the only FDA-approved, single-dose oral vaccine for the prevention of cholera caused by V cholerae serogroup O1 in adult travelers from the United States going to cholera-affected areas. Safety and efficacy has not been established in children, immunocompromised persons, and pregnant or breastfeeding women or those living in cholera-endemic areas.

Piloting relationship education for female same-sex couples: Results of a small randomized waitlist-control trial.

PubMed

Whitton, Sarah W; Scott, Shelby B; Dyar, Christina; Weitbrecht, Eliza M; Hutsell, David W; Kuryluk, Amanda D

2017-10-01

Relationship education represents a promising, nonstigmatizing approach to promoting the health and stability of same-sex couples. A new culturally sensitive adaptation of relationship education was developed specifically for female same-sex couples (The Strengthening Same-Sex Relationships Program, Female version; SSSR-F). SSSR-F includes adaptations of evidence-based strategies to build core relationship skills (e.g., communication skills training) as well as new content to address unique challenges faced by this population (e.g., discrimination; low social support). A small randomized waitlist-control trial (N = 37 couples) was conducted to evaluate program feasibility, acceptability, and efficacy. Three proximal outcomes targeted by SSSR-F (communication, perceived stress, social support) and 3 distal outcomes (global relationship satisfaction, instability, and confidence) were assessed at pre- and posttreatment and 3-month follow-up. Results of multilevel models accounting for nonindependence in dyadic data indicated statistically significant program effects on positive and negative couple communication, relationship satisfaction, and relationship confidence and small, nonsignificant program effects on stress, social support, and relationship instability. Analyses of follow-up data suggest maintenance of effects on the proximal but not the distal outcomes. Ratings of program satisfaction were high. Overall, findings support the feasibility, acceptability, and initial efficacy of SSSR-F, highlighting the potential value of culturally sensitive relationship education for same-sex couples. Continued efforts are needed to increase sustainability of program effects on global relationship quality over time. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

The developments and achievements of endoscopic surgery, robotic surgery and function-preserving surgery.

PubMed

Yoshida, Masashi; Furukawa, Toshiharu; Morikawa, Yasuhide; Kitagawa, Yuko; Kitajima, Masaki

2010-09-01

The breakthrough in laparoscopic surgery has been the development of a charge-coupled device camera system and Mouret performing cholecystectomy in 1987. The short-term benefits of laparoscopic surgery are widely accepted and the long-term benefit of less incidence of bowel obstruction can be expected. The important developments have been the articulating instrumentation via new laparoscopic access ports. Since 2007, single-incision laparoscopic surgery has spread all over the world. Not only single-scar but also no-scar operation is a current topic. In 2004, Kalloo reported the flexible transgastric peritoneoscopy as a novel approach to therapeutic interventions. In 2007, Marescaux reported transvaginal cholecystectomy in a patient. The breakthrough in robotic surgery was the development of the da Vinci Surgical System. It was introduced to Keio University Hospital in March 2000. Precision in the surgery will reach a higher level with the use of robotics. In collaboration with the faculty of technology and science, Keio University, the combined master-slave manipulator has been developed. The haptic forceps, which measure the elasticity of organs, have also been developed. The first possible sites of lymphatic metastasis are known as sentinel nodes. Otani reported vagus-sparing segmental gastrectomy under sentinel node navigation. This kind of function-preserving surgery will be performed frequently if the results of the multicenter prospective trial of the dual tracer method are favorable. Indocyanine green fluorescence-guided method using the HyperEye charge-coupled device camera system can be a highly sensitive method without using the radioactive colloid. 'Minimally invasive, function-preserving and precise surgery under sentinel node navigation in community hospital' may be a goal for us.

A P300-based Brain-Computer Interface with Stimuli on Moving Objects: Four-Session Single-Trial and Triple-Trial Tests with a Game-Like Task Design

PubMed Central

Ganin, Ilya P.; Shishkin, Sergei L.; Kaplan, Alexander Y.

2013-01-01

Brain-computer interfaces (BCIs) are tools for controlling computers and other devices without using muscular activity, employing user-controlled variations in signals recorded from the user’s brain. One of the most efficient noninvasive BCIs is based on the P300 wave of the brain’s response to stimuli and is therefore referred to as the P300 BCI. Many modifications of this BCI have been proposed to further improve the BCI’s characteristics or to better adapt the BCI to various applications. However, in the original P300 BCI and in all of its modifications, the spatial positions of stimuli were fixed relative to each other, which can impose constraints on designing applications controlled by this BCI. We designed and tested a P300 BCI with stimuli presented on objects that were freely moving on a screen at a speed of 5.4°/s. Healthy participants practiced a game-like task with this BCI in either single-trial or triple-trial mode within four sessions. At each step, the participants were required to select one of nine moving objects. The mean online accuracy of BCI-based selection was 81% in the triple-trial mode and 65% in the single-trial mode. A relatively high P300 amplitude was observed in response to targets in most participants. Self-rated interest in the task was high and stable over the four sessions (the medians in the 1st/4th sessions were 79/84% and 76/71% in the groups practicing in the single-trial and triple-trial modes, respectively). We conclude that the movement of stimulus positions relative to each other may not prevent the efficient use of the P300 BCI by people controlling their gaze, e.g., in robotic devices and in video games. PMID:24302977

Behaviorally-based couple therapies reduce emotional arousal during couple conflict.

PubMed

Baucom, Brian R; Sheng, Elisa; Christensen, Andrew; Georgiou, Panayiotis G; Narayanan, Shrikanth S; Atkins, David C

2015-09-01

Emotional arousal during relationship conflict is a major target for intervention in couple therapies. The current study examines changes in conflict-related emotional arousal in 104 couples that participated in a randomized clinical trial of two behaviorally-based couple therapies. Emotional arousal is measured using mean fundamental frequency of spouse's speech, and changes in emotional arousal from pre-to post-therapy are examined using multilevel models. Overall emotional arousal, the rate of increase in emotional arousal at the beginning of conflict, and the duration of emotional arousal declined for all couples. Reductions in overall arousal were stronger for TBCT wives than for IBCT wives but not significantly different for IBCT and TBCT husbands. Reductions in the rate of initial arousal were larger for TBCT couples than IBCT couples. Reductions in duration were larger for IBCT couples than TBCT couples. These findings suggest that both therapies can reduce emotional arousal, but that the two therapies create different kinds of change in emotional arousal. Copyright © 2015 Elsevier Ltd. All rights reserved.

Using Single-trial EEG to Predict and Analyze Subsequent Memory

PubMed Central

Noh, Eunho; Herzmann, Grit; Curran, Tim; de Sa, Virginia R.

2013-01-01

We show that it is possible to successfully predict subsequent memory performance based on single-trial EEG activity before and during item presentation in the study phase. Two-class classification was conducted to predict subsequently remembered vs. forgotten trials based on subjects’ responses in the recognition phase. The overall accuracy across 18 subjects was 59.6 % by combining pre- and during-stimulus information. The single-trial classification analysis provides a dimensionality reduction method to project the high-dimensional EEG data onto a discriminative space. These projections revealed novel findings in the pre- and during-stimulus period related to levels of encoding. It was observed that the pre-stimulus information (specifically oscillatory activity between 25–35Hz) −300 to 0 ms before stimulus presentation and during-stimulus alpha (7–12 Hz) information between 1000–1400 ms after stimulus onset distinguished between recollection and familiarity while the during-stimulus alpha information and temporal information between 400–800 ms after stimulus onset mapped these two states to similar values. PMID:24064073

Single-photon absorption by single photosynthetic light-harvesting complexes

NASA Astrophysics Data System (ADS)

Chan, Herman C. H.; Gamel, Omar E.; Fleming, Graham R.; Whaley, K. Birgitta

2018-03-01

We provide a unified theoretical approach to the quantum dynamics of absorption of single photons and subsequent excitonic energy transfer in photosynthetic light-harvesting complexes. Our analysis combines a continuous mode < n > -photon quantum optical master equation for the chromophoric system with the hierarchy of equations of motion describing excitonic dynamics in presence of non-Markovian coupling to vibrations of the chromophores and surrounding protein. We apply the approach to simulation of absorption of single-photon coherent states by pigment-protein complexes containing between one and seven chromophores, and compare with results obtained by excitation using a thermal radiation field. We show that the values of excitation probability obtained under single-photon absorption conditions can be consistently related to bulk absorption cross-sections. Analysis of the timescale and efficiency of single-photon absorption by light-harvesting systems within this full quantum description of pigment-protein dynamics coupled to a quantum radiation field reveals a non-trivial dependence of the excitation probability and the excited state dynamics induced by exciton-phonon coupling during and subsequent to the pulse, on the bandwidth of the incident photon pulse. For bandwidths equal to the spectral bandwidth of Chlorophyll a, our results yield an estimation of an average time of ˜0.09 s for a single chlorophyll chromophore to absorb the energy equivalent of one (single-polarization) photon under irradiation by single-photon states at the intensity of sunlight.

Localized one-dimensional single voxel magnetic resonance spectroscopy without J coupling modulations.

PubMed

Lin, Yanqin; Lin, Liangjie; Wei, Zhiliang; Zhong, Jianhui; Chen, Zhong

2016-12-01

To acquire single voxel localized one-dimensional 1 H magnetic resonance spectroscopy (MRS) without J coupling modulations, free from amplitude and phase distortions. A pulse sequence, named PRESSIR, is developed for volume localized MRS without J modulations at arbitrary echo time (TE). The J coupling evolution is suppressed by the J-refocused module that uses a 90° pulse at the midpoint of a double spin echo. The localization performance of the PRESSIR sequence was tested with a two-compartment phantom. The proposed sequence shows similar voxel localization accuracy as PRESS. Both PRESSIR and PRESS sequences were performed on MRS brain phantom and pig brain tissue. PRESS spectra suffer from amplitude and phase distortions due to J modulations, especially under moderate and long TEs, while PRESSIR spectra are almost free from distortions. The PRESSIR sequence proposed herein enables the acquisition of single voxel in-phase MRS within a single scan. It allows an enhanced signal intensity of J coupling metabolites and reducing undesired broad resonances with short T2s while suppressing J modulations. Moreover, it provides an approach for direct measurement of nonoverlapping J coupling peaks and of transverse relaxation times T2s. Magn Reson Med 76:1661-1667, 2016. © 2015 International Society for Magnetic Resonance in Medicine. © 2015 International Society for Magnetic Resonance in Medicine.

Linear dynamic coupling in geared rotor systems

NASA Technical Reports Server (NTRS)

David, J. W.; Mitchell, L. D.

1986-01-01

The effects of high frequency oscillations caused by the gear mesh, on components of a geared system that can be modeled as rigid discs are analyzed using linear dynamic coupling terms. The coupled, nonlinear equations of motion for a disc attached to a rotating shaft are presented. The results of a trial problem analysis show that the inclusion of the linear dynamic coupling terms can produce significant changes in the predicted response of geared rotor systems, and that the produced sideband responses are greater than the unbalanced response. The method is useful in designing gear drives for heavy-lift helicopters, industrial speed reducers, naval propulsion systems, and heavy off-road equipment.

Single-mode very wide tunability in laterally coupled semiconductor lasers with electrically controlled reflectivities

NASA Astrophysics Data System (ADS)

Griffel, Giora; Chen, Howard Z.; Grave, Ilan; Yariv, Amnon

1991-04-01

The operation of a novel multisection structure comprised of laterally coupled gain-guided semiconductor lasers is demonstrated. It is shown that tunable single longitudinal mode operation can be achieved with a high degree of frequency selectivity. The device has a tuning range of 14.5 nm, the widest observed to date in a monolithic device.

Tuning of multiple luminescence outputs and white-light emission from a single gelator molecule through an ESIPT coupled AIEE process.

PubMed

Maity, Arunava; Ali, Firoj; Agarwalla, Hridesh; Anothumakkool, Bihag; Das, Amitava

2015-02-07

A unique example of an ESIPT coupled AIEE process, associated with a single molecule (1), is utilized for generating multiple luminescent colors (blue-green-white-yellow). The J-aggregated state of 1 forms a luminescent gel in THF and this luminescent property is retained even in the solid state.

Light coupling and distribution for Si3N4/SiO2 integrated multichannel single-mode sensing system

NASA Astrophysics Data System (ADS)

Kaźmierczak, Andrzej; Dortu, Fabian; Schrevens, Olivier; Giannone, Domenico; Bouville, David; Cassan, Eric; Gylfason, Kristinn B.; Sohlström, Hans; Sanchez, Benito; Griol, Amadeu; Hill, Daniel

2009-01-01

We present an efficient and highly alignment-tolerant light coupling and distribution system for a multichannel Si3N4/SiO2 single-mode photonics sensing chip. The design of the input and output couplers and the distribution splitters is discussed. Examples of multichannel data obtained with the system are given.

Single-mode laser studies: Design and performance of a fixed-wave length source and coupling of lasers to thin-film optical waveguides

NASA Technical Reports Server (NTRS)

Ladany, I.; Hammer, J. M.

1980-01-01

A module developed for the generation of a stable single wavelength to be used for a fiber optic multiplexing scheme is described. The laser is driven with RZ pulses, and the temperature is stabilized thermoelectrically. The unit is capable of maintaining a fixed wavelength within about 6 A as the pulse duty cycle is changed between 0 and 100 percent. This is considered the most severe case, and much tighter tolerances are obtainable for constant input power coding schemes. Using a constricted double heterostructure laser, a wavelength shift of 0.083 A mA is obtained due to laser self-heating by a dc driving current. The thermoelectric unit is capable of maintaining a constant laser heat-sink temperature within 0.02 C. In addition, miniature lenses and couplers are described which allow efficient coupling of single wavelength modes of junction lasers to thin film optical waveguides. The design of the miniature cylinder lenses and the prism coupling techniques allow 2 mW of single wavelength mode junction laser light to b coupled into thin film waveguides using compact assemblies. Selective grating couplers are also studied.

Dynamical theory of single-photon transport in a one-dimensional waveguide coupled to identical and nonidentical emitters

NASA Astrophysics Data System (ADS)

Liao, Zeyang; Nha, Hyunchul; Zubairy, M. Suhail

2016-11-01

We develop a general dynamical theory for studying a single-photon transport in a one-dimensional (1D) waveguide coupled to multiple emitters which can be either identical or nonidentical. In this theory, both the effects of the waveguide and non-waveguide vacuum modes are included. This theory enables us to investigate the propagation of an emitter excitation or an arbitrary single-photon pulse along an array of emitters coupled to a 1D waveguide. The dipole-dipole interaction induced by the non-waveguide modes, which is usually neglected in the literature, can significantly modify the dynamics of the emitter system as well as the characteristics of the output field if the emitter separation is much smaller than the resonance wavelength. Nonidentical emitters can also strongly couple to each other if their energy difference is less than or of the order of the dipole-dipole energy shift. Interestingly, if their energy difference is close but nonzero, a very narrow transparency window around the resonance frequency can appear which does not occur for identical emitters. This phenomenon may find important applications in quantum waveguide devices such as optical switches and ultranarrow single-photon frequency comb generator.

Integrated nanoplasmonic quantum interfaces for room-temperature single-photon sources

NASA Astrophysics Data System (ADS)

Peyskens, Frédéric; Englund, Dirk; Chang, Darrick

2017-12-01

We describe a general analytical framework of a nanoplasmonic cavity-emitter system interacting with a dielectric photonic waveguide. Taking into account emitter quenching and dephasing, our model directly reveals the single-photon extraction efficiency η as well as the indistinguishability I of photons coupled into the waveguide mode. Rather than minimizing the cavity modal volume, our analysis predicts an optimum modal volume to maximize η that balances waveguide coupling and spontaneous emission rate enhancement. Surprisingly, our model predicts that near-unity indistinguishability is possible, but this requires a much smaller modal volume, implying a fundamental performance trade-off between high η and I at room temperature. Finally, we show that maximizing η I requires that the system has to be driven in the weak coupling regime because quenching effects and decreased waveguide coupling drastically reduce η in the strong coupling regime.

Millimeter Wave Sensor For On-Line Inspection Of Thin Sheet Dielectrics

DOEpatents

Bakhtiari, Sasan; Gopalsami, Nachappa; Raptis, Apostolos C.

1999-03-23

A millimeter wave sensor is provided for non-destructive inspection of thin sheet dielectric materials. The millimeter wave sensor includes a Gunn diode oscillator (GDO) source generating a mill meter wave electromagnetic energy signal having a single frequency. A heater is coupled to the GDO source for stabilizing the single frequency. A small size antenna is coupled to the GDO source for transmitting the millimeter wave electromagnetic energy signal to a sample material and for receiving a reflected millimeter wave electromagnetic energy signal from the sample material. Ferrite circulator isolators coupled between the GDO source and the antenna separate the millimeter wave electromagnetic energy signal into transmitted and received electromagnetic energy signal components and a detector detects change in both amplitude and phase of the transmitted and received electromagnetic energy signal components. A millimeter wave sensor is provided for non-destructive inspection of thin sheet dielectric materials. The millimeter wave sensor includes a Gunn diode oscillator (GDO) source generating a mill meter wave electromagnetic energy signal having a single frequency. A heater is coupled to the GDO source for stabilizing the single frequency. A small size antenna is coupled to the GDO source for transmitting the millimeter wave electromagnetic energy signal to a sample material and for receiving a reflected millimeter wave electromagnetic energy signal from the sample material. Ferrite circulator isolators coupled between the GDO source and the antenna separate the millimeter wave electromagnetic energy signal into transmitted and received electromagnetic energy signal components and a detector detects change in both amplitude and phase of the transmitted and received electromagnetic energy signal components.

Electrical coupling in ensembles of nonexcitable cells: modeling the spatial map of single cell potentials.

PubMed

Cervera, Javier; Manzanares, Jose Antonio; Mafe, Salvador

2015-02-19

We analyze the coupling of model nonexcitable (non-neural) cells assuming that the cell membrane potential is the basic individual property. We obtain this potential on the basis of the inward and outward rectifying voltage-gated channels characteristic of cell membranes. We concentrate on the electrical coupling of a cell ensemble rather than on the biochemical and mechanical characteristics of the individual cells, obtain the map of single cell potentials using simple assumptions, and suggest procedures to collectively modify this spatial map. The response of the cell ensemble to an external perturbation and the consequences of cell isolation, heterogeneity, and ensemble size are also analyzed. The results suggest that simple coupling mechanisms can be significant for the biophysical chemistry of model biomolecular ensembles. In particular, the spatiotemporal map of single cell potentials should be relevant for the uptake and distribution of charged nanoparticles over model cell ensembles and the collective properties of droplet networks incorporating protein ion channels inserted in lipid bilayers.

New Circuit QED system based on Triple-leg Stripline Resonator.

NASA Astrophysics Data System (ADS)

Kim, Dongmin; Moon, Kyungsun

Conventional circuit QED system consists of a qubit located inside a linear stripline resonator, which has successfully demonstrated a strong coupling between a single photon and a qubit. Here we present a new circuit QED system, where the qubit is coupled to triple-leg stripline resonator (TSR). We have shown that TSR supports two-fold degenerate photon modes among others. By coupling them to a single qubit, we have obtained the dressed states of a coupled system of a single qubit and two-fold degenerate photon modes. By locating two qubits at two legs of TSR, we have studied a potential two-bit gate operation (e.g., CNOT gate) of the system. We will discuss the main advantage of utilizing two-fold degenerate photon modes This work is partially supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (NRF-2016R1D1A1B01013756).

Scalable quantum computer architecture with coupled donor-quantum dot qubits

DOEpatents

Schenkel, Thomas; Lo, Cheuk Chi; Weis, Christoph; Lyon, Stephen; Tyryshkin, Alexei; Bokor, Jeffrey

2014-08-26

A quantum bit computing architecture includes a plurality of single spin memory donor atoms embedded in a semiconductor layer, a plurality of quantum dots arranged with the semiconductor layer and aligned with the donor atoms, wherein a first voltage applied across at least one pair of the aligned quantum dot and donor atom controls a donor-quantum dot coupling. A method of performing quantum computing in a scalable architecture quantum computing apparatus includes arranging a pattern of single spin memory donor atoms in a semiconductor layer, forming a plurality of quantum dots arranged with the semiconductor layer and aligned with the donor atoms, applying a first voltage across at least one aligned pair of a quantum dot and donor atom to control a donor-quantum dot coupling, and applying a second voltage between one or more quantum dots to control a Heisenberg exchange J coupling between quantum dots and to cause transport of a single spin polarized electron between quantum dots.

Purcell-enhanced quantum yield from carbon nanotube excitons coupled to plasmonic nanocavities

DOE PAGES

Luo, Yue; Ahmadi, Ehsaneh D.; Shayan, Kamran; ...

2017-11-10

Single-walled carbon nanotubes (SWCNTs) are promising absorbers and emitters to enable novel photonic applications and devices but are also known to suffer from low optical quantum yields. Here we demonstrate SWCNT excitons coupled to plasmonic nanocavity arrays reaching deeply into the Purcell regime with Purcell factors (F P) up to F P = 180 (average F P = 57), Purcell-enhanced quantum yields of 62% (average 42%), and a photon emission rate of 15 MHz into the first lens. The cavity coupling is quasi-deterministic since the photophysical properties of every SWCNT are enhanced by at least one order of magnitude. Furthermore,more » the measured ultra-narrow exciton linewidth (18 ueV) reaches the radiative lifetime limit, which is promising towards generation of transform-limited single photons. Furthermore, to demonstrate utility beyond quantum light sources we show that nanocavity-coupled SWCNTs perform as single-molecule thermometers detecting plasmonically induced heat at cryogenic temperatures in a unique interplay of excitons, phonons, and plasmons at the nanoscale.« less

Robust inference for group sequential trials.

PubMed

Ganju, Jitendra; Lin, Yunzhi; Zhou, Kefei

2017-03-01

For ethical reasons, group sequential trials were introduced to allow trials to stop early in the event of extreme results. Endpoints in such trials are usually mortality or irreversible morbidity. For a given endpoint, the norm is to use a single test statistic and to use that same statistic for each analysis. This approach is risky because the test statistic has to be specified before the study is unblinded, and there is loss in power if the assumptions that ensure optimality for each analysis are not met. To minimize the risk of moderate to substantial loss in power due to a suboptimal choice of a statistic, a robust method was developed for nonsequential trials. The concept is analogous to diversification of financial investments to minimize risk. The method is based on combining P values from multiple test statistics for formal inference while controlling the type I error rate at its designated value.This article evaluates the performance of 2 P value combining methods for group sequential trials. The emphasis is on time to event trials although results from less complex trials are also included. The gain or loss in power with the combination method relative to a single statistic is asymmetric in its favor. Depending on the power of each individual test, the combination method can give more power than any single test or give power that is closer to the test with the most power. The versatility of the method is that it can combine P values from different test statistics for analysis at different times. The robustness of results suggests that inference from group sequential trials can be strengthened with the use of combined tests. Copyright © 2017 John Wiley & Sons, Ltd.

Comparison of the benefits of cochlear implantation versus contra-lateral routing of signal hearing aids in adult patients with single-sided deafness: study protocol for a prospective within-subject longitudinal trial

PubMed Central

2014-01-01

Background Individuals with a unilateral severe-to-profound hearing loss, or single-sided deafness, report difficulty with listening in many everyday situations despite having access to well-preserved acoustic hearing in one ear. The standard of care for single-sided deafness available on the UK National Health Service is a contra-lateral routing of signals hearing aid which transfers sounds from the impaired ear to the non-impaired ear. This hearing aid has been found to improve speech understanding in noise when the signal-to-noise ratio is more favourable at the impaired ear than the non-impaired ear. However, the indiscriminate routing of signals to a single ear can have detrimental effects when interfering sounds are located on the side of the impaired ear. Recent published evidence has suggested that cochlear implantation in individuals with a single-sided deafness can restore access to the binaural cues which underpin the ability to localise sounds and segregate speech from other interfering sounds. Methods/Design The current trial was designed to assess the efficacy of cochlear implantation compared to a contra-lateral routing of signals hearing aid in restoring binaural hearing in adults with acquired single-sided deafness. Patients are assessed at baseline and after receiving a contra-lateral routing of signals hearing aid. A cochlear implant is then provided to those patients who do not receive sufficient benefit from the hearing aid. This within-subject longitudinal design reflects the expected care pathway should cochlear implantation be provided for single-sided deafness on the UK National Health Service. The primary endpoints are measures of binaural hearing at baseline, after provision of a contra-lateral routing of signals hearing aid, and after cochlear implantation. Binaural hearing is assessed in terms of the accuracy with which sounds are localised and speech is perceived in background noise. The trial is also designed to measure the impact of the interventions on hearing- and health-related quality of life. Discussion This multi-centre trial was designed to provide evidence for the efficacy of cochlear implantation compared to the contra-lateral routing of signals. A purpose-built sound presentation system and established measurement techniques will provide reliable and precise measures of binaural hearing. Trial registration Current Controlled Trials http://www.controlled-trials.com/ISRCTN33301739 (05/JUL/2013) PMID:25152694

Single atom emission in an optical resonator

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

Childs, J.J.; An, K.; Dasari, R.R.

A single atom coupled to a single mode of a radiation field is a fundamental system for studying the interaction of radiation with matter. The study of such systems has come to be called cavity quantum electrodynamics (QED). Atoms coupled to a single mode of a resonator have been studied experimentally and theoretically in several interesting regimes since this basic system was first considered theoretically by Janes and Cummings. The objective of the present chapter is to provide a theoretical framework and present a unifying picture of the various phenomena which can occur in such a system. 35 refs., 11more » figs.« less

Bright nanowire single photon source based on SiV centers in diamond

DOE PAGES

Marseglia, L.; Saha, K.; Ajoy, A.; ...

2018-01-01

The practical implementation of quantum technologies such as quantum commu- nication and quantum cryptography relies on the development of indistinguishable, robust, and bright single photon sources that works at room temperature. The silicon- vacancy (SiV -) center in diamond has emerged as a possible candidate for a single photon source with all these characteristics. Unfortunately, due to the high refraction index mismatch between diamond and air, color centers in diamond show low photon out-coupling. This drawback can be overcome by fabrication of photonic structures that improve the in-coupling of excitation laser to the diamond defect as well as the out-couplingmore » emission from the color centers. An additional shortcoming is due to the random localization of native defects in the diamond sample. Here we demonstrate deterministic implantation of Si ions with high conversion effciency to single SiV -, targeted to fabricated nanowires. The co-localization of single SiV - defects with the nanostructures yields a ten times higher light coupling effciency as compared to single SiV - in the bulk. This result, with its intrinsic scalability, enables a new class of devices for integrated photonics and quantum information processing.« less

Single and Double Photoionization of Mg

NASA Astrophysics Data System (ADS)

Abdel-Naby, Shahin; Pindzola, M. S.; Colgan, J.

2014-05-01

Single and double photoionization cross sections for Mg are calculated using a time-dependent close-coupling method. The correlation between the two 3 s subshell electrons of Mg is obtained by relaxation of the close-coupled equations in imaginary time. An implicit method is used to propagate the close-coupled equations in real time to obtain single and double ionization cross sections for Mg. Energy and angle triple differential cross sections for double photoionization at equal energy sharing of E1 =E2 = 16 . 4 eV are compared with Elettra experiments and previous theoretical calculations. This work was supported in part by grants from NSF and US DoE. Computational work was carried out at NERSC in Oakland, California, NICS in Knoxville, Tennessee, and OLCF in Oak Ridge, Tennessee.

Strong spin-photon coupling in silicon

NASA Astrophysics Data System (ADS)

Samkharadze, N.; Zheng, G.; Kalhor, N.; Brousse, D.; Sammak, A.; Mendes, U. C.; Blais, A.; Scappucci, G.; Vandersypen, L. M. K.

2018-03-01

Long coherence times of single spins in silicon quantum dots make these systems highly attractive for quantum computation, but how to scale up spin qubit systems remains an open question. As a first step to address this issue, we demonstrate the strong coupling of a single electron spin and a single microwave photon. The electron spin is trapped in a silicon double quantum dot, and the microwave photon is stored in an on-chip high-impedance superconducting resonator. The electric field component of the cavity photon couples directly to the charge dipole of the electron in the double dot, and indirectly to the electron spin, through a strong local magnetic field gradient from a nearby micromagnet. Our results provide a route to realizing large networks of quantum dot–based spin qubit registers.

Strong exciton-photon coupling in organic single crystal microcavity with high molecular orientation

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

Goto, Kaname; Yamashita, Kenichi, E-mail: yamasita@kit.ac.jp; Yanagi, Hisao

2016-08-08

Strong exciton-photon coupling has been observed in a highly oriented organic single crystal microcavity. This microcavity consists of a thiophene/phenylene co-oligomer (TPCO) single crystal laminated on a high-reflection distributed Bragg reflector. In the TPCO crystal, molecular transition dipole was strongly polarized along a certain horizontal directions with respect to the main crystal plane. This dipole polarization causes significantly large anisotropies in the exciton transition and optical constants. Especially the anisotropic exciton transition was found to provide the strong enhancement in the coupling with the cavity mode, which was demonstrated by a Rabi splitting energy as large as ∼100 meV even inmore » the “half-vertical cavity surface emitting lasing” microcavity structure.« less

On the measurement of intensity correlations from laboratory and astronomical sources with SPADs and SNSPDs

NASA Astrophysics Data System (ADS)

Schroeder, Edward; Mauskopf, Philip; Pilyavsky, Genady; Sinclair, Adrian; Smith, Nathan; Bryan, Sean; Mani, Hamdi; Morozov, Dmitry; Berggren, Karl; Zhu, Di; Smirnov, Konstantin; Vakhtomin, Yuriy

2016-08-01

We describe the performance of detector modules containing silicon single photon avalanche photodiodes (SPADs) and superconducting nanowire single photon detectors (SNSPDs) to be used for intensity interferometry. The SPADs are mounted in fiber-coupled and free-space coupled packages. The SNSPDs are mounted in a small liquid helium cryostat coupled to single mode fiber optic cables which pass through a hermetic feed-through. The detectors are read out with microwave amplifiers and FPGA-based coincidence electronics. We present progress on measurements of intensity correlations from incoherent sources including gas-discharge lamps and stars with these detectors. From the measured laboratory performance of the correlation system, we estimate the sensitivity to intensity correlations from stars using commercial telescopes and larger existing research telescopes.

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

Marseglia, L.; Saha, K.; Ajoy, A.

The practical implementation of quantum technologies such as quantum commu- nication and quantum cryptography relies on the development of indistinguishable, robust, and bright single photon sources that works at room temperature. The silicon- vacancy (SiV -) center in diamond has emerged as a possible candidate for a single photon source with all these characteristics. Unfortunately, due to the high refraction index mismatch between diamond and air, color centers in diamond show low photon out-coupling. This drawback can be overcome by fabrication of photonic structures that improve the in-coupling of excitation laser to the diamond defect as well as the out-couplingmore » emission from the color centers. An additional shortcoming is due to the random localization of native defects in the diamond sample. Here we demonstrate deterministic implantation of Si ions with high conversion effciency to single SiV -, targeted to fabricated nanowires. The co-localization of single SiV - defects with the nanostructures yields a ten times higher light coupling effciency as compared to single SiV - in the bulk. This result, with its intrinsic scalability, enables a new class of devices for integrated photonics and quantum information processing.« less

Single-trial classification of motor imagery differing in task complexity: a functional near-infrared spectroscopy study

PubMed Central

2011-01-01

Background For brain computer interfaces (BCIs), which may be valuable in neurorehabilitation, brain signals derived from mental activation can be monitored by non-invasive methods, such as functional near-infrared spectroscopy (fNIRS). Single-trial classification is important for this purpose and this was the aim of the presented study. In particular, we aimed to investigate a combined approach: 1) offline single-trial classification of brain signals derived from a novel wireless fNIRS instrument; 2) to use motor imagery (MI) as mental task thereby discriminating between MI signals in response to different tasks complexities, i.e. simple and complex MI tasks. Methods 12 subjects were asked to imagine either a simple finger-tapping task using their right thumb or a complex sequential finger-tapping task using all fingers of their right hand. fNIRS was recorded over secondary motor areas of the contralateral hemisphere. Using Fisher's linear discriminant analysis (FLDA) and cross validation, we selected for each subject a best-performing feature combination consisting of 1) one out of three channel, 2) an analysis time interval ranging from 5-15 s after stimulation onset and 3) up to four Δ[O2Hb] signal features (Δ[O2Hb] mean signal amplitudes, variance, skewness and kurtosis). Results The results of our single-trial classification showed that using the simple combination set of channels, time intervals and up to four Δ[O2Hb] signal features comprising Δ[O2Hb] mean signal amplitudes, variance, skewness and kurtosis, it was possible to discriminate single-trials of MI tasks differing in complexity, i.e. simple versus complex tasks (inter-task paired t-test p ≤ 0.001), over secondary motor areas with an average classification accuracy of 81%. Conclusions Although the classification accuracies look promising they are nevertheless subject of considerable subject-to-subject variability. In the discussion we address each of these aspects, their limitations for future approaches in single-trial classification and their relevance for neurorehabilitation. PMID:21682906

Multi-Tasking and Choice of Training Data Influencing Parietal ERP Expression and Single-Trial Detection-Relevance for Neuroscience and Clinical Applications.

PubMed

Kirchner, Elsa A; Kim, Su Kyoung

2018-01-01

Event-related potentials (ERPs) are often used in brain-computer interfaces (BCIs) for communication or system control for enhancing or regaining control for motor-disabled persons. Especially results from single-trial EEG classification approaches for BCIs support correlations between single-trial ERP detection performance and ERP expression. Hence, BCIs can be considered as a paradigm shift contributing to new methods with strong influence on both neuroscience and clinical applications. Here, we investigate the relevance of the choice of training data and classifier transfer for the interpretability of results from single-trial ERP detection. In our experiments, subjects performed a visual-motor oddball task with motor-task relevant infrequent ( targets ), motor-task irrelevant infrequent ( deviants ), and motor-task irrelevant frequent ( standards ) stimuli. Under dual-task condition, a secondary senso-motor task was performed, compared to the simple-task condition. For evaluation, average ERP analysis and single-trial detection analysis with different numbers of electrodes were performed. Further, classifier transfer was investigated between simple and dual task. Parietal positive ERPs evoked by target stimuli (but not by deviants) were expressed stronger under dual-task condition, which is discussed as an increase of task emphasis and brain processes involved in task coordination and change of task set. Highest classification performance was found for targets irrespective whether all 62, 6 or 2 parietal electrodes were used. Further, higher detection performance of targets compared to standards was achieved under dual-task compared to simple-task condition in case of training on data from 2 parietal electrodes corresponding to results of ERP average analysis. Classifier transfer between tasks improves classification performance in case that training took place on more varying examples (from dual task). In summary, we showed that P300 and overlaying parietal positive ERPs can successfully be detected while subjects are performing additional ongoing motor activity. This supports single-trial detection of ERPs evoked by target events to, e.g., infer a patient's attentional state during therapeutic intervention.

Multi-Tasking and Choice of Training Data Influencing Parietal ERP Expression and Single-Trial Detection—Relevance for Neuroscience and Clinical Applications

PubMed Central

Kirchner, Elsa A.; Kim, Su Kyoung

2018-01-01

Event-related potentials (ERPs) are often used in brain-computer interfaces (BCIs) for communication or system control for enhancing or regaining control for motor-disabled persons. Especially results from single-trial EEG classification approaches for BCIs support correlations between single-trial ERP detection performance and ERP expression. Hence, BCIs can be considered as a paradigm shift contributing to new methods with strong influence on both neuroscience and clinical applications. Here, we investigate the relevance of the choice of training data and classifier transfer for the interpretability of results from single-trial ERP detection. In our experiments, subjects performed a visual-motor oddball task with motor-task relevant infrequent (targets), motor-task irrelevant infrequent (deviants), and motor-task irrelevant frequent (standards) stimuli. Under dual-task condition, a secondary senso-motor task was performed, compared to the simple-task condition. For evaluation, average ERP analysis and single-trial detection analysis with different numbers of electrodes were performed. Further, classifier transfer was investigated between simple and dual task. Parietal positive ERPs evoked by target stimuli (but not by deviants) were expressed stronger under dual-task condition, which is discussed as an increase of task emphasis and brain processes involved in task coordination and change of task set. Highest classification performance was found for targets irrespective whether all 62, 6 or 2 parietal electrodes were used. Further, higher detection performance of targets compared to standards was achieved under dual-task compared to simple-task condition in case of training on data from 2 parietal electrodes corresponding to results of ERP average analysis. Classifier transfer between tasks improves classification performance in case that training took place on more varying examples (from dual task). In summary, we showed that P300 and overlaying parietal positive ERPs can successfully be detected while subjects are performing additional ongoing motor activity. This supports single-trial detection of ERPs evoked by target events to, e.g., infer a patient's attentional state during therapeutic intervention. PMID:29636660

The Tendril Plot-a novel visual summary of the incidence, significance and temporal aspects of adverse events in clinical trials.

PubMed

Karpefors, Martin; Weatherall, James

2018-03-21

In contrast to efficacy, safety hypotheses of clinical trials are not always pre-specified, and therefore, the safety interpretation work of a trial tends to be more exploratory, often reactive, and the analysis more statistically and graphically challenging. We introduce a new means of visualizing the adverse event data across an entire clinical trial. The approach overcomes some of the current limitations of adverse event analysis and streamlines the way safety data can be explored, interpreted and analyzed. Using a phase II study, we describe and exemplify how the tendril plot effectively summarizes the time-resolved safety profile of two treatment arms in a single plot and how that can provide scientists with a trial safety overview that can support medical decision making. To our knowledge, the tendril plot is the only way to graphically show important treatment differences with preserved temporal information, across an entire clinical trial, in a single view.

Mortality in members of HIV-1 serodiscordant couples in Africa and implications for antiretroviral therapy initiation: Results of analyses from a multicenter randomized trial

PubMed Central

2012-01-01

Background The risk of HIV-1 related mortality is strongly related to CD4 count. Guidance on optimal timing for initiation of antiretroviral therapy (ART) is still evolving, but the contribution of HIV-1 infection to excess mortality at CD4 cell counts above thresholds for HIV-1 treatment has not been fully described, especially in resource-poor settings. To compare mortality among HIV-1 infected and uninfected members of HIV-1 serodiscordant couples followed for up to 24 months, we conducted a secondary data analysis examining mortality among HIV-1 serodiscordant couples participating in a multicenter, randomized controlled trial at 14 sites in seven sub-Saharan African countries. Methods Predictors of death were examined using Cox regression and excess mortality by CD4 count and plasma HIV-1 RNA was computed using Poisson regression for correlated data. Results Among 3295 HIV serodiscordant couples, we observed 109 deaths from any cause (74 deaths among HIV-1 infected and 25 among HIV-1 uninfected persons). Among HIV-1 infected persons, the risk of death increased with lower CD4 count and higher plasma viral levels. HIV-1 infected persons had excess mortality due to medical causes of 15.2 deaths/1000 person years at CD4 counts of 250 – 349 cells/μl and 8.9 deaths at CD4 counts of 350 – 499 cells/μl. Above a CD4 count of 500 cells/μl, mortality was comparable among HIV-1 infected and uninfected persons. Conclusions Among African serodiscordant couples, there is a high rate of mortality attributable to HIV-1 infection at CD4 counts above the current threshold (200 – 350 cells/μl) for ART initiation in many African countries. These data indicate that earlier initiation of treatment is likely to provide clinical benefit if further expansion of ART access can be achieved. Trial Registration Clinicaltrials.gov (NCT00194519) PMID:23130818

Perception-Action and Adaptation in Postural Control of Children and Adolescents with Cerebral Palsy

ERIC Educational Resources Information Center

Barela, Jose A.; Focks, Grietje M. Jaspers; Hilgeholt, Toke; Barela, Ana M. F.; Carvalho, Raquel de P.; Savelsbergh, Geert J. P.

2011-01-01

The aim of this study was to examine the coupling between visual information and body sway and the adaptation in this coupling of individuals with cerebral palsy (CP). Fifteen children with and 15 without CP, 6-15 years old, were required to stand upright inside of a moving room. All children first performed two trials with no movement of the room…

Meeting the Challenge: The National Cancer Institute's Central Institutional Review Board for Multi-Site Research.

PubMed

Massett, Holly A; Hampp, Sharon L; Goldberg, Jacquelyn L; Mooney, Margaret; Parreco, Linda K; Minasian, Lori; Montello, Mike; Mishkin, Grace E; Davis, Catasha; Abrams, Jeffrey S

2018-03-10

The National Institutes of Health (NIH) issued a new policy that requires a single institutional review board (IRB) of record be used for all protocols funded by the NIH that are carried out at more than one site in the United States, effective January 2018. This policy affects several hundred clinical trials opened annually across the NIH. Limited data exist to compare the use of a single IRB to that of multiple local IRBs, so some institutions are resistant to or distrustful of single IRBs. Since 2001, the National Cancer Institute (NCI) has funded a central IRB (CIRB) that provides human patient reviews for its extensive national cancer clinical trials program. This paper presents data to show the adoption, efficiencies gained, and satisfaction of the CIRB among NCI trial networks and reviews key lessons gleaned from 16 years of experience that may be informative for others charged with implementation of the new NIH single-IRB policy.

A grating coupler with a trapezoidal hole array for perfectly vertical light coupling between optical fibers and waveguides

NASA Astrophysics Data System (ADS)

Mizutani, Akio; Eto, Yohei; Kikuta, Hisao

2017-12-01

A grating coupler with a trapezoidal hole array was designed and fabricated for perfectly vertical light coupling between a single-mode optical fiber and a silicon waveguide on a silicon-on-insulator (SOI) substrate. The grating coupler with an efficiency of 53% was computationally designed at a 1.1-µm-thick buried oxide (BOX) layer. The grating coupler and silicon waveguide were fabricated on the SOI substrate with a 3.0-µm-thick BOX layer by a single full-etch process. The measured coupling efficiency was 24% for TE-polarized light at 1528 nm wavelength, which was 0.69 times of the calculated coupling efficiency for the 3.0-µm-thick BOX layer.

Resonator modes and mode dynamics for an external cavity-coupled laser array

NASA Astrophysics Data System (ADS)

Nair, Niketh; Bochove, Erik J.; Aceves, Alejandro B.; Zunoubi, Mohammad R.; Braiman, Yehuda

2015-03-01

Employing a Fox-Li approach, we derived the cold-cavity mode structure and a coupled mode theory for a phased array of N single-transverse-mode active waveguides with feedback from an external cavity. We applied the analysis to a system with arbitrary laser lengths, external cavity design and coupling strengths to the external cavity. The entire system was treated as a single resonator. The effect of the external cavity was modeled by a set of boundary conditions expressed by an N-by-N frequency-dependent matrix relation between incident and reflected fields at the interface with the external cavity. The coupled mode theory can be adapted to various types of gain media and internal and external cavity designs.

Strong coupling of a single electron in silicon to a microwave photon.

PubMed

Mi, X; Cady, J V; Zajac, D M; Deelman, P W; Petta, J R

2017-01-13

Silicon is vital to the computing industry because of the high quality of its native oxide and well-established doping technologies. Isotopic purification has enabled quantum coherence times on the order of seconds, thereby placing silicon at the forefront of efforts to create a solid-state quantum processor. We demonstrate strong coupling of a single electron in a silicon double quantum dot to the photonic field of a microwave cavity, as shown by the observation of vacuum Rabi splitting. Strong coupling of a quantum dot electron to a cavity photon would allow for long-range qubit coupling and the long-range entanglement of electrons in semiconductor quantum dots. Copyright © 2017, American Association for the Advancement of Science.

Piezoelectric coupling factor calculations for plates of langatate driven in simple thickness modes by lateral-field-excitation.

PubMed

Khan, Ajmal; Ballato, Arthur

2002-07-01

Piezoelectric coupling factors for langatate (La3Ga5.5Ta0.5O14) single-crystals driven by lateral-field-excitation have been calculated using the extended Christoffel-Bechmann method. Calculations were made using published materials constants. The results are presented in terms of the lateral piezoelectric coupling factor as functions of in-plane (azimuthal) rotation angle for the three simple thickness vibration modes of some non-rotated, singly-rotated, and doubly-rotated orientations. It is shown that lateral-field-excitation offers the potential to eliminate unwanted vibration modes and to achieve considerably greater piezoelectric coupling versus thickness-field-excitation for the rotated cuts considered and for a doubly-rotated cut that is of potential technological interest.

Effect of proton transfer on the electronic coupling in DNA

NASA Astrophysics Data System (ADS)

Rak, Janusz; Makowska, Joanna; Voityuk, Alexander A.

2006-06-01

The effects of single and double proton transfer within Watson-Crick base pairs on donor-acceptor electronic couplings, Vda, in DNA are studied on the bases of quantum chemical calculations. Four dimers [AT,AT], [GC,GC], [GC,AT] and [GC,TA)] are considered. Three techniques - the generalized Mulliken-Hush scheme, the fragment charge method and the diabatic states method - are employed to estimate Vda for hole transfer between base pairs. We show that both single- and double proton transfer (PT) reactions may substantially affect the electronic coupling in DNA. The electronic coupling in [AT,AT] is predicted to be most sensitive to PT. Single PT within the first base pair in the dimer leads to increase in the hole transfer efficiency by a factor of 4, while proton transfer within the second pair should substantially, by 2.7 times, decrease the rate of charge transfer. Thus, directional asymmetry of the PT effects on the electronic coupling is predicted. The changes in the Vda matrix elements correlate with the topological properties of orbitals of donor and acceptor and can be qualitatively rationalized in terms of resonance structures of donor and acceptor. Atomic pair contributions to the Vda matrix elements are also analyzed.

Visible high power fiber coupled diode lasers

NASA Astrophysics Data System (ADS)

Köhler, Bernd; Drovs, Simon; Stoiber, Michael; Dürsch, Sascha; Kissel, Heiko; Könning, Tobias; Biesenbach, Jens; König, Harald; Lell, Alfred; Stojetz, Bernhard; Löffler, Andreas; Strauß, Uwe

2018-02-01

In this paper we report on further development of fiber coupled high-power diode lasers in the visible spectral range. New visible laser modules presented in this paper include the use of multi single emitter arrays @ 450 nm leading to a 120 W fiber coupled unit with a beam quality of 44 mm x mrad, as well as very compact modules with multi-W output power from 405 nm to 640 nm. However, as these lasers are based on single emitters, power scaling quickly leads to bulky laser units with a lot of optical components to be aligned. We also report on a new approach based on 450 nm diode laser bars, which dramatically reduces size and alignment effort. These activities were performed within the German government-funded project "BlauLas": a maximum output power of 80 W per bar has been demonstrated @ 450 nm. We show results of a 200 μm NA0.22 fiber coupled 35 W source @ 450 nm, which has been reduced in size by a factor of 25 compared to standard single emitter approach. In addition, we will present a 200 μm NA0.22 fiber coupled laser unit with an output power of 135 W.

Apparatus for recording emissions from a rapidly generated plasma from a single plasma producing event

DOEpatents

Tan, Tai Ho; Williams, Arthur H.

1985-01-01

An optical fiber-coupled detector visible streak camera plasma diagnostic apparatus. Arrays of optical fiber-coupled detectors are placed on the film plane of several types of particle, x-ray and visible spectrometers or directly in the path of the emissions to be measured and the output is imaged by a visible streak camera. Time and spatial dependence of the emission from plasmas generated from a single pulse of electromagnetic radiation or from a single particle beam burst can be recorded.

Apparatus for recording emissions from a rapidly generated plasma from a single plasma producing event

DOEpatents

Tan, T.H.; Williams, A.H.

An optical fiber-coupled detector visible streak camera plasma diagnostic apparatus. Arrays of optical fiber-coupled detectors are placed on the film plane of several types of particle, x-ray and visible spectrometers or directly in the path of the emissions to be measured and the output is imaged by a visible streak camera. Time and spatial dependence of the emission from plasma generated from a single pulse of electromagnetic radiation or from a single particle beam burst can be recorded.

Molecular electronics with single molecules in solid-state devices.

PubMed

Moth-Poulsen, Kasper; Bjørnholm, Thomas

2009-09-01

The ultimate aim of molecular electronics is to understand and master single-molecule devices. Based on the latest results on electron transport in single molecules in solid-state devices, we focus here on new insights into the influence of metal electrodes on the energy spectrum of the molecule, and on how the electron transport properties of the molecule depend on the strength of the electronic coupling between it and the electrodes. A variety of phenomena are observed depending on whether this coupling is weak, intermediate or strong.

An approach for coupled-code multiphysics core simulations from a common input

DOE PAGES

Schmidt, Rodney; Belcourt, Kenneth; Hooper, Russell; ...

2014-12-10

This study describes an approach for coupled-code multiphysics reactor core simulations that is being developed by the Virtual Environment for Reactor Applications (VERA) project in the Consortium for Advanced Simulation of Light-Water Reactors (CASL). In this approach a user creates a single problem description, called the “VERAIn” common input file, to define and setup the desired coupled-code reactor core simulation. A preprocessing step accepts the VERAIn file and generates a set of fully consistent input files for the different physics codes being coupled. The problem is then solved using a single-executable coupled-code simulation tool applicable to the problem, which ismore » built using VERA infrastructure software tools and the set of physics codes required for the problem of interest. The approach is demonstrated by performing an eigenvalue and power distribution calculation of a typical three-dimensional 17 × 17 assembly with thermal–hydraulic and fuel temperature feedback. All neutronics aspects of the problem (cross-section calculation, neutron transport, power release) are solved using the Insilico code suite and are fully coupled to a thermal–hydraulic analysis calculated by the Cobra-TF (CTF) code. The single-executable coupled-code (Insilico-CTF) simulation tool is created using several VERA tools, including LIME (Lightweight Integrating Multiphysics Environment for coupling codes), DTK (Data Transfer Kit), Trilinos, and TriBITS. Parallel calculations are performed on the Titan supercomputer at Oak Ridge National Laboratory using 1156 cores, and a synopsis of the solution results and code performance is presented. Finally, ongoing development of this approach is also briefly described.« less

Blastocyst culture using single versus sequential media in clinical IVF: a systematic review and meta-analysis of randomized controlled trials.

PubMed

Sfontouris, Ioannis A; Martins, Wellington P; Nastri, Carolina O; Viana, Iara G R; Navarro, Paula A; Raine-Fenning, Nick; van der Poel, Sheryl; Rienzi, Laura; Racowsky, Catherine

2016-10-01

The purpose of this study was to undertake a review of the available evidence comparing the use of a single medium versus sequential media for embryo culture to the blastocyst stage in clinical IVF. We searched the Cochrane Central, PubMed, Scopus, ClinicalTrials.gov, Current Controlled Trials and WHO International Clinical Trials Registry Platform to identify randomized controlled trials comparing single versus sequential media for blastocyst culture and ongoing pregnancy rate. Included studies randomized either oocytes/zygotes or women. Eligible oocyte/zygote studies were analyzed to assess the risk difference (RD) and 95 % confidence intervals (CI) between the two media systems; eligible woman-based studies were analyzed to assess the risk ratio (RR) and 95 % CI for clinical pregnancy rate. No differences were observed between single and sequential media for either ongoing pregnancy per randomized woman (relative risk (RR) = 0.9, 95 % CI = 0.7 to 1.3, two studies including 246 women, I 2  = 0 %) or clinical pregnancy per randomized woman (RR = 1.0, 95 % CI = 0.7 to 1.4, one study including 100 women); or miscarriage per clinical pregnancy: RR = 1.3, 95 % CI = 0.4 to 4.3, two studies including 246 participants, I 2  = 0 %). Single media use was associated with an increase blastocyst formation per randomized oocyte/zygote (relative distribution (RD) = +0.06, 95 % CI = +0.01 to +0.12, ten studies including 7455 oocytes/zygotes, I 2  = 83 %) but not top/high blastocyst formation (RD = +0.05, 95 % CI = -0.01 to +0.11, five studies including 3879 oocytes/zygotes, I 2  = 93 %). The overall quality of the evidence was very low for all these four outcomes. Although using a single medium for extended culture has some practical advantages and blastocyst formation rates appear to be higher, there is insufficient evidence to recommend either sequential or single-step media as being superior for the culture of embryos to days 5/6. Future studies comparing these two media systems in well-designed trials should be performed.

Comparison of the benefits of cochlear implantation versus contra-lateral routing of signal hearing aids in adult patients with single-sided deafness: study protocol for a prospective within-subject longitudinal trial.

PubMed

Kitterick, Pádraig T; O'Donoghue, Gerard M; Edmondson-Jones, Mark; Marshall, Andrew; Jeffs, Ellen; Craddock, Louise; Riley, Alison; Green, Kevin; O'Driscoll, Martin; Jiang, Dan; Nunn, Terry; Saeed, Shakeel; Aleksy, Wanda; Seeber, Bernhard U

2014-01-01

Individuals with a unilateral severe-to-profound hearing loss, or single-sided deafness, report difficulty with listening in many everyday situations despite having access to well-preserved acoustic hearing in one ear. The standard of care for single-sided deafness available on the UK National Health Service is a contra-lateral routing of signals hearing aid which transfers sounds from the impaired ear to the non-impaired ear. This hearing aid has been found to improve speech understanding in noise when the signal-to-noise ratio is more favourable at the impaired ear than the non-impaired ear. However, the indiscriminate routing of signals to a single ear can have detrimental effects when interfering sounds are located on the side of the impaired ear. Recent published evidence has suggested that cochlear implantation in individuals with a single-sided deafness can restore access to the binaural cues which underpin the ability to localise sounds and segregate speech from other interfering sounds. The current trial was designed to assess the efficacy of cochlear implantation compared to a contra-lateral routing of signals hearing aid in restoring binaural hearing in adults with acquired single-sided deafness. Patients are assessed at baseline and after receiving a contra-lateral routing of signals hearing aid. A cochlear implant is then provided to those patients who do not receive sufficient benefit from the hearing aid. This within-subject longitudinal design reflects the expected care pathway should cochlear implantation be provided for single-sided deafness on the UK National Health Service. The primary endpoints are measures of binaural hearing at baseline, after provision of a contra-lateral routing of signals hearing aid, and after cochlear implantation. Binaural hearing is assessed in terms of the accuracy with which sounds are localised and speech is perceived in background noise. The trial is also designed to measure the impact of the interventions on hearing- and health-related quality of life. This multi-centre trial was designed to provide evidence for the efficacy of cochlear implantation compared to the contra-lateral routing of signals. A purpose-built sound presentation system and established measurement techniques will provide reliable and precise measures of binaural hearing. Current Controlled Trials http://www.controlled-trials.com/ISRCTN33301739 (05/JUL/2013).

Cluster Randomized Controlled Trial Evaluation of a Gender Equity and Family Planning Intervention for Married Men and Couples in Rural India

PubMed Central

Raj, Anita; Ghule, Mohan; Ritter, Julie; Battala, Madhusudana; Gajanan, Velhal; Nair, Saritha; Dasgupta, Anindita; Silverman, Jay G.; Balaiah, Donta; Saggurti, Niranjan

2016-01-01

Background Despite ongoing recommendations to increase male engagement and gender-equity (GE) counseling in family planning (FP) services, few such programs have been implemented and rigorously evaluated. This study evaluates the impact of CHARM, a three-session GE+FP counseling intervention delivered by male health care providers to married men, alone (sessions 1&2) and with their wives (session 3) in India. Methods and Findings A two-armed cluster randomized controlled trial was conducted with young married couples (N = 1081 couples) recruited from 50 geographic clusters (25 clusters randomized to CHARM and a control condition, respectively) in rural Maharashtra, India. Couples were surveyed on demographics, contraceptive behaviors, and intimate partner violence (IPV) attitudes and behaviors at baseline and 9 &18-month follow-ups, with pregnancy testing at baseline and 18-month follow-up. Outcome effects on contraceptive use and incident pregnancy, and secondarily, on contraceptive communication and men’s IPV attitudes and behaviors, were assessed using logistic generalized linear mixed models. Most men recruited from CHARM communities (91.3%) received at least one CHARM intervention session; 52.5% received the couple’s session with their wife. Findings document that women from the CHARM condition, relative to controls, were more likely to report contraceptive communication at 9-month follow-up (AOR = 1.77, p = 0.04) and modern contraceptive use at 9 and 18-month follow-ups (AORs = 1.57–1.58, p = 0.05), and they were less likely to report sexual IPV at 18-month follow-up (AOR = 0.48, p = 0.01). Men in the CHARM condition were less likely than those in the control clusters to report attitudes accepting of sexual IPV at 9-month (AOR = 0.64, p = 0.03) and 18-month (AOR = 0.51, p = 0.004) follow-up, and attitudes accepting of physical IPV at 18-month follow-up (AOR = 0.64, p = 0.02). No significant effect on pregnancy was seen. Conclusions Findings demonstrate that men can be engaged in FP programming in rural India, and that such an approach inclusive of GE counseling can improve contraceptive practices and reduce sexual IPV in married couples. Trial Registration ClinicalTrials.gov NCT01593943 PMID:27167981

Quantum memory and gates using a Λ -type quantum emitter coupled to a chiral waveguide

NASA Astrophysics Data System (ADS)

Li, Tao; Miranowicz, Adam; Hu, Xuedong; Xia, Keyu; Nori, Franco

2018-06-01

By coupling a Λ -type quantum emitter to a chiral waveguide, in which the polarization of a photon is locked to its propagation direction, we propose a controllable photon-emitter interface for quantum networks. We show that this chiral system enables the swap gate and a hybrid-entangling gate between the emitter and a flying single photon. It also allows deterministic storage and retrieval of single-photon states with high fidelities and efficiencies. In short, this chirally coupled emitter-photon interface can be a critical building block toward a large-scale quantum network.

Agonist-specific coupling of a cloned Drosophila octopamine/tyramine receptor to multiple second messenger systems.

PubMed Central

Robb, S; Cheek, T R; Hannan, F L; Hall, L M; Midgley, J M; Evans, P D

1994-01-01

A cloned seven transmembrane-spanning Drosophila octopamine/tyramine receptor, permanently expressed in a Chinese hamster ovary cell line, both inhibits adenylate cyclase activity and leads to the elevation of intracellular Ca2+ levels by separate G-protein-coupled pathways. Agonists of this receptor (octopamine and tyramine), differing by only a single hydroxyl group in their side chain, may be capable of differentially coupling it to different second messenger systems. Thus, a single receptor may have a different pharmacological profile depending on which second messenger system is used to assay its efficacy. PMID:8137817

Strong coupling between a single nitrogen-vacancy spin and the rotational mode of diamonds levitating in an ion trap

NASA Astrophysics Data System (ADS)

Delord, T.; Nicolas, L.; Chassagneux, Y.; Hétet, G.

2017-12-01

A scheme for strong coupling between a single atomic spin and the rotational mode of levitating nanoparticles is proposed. The idea is based on spin readout of nitrogen-vacancy centers embedded in aspherical nanodiamonds levitating in an ion trap. We show that the asymmetry of the diamond induces a rotational confinement in the ion trap. Using a weak homogeneous magnetic field and a strong microwave driving we then demonstrate that the spin of the nitrogen-vacancy center can be strongly coupled to the rotational mode of the diamond.

Control of slow-to-fast light and single-to-double optomechanically induced transparency in a compound resonator system: A theoretical approach

NASA Astrophysics Data System (ADS)

Ziauddin; Rahman, Mujeeb ur; Ahmad, Iftikhar; Qamar, Sajid

2017-10-01

The transmission characteristics of probe light field is investigated theoretically in a compound system of two coupled resonators. The proposed system consisted of two high-Q Fabry-Perot resonators in which one of the resonators is optomechanical. Optomechanically induced transparency (OMIT), having relatively large window, is noticed via strong coupling between the two resonators. We investigate tunable switching from single to double OMIT by increasing amplitude of the pump field. We notice that, control of slow and fast light can be obtained via the coupling strength between the two resonators.

High performance static latches with complete single event upset immunity

DOEpatents

Corbett, Wayne T.; Weaver, Harry T.

1994-01-01

An asymmetric response latch providing immunity to single event upset without loss of speed. The latch has cross-coupled inverters having a hardened logic state and a soft state, wherein the logic state of the first inverter can only be changed when the voltage on the coupling node of that inverter is low and the logic state of the second inverter can only be changed when the coupling of that inverter is high. One of more of the asymmetric response latches may be configured into a memory cell having complete immunity, which protects information rather than logic states.

Spatiotemporal analysis of single-trial EEG of emotional pictures based on independent component analysis and source location

NASA Astrophysics Data System (ADS)

Liu, Jiangang; Tian, Jie

2007-03-01

The present study combined the Independent Component Analysis (ICA) and low-resolution brain electromagnetic tomography (LORETA) algorithms to identify the spatial distribution and time course of single-trial EEG record differences between neural responses to emotional stimuli vs. the neutral. Single-trial multichannel (129-sensor) EEG records were collected from 21 healthy, right-handed subjects viewing the emotion emotional (pleasant/unpleasant) and neutral pictures selected from International Affective Picture System (IAPS). For each subject, the single-trial EEG records of each emotional pictures were concatenated with the neutral, and a three-step analysis was applied to each of them in the same way. First, the ICA was performed to decompose each concatenated single-trial EEG records into temporally independent and spatially fixed components, namely independent components (ICs). The IC associated with artifacts were isolated. Second, the clustering analysis classified, across subjects, the temporally and spatially similar ICs into the same clusters, in which nonparametric permutation test for Global Field Power (GFP) of IC projection scalp maps identified significantly different temporal segments of each emotional condition vs. neutral. Third, the brain regions accounted for those significant segments were localized spatially with LORETA analysis. In each cluster, a voxel-by-voxel randomization test identified significantly different brain regions between each emotional condition vs. the neutral. Compared to the neutral, both emotional pictures elicited activation in the visual, temporal, ventromedial and dorsomedial prefrontal cortex and anterior cingulated gyrus. In addition, the pleasant pictures activated the left middle prefrontal cortex and the posterior precuneus, while the unpleasant pictures activated the right orbitofrontal cortex, posterior cingulated gyrus and somatosensory region. Our results were well consistent with other functional imaging studies, while revealed temporal dynamics of emotional processing of specific brain structure with high temporal resolution.

Enhanced brainstem and cortical evoked response amplitudes: single-trial covariance analysis.

PubMed

Galbraith, G C

2001-06-01

The purpose of the present study was to develop analytic procedures that improve the definition of sensory evoked response components. Such procedures could benefit all recordings but would especially benefit difficult recordings where many trials are contaminated by muscle and movement artifacts. First, cross-correlation and latency adjustment analyses were applied to the human brainstem frequency-following response and cortical auditory evoked response recorded on the same trials. Lagged cross-correlation functions were computed, for each of 17 subjects, between single-trial data and templates consisting of the sinusoid stimulus waveform for the brainstem response and the subject's own smoothed averaged evoked response P2 component for the cortical response. Trials were considered in the analysis only if the maximum correlation-squared (r2) exceeded .5 (negatively correlated trials were thus included). Identical correlation coefficients may be based on signals with quite different amplitudes, but it is possible to assess amplitude by the nonnormalized covariance function. Next, an algorithm is applied in which each trial with negative covariance is matched to a trial with similar, but positive, covariance and these matched-trial pairs are deleted. When an evoked response signal is present in the data, the majority of trials positively correlate with the template. Thus, a residual of positively correlated trials remains after matched covariance trials are deleted. When these residual trials are averaged, the resulting brainstem and cortical responses show greatly enhanced amplitudes. This result supports the utility of this analysis technique in clarifying and assessing evoked response signals.

Intelligent single switch wheelchair navigation.

PubMed

Ka, Hyun W; Simpson, Richard; Chung, Younghyun

2012-11-01

We have developed an intelligent single switch scanning interface and wheelchair navigation assistance system, called intelligent single switch wheelchair navigation (ISSWN), to improve driving safety, comfort and efficiency for individuals who rely on single switch scanning as a control method. ISSWN combines a standard powered wheelchair with a laser rangefinder, a single switch scanning interface and a computer. It provides the user with context sensitive and task specific scanning options that reduce driving effort based on an interpretation of sensor data together with user input. Trials performed by 9 able-bodied participants showed that the system significantly improved driving safety and efficiency in a navigation task by significantly reducing the number of switch presses to 43.5% of traditional single switch wheelchair navigation (p < 0.001). All participants made a significant improvement (39.1%; p < 0.001) in completion time after only two trials.

Intertrial Temporal Contextual Cuing: Association across Successive Visual Search Trials Guides Spatial Attention

ERIC Educational Resources Information Center

Ono, Fuminori; Jiang, Yuhong; Kawahara, Jun-ichiro

2005-01-01

Contextual cuing refers to the facilitation of performance in visual search due to the repetition of the same displays. Whereas previous studies have focused on contextual cuing within single-search trials, this study tested whether 1 trial facilitates visual search of the next trial. Participants searched for a T among Ls. In the training phase,…

Cognitive existential couple therapy (CECT) in men and partners facing localised prostate cancer: a randomised controlled trial.

PubMed

Couper, Jeremy; Collins, Anna; Bloch, Sidney; Street, Annette; Duchesne, Gillian; Jones, Tessa; Olver, James; Love, Anthony

2015-04-01

To assess the efficacy of cognitive existential couple therapy (CECT) for relationship function, coping, cancer distress and mental health in men with localised prostate cancer and in their partners. A randomised controlled trial was conducted with 62 couples randomly assigned to the six-session CECT programme or care as usual. The couple's relationship function (primary outcome), and coping, cancer distress and mental health (secondary outcomes) were evaluated at T0 (baseline), T1 (after treatment) and T2 (9 months from T0). A repeated-measures analysis of covariance model, which incorporated T0 measurements as a covariate, was used to compare treatment groups at T1 and T2. After CECT, patients reported significantly greater use of adaptive coping (P = 0.03) and problem-focused coping (P = 0.01). These gains were maintained at follow-up, while relationship cohesion had improved (P = 0.03), as had relationship function for younger patients (P = 0.01). Younger partners reported less cancer-specific distress (P = 0.008), avoidance (P = 0.04), intrusive thought (P = 0.006), and hyperarousal (P = 0.01). Gains were maintained at follow-up, while relationship cohesion (P = 0.007), conflict resolution (P = 0.01) and relational function (P = 0.009) all improved. CECT resulted in improved coping for patients and lower cancer-distress for partners. Maintained over time this manifests as improved relationship function. CECT was acceptable to couples, alleviated long-term relationship decline, and is therefore suitable as a preventative mental health intervention for couples facing prostate cancer. Given resourcing demands, we recommend dissemination of CECT be targeted at younger couples, as CECT was more acceptable to the younger group, and they derived greater benefit from it. © 2015 The Authors. BJU International © 2015 BJU International.

A single-center randomized, controlled trial investigating the efficacy of a mHealth ECG technology intervention to improve the detection of atrial fibrillation: the iHEART study protocol.

PubMed

Hickey, Kathleen T; Hauser, Nicole R; Valente, Laura E; Riga, Teresa C; Frulla, Ashton P; Masterson Creber, Ruth; Whang, William; Garan, Hasan; Jia, Haomiao; Sciacca, Robert R; Wang, Daniel Y

2016-07-16

Atrial fibrillation is a major public health problem and is the most common cardiac arrhythmia, affecting an estimated 2.7 million Americans. The true prevalence of atrial fibrillation is likely underestimated because episodes are often sporadic; therefore, it is challenging to detect and record an occurrence in a "real world" setting. To date, mobile health tools that promote earlier detection and treatment of atrial fibrillation and improvement in self-management behaviors and knowledge have not been evaluated. This study will be the first to address the epidemic problem of atrial fibrillation with a novel approach utilizing advancements in mobile health electrocardiogram technology to empower patients to actively engage in their healthcare and to evaluate impact on quality of life and quality-adjusted life years. Furthermore, sending a daily electrocardiogram transmission, coupled with receiving educational and motivational text messages aimed at promoting self-management and a healthy lifestyle may improve the management of chronic cardiovascular conditions (e.g., hypertension, diabetes, heart failure, etc.). Therefore, we are currently conducting a randomized controlled trial to assess the efficacy of a mobile health intervention, iPhone® Helping Evaluate Atrial fibrillation Rhythm through Technology (iHEART) versus usual cardiac care. The iHEART study is a single center, prospective, randomized controlled trial. A total of 300 participants with a recent history of atrial fibrillation will be enrolled. Participants will be randomized 1:1 to receive the iHEART intervention, receiving an iPhone® equipped with an AliveCor® Mobile ECG and accompanying Kardia application and behavioral altering motivational text messages or usual cardiac care for 6 months. This will be the first study to investigate the utility of a mobile health intervention in a "real world" setting. We will evaluate the ability of the iHEART intervention to improve the detection and treatment of recurrent atrial fibrillation and assess the intervention's impact on improving clinical outcomes, quality of life, quality-adjusted life-years and disease-specific knowledge. NCT02731326 ; Verified April 2016.

Strong coupling-like phenomenon in single metallic nanoparticle embedded in molecular J-aggregates

NASA Astrophysics Data System (ADS)

Feng, Xin; Wang, Chen; Ma, Hongjing; Chen, Yuanyuan; Duan, Gaoyan; Zhang, Pengfei; Song, Gang

2018-02-01

Strong coupling-like phenomenon between plasmonic cavities and emitters provides a new way to realize the quantum-like effect controlling at microscale/nanoscale. We investigate the strong coupling-like phenomenon in the structure of single metallic nanoparticle embedded in molecular J-aggregates by the classical simulation method and show that the size of the metallic nanoparticle and the oscillator strength of molecular J-aggregates impact the strong coupling-like phenomenon. The strong coupling-like phenomenon is induced by the interactions between two dipoles formed by the metallic nanoparticle and molecular J-aggregates or the interactions between the dipole generated from molecular J-aggregates and the quadrupole generated from the metallic nanoparticle. The strong coupling-like phenomenon appears evidently with the increase in oscillator strength of molecular J-aggregates. The detuning energy linearly decreases with the increase in radius of the metallic nanoparticle. Our structure has potential applications in quantum networks, quantum key distributions and so on.

Continuous transition between weak and ultrastrong coupling through exceptional points in carbon nanotube microcavity exciton-polaritons

NASA Astrophysics Data System (ADS)

Gao, Weilu; Li, Xinwei; Bamba, Motoaki; Kono, Junichiro

2018-06-01

Non-perturbative coupling of photons and excitons produces hybrid particles, exciton-polaritons, which have exhibited a variety of many-body phenomena in various microcavity systems. However, the vacuum Rabi splitting (VRS), which defines the strength of photon-exciton coupling, is usually a single constant for a given system. Here, we have developed a unique architecture in which excitons in an aligned single-chirality carbon nanotube film interact with cavity photons in polarization-dependent manners. The system reveals ultrastrong coupling (VRS up to 329 meV or a coupling-strength-to-transition-energy ratio of 13.3%) for polarization parallel to the nanotube axis, whereas VRS is absent for perpendicular polarization. Between these two extremes, VRS is continuously tunable through polarization rotation with exceptional points separating crossing and anticrossing. The points between exceptional points form equienergy arcs onto which the upper and lower polaritons coalesce. The demonstrated on-demand ultrastrong coupling provides ways to explore topological properties of polaritons and quantum technology applications.

Classifying four-category visual objects using multiple ERP components in single-trial ERP.

PubMed

Qin, Yu; Zhan, Yu; Wang, Changming; Zhang, Jiacai; Yao, Li; Guo, Xiaojuan; Wu, Xia; Hu, Bin

2016-08-01

Object categorization using single-trial electroencephalography (EEG) data measured while participants view images has been studied intensively. In previous studies, multiple event-related potential (ERP) components (e.g., P1, N1, P2, and P3) were used to improve the performance of object categorization of visual stimuli. In this study, we introduce a novel method that uses multiple-kernel support vector machine to fuse multiple ERP component features. We investigate whether fusing the potential complementary information of different ERP components (e.g., P1, N1, P2a, and P2b) can improve the performance of four-category visual object classification in single-trial EEGs. We also compare the classification accuracy of different ERP component fusion methods. Our experimental results indicate that the classification accuracy increases through multiple ERP fusion. Additional comparative analyses indicate that the multiple-kernel fusion method can achieve a mean classification accuracy higher than 72 %, which is substantially better than that achieved with any single ERP component feature (55.07 % for the best single ERP component, N1). We compare the classification results with those of other fusion methods and determine that the accuracy of the multiple-kernel fusion method is 5.47, 4.06, and 16.90 % higher than those of feature concatenation, feature extraction, and decision fusion, respectively. Our study shows that our multiple-kernel fusion method outperforms other fusion methods and thus provides a means to improve the classification performance of single-trial ERPs in brain-computer interface research.

The patient general satisfaction of mandibular single-implant overdentures and conventional complete dentures: Study protocol for a randomized crossover trial.

PubMed

Kanazawa, Manabu; Tanoue, Mariko; Miyayasu, Anna; Takeshita, Shin; Sato, Daisuke; Asami, Mari; Lam, Thuy Vo; Thu, Khaing Myat; Oda, Ken; Komagamine, Yuriko; Minakuchi, Shunsuke; Feine, Jocelyne

2018-05-01

Mandibular overdentures retained by a single implant placed in the midline of edentulous mandible have been reported to be more comfortable and function better than complete dentures. Although single-implant overdentures are still more costly than conventional complete dentures, there are a few studies which investigated whether mandibular single-implant overdentures are superior to complete dentures when patient general satisfaction is compared. The aim of this study is to assess patient general satisfaction with mandibular single-implant overdentures and complete dentures. This study is a randomized crossover trial to compare mandibular single-implant overdentures and complete dentures in edentulous individuals. Participant recruitment is ongoing at the time of this submission. Twenty-two participants will be recruited. New mandibular complete dentures will be fabricated. A single implant will be placed in the midline of the edentulous mandible. The mucosal surface of the complete denture around the implant will be relieved for 3 months. The participants will then be randomly allocated into 2 groups according to the order of the interventions; group 1 will receive single-implant overdentures first and will wear them for 2 months, followed by complete dentures for 2 months. Group 2 will receive the same treatments in a reverse order. After experiencing the 2 interventions, the participants will choose one of the mandibular prostheses, and yearly follow-up visits are planned for 5 years. The primary outcome of this trial is patient ratings of general satisfaction on 100 mm visual analog scales. Assessments of the prostheses and oral health-related quality of life will also be recorded as patient-reported outcomes. The secondary outcomes are cost and time for treatment. Masticatory efficiency and cognitive capacity will also be recorded. Furthermore, qualitative research will be performed to investigate the factors associated with success of these mandibular denture types. Clinical outcomes, such as implant survival rate, marginal bone loss, and prosthodontic complications, will also be recorded. The results of this randomized crossover trial will clarify whether mandibular single implants and overdentures for edentulous individuals provide better patient general satisfaction when compared to conventional complete dentures. This clinical trial was registered at the University Hospital Medical Information Network (UMIN) Center (UMIN000017883).

Quantum optics. All-optical routing of single photons by a one-atom switch controlled by a single photon.

PubMed

Shomroni, Itay; Rosenblum, Serge; Lovsky, Yulia; Bechler, Orel; Guendelman, Gabriel; Dayan, Barak

2014-08-22

The prospect of quantum networks, in which quantum information is carried by single photons in photonic circuits, has long been the driving force behind the effort to achieve all-optical routing of single photons. We realized a single-photon-activated switch capable of routing a photon from any of its two inputs to any of its two outputs. Our device is based on a single atom coupled to a fiber-coupled, chip-based microresonator. A single reflected control photon toggles the switch from high reflection (R ~ 65%) to high transmission (T ~ 90%), with an average of ~1.5 control photons per switching event (~3, including linear losses). No additional control fields are required. The control and target photons are both in-fiber and practically identical, making this scheme compatible with scalable architectures for quantum information processing. Copyright © 2014, American Association for the Advancement of Science.

Rashba effect in single-layer antimony telluroiodide SbTeI

DOE PAGES

Zhuang, Houlong L.; Cooper, Valentino R.; Xu, Haixuan; ...

2015-09-04

Exploring spin-orbit coupling (SOC) in single-layer materials is important for potential spintronics applications. In this paper, using first-principles calculations, we show that single-layer antimony telluroiodide SbTeI behaves as a two-dimensional semiconductor exhibiting a G 0W 0 band gap of 1.82 eV. More importantly, we observe the Rashba spin splitting in the SOC band structure of single-layer SbTeI with a sizable Rashba coupling parameter of 1.39 eV Å, which is significantly larger than that of a number of two-dimensional systems including surfaces and interfaces. The low formation energy and real phonon modes of single-layer SbTeI imply that it is stable. Finally,more » our study suggests that single-layer SbTeI is a candidate single-layer material for applications in spintronics devices.« less

Single-longitudinal-mode, narrow bandwidth double-ring fiber laser stabilized by an efficiently taper-coupled high roundness microsphere resonator

NASA Astrophysics Data System (ADS)

Wan, Hongdan; Liu, Linqian; Ding, Zuoqin; Wang, Jie; Xiao, Yu; Zhang, Zuxing

2018-06-01

This paper proposes and demonstrates a single-longitudinal-mode, narrow bandwidth fiber laser, using an ultra-high roundness microsphere resonator (MSR) with a stabilized package as the single-longitudinal-mode selector inside a double-ring fiber cavity. By improving the heating technology and surface cleaning process, MSR with high Q factor are obtained. With the optimized coupling condition, light polarization state and fiber taper diameter, we achieve whispering gallery mode (WGM) spectra with a high extinction ratio of 23 dB, coupling efficiency of 99.5%, a 3 dB bandwidth of 1 pm and a side-mode-suppression-ratio of 14.5 dB. The proposed fiber laser produces single-longitudinal-mode laser output with a 20-dB frequency linewidth of about 340 kHz, a signal-to-background ratio of 54 dB and a high long-term stability without mode-hopping, which is potential for optical communication and sensing applications.

Time evolution of the one-dimensional Jaynes-Cummings-Hubbard Hamiltonian

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

Makin, M. I.; Hill, Charles D.; Greentree, Andrew D.

2009-10-15

The Jaynes-Cummings-Hubbard (JCH) system describes a network of single-mode photonic cavities connected via evanescent coupling. Each cavity contains a single two-level system which can be tuned in resonance with the cavity. Here, we explore the behavior of single excitations (where an excitation can be either photonic or atomic) in the linear JCH system, which describes a coupled cavity waveguide. We use direct, analytic diagonalization of the Hamiltonian to study cases where intercavity coupling is either uniform or varies parabolically along the chain. Both excitations located in a single cavity, as well as one excitation as a Gaussian pulse spread overmore » many cavities, are investigated as initial states. We predict unusual behavior of this system in the time domain, including slower than expected propagation of the excitation and also splitting of the excitation into two distinct pulses, which travel at distinct speeds. In certain limits, we show that the JCH system mimics two Heisenberg spin chains.« less

Laterally Coupled Quantum-Dot Distributed-Feedback Lasers

NASA Technical Reports Server (NTRS)

Qui, Yueming; Gogna, Pawan; Muller, Richard; Maker, paul; Wilson, Daniel; Stintz, Andreas; Lester, Luke

2003-01-01

InAs quantum-dot lasers that feature distributed feedback and lateral evanescent- wave coupling have been demonstrated in operation at a wavelength of 1.3 m. These lasers are prototypes of optical-communication oscillators that are required to be capable of stable single-frequency, single-spatial-mode operation. A laser of this type (see figure) includes an active layer that comprises multiple stacks of InAs quantum dots embedded within InGaAs quantum wells. Distributed feedback is provided by gratings formed on both sides of a ridge by electron lithography and reactive-ion etching on the surfaces of an AlGaAs/GaAs waveguide. The lateral evanescent-wave coupling between the gratings and the wave propagating in the waveguide is strong enough to ensure operation at a single frequency, and the waveguide is thick enough to sustain a stable single spatial mode. In tests, the lasers were found to emit continuous-wave radiation at temperatures up to about 90 C. Side modes were found to be suppressed by more than 30 dB.

Quantum memory and non-demolition measurement of single phonon state with nitrogen-vacancy centers ensemble.

PubMed

Wang, Rui-Xia; Cai, Kang; Yin, Zhang-Qi; Long, Gui-Lu

2017-11-27

In a diamond, the mechanical vibration-induced strain can lead to interaction between the mechanical mode and the nitrogen-vacancy (NV) centers. In this work, we propose to utilize the strain-induced coupling for the quantum non-demolition (QND) single phonon measurement and memory in a diamond. The single phonon in a diamond mechanical resonator can be perfectly absorbed and emitted by the NV centers ensemble (NVE) with adiabatically tuning the microwave driving. An optical laser drives the NVE to the excited states, which have much larger coupling strength to the mechanical mode. By adiabatically eliminating the excited states under large detuning limit, the effective coupling between the mechanical mode and the NVE can be used for QND measurement of the single phonon state. Under realistic experimental conditions, we numerically simulate the scheme. It is found that the fidelity of the absorbing and emitting process can reach a much high value. The overlap between the input and the output phonon shapes can reach 98.57%.

Tunable Fano Resonance and Plasmon-Exciton Coupling in Single Au Nanotriangles on Monolayer WS2 at Room Temperature.

PubMed

Wang, Mingsong; Krasnok, Alex; Zhang, Tianyi; Scarabelli, Leonardo; Liu, He; Wu, Zilong; Liz-Marzán, Luis M; Terrones, Mauricio; Alù, Andrea; Zheng, Yuebing

2018-05-01

Tunable Fano resonances and plasmon-exciton coupling are demonstrated at room temperature in hybrid systems consisting of single plasmonic nanoparticles deposited on top of the transition metal dichalcogenide monolayers. By using single Au nanotriangles (AuNTs) on monolayer WS 2 as model systems, Fano resonances are observed from the interference between a discrete exciton band of monolayer WS 2 and a broadband plasmonic mode of single AuNTs. The Fano lineshape depends on the exciton binding energy and the localized surface plasmon resonance strength, which can be tuned by the dielectric constant of surrounding solvents and AuNT size, respectively. Moreover, a transition from weak to strong plasmon-exciton coupling with Rabi splitting energies of 100-340 meV is observed by rationally changing the surrounding solvents. With their tunable plasmon-exciton interactions, the proposed WS 2 -AuNT hybrids can open new pathways to develop active nanophotonic devices. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A Double-Blind, Double-Dummy, Flexible-Design Randomized Multicenter Trial: Early Safety of Single- Versus Divided-Dose Rabbit Anti-Thymocyte Globulin Induction in Renal Transplantation.

PubMed

Stevens, R B; Wrenshall, L E; Miles, C D; Farney, A C; Jie, T; Sandoz, J P; Rigley, T H; Osama Gaber, A

2016-06-01

A previous nonblinded, randomized, single-center renal transplantation trial of single-dose rabbit anti-thymocyte globulin induction (SD-rATG) showed improved efficacy compared with conventional divided-dose (DD-rATG) administration. The present multicenter, double-blind/double-dummy STAT trial (Single dose vs. Traditional Administration of Thymoglobulin) evaluated SD-rATG versus DD-rATG induction for noninferiority in early (7-day) safety and tolerability. Ninety-five patients (randomized 1:1) received 6 mg/kg SD-rATG or 1.5 mg/kg/dose DD-rATG, with tacrolimus-mycophenolate maintenance immunosuppression. The primary end point was a composite of fever, hypoxia, hypotension, cardiac complications, and delayed graft function. Secondary end points included 12-month patient survival, graft survival, and rejection. Target enrollment was 165 patients with an interim analysis scheduled after 80 patients. Interim analysis showed primary end point noninferiority of SD-rATG induction (p = 0.6), and a conditional probability of <1.73% of continued enrollment producing a significant difference (futility analysis), leading to early trial termination. Final analysis (95 patients) showed no differences in occurrence of primary end point events (p = 0.58) or patients with no, one, or more than one event (p = 0.81), or rejection, graft, or patient survival (p = 0.78, 0.47, and 0.35, respectively). In this rigorously blinded trial in adult renal transplantation, we have shown SD-rATG induction to be noninferior to DD-rATG induction in early tolerability and equivalent in 12-month safety. (Clinical Trials.gov #NCT00906204.). © Copyright 2016 The Authors. American Journal of Transplantation published by Wiley Periodicals, Inc. on behalf of the American Society of Transplantation and the American Society of Transplant Surgeons.

Clinical trials in dentistry in India: Analysis from trial registry.

PubMed

Gowri, S; Kannan, Sridharan

2017-01-01

Evidence-based practice requires clinical trials to be performed. In India, if any clinical trial has to be performed, it has to be registered with clinical trial registry of India. Studies have shown that the report of clinical trials is poor in dentistry. Hence, the present study has been conducted to assess the type and trends of clinical trials being undertaken in dentistry in India over a span of 6 years. All the clinical trials which were registered with the Central Trial Registry of India (CTRI) (www.ctri.nic.in) from January 1, 2007 to March 3, 2014 were evaluated using the keyword "dental." Following information were collected for each of the clinical trials obtained from the search; number of centres (single center/multicentric), type of the institution undertaking the research (government/private/combined), study (observational/interventional), study design (randomized/single blinded/double-blinded), type of health condition, type of participants (healthy/patients), sponsors (academia/commercial), phase of clinical trial (Phase 1/2/3/4), publication details (published/not published), whether it was a postgraduate thesis or not and prospective or retrospective registration of clinical trials, methodological quality (method of randomization, allocation concealment). Descriptive statistics was used for analysis of various categories. Trend analysis was done to assess the changes over a period of time. The search yielded a total of 84 trials of which majority of them were single centered. Considering the study design more than half of the registered clinical trials were double-blinded (47/84 [56%]). With regard to the place of conducting a trial, most of the trials were planned to be performed in private hospitals (56/84 [66.7%]). Most (79/84, 94.1%) of the clinical trials were interventional while only 5/84 (5.9%) were observational. Majority (65/84, 77.4%) of the registered clinical trials were recruiting patients while the rest were being done in healthy participants. From 2011, some of the postgraduate thesis trials had also been registered (2011-8; 2012-8; 2013-13; 2014-6). Inadequacy in reporting the method of randomization and allocation concealment was observed in 37/67 (55.2%) and 31/67 (46.2%) clinical trials respectively. A considerable number of postgraduate theses was also registered with CTRI in dentistry and majority of the clinical trials despite being completed are not yet published. The number of clinical trials in dentistry are low in India, and more focus should be placed by dental investigators regarding the reporting standards. Furthermore, researchers and trial sponsors should aim at publication of the research findings so that it is made publically available for use. A clear-cut need exists for an increase in both the quantity and quality of clinical trials in dentistry.

System Simulation by Recursive Feedback: Coupling a Set of Stand-Alone Subsystem Simulations

NASA Technical Reports Server (NTRS)

Nixon, D. D.

2001-01-01

Conventional construction of digital dynamic system simulations often involves collecting differential equations that model each subsystem, arran g them to a standard form, and obtaining their numerical gin solution as a single coupled, total-system simultaneous set. Simulation by numerical coupling of independent stand-alone subsimulations is a fundamentally different approach that is attractive because, among other things, the architecture naturally facilitates high fidelity, broad scope, and discipline independence. Recursive feedback is defined and discussed as a candidate approach to multidiscipline dynamic system simulation by numerical coupling of self-contained, single-discipline subsystem simulations. A satellite motion example containing three subsystems (orbit dynamics, attitude dynamics, and aerodynamics) has been defined and constructed using this approach. Conventional solution methods are used in the subsystem simulations. Distributed and centralized implementations of coupling have been considered. Numerical results are evaluated by direct comparison with a standard total-system, simultaneous-solution approach.

RPA binds histone H3-H4 and functions in DNA replication-coupled nucleosome assembly.

PubMed

Liu, Shaofeng; Xu, Zhiyun; Leng, He; Zheng, Pu; Yang, Jiayi; Chen, Kaifu; Feng, Jianxun; Li, Qing

2017-01-27

DNA replication-coupled nucleosome assembly is essential to maintain genome integrity and retain epigenetic information. Multiple involved histone chaperones have been identified, but how nucleosome assembly is coupled to DNA replication remains elusive. Here we show that replication protein A (RPA), an essential replisome component that binds single-stranded DNA, has a role in replication-coupled nucleosome assembly. RPA directly binds free H3-H4. Assays using a synthetic sequence that mimics freshly unwound single-stranded DNA at replication fork showed that RPA promotes DNA-(H3-H4) complex formation immediately adjacent to double-stranded DNA. Further, an RPA mutant defective in H3-H4 binding exhibited attenuated nucleosome assembly on nascent chromatin. Thus, we propose that RPA functions as a platform for targeting histone deposition to replication fork, through which RPA couples nucleosome assembly with ongoing DNA replication. Copyright © 2017, American Association for the Advancement of Science.

High-brightness 800nm fiber-coupled laser diodes

NASA Astrophysics Data System (ADS)

Berk, Yuri; Levy, Moshe; Rappaport, Noam; Tessler, Renana; Peleg, Ophir; Shamay, Moshe; Yanson, Dan; Klumel, Genadi; Dahan, Nir; Baskin, Ilya; Shkedi, Lior

2014-03-01

Fiber-coupled laser diodes have become essential sources for fiber laser pumping and direct energy applications. Single emitters offer reliable multi-watt output power from a 100 m lateral emission aperture. By their combination and fiber coupling, pump powers up to 100 W can be achieved from a low-NA fiber pigtail. Whilst in the 9xx nm spectral range the single emitter technology is very mature with <10W output per chip, at 800nm the reliable output power from a single emitter is limited to 4 W - 5 W. Consequently, commercially available fiber coupled modules only deliver 5W - 15W at around 800nm, almost an order of magnitude down from the 9xx range pumps. To bridge this gap, we report our advancement in the brightness and reliability of 800nm single emitters. By optimizing the wafer structure, laser cavity and facet passivation process we have demonstrated QCW device operation up to 19W limited by catastrophic optical damage to the 100 μm aperture. In CW operation, the devices reach 14 W output followed by a reversible thermal rollover and a complete device shutdown at high currents, with the performance fully rebounded after cooling. We also report the beam properties of our 800nm single emitters and provide a comparative analysis with the 9xx nm single emitter family. Pump modules integrating several of these emitters with a 105 μm / 0.15 NA delivery fiber reach 35W in CW at 808 nm. We discuss the key opto-mechanical parameters that will enable further brightness scaling of multi-emitter pump modules.

Quantification of causal couplings via dynamical effects: A unifying perspective

NASA Astrophysics Data System (ADS)

Smirnov, Dmitry A.

2014-12-01

Quantitative characterization of causal couplings from time series is crucial in studies of complex systems of different origin. Various statistical tools for that exist and new ones are still being developed with a tendency to creating a single, universal, model-free quantifier of coupling strength. However, a clear and generally applicable way of interpreting such universal characteristics is lacking. This work suggests a general conceptual framework for causal coupling quantification, which is based on state space models and extends the concepts of virtual interventions and dynamical causal effects. Namely, two basic kinds of interventions (state space and parametric) and effects (orbital or transient and stationary or limit) are introduced, giving four families of coupling characteristics. The framework provides a unifying view of apparently different well-established measures and allows us to introduce new characteristics, always with a definite "intervention-effect" interpretation. It is shown that diverse characteristics cannot be reduced to any single coupling strength quantifier and their interpretation is inevitably model based. The proposed set of dynamical causal effect measures quantifies different aspects of "how the coupling manifests itself in the dynamics," reformulating the very question about the "causal coupling strength."

On the incorporation of the geometric phase in general single potential energy surface dynamics: A removable approximation to ab initio data.

PubMed

Malbon, Christopher L; Zhu, Xiaolei; Guo, Hua; Yarkony, David R

2016-12-21

For two electronic states coupled by conical intersections, the line integral of the derivative coupling can be used to construct a complex-valued multiplicative phase factor that makes the real-valued adiabatic electronic wave function single-valued, provided that the curl of the derivative coupling is zero. Unfortunately for ab initio determined wave functions, the curl is never rigorously zero. However, when the wave functions are determined from a coupled two diabatic state Hamiltonian H d (fit to ab initio data), the resulting derivative couplings are by construction curl free, except at points of conical intersection. In this work we focus on a recently introduced diabatization scheme that produces the H d by fitting ab initio determined energies, energy gradients, and derivative couplings to the corresponding H d determined quantities in a least squares sense, producing a removable approximation to the ab initio determined derivative coupling. This approach and related numerical issues associated with the nonremovable ab initio derivative couplings are illustrated using a full 33-dimensional representation of phenol photodissociation. The use of this approach to provide a general framework for treating the molecular Aharonov Bohm effect is demonstrated.

Cell-cell bioelectrical interactions and local heterogeneities in genetic networks: a model for the stabilization of single-cell states and multicellular oscillations.

PubMed

Cervera, Javier; Manzanares, José A; Mafe, Salvador

2018-04-04

Genetic networks operate in the presence of local heterogeneities in single-cell transcription and translation rates. Bioelectrical networks and spatio-temporal maps of cell electric potentials can influence multicellular ensembles. Could cell-cell bioelectrical interactions mediated by intercellular gap junctions contribute to the stabilization of multicellular states against local genetic heterogeneities? We theoretically analyze this question on the basis of two well-established experimental facts: (i) the membrane potential is a reliable read-out of the single-cell electrical state and (ii) when the cells are coupled together, their individual cell potentials can be influenced by ensemble-averaged electrical potentials. We propose a minimal biophysical model for the coupling between genetic and bioelectrical networks that associates the local changes occurring in the transcription and translation rates of an ion channel protein with abnormally low (depolarized) cell potentials. We then analyze the conditions under which the depolarization of a small region (patch) in a multicellular ensemble can be reverted by its bioelectrical coupling with the (normally polarized) neighboring cells. We show also that the coupling between genetic and bioelectric networks of non-excitable cells, modulated by average electric potentials at the multicellular ensemble level, can produce oscillatory phenomena. The simulations show the importance of single-cell potentials characteristic of polarized and depolarized states, the relative sizes of the abnormally polarized patch and the rest of the normally polarized ensemble, and intercellular coupling.

75 FR 4827 - Submission for OMB Review; Comment Request Clinical Trials Reporting Program (CTRP) Database (NCI)

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-29

...; Comment Request Clinical Trials Reporting Program (CTRP) Database (NCI) Summary: Under the provisions of... Collection: Title: Clinical Trials Reporting Program (CTRP) Database. Type of Information Collection Request... Program (CTRP) Database, to serve as a single, definitive source of information about all NCI-supported...

Trial Sequential Methods for Meta-Analysis

ERIC Educational Resources Information Center

Kulinskaya, Elena; Wood, John

2014-01-01

Statistical methods for sequential meta-analysis have applications also for the design of new trials. Existing methods are based on group sequential methods developed for single trials and start with the calculation of a required information size. This works satisfactorily within the framework of fixed effects meta-analysis, but conceptual…

C-C Coupling on Single-Atom-Based Heterogeneous Catalyst.

PubMed

Zhang, Xiaoyan; Sun, Zaicheng; Wang, Bin; Tang, Yu; Nguyen, Luan; Li, Yuting; Tao, Franklin Feng

2018-01-24

Compared to homogeneous catalysis, heterogeneous catalysis allows for ready separation of products from the catalyst and thus reuse of the catalyst. C-C coupling is typically performed on a molecular catalyst which is mixed with reactants in liquid phase during catalysis. This homogeneous mixing at a molecular level in the same phase makes separation of the molecular catalyst extremely challenging and costly. Here we demonstrated that a TiO 2 -based nanoparticle catalyst anchoring singly dispersed Pd atoms (Pd 1 /TiO 2 ) is selective and highly active for more than 10 Sonogashira C-C coupling reactions (R≡CH + R'X → R≡R'; X = Br, I; R' = aryl or vinyl). The coupling between iodobenzene and phenylacetylene on Pd 1 /TiO 2 exhibits a turnover rate of 51.0 diphenylacetylene molecules per anchored Pd atom per minute at 60 °C, with a low apparent activation barrier of 28.9 kJ/mol and no cost of catalyst separation. DFT calculations suggest that the single Pd atom bonded to surface lattice oxygen atoms of TiO 2 acts as a site to dissociatively chemisorb iodobenzene to generate an intermediate phenyl, which then couples with phenylacetylenyl bound to a surface oxygen atom. This coupling of phenyl adsorbed on Pd 1 and phenylacetylenyl bound to O ad of TiO 2 forms the product molecule, diphenylacetylene.

Photon pair source via two coupling single quantum emitters

NASA Astrophysics Data System (ADS)

Peng, Yong-Gang; Zheng, Yu-Jun

2015-10-01

We study the two coupling two-level single molecules driven by an external field as a photon pair source. The probability of emitting two photons, P2, is employed to describe the photon pair source quality in a short time, and the correlation coefficient RAB is employed to describe the photon pair source quality in a long time limit. The results demonstrate that the coupling single quantum emitters can be considered as a stable photon pair source. Project supported by the National Natural Science Foundation of China (Grand Nos. 91021009, 21073110, and 11374191), the Natural Science Foundation of Shandong Province, China (Grant No. ZR2013AQ020), the Postdoctoral Science Foundation of China (Grant No. 2013M531584), the Doctoral Program of Higher Education of China (Grant Nos. 20130131110005 and 20130131120006), and the Taishan Scholarship Project of Shandong Province, China.

Macroscopic Entangled State Generation with Optomechanical Coupling of Two Mechanical Modes

NASA Astrophysics Data System (ADS)

Weaver, Matthew; Luna, Fernando; Buters, Frank; Heeck, Kier; de Man, Sven; Bouwmeester, Dirk

Mechanical resonators with a large quantum position uncertainty are an excellent test system for proposed decoherence mechanisms in massive systems. We present a scheme to optomechanically entangle two mechanical resonators with large frequency separation via two tone driving and single photon projection measurements. The quantum position uncertainty can be tuned with a variable optical pulse displacement operation, and independent single photon readout of the two resonators provides robust verification of the quantum states of the system. This scheme is currently experimentally feasible in a number of high mass opto- and electro-mechanical systems. We demonstrate one such system with two spatially and frequency separated Si3N4 trampoline resonators. We also show how the resonators can be coupled with two tone driving and the single photon optomechanical coupling rates can be tuned.

Hippocampal-prefrontal theta-gamma coupling during performance of a spatial working memory task.

PubMed

Tamura, Makoto; Spellman, Timothy J; Rosen, Andrew M; Gogos, Joseph A; Gordon, Joshua A

2017-12-19

Cross-frequency coupling supports the organization of brain rhythms and is present during a range of cognitive functions. However, little is known about whether and how long-range cross-frequency coupling across distant brain regions subserves working memory. Here we report that theta-slow gamma coupling between the hippocampus and medial prefrontal cortex (mPFC) is augmented in a genetic mouse model of cognitive dysfunction. This increased cross-frequency coupling is observed specifically when the mice successfully perform a spatial working memory task. In wild-type mice, increasing task difficulty by introducing a long delay or by optogenetically interfering with encoding, also increases theta-gamma coupling during correct trials. Finally, epochs of high hippocampal theta-prefrontal slow gamma coupling are associated with increased synchronization of neurons within the mPFC. These findings suggest that enhancement of theta-slow gamma coupling reflects a compensatory mechanism to maintain spatial working memory performance in the setting of increased difficulty.

Room temperature, single mode emission from two-section coupled cavity InGaAs/AlGaAs/GaAs quantum cascade laser

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

Pierściński, K., E-mail: kamil.pierscinski@ite.waw.pl; Pierścińska, D.; Pluska, M.

2015-10-07

Room temperature, single mode, pulsed emission from two-section coupled cavity InGaAs/AlGaAs/GaAs quantum cascade laser fabricated by focused ion beam processing is demonstrated and analyzed. The single mode emission is centered at 1059.4 cm{sup −1} (9.44 μm). A side mode suppression ratio of 43 dB was achieved. The laser exhibits a peak output power of 15 mW per facet at room temperature. The stable, single mode emission is observed within temperature tuning range, exhibiting shift at rate of 0.59 nm/K.

AAB and ABA Renewal as a Function of the Number of Extinction Trials in Conditioned Taste Aversion

ERIC Educational Resources Information Center

Rosas, Juan M.; Garcia-Gutierrez, Ana; Callejas-Aguilera, Jose E.

2007-01-01

Three experiments explored renewal in conditioned taste aversion after different amounts of extinction. In Experiment 1, three groups of rats received a single conditioning trial where a saccharin solution was paired with LiCl, followed by 3 extinction trials, and a two-trial test. Groups differed in the context where they received each of the…

Quality of Life, Coping Styles, Stress Levels, and Time Use in Mothers of Children with Autism Spectrum Disorders: Comparing Single versus Coupled Households

ERIC Educational Resources Information Center

McAuliffe, Tomomi; Cordier, Reinie; Vaz, Sharmila; Thomas, Yvonne; Falkmer, Torbjorn

2017-01-01

This study aimed to examine the influence of differences in household status on the parental stress, coping, time use and quality of life (QoL) among mothers of children with autism spectrum disorders. Forty-three single and 164 coupled mothers completed the survey. Data were analysed using multivariate logistic regression. We found that single…

Fiber Grating Coupled Light Source Capable of Tunable, Single Frequency Operation

NASA Technical Reports Server (NTRS)

Krainak, Michael A. (Inventor); Duerksen, Gary L. (Inventor)

2001-01-01

Fiber Bragg grating coupled light sources can achieve tunable single-frequency (single axial and lateral spatial mode) operation by correcting for a quadratic phase variation in the lateral dimension using an aperture stop. The output of a quasi-monochromatic light source such as a Fabry Perot laser diode is astigmatic. As a consequence of the astigmatism, coupling geometries that accommodate the transverse numerical aperture of the laser are defocused in the lateral dimension, even for apsherical optics. The mismatch produces the quadratic phase variation in the feedback along the lateral axis at the facet of the laser that excites lateral modes of higher order than the TM(sub 00). Because the instability entails excitation of higher order lateral submodes, single frequency operation also is accomplished by using fiber Bragg gratings whose bandwidth is narrower than the submode spacing. This technique is particularly pertinent to the use of lensed fiber gratings in lieu of discrete coupling optics. Stable device operation requires overall phase match between the fed-back signal and the laser output. The fiber Bragg grating acts as a phase-preserving mirror when the Bragg condition is met precisely. The phase-match condition is maintained throughout the fiber tuning range by matching the Fabry-Perot axial mode wavelength to the passband center wavelength of the Bragg grating.

Coupling motion between rearfoot and hip and knee joints during walking and single-leg landing.

PubMed

Koshino, Yuta; Yamanaka, Masanori; Ezawa, Yuya; Okunuki, Takumi; Ishida, Tomoya; Samukawa, Mina; Tohyama, Harukazu

2017-12-01

The objective of the current study was to investigate the kinematic relationships between the rearfoot and hip/knee joint during walking and single-leg landing. Kinematics of the rearfoot relative to the shank, knee and hip joints during walking and single-leg landing were analyzed in 22 healthy university students. Kinematic relationships between two types of angular data were assessed by zero-lag cross-correlation coefficients and coupling angles, and were compared between joints and between tasks. During walking, rearfoot eversion/inversion and external/internal rotation were strongly correlated with hip adduction/abduction (R=0.69 and R=0.84), whereas correlations with knee kinematics were not strong (R≤0.51) and varied between subjects. The correlations with hip adduction/abduction were stronger than those with knee kinematics (P<0.001). Most coefficients during single-leg landing were strong (R≥0.70), and greater than those during walking (P<0.001). Coupling angles indicated that hip motion relative to rearfoot motion was greater than knee motion relative to rearfoot motion during both tasks (P<0.001). Interventions to control rearfoot kinematics may affect hip kinematics during dynamic tasks. The coupling motion between the rearfoot and hip/knee joints, especially in the knee, should be considered individually. Copyright © 2017 Elsevier Ltd. All rights reserved.

Single and low order mode interrogation of a multimode sapphire fibre Bragg grating sensor with tapered fibres

NASA Astrophysics Data System (ADS)

Grobnic, D.; Mihailov, S. J.; Ding, H.; Bilodeau, F.; Smelser, C. W.

2006-05-01

Multimode sapphire fibre Bragg gratings (SFBG) made with an ultrafast Ti:sapphire 800 nm laser and a phase mask were probed using a tapered single mode fibre of different taper diameters to produce single and low order mode reflection/transmission responses. A configuration made of an input single mode tapered fibre and multimode silica fibre used for output coupling was also tested and has delivered a filtered multimode transmission spectrum. The tapered coupling improved the spectral resolution of the SFBG. Such improvements facilitate the utilization of the SFBG as a high temperature sensor. Wavelength shifts of the single mode response were monitored as a function of temperature up to 1500 °C with no detectable degradation in the grating strength or hysteresis in the Bragg resonance.

New concept single screw compressors and their manufacture technology

NASA Astrophysics Data System (ADS)

Feng, Q.; Liu, F.; Chang, L.; Feng, C.; Peng, C.; Xie, J.; van den Broek, M.

2017-08-01

Single screw compressors were generally acknowledged as one of the nearly perfect machines by compressor researchers and manufacturers. However the rapid wear of the star-wheel in a single screw compressor during operation is a key reason why it hasn’t previously joined the main current compressors’ market. After more than ten years of effective work, the authors of this paper have proposed a new concept single screw compressor whose mesh-couple profile is enveloped with multi-column. Also a new design method and manufacture equipment for this kind of compressor have been developed and are described in this paper. A lot of prototype tests and a long period of industrial operations under full loading conditions have shown that the mesh-couple profiles of the new concept single compressors have excellent anti-wearness.

The coupling of engines

NASA Technical Reports Server (NTRS)

Boccaccio, Paul

1921-01-01

This report examines the idea of coupling numerous engines together to turn a single propeller, which the author feels would free aircraft design from the problems of multi-engine and propeller design.

Predicting the Coupling Properties of Axially-Textured Materials.

PubMed

Fuentes-Cobas, Luis E; Muñoz-Romero, Alejandro; Montero-Cabrera, María E; Fuentes-Montero, Luis; Fuentes-Montero, María E

2013-10-30

A description of methods and computer programs for the prediction of "coupling properties" in axially-textured polycrystals is presented. Starting data are the single-crystal properties, texture and stereography. The validity and proper protocols for applying the Voigt, Reuss and Hill approximations to estimate coupling properties effective values is analyzed. Working algorithms for predicting mentioned averages are given. Bunge's symmetrized spherical harmonics expansion of orientation distribution functions, inverse pole figures and (single and polycrystals) physical properties is applied in all stages of the proposed methodology. The established mathematical route has been systematized in a working computer program. The discussion of piezoelectricity in a representative textured ferro-piezoelectric ceramic illustrates the application of the proposed methodology. Polycrystal coupling properties, predicted by the suggested route, are fairly close to experimentally measured ones.

Predicting the Coupling Properties of Axially-Textured Materials

PubMed Central

Fuentes-Cobas, Luis E.; Muñoz-Romero, Alejandro; Montero-Cabrera, María E.; Fuentes-Montero, Luis; Fuentes-Montero, María E.

2013-01-01

A description of methods and computer programs for the prediction of “coupling properties” in axially-textured polycrystals is presented. Starting data are the single-crystal properties, texture and stereography. The validity and proper protocols for applying the Voigt, Reuss and Hill approximations to estimate coupling properties effective values is analyzed. Working algorithms for predicting mentioned averages are given. Bunge’s symmetrized spherical harmonics expansion of orientation distribution functions, inverse pole figures and (single and polycrystals) physical properties is applied in all stages of the proposed methodology. The established mathematical route has been systematized in a working computer program. The discussion of piezoelectricity in a representative textured ferro-piezoelectric ceramic illustrates the application of the proposed methodology. Polycrystal coupling properties, predicted by the suggested route, are fairly close to experimentally measured ones. PMID:28788370

A theoretical and experimental benchmark study of core-excited states in nitrogen

NASA Astrophysics Data System (ADS)

Myhre, Rolf H.; Wolf, Thomas J. A.; Cheng, Lan; Nandi, Saikat; Coriani, Sonia; Gühr, Markus; Koch, Henrik

2018-02-01

The high resolution near edge X-ray absorption fine structure spectrum of nitrogen displays the vibrational structure of the core-excited states. This makes nitrogen well suited for assessing the accuracy of different electronic structure methods for core excitations. We report high resolution experimental measurements performed at the SOLEIL synchrotron facility. These are compared with theoretical spectra calculated using coupled cluster theory and algebraic diagrammatic construction theory. The coupled cluster singles and doubles with perturbative triples model known as CC3 is shown to accurately reproduce the experimental excitation energies as well as the spacing of the vibrational transitions. The computational results are also shown to be systematically improved within the coupled cluster hierarchy, with the coupled cluster singles, doubles, triples, and quadruples method faithfully reproducing the experimental vibrational structure.

Two-state semiconductor laser self-mixing velocimetry exploiting coupled quantum-dot emission-states: experiment, simulation and theory

PubMed Central

Gioannini, Mariangela; Dommermuth, Marius; Drzewietzki, Lukas; Krestnikov, Igor; Livshits, Daniil; Krakowski, Michel; Breuer, Stefan

2014-01-01

We exploit the coupled emission-states of a single-chip semiconductor InAs/GaAs quantum-dot laser emitting simultaneously on ground-state (λGS = 1245 nm) and excited-state (λES = 1175 nm) to demonstrate coupled-two-state self-mixing velocimetry for a moving diffuse reflector. A 13 Hz-narrow Doppler beat frequency signal at 317 Hz is obtained for a reflector velocity of 3 mm/s, which exemplifies a 66-fold improvement in width as compared to single-wavelength self-mixing velocimetry. Simulation results reveal the physical origin of this signal, the coupling of excited-state and ground-state photons via the carriers, which is unique for quantum-dot lasers and reproduce the experimental results with excellent agreement. PMID:25321809

Direct photonic coupling of a semiconductor quantum dot and a trapped ion.

PubMed

Meyer, H M; Stockill, R; Steiner, M; Le Gall, C; Matthiesen, C; Clarke, E; Ludwig, A; Reichel, J; Atatüre, M; Köhl, M

2015-03-27

Coupling individual quantum systems lies at the heart of building scalable quantum networks. Here, we report the first direct photonic coupling between a semiconductor quantum dot and a trapped ion and we demonstrate that single photons generated by a quantum dot controllably change the internal state of a Yb^{+} ion. We ameliorate the effect of the 60-fold mismatch of the radiative linewidths with coherent photon generation and a high-finesse fiber-based optical cavity enhancing the coupling between the single photon and the ion. The transfer of information presented here via the classical correlations between the σ_{z} projection of the quantum-dot spin and the internal state of the ion provides a promising step towards quantum-state transfer in a hybrid photonic network.

Duplex Wrench

NASA Technical Reports Server (NTRS)

Canada, C. N.

1987-01-01

Special tool enables one worker to do two-worker job. Wrench holds two nuts in place while third nut, coaxial with others, turned. Developed for tightening delicate couplings on gas-supply panel. Single operator restrains coupling pressure cap and connector body nut with one hand. Other hand free to tighten coupling nut with torque wrench.

The benefit of tissue contact monitoring with an electrical coupling index during ablation of typical atrial flutter--a prospective randomised control trial.

PubMed

Jones, Michael A; Webster, David; Wong, Kelvin C K; Hayes, Christopher; Qureshi, Norman; Rajappan, Kim; Bashir, Yaver; Betts, Timothy R

2014-12-01

We sought to investigate the use of tissue contact monitoring by means of the electrical coupling index (ECI) in a prospective randomised control trial of patients undergoing cavotricuspid isthmus (CTI) ablation for atrial flutter. Patients with ECG-documented typical flutter undergoing their first CTI ablation were randomised to ECI™-guided or non-ECI™-guided ablation. An irrigated-tip ablation catheter was used in all cases. Consecutive 50-W, 60-s radiofrequency lesions were applied to the CTI, from the tricuspid valve to inferior vena cava, with no catheter movement permitted during radiofrequency (RF) delivery. The ablation endpoint was durable CTI block at 20 min post-ablation. Patients underwent routine clinic follow-up post-operatively. A total of 101 patients (79 male), mean age 66 (+/-11), 50 ECI-guided and 51 control cases were enrolled in the study. CTI block was achieved in all. There were no acute complications. All patients were alive at follow-up. CTI block was achieved in a single pass in 36 ECI-guided and 30 control cases (p = 0.16), and at 20 min post-ablation, re-conduction was seen in 5 and 12 cases, respectively (p = 0.07). There was no significant difference in total procedure time (62.7 ± 33 vs. 62.3 ± 33 min, p = 0.92), RF requirement (580 ± 312 vs. 574 ± 287 s, p = 0.11) or fluoroscopy time (718 ± 577 vs. 721 ± 583 s, p = 0.78). After 6 ± 4 months, recurrence of flutter had occurred in 1 (2 %) ECI vs. 8 (16 %) control cases (OR 0.13, 95 % CI 0.01-1.08, p = 0.06). ECI-guided CTI ablation demonstrated a non-statistically significant reduction in late recurrence of atrial flutter, at no cost to procedural time, radiation exposure or RF requirement.

Rating the methodological quality of single-subject designs and n-of-1 trials: introducing the Single-Case Experimental Design (SCED) Scale.

PubMed

Tate, Robyn L; McDonald, Skye; Perdices, Michael; Togher, Leanne; Schultz, Regina; Savage, Sharon

2008-08-01

Rating scales that assess methodological quality of clinical trials provide a means to critically appraise the literature. Scales are currently available to rate randomised and non-randomised controlled trials, but there are none that assess single-subject designs. The Single-Case Experimental Design (SCED) Scale was developed for this purpose and evaluated for reliability. Six clinical researchers who were trained and experienced in rating methodological quality of clinical trials developed the scale and participated in reliability studies. The SCED Scale is an 11-item rating scale for single-subject designs, of which 10 items are used to assess methodological quality and use of statistical analysis. The scale was developed and refined over a 3-year period. Content validity was addressed by identifying items to reduce the main sources of bias in single-case methodology as stipulated by authorities in the field, which were empirically tested against 85 published reports. Inter-rater reliability was assessed using a random sample of 20/312 single-subject reports archived in the Psychological Database of Brain Impairment Treatment Efficacy (PsycBITE). Inter-rater reliability for the total score was excellent, both for individual raters (overall ICC = 0.84; 95% confidence interval 0.73-0.92) and for consensus ratings between pairs of raters (overall ICC = 0.88; 95% confidence interval 0.78-0.95). Item reliability was fair to excellent for consensus ratings between pairs of raters (range k = 0.48 to 1.00). The results were replicated with two independent novice raters who were trained in the use of the scale (ICC = 0.88, 95% confidence interval 0.73-0.95). The SCED Scale thus provides a brief and valid evaluation of methodological quality of single-subject designs, with the total score demonstrating excellent inter-rater reliability using both individual and consensus ratings. Items from the scale can also be used as a checklist in the design, reporting and critical appraisal of single-subject designs, thereby assisting to improve standards of single-case methodology.

Efficacy of Single-Dose and Triple-Dose Albendazole and Mebendazole against Soil-Transmitted Helminths and Taenia spp.: A Randomized Controlled Trial

PubMed Central

Steinmann, Peter; Utzinger, Jürg; Du, Zun-Wei; Jiang, Jin-Yong; Chen, Jia-Xu; Hattendorf, Jan; Zhou, Hui; Zhou, Xiao-Nong

2011-01-01

Background The control of soil-transmitted helminth (STH) infections currently relies on the large-scale administration of single-dose oral albendazole or mebendazole. However, these treatment regimens have limited efficacy against hookworm and Trichuris trichiura in terms of cure rates (CR), whereas fecal egg reduction rates (ERR) are generally high for all common STH species. We compared the efficacy of single-dose versus triple-dose treatment against hookworm and other STHs in a community-based randomized controlled trial in the People's Republic of China. Methodology/Principal findings The hookworm CR and fecal ERR were assessed in 314 individuals aged ≥5 years who submitted two stool samples before and 3–4 weeks after administration of single-dose oral albendazole (400 mg) or mebendazole (500 mg) or triple-dose albendazole (3×400 mg over 3 consecutive days) or mebendazole (3×500 mg over 3 consecutive days). Efficacy against T. trichiura, Ascaris lumbricoides, and Taenia spp. was also assessed. Albendazole cured significantly more hookworm infections than mebendazole in both treatment regimens (single dose: respective CRs 69% (95% confidence interval [CI]: 55–81%) and 29% (95% CI: 20–45%); triple dose: respective CRs 92% (95% CI: 81–98%) and 54% (95% CI: 46–71%)). ERRs followed the same pattern (single dose: 97% versus 84%; triple dose: 99.7% versus 96%). Triple-dose regimens outperformed single doses against T. trichiura; three doses of mebendazole – the most efficacious treatment tested – cured 71% (95% CI: 57–82%). Both single and triple doses of either drug were highly efficacious against A. lumbricoides (CR: 93–97%; ERR: all >99.9%). Triple dose regimens cured all Taenia spp. infections, whereas single dose applications cured only half of them. Conclusions/Significance Single-dose oral albendazole is more efficacious against hookworm than mebendazole. To achieve high CRs against both hookworm and T. trichiura, triple-dose regimens are warranted. Trial Registration www.controlled-trials.com ISRCTN47375023 PMID:21980373

Multiplexed single-mode wavelength-to-time mapping of multimode light

PubMed Central

Chandrasekharan, Harikumar K; Izdebski, Frauke; Gris-Sánchez, Itandehui; Krstajić, Nikola; Walker, Richard; Bridle, Helen L.; Dalgarno, Paul A.; MacPherson, William N.; Henderson, Robert K.; Birks, Tim A.; Thomson, Robert R.

2017-01-01

When an optical pulse propagates along an optical fibre, different wavelengths travel at different group velocities. As a result, wavelength information is converted into arrival-time information, a process known as wavelength-to-time mapping. This phenomenon is most cleanly observed using a single-mode fibre transmission line, where spatial mode dispersion is not present, but the use of such fibres restricts possible applications. Here we demonstrate that photonic lanterns based on tapered single-mode multicore fibres provide an efficient way to couple multimode light to an array of single-photon avalanche detectors, each of which has its own time-to-digital converter for time-correlated single-photon counting. Exploiting this capability, we demonstrate the multiplexed single-mode wavelength-to-time mapping of multimode light using a multicore fibre photonic lantern with 121 single-mode cores, coupled to 121 detectors on a 32 × 32 detector array. This work paves the way to efficient multimode wavelength-to-time mapping systems with the spectral performance of single-mode systems. PMID:28120822

Strong Light-Matter Interactions in Single Open Plasmonic Nanocavities at the Quantum Optics Limit.

PubMed

Liu, Renming; Zhou, Zhang-Kai; Yu, Yi-Cong; Zhang, Tengwei; Wang, Hao; Liu, Guanghui; Wei, Yuming; Chen, Huanjun; Wang, Xue-Hua

2017-06-09

Reaching the quantum optics limit of strong light-matter interactions between a single exciton and a plasmon mode is highly desirable, because it opens up possibilities to explore room-temperature quantum devices operating at the single-photon level. However, two challenges severely hinder the realization of this limit: the integration of single-exciton emitters with plasmonic nanostructures and making the coupling strength at the single-exciton level overcome the large damping of the plasmon mode. Here, we demonstrate that these two hindrances can be overcome by attaching individual J aggregates to single cuboid Au@Ag nanorods. In such hybrid nanosystems, both the ultrasmall mode volume of ∼71  nm^{3} and the ultrashort interaction distance of less than 0.9 nm make the coupling coefficient between a single J-aggregate exciton and the cuboid nanorod as high as ∼41.6  meV, enabling strong light-matter interactions to be achieved at the quantum optics limit in single open plasmonic nanocavities.

Canadian mock juror attitudes and decisions in domestic violence cases involving asian and white interracial and intraracial couples.

PubMed

Maeder, Evelyn M; Mossière, Annik; Cheung, Liann

2013-03-01

This study manipulated the race of the defendant and the victim (White/White, White/Asian, Asian/Asian, and Asian/White) in a domestic violence case to examine the potential prejudicial impact of race on juror decision making. A total of 181 undergraduate students read a trial transcript involving an allegation of spousal abuse in which defendant and victim race were manipulated using photographs. They then provided a verdict and confidence rating, a sentence, and responsibility attributions, and completed various scales measuring attitudes toward wife abuse and women. Findings revealed that female jurors were harsher toward the defendant than were male jurors. When controlling for attitudes toward Asians, jurors found the defendant guilty more often in cases involving interracial couples, as compared to same-race couples. Path analyses revealed various factors and attitudes involved in domestic violence trial outcomes. Findings contribute to the scarce literature on legal proceedings involving Asians, particularly in domestic violence cases. Outcomes also provide a model for relevant factors and characteristics of jurors in domestic violence cases. Roadblocks inherent in jury research are also discussed.

The Effects of a Couples-Based Health Behavior Intervention During Pregnancy on Latino Couples' Dyadic Satisfaction Postpartum.

PubMed

Coop Gordon, Kristina; Roberson, Patricia N E; Hughes, Jessica A; Khaddouma, Alexander M; Swamy, Geeta K; Noonan, Devon; Gonzalez, Alicia M; Fish, Laura; Pollak, Kathryn I

2018-03-30

Many couples tend to report steadily decreasing relationship quality following the birth of a child. However, little is known about the postpartum period for Latino couples, a rapidly growing ethnic group who are notably underserved by mental and physical health caregivers in the United States. Thus, this study investigated whether a brief couples' intervention focused on helping couples support each other while increasing healthy behaviors might improve dyadic functioning postpartum. This study presents secondary analyses of data regarding couple functioning from a larger randomized controlled trial with 348 Latino couples to promote smoking cessation. Portions of the intervention taught the couple communication and problem-solving skills to increase healthy behavior. Couples participated in four face-to-face assessments across 1 year starting at the end of the first trimester. Latent growth curve analyses revealed that the treatment group reported an increase in relationship satisfaction and constructive communication after the intervention, which diminished by 1-year follow-up, returning couples to their baseline levels of satisfaction. Results suggest that incorporating a brief couple intervention as part of a larger health intervention for Latinos may prevent postpartum decreases in relationship satisfaction. © 2018 Family Process Institute.

Exchange coupling and magnetic anisotropy in a family of bipyrimidyl radical-bridged dilanthanide complexes: density functional theory and ab initio calculations.

PubMed

Zhang, Yi-Quan; Luo, Cheng-Lin; Zhang, Qiang

2014-05-05

The origin of the magnetic anisotropy energy barriers in a series of bpym(-) (bpym = 2,2'-bipyrimidine) radical-bridged dilanthanide complexes [(Cp*2Ln)2(μ-bpym)](+) [Cp* = pentamethylcyclopentadienyl; Ln = Gd(III) (1), Tb(III) (2), Dy(III) (3), Ho(III) (4), Er(III) (5)] has been explored using density functional theory (DFT) and ab initio methods. DFT calculations show that the exchange coupling between the two lanthanide ions for each complex is very weak, but the antiferromagnetic Ln-bpym(-) couplings are strong. Ab initio calculations show that the effective energy barrier of 2 or 3 mainly comes from the contribution of a single Tb(III) or Dy(III) fragment, which is only about one third of a single Ln energy barrier. For 4 or 5, however, both of the two Ho(III) or Er(III) fragments contribute to the total energy barrier. Thus, it is insufficient to only increase the magnetic anisotropy energy barrier of a single Ln ion, while enhancing the Ln-bpym(-) couplings is also very important. Copyright © 2014 Wiley Periodicals, Inc.

Quantum Yield of Single Surface Plasmons Generated by a Quantum Dot Coupled with a Silver Nanowire.

PubMed

Li, Qiang; Wei, Hong; Xu, Hongxing

2015-12-09

The interactions between surface plasmons (SPs) in metal nanostructures and excitons in quantum emitters (QEs) lead to many interesting phenomena and potential applications that are strongly dependent on the quantum yield of SPs. The difficulty in distinguishing all the possible exciton recombination channels hinders the experimental determination of SP quantum yield. Here, we experimentally measured for the first time the quantum yield of single SPs generated by the exciton-plasmon coupling in a system composed of a single quantum dot and a silver nanowire (NW). By utilizing the SP guiding property of the NW, the decay rates of all the exciton recombination channels, i.e., direct free space radiation channel, SP generation channel, and nonradiative damping channel, are quantitatively obtained. It is determined that the optimum emitter-NW coupling distance for the largest SP quantum yield is about 10 nm, resulting from the different distance-dependent decay rates of the three channels. These results are important for manipulating the coupling between plasmonic nanostructures and QEs and developing on-chip quantum plasmonic devices for potential nanophotonic and quantum information applications.

High-brightness 9xxnm fiber coupled diode lasers

NASA Astrophysics Data System (ADS)

Liu, Rui; Jiang, Xiaochen; Yang, Thomas; He, Xiaoguang; Gao, Yanyan; Zhu, Jing; Zhang, Tujia; Guo, Weirong; Wang, Baohua; Guo, Zhijie; Zhang, Luyan; Chen, Louisa

2015-03-01

We developed a high brightness fiber coupled diode laser module providing more than 140W output power from a 105μm NA 0.15 fiber at the wavelength of 915nm.The high brightness module has an electrical to optical efficiency better than 45% and power enclosure more than 90% within NA 0.13. It is based on multi-single emitters using optical and polarization beam combining and fiber coupling technique. With the similar technology, over 100W of optical power into a 105μm NA 0.15 fiber at 976nm is also achieved which can be compatible with the volume Bragg gratings to receive narrow and stabilized spectral linewidth. The light within NA 0.12 is approximately 92%. The reliability test data of single and multiple single emitter laser module under high optical load are also presented and analyzed using a reliability model with an emitting aperture optimized for coupling into 105μm core fiber. The total MTTF shows exceeding 100,000 hours within 60% confidence level. The packaging processes and optical design are ready for commercial volume production.

Efficient multi-mode to single-mode coupling in a photonic lantern.

PubMed

Noordegraaf, Danny; Skovgaard, Peter M W; Nielsen, Martin D; Bland-Hawthorn, Joss

2009-02-02

We demonstrate the fabrication of a high performance multi-mode (MM) to single-mode (SM) splitter or "photonic lantern", first described by Leon-Saval et al. (2005). Our photonic lantern is a solid all-glass version, and we show experimentally that this device can be used to achieve efficient and reversible coupling between a MM fiber and a number of SM fibers, when perfectly matched launch conditions into the MM fiber are ensured. The fabricated photonic lantern has a coupling loss for a MM to SM tapered transition of only 0.32 dB which proves the feasibility of the technology.

High performance static latches with complete single event upset immunity

DOEpatents

Corbett, W.T.; Weaver, H.T.

1994-04-26

An asymmetric response latch providing immunity to single event upset without loss of speed is described. The latch has cross-coupled inverters having a hardened logic state and a soft state, wherein the logic state of the first inverter can only be changed when the voltage on the coupling node of that inverter is low and the logic state of the second inverter can only be changed when the coupling of that inverter is high. One of more of the asymmetric response latches may be configured into a memory cell having complete immunity, which protects information rather than logic states. 5 figures.

A Randomized Controlled Trial of Brief Coparenting and Relationship Interventions During the Transition to Parenthood

PubMed Central

Doss, Brian D.; Cicila, Larisa N.; Hsueh, Annie C.; Morrison, Kristen R.; Carhart, Kathryn

2014-01-01

The transition to parenthood has been repeatedly identified as a stressful period, with couples reporting difficulties in domains of individual, coparenting, and relationship functioning. Moreover, these difficulties have been shown to impact children’s development. To buffer against these difficulties, numerous effective parenting, couple, and combined interventions have been developed; however, these interventions are typically lengthy, which limits their potential for dissemination. Therefore, in the present study, we developed and tested separate six-hour interventions that focused exclusively on improving either coparenting or relationship functioning. In a randomized control trial, 90 heterosexual couples (180 individuals) were randomly assigned to an information control group, a coparenting intervention, or a relationship intervention and assessed on seven occasions during the two years following birth. Results revealed that women and high-risk men in both the couple and coparenting interventions showed fewer declines in relationship satisfaction (Cohen’s d = 0.53–0.99) and other areas of relationship functioning. Women also reported improved coparenting in both intervention groups (Cohen’s d = 0.47–1.06). Additionally, women in both interventions experienced less perceived stress during the first year after birth. Given similar effects of the two interventions on coparenting and relationship functioning, future dissemination may be enhanced by delivery of coparenting interventions, as coparenting (compared to relationship) interventions seem to attract more interest from couples and are likely easier to integrate into existing services. PMID:25090255

Subthreshold muscle twitches dissociate oscillatory neural signatures of conflicts from errors.

PubMed

Cohen, Michael X; van Gaal, Simon

2014-02-01

We investigated the neural systems underlying conflict detection and error monitoring during rapid online error correction/monitoring mechanisms. We combined data from four separate cognitive tasks and 64 subjects in which EEG and EMG (muscle activity from the thumb used to respond) were recorded. In typical neuroscience experiments, behavioral responses are classified as "error" or "correct"; however, closer inspection of our data revealed that correct responses were often accompanied by "partial errors" - a muscle twitch of the incorrect hand ("mixed correct trials," ~13% of the trials). We found that these muscle twitches dissociated conflicts from errors in time-frequency domain analyses of EEG data. In particular, both mixed-correct trials and full error trials were associated with enhanced theta-band power (4-9Hz) compared to correct trials. However, full errors were additionally associated with power and frontal-parietal synchrony in the delta band. Single-trial robust multiple regression analyses revealed a significant modulation of theta power as a function of partial error correction time, thus linking trial-to-trial fluctuations in power to conflict. Furthermore, single-trial correlation analyses revealed a qualitative dissociation between conflict and error processing, such that mixed correct trials were associated with positive theta-RT correlations whereas full error trials were associated with negative delta-RT correlations. These findings shed new light on the local and global network mechanisms of conflict monitoring and error detection, and their relationship to online action adjustment. © 2013.

Coherent control of the single-photon multichannel scattering in the dissipation case

NASA Astrophysics Data System (ADS)

Shi, Yun-Xia; Wang, Hang-Yu; Ma, Jin-Lou; Li, Qing; Tan, Lei

2018-03-01

Based on the quasi-boson approach, a model of a Λ-type three-level atom coupled to a X-shaped coupled cavity arrays (CCAs) is used to study the transport properties of a single-photon in the dissipative case, and a classical field is introduced to motivate the one transition of the Λ-type three-level atom (ΛTLA). The analytical expressions of transmission and transfer rate are obtained. Our results show that the cavity dissipation will obviously weaken the single-photon transfer rate where the incident energy of the single photon is resonant with the excited energy of the atom. Whether the cavity dissipation exists or not, the single photon can be almost confined in the incident channel at large detuning, and we can regulate the intensity of the classical field to control the total transmission of the single-photon.

Distribution of guidance models for cardiac resynchronization therapy in the setting of multi-center clinical trials

NASA Astrophysics Data System (ADS)

Rajchl, Martin; Abhari, Kamyar; Stirrat, John; Ukwatta, Eranga; Cantor, Diego; Li, Feng P.; Peters, Terry M.; White, James A.

2014-03-01

Multi-center trials provide the unique ability to investigate novel techniques across a range of geographical sites with sufficient statistical power, the inclusion of multiple operators determining feasibility under a wider array of clinical environments and work-flows. For this purpose, we introduce a new means of distributing pre-procedural cardiac models for image-guided interventions across a large scale multi-center trial. In this method, a single core facility is responsible for image processing, employing a novel web-based interface for model visualization and distribution. The requirements for such an interface, being WebGL-based, are minimal and well within the realms of accessibility for participating centers. We then demonstrate the accuracy of our approach using a single-center pacemaker lead implantation trial with generic planning models.

[The P300 based brain-computer interface: effect of stimulus position in a stimulus train].

PubMed

Ganin, I P; Shishkin, S L; Kochetova, A G; Kaplan, A Ia

2012-01-01

The P300 brain-computer interface (BCI) is currently the most efficient BCI. This interface is based on detection of the P300 wave of the brain potentials evoked when a symbol related to the intended input is highlighted. To increase operation speed of the P300 BCI, reduction of the number of stimuli repetitions is needed. This reduction leads to increase of the relative contribution to the input symbol detection from the reaction to the first target stimulus. It is known that the event-related potentials (ERP) to the first stimulus presentations can be different from the ERP to stimuli presented latter. In particular, the amplitude of responses to the first stimulus presentations is often increased, which is beneficial for their recognition by the BCI. However, this effect was not studied within the BCI framework. The current study examined the ERP obtained from healthy participants (n = 14) in the standard P300 BCI paradigm using 10 trials, as well as in the modified P300 BCI with stimuli presented on moving objects in triple-trial (n = 6) and single-trial (n = 6) stimulation modes. Increased ERP amplitude was observed in response to the first target stimuli in both conditions, as well as in the single-trial mode comparing to triple-trial. We discuss the prospects of using the specific features of the ERP to first stimuli and the single-trial ERP for optimizing the high-speed modes in the P300 BCIs.

Postprandial improvement in insulin sensitivity after a single exercise session in adolescents with low aerobic fitness and physical activity.

PubMed

Short, Kevin R; Pratt, Lauren V; Teague, April M; Man, Chiara Dalla; Cobelli, Claudio

2013-03-01

The purpose of this study was to determine the acute and residual impact of a single exercise bout on meal glucose control in adolescents with habitually low physical activity. Twelve adolescents (seven females/five males, 14 ± 2 yr) completed three trials. One trial [No Exercise (No Ex)] was completed after refraining from vigorous activity for ≥ 3 d. On the other two trials, a 45-min aerobic exercise bout at 75% peak heart rate was performed either 17-h Prior Day Exercise (Prior Day Ex) trial or 1-h Same Day Exercise (Same Day Ex) trial before consuming the test meal (2803 kJ, 45/40/15% energy as carbohydrate/fat/protein, respectively). Compared to No Ex, insulin sensitivity (SI) (minimal model analysis) was increased by 45% (p < 0.03) and 78% (p < 0.01) on the Prior Day Ex and Same Day Ex trials, respectively. This improvement in glucose control was supported by corresponding reductions in the net area under the curve for glucose, insulin, and c-peptide, although there was no change in postprandial suppression of fatty acids. These results show that SI is improved with a single bout of moderate intensity exercise in adolescents with habitually low physical activity and that the residual beneficial effect of exercise lasts at least 17 h. This finding highlights the plasticity of exercise responses in youth and the importance of daily exercise for metabolic health. © 2012 John Wiley & Sons A/S.

Opto-electronic oscillator and its applications

NASA Astrophysics Data System (ADS)

Yao, X. S.; Maleki, Lute

1997-04-01

We review the properties of a new class of microwave oscillators called opto-electronic oscillators (OEO). We present theoretical and experimental results of a multi-loop technique for single mode selection. We then describe a new development called coupled OEO (COEO) in which the electrical oscillation is directly coupled with the optical oscillation, producing an OEO that generates stable optical pulses and single mode microwave oscillation simultaneously. Finally we discuss various applications of OEO.

CW Performance of an InGaAs-GaAs-AlGaAs Laterally-Coupled Distributed Feedback (LC-DFB) Ridge Laser Diode

NASA Technical Reports Server (NTRS)

Martin, R. D.; Forouhar, S.; Keo, S.; Lang, R. J.; Hunsperger, R. G.; Tiberio, R. C.; Chapman, P. F.

1995-01-01

Single-mode distributed feedback (DFB) laser diodes typically require a two-step epitaxial growth or use of a corrugated substrate. We demonstrate InGaAs-GaAs-AlGaAs DFB lasers fabricated from a single epitaxial growth using lateral evanescent coupling of the optical field to a surface grating etehed along the sides of the ridge. A CW threshold current of 25 mA and external quantum efficiency of 0.48 mW/mA per facet were measured for a 1 mm cavity length device with anti-reflection coated facets. Single-mode output powers as high as 11 mW per facet at 935 nm wavelength were attained. A coupling coefficient of at least 5.8/cm was calculated from the subthreshold spectrum taking into account the 2% residual facet reflectivity.

Low-Loss Coupling of Quantum Cascade Lasers into Hollow-Core Waveguides with Single-Mode Output in the 3.7-7.6 μm Spectral Range.

PubMed

Patimisco, Pietro; Sampaolo, Angelo; Mihai, Laura; Giglio, Marilena; Kriesel, Jason; Sporea, Dan; Scamarcio, Gaetano; Tittel, Frank K; Spagnolo, Vincenzo

2016-04-13

We demonstrated low-loss and single-mode laser beam delivery through hollow-core waveguides (HCWs) operating in the 3.7-7.6 μm spectral range. The employed HCWs have a circular cross section with a bore diameter of 200 μm and metallic/dielectric internal coatings deposited inside a glass capillary tube. The internal coatings have been produced to enhance the spectral response of the HCWs in the range 3.5-12 µm. We demonstrated Gaussian-like outputs throughout the 4.5-7.6 µm spectral range. A quasi single-mode output beam with only small beam distortions was achieved when the wavelength was reduced to 3.7 μm. With a 15-cm-long HCW and optimized coupling conditions, we measured coupling efficiencies of >88% and transmission losses of <1 dB in the investigated infrared spectral range.

Progress Towards High-Sensitivity Arrays of Detectors of Sub-mm Radiation Using Superconducting Tunnel Junctions with Integrated Radio Frequency Single-Electron Transistors

NASA Technical Reports Server (NTRS)

Stevenson, T. R.; Hsieh, W.-T.; Li, M. J.; Prober, D. E.; Rhee, K. W.; Schoelkopf, R. J.; Stahle, C. M.; Teufel, J.; Wollack, E. J.

2004-01-01

For high resolution imaging and spectroscopy in the FIR and submillimeter, space observatories will demand sensitive, fast, compact, low-power detector arrays with 104 pixels and sensitivity less than 10(exp -20) W/Hz(sup 0.5). Antenna-coupled superconducting tunnel junctions with integrated rf single-electron transistor readout amplifiers have the potential for achieving this high level of sensitivity, and can take advantage of an rf multiplexing technique. The device consists of an antenna to couple radiation into a small superconducting volume and cause quasiparticle excitations, and a single-electron transistor to measure current through junctions contacting the absorber. We describe optimization of device parameters, and results on fabrication techniques for producing devices with high yield for detector arrays. We also present modeling of expected saturation power levels, antenna coupling, and rf multiplexing schemes.

Areas V1 and V2 show microsaccade-related 3-4-Hz covariation in gamma power and frequency.

PubMed

Lowet, E; Roberts, M J; Bosman, C A; Fries, P; De Weerd, P

2016-05-01

Neuronal gamma-band synchronization (25-80 Hz) in visual cortex appears sustained and stable during prolonged visual stimulation when investigated with conventional averages across trials. However, recent studies in macaque visual cortex have used single-trial analyses to show that both power and frequency of gamma oscillations exhibit substantial moment-by-moment variation. This has raised the question of whether these apparently random variations might limit the functional role of gamma-band synchronization for neural processing. Here, we studied the moment-by-moment variation in gamma oscillation power and frequency, as well as inter-areal gamma synchronization, by simultaneously recording local field potentials in V1 and V2 of two macaque monkeys. We additionally analyzed electrocorticographic V1 data from a third monkey. Our analyses confirm that gamma-band synchronization is not stationary and sustained but undergoes moment-by-moment variations in power and frequency. However, those variations are neither random and nor a possible obstacle to neural communication. Instead, the gamma power and frequency variations are highly structured, shared between areas and shaped by a microsaccade-related 3-4-Hz theta rhythm. Our findings provide experimental support for the suggestion that cross-frequency coupling might structure and facilitate the information flow between brain regions. © 2015 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Behavioral Determinants of Switching to Arsenic-Safe Water Wells: An Analysis of a Randomized Controlled Trial of Health Education Interventions Coupled With Water Arsenic Testing

ERIC Educational Resources Information Center

George, Christine Marie; Inauen, Jennifer; Perin, Jamie; Tighe, Jennifer; Hasan, Khaled; Zheng, Yan

2017-01-01

More than 100 million people globally are estimated to be exposed to arsenic in drinking water that exceeds the World Health Organization guideline of 10 µg/L. In an effort to develop and test a low-cost sustainable approach for water arsenic testing in Bangladesh, we conducted a randomized controlled trial which found arsenic educational…

Smartphone application for multi-phasic interventional trials in psychiatry: Technical design of a smart server.

PubMed

Zhang, Melvyn W B; Ho, Roger C M

2017-01-01

Smartphones and their accompanying applications are currently widely utilized in various healthcare interventions. Prior to the deployment of these tools for healthcare intervention, typically, proof of concept feasibility studies, as well as randomized trials are conducted to determine that these tools are efficacious prior to their actual implementation. In the field of psychiatry, most of the current interventions seek to compare smartphone based intervention against conventional care. There remains a paucity of research evaluating different forms of interventions using a single smartphone application. In the field of nutrition, there has been recent pioneering research demonstrating how a multi-phasic randomized controlled trial could be conducted using a single smartphone application. Despite the innovativeness of the previous smartphone conceptualization, there remains a paucity of technical information underlying the conceptualization that would support a multi-phasic interventional trial. It is thus the aim of the current technical note to share insights into an innovative server design that would enable the delivery of multi-phasic trials.

A Bayesian-frequentist two-stage single-arm phase II clinical trial design.

PubMed

Dong, Gaohong; Shih, Weichung Joe; Moore, Dirk; Quan, Hui; Marcella, Stephen

2012-08-30

It is well-known that both frequentist and Bayesian clinical trial designs have their own advantages and disadvantages. To have better properties inherited from these two types of designs, we developed a Bayesian-frequentist two-stage single-arm phase II clinical trial design. This design allows both early acceptance and rejection of the null hypothesis ( H(0) ). The measures (for example probability of trial early termination, expected sample size, etc.) of the design properties under both frequentist and Bayesian settings are derived. Moreover, under the Bayesian setting, the upper and lower boundaries are determined with predictive probability of trial success outcome. Given a beta prior and a sample size for stage I, based on the marginal distribution of the responses at stage I, we derived Bayesian Type I and Type II error rates. By controlling both frequentist and Bayesian error rates, the Bayesian-frequentist two-stage design has special features compared with other two-stage designs. Copyright © 2012 John Wiley & Sons, Ltd.

Birth weight and prematurity in infants with single ventricle physiology: pediatric heart network infant single ventricle trial screened population.

PubMed

Williams, Richard V; Ravishankar, Chitra; Zak, Victor; Evans, Frank; Atz, Andrew M; Border, William L; Levine, Jami; Li, Jennifer S; Mahony, Lynn; Mital, Seema; Pearson, Gail D; Prakash, Ashwin; Hsu, Daphne T

2010-01-01

Although congenital heart disease is associated with low birth weight and prematurity, there is little information about these birth outcomes in infants with single ventricle physiology. We describe the birth outcomes (i.e., gestational age and birth weight) in neonates with single ventricle physiology screened for enrollment in the Pediatric Heart Network's Infant Single Ventricle Trial, compare these outcomes with US norms, and examine the association of birth outcomes with anatomic diagnosis and race. All neonates with single ventricle physiology presenting to Infant Single Ventricle Trial centers were screened for enrollment. Demographic data and anatomic diagnoses were obtained from medical records. A total of 1245 neonates with single ventricle physiology were screened at 10 centers (63 to 266 per center). Diagnoses included hypoplastic left heart syndrome in 49%, unbalanced atrioventricular septal defect in 12%, and tricuspid atresia in 9%. Preterm birth occurred in 16% of neonates with single ventricle physiology vs. 12% in normal neonates (P < .001), low birth weight (<2.5 kg) in 18% vs. 8% in normals (P < .001), and small for gestational age (<10th percentile by definition) in 22% vs. 10% in normals (P < .001). A genetic syndrome was reported in 8%. The percentage of preterm birth, low birth weight, and small for gestational age was similar between screened neonates with and without hypoplastic left heart syndrome. In this large, contemporary cohort of neonates with single ventricle physiology, rates of preterm birth, low birth weight, and small for gestational age were higher than in the general population, but similar between screened neonates with and without hypoplastic left heart syndrome.

Analysis of phase II studies on targeted agents and subsequent phase III trials: what are the predictors for success?

PubMed

Chan, John K; Ueda, Stefanie M; Sugiyama, Valerie E; Stave, Christopher D; Shin, Jacob Y; Monk, Bradley J; Sikic, Branimir I; Osann, Kathryn; Kapp, Daniel S

2008-03-20

To identify the characteristics of phase II studies that predict for subsequent "positive" phase III trials (those that reached the proposed primary end points of study or those wherein the study drug was superior to the standard regimen investigating targeted agents in advanced tumors. We identified all phase III clinical trials of targeted therapies against advanced cancers published from 1985 to 2005. Characteristics of the preceding phase II studies were reviewed to identify predictive factors for success of the subsequent phase III trial. Data were analyzed using the chi(2) test and logistic regression models. Of 351 phase II studies, 167 (47.6%) subsequent phase III trials were positive and 184 (52.4%) negative. Phase II studies from multiple rather than single institutions were more likely to precede a successful trial (60.4% v 39.4%; P < .001). Positive phase II results were more likely to lead to a successful phase III trial (50.8% v 22.5%; P = .003). The percentage of successful trials from pharmaceutical companies was significantly higher compared with academic, cooperative groups, and research institutes (89.5% v 44.2%, 45.2%, and 46.3%, respectively; P = .002). On multivariate analysis, these factors and shorter time interval between publication of phase II results and III study publication were independent predictive factors for a positive phase III trial. In phase II studies of targeted agents, multiple- versus single-institution participation, positive phase II trial, pharmaceutical company-based trials, and shorter time period between publication of phase II to phase III trial were independent predictive factors of success in a phase III trial. Investigators should be cognizant of these factors in phase II studies before designing phase III trials.

Lupus community panel proposals for optimising clinical trials: 2018

PubMed Central

Merrill, Joan T; Manzi, Susan; Aranow, Cynthia; Askenase, Anca; Bruce, Ian; Chakravarty, Eliza; Chong, Ben; Costenbader, Karen; Dall’Era, Maria; Ginzler, Ellen; Hanrahan, Leslie; Kalunian, Ken; Merola, Joseph; Raymond, Sandra; Rovin, Brad; Saxena, Amit; Werth, Victoria P

2018-01-01

Formidable impediments stand in the way of treatment development for lupus. These include the unwieldy size of current trials, international competition for scarce patients, complex outcome measures and a poor understanding of these outcomes in the world at large. The heterogeneity of the disease itself coupled to superimposition of variegated background polypharmacy has created enough immunological noise to virtually ensure the failure of lupus treatment trials, leaving an understandable suspicion that at least some of the results in testing failed drugs over the years may not have been negative, but merely uninterpretable. The authors have consulted with many clinical trial investigators, biopharmaceutical developers and stakeholders from government and voluntary sectors. This paper examines the available evidence that supports workable trial designs and proposes approaches to improve the odds of completing interpretable treatment development programs for lupus. PMID:29657738

Sampling of the telescope image plane using single- and few-mode fibre arrays

NASA Astrophysics Data System (ADS)

Corbett, Jason C.

2009-02-01

The coupling efficiency of starlight into single and few-mode fibres fed with lenslet arrays to provide a continuous field of view is investigated. The single-mode field of view (FOV) and overall transmission is a highly complicated function of wavelength and fibre size leading to a continuous sample only in cases of poor throughput. Significant improvements are found in the few-mode regime with a continuous and efficient sample of the image plane shown to be possible with as few as 4 modes. This work is of direct relevance to the coupling of celestial light into photonic instrumentation and the removal of image scrambling and reduction of focal ratio degradation (FRD) using multi-mode fibre to single-mode fibre array converters.

Continuous tuning of two-section, single-mode terahertz quantum-cascade lasers by fiber-coupled, near-infrared illumination

NASA Astrophysics Data System (ADS)

Hempel, Martin; Röben, Benjamin; Niehle, Michael; Schrottke, Lutz; Trampert, Achim; Grahn, Holger T.

2017-05-01

The dynamical tuning due to rear facet illumination of single-mode, terahertz (THz) quantum-cascade lasers (QCLs) which employ distributed feedback gratings are compared to the tuning of single-mode QCLs based on two-section cavities. The THz QCLs under investigation emit in the range of 3 to 4.7 THz. The tuning is achieved by illuminating the rear facet of the QCL with a fiber-coupled light source emitting at 777 nm. Tuning ranges of 5.0 and 11.9 GHz under continuous-wave and pulsed operation, respectively, are demonstrated for a single-mode, two-section cavity QCL emitting at about 3.1 THz, which exhibits a side-mode suppression ratio better than -25 dB.

Degenerate quantum gases with spin-orbit coupling: a review.

PubMed

Zhai, Hui

2015-02-01

This review focuses on recent developments in synthetic spin-orbit (SO) coupling in ultracold atomic gases. Two types of SO coupling are discussed. One is Raman process induced coupling between spin and motion along one of the spatial directions and the other is Rashba SO coupling. We emphasize their common features in both single-particle and two-body physics and the consequences of both in many-body physics. For instance, single particle ground state degeneracy leads to novel features of superfluidity and a richer phase diagram; increased low-energy density-of-state enhances interaction effects; the absence of Galilean invariance and spin-momentum locking gives rise to intriguing behaviours of superfluid critical velocity and novel quantum dynamics; and the mixing of two-body singlet and triplet states yields a novel fermion pairing structure and topological superfluids. With these examples, we show that investigating SO coupling in cold atom systems can, enrich our understanding of basic phenomena such as superfluidity, provide a good platform for simulating condensed matter states such as topological superfluids and more importantly, result in novel quantum systems such as SO coupled unitary Fermi gas and high spin quantum gases. Finally we also point out major challenges and some possible future directions.

Coupled Data Assimilation in Navy ESPC

NASA Astrophysics Data System (ADS)

Barron, C. N.; Spence, P. L.; Frolov, S.; Rowley, C. D.; Bishop, C. H.; Wei, M.; Ruston, B.; Smedstad, O. M.

2017-12-01

Data assimilation under global coupled Earth System Prediction Capability (ESPC) presents significantly greater challenges than data assimilation in forecast models of a single earth system like the ocean and atmosphere. In forecasts of a single component, data assimilation has broad flexibility in adjusting boundary conditions to reduce forecast errors; coupled ESPC requires consistent simultaneous adjustment of multiple components within the earth system: air, ocean, ice, and others. Data assimilation uses error covariances to express how to consistently adjust model conditions in response to differences between forecasts and observations; in coupled ESPC, these covariances must extend from air to ice to ocean such that changes within one fluid are appropriately balanced with corresponding adjustments in the other components. We show several algorithmic solutions that allow us to resolve these challenges. Specifically, we introduce the interface solver method that augments existing stand-alone systems for ocean and atmosphere by allowing them to be influenced by relevant measurements from the coupled fluid. Plans are outlined for implementing coupled data assimilation within ESPC for the Navy's global coupled model. Preliminary results show the impact of assimilating SST-sensitive radiances in the atmospheric model and first results of hybrid DA in a 1/12 degree model of the global ocean.

Polymer taper bridge for silicon waveguide to single mode waveguide coupling

NASA Astrophysics Data System (ADS)

Kruse, Kevin; Middlebrook, Christopher T.

2016-03-01

Coupling of optical power from high-density silicon waveguides to silica optical fibers for signal routing can incur high losses and often requires complex end-face preparation/processing. Novel coupling device taper structures are proposed for low coupling loss between silicon photonic waveguides and single mode fibers are proposed and devices are fabricated and measured in terms of performance. Theoretical mode conversion models for waveguide tapers are derived for optimal device structure design and performance. Commercially viable vertical and multi-layer taper designs using polymer waveguide materials are proposed as innovative, cost-efficient, and mass-manufacturable optical coupling devices. The coupling efficiency for both designs is determined to evaluate optimal device dimensions and alignment tolerances with both silicon rib waveguides and silicon nanowire waveguides. Propagation loss as a function of waveguide roughness and metallic loss are determined and correlated to waveguide dimensions to obtain total insertion loss for the proposed taper designs. Multi-layer tapers on gold-sputtered substrates are fabricated through photolithography as proof-of-concept devices and evaluated for device loss optimization. Tapered waveguide coupling loss with Si WGs (2.74 dB) was experimentally measured with high correlation to theoretical results.

Undisclosed antiretroviral drug use in a multinational clinical trial (HIV Prevention Trials Network 052).

PubMed

Fogel, Jessica M; Wang, Lei; Parsons, Teresa L; Ou, San-San; Piwowar-Manning, Estelle; Chen, Ying; Mudhune, Victor O; Hosseinipour, Mina C; Kumwenda, Johnstone; Hakim, James G; Chariyalertsak, Suwat; Panchia, Ravindre; Sanne, Ian; Kumarasamy, Nagalingeswaran; Grinsztejn, Beatriz; Makhema, Joseph; Pilotto, Jose; Santos, Breno R; Mayer, Kenneth H; McCauley, Marybeth; Gamble, Theresa; Bumpus, Namandjé N; Hendrix, Craig W; Cohen, Myron S; Eshleman, Susan H

2013-11-15

The HIV Prevention Trials Network 052 study enrolled serodiscordant couples. Index participants infected with human immunodeficiency virus reported no prior antiretroviral (ARV) treatment at enrollment. ARV drug testing was performed retrospectively using enrollment samples from a subset of index participants. ARV drugs were detected in 45 of 96 participants (46.9%) with an undetectable viral load, 2 of 48 (4.2%) with a low viral load, and 1 of 65 (1.5%) with a high viral load (P < .0001); they were also detected in follow-up samples from participants who were not receiving study-administered treatment. ARV drug testing may be useful in addition to self-report of ARV drug use in some clinical trial settings.

Heralding efficiency and correlated-mode coupling of near-IR fiber-coupled photon pairs

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

Dixon, P. Ben; Rosenberg, Danna; Stelmakh, Veronika

We report on a systematic experimental study of heralding efficiency and generation rate of telecom-band infrared photon pairs generated by spontaneous parametric down-conversion and coupled to single mode optical fibers. We define the correlated-mode coupling efficiency--an inherent source efficiency--and explain its relation to heralding efficiency. For our experiment, we developed a reconfigurable computer controlled pump-beam and collection-mode optical apparatus which we used to measure the generation rate and correlated-mode coupling efficiency. The use of low-noise, high-efficiency superconducting-nanowire single-photon-detectors in this setup allowed us to explore focus configurations with low overall photon flux. The measured data agree well with theory andmore » we demonstrated a correlated-mode coupling efficiency of 97%±2%, which is the highest efficiency yet achieved for this type of system. These results confirm theoretical treatments and demonstrate that very high overall heralding efficiencies can, in principle, be achieved in quantum optical systems. We expect that these results and techniques will be widely incorporated into future systems that require, or benefit from, a high heralding efficiency.« less

Heralding efficiency and correlated-mode coupling of near-IR fiber-coupled photon pairs

DOE PAGES

Dixon, P. Ben; Rosenberg, Danna; Stelmakh, Veronika; ...

2014-10-06

We report on a systematic experimental study of heralding efficiency and generation rate of telecom-band infrared photon pairs generated by spontaneous parametric down-conversion and coupled to single mode optical fibers. We define the correlated-mode coupling efficiency--an inherent source efficiency--and explain its relation to heralding efficiency. For our experiment, we developed a reconfigurable computer controlled pump-beam and collection-mode optical apparatus which we used to measure the generation rate and correlated-mode coupling efficiency. The use of low-noise, high-efficiency superconducting-nanowire single-photon-detectors in this setup allowed us to explore focus configurations with low overall photon flux. The measured data agree well with theory andmore » we demonstrated a correlated-mode coupling efficiency of 97%±2%, which is the highest efficiency yet achieved for this type of system. These results confirm theoretical treatments and demonstrate that very high overall heralding efficiencies can, in principle, be achieved in quantum optical systems. We expect that these results and techniques will be widely incorporated into future systems that require, or benefit from, a high heralding efficiency.« less

Single and low order mode interrogation of a multimode sapphire fiber Bragg grating sensor with tapered fibers

NASA Astrophysics Data System (ADS)

Grobnic, Dan; Mihailov, Stephen J.; Ding, H.; Bilodeau, F.; Smelser, Christopher W.

2005-05-01

Multimode sapphire fiber Bragg gratings (SFBG) made with an IR femtosecond laser and a phase mask were probed using tapered single mode fibers of different taper diameters producing single and low order mode reflection/transmission responses. A configuration made of an input single mode tapered fiber and multimode silica fiber used for output coupling was also tested and has delivered a filtered multimode transmission spectrum. The tapered coupling improved the spectral resolution of the SFBG as compared to its multimode responses previously reported. Such improvements facilitate the utilization of the SFBG as a high temperature sensor. Wavelength shifts of the single mode response were monitored as a function of temperature up to 1500 °C and were consistent with the measurement obtained from the multimode response published previously.

Characteristics and trends of clinical trials funded by the National Institutes of Health between 2005 and 2015.

PubMed

Gresham, Gillian K; Ehrhardt, Stephan; Meinert, Jill L; Appel, Lawrence J; Meinert, Curtis L

2018-02-01

Background The National Institutes of Health is one of the largest biomedical research agencies in the world. Clinical trials are an important component of National Institutes of Health research efforts. Given the recent updates in National Institutes of Health trial reporting requirements, more information regarding the current state of National Institutes of Health-funded clinical trials is warranted. The objective of this analysis was to describe characteristics and trends of clinical trials funded by the National Institutes of Health over time and by Institutes and Centers of the National Institutes of Health. Methods Interventional studies funded by the National Institutes of Health and registered in ClinicalTrials.gov between 2005 and 2015 were included in the analysis. Trials were identified from the 27 March 2016 Clinical Trials Transformation Initiative Aggregate Analysis of ClinicalTrials.gov database. A descriptive analysis of trials by year and National Institutes of Health Institute/Center was performed. Results There were 12,987 National Institutes of Health-funded clinical trials registered between 2005 and 2015. There were 1,580, 1,116, and 930 trials registered in 2005, 2010, and 2015, respectively. The majority were early-development trials (phases 0, 1, or 2; 53%), randomized (61%), and single-center (63%). Trial demographics have remained unchanged over time. Median trial sample size was 64 (interquartile range 29-192) with 10% of trials enrolling ≥500 participants. Most trials were completed within 5 years of enrollment start (69%). Trial characteristics varied considerably across National Institutes of Health Institutes and Centers. Results were reported under the assumptions that most National Institutes of Health-funded trials are registered in ClinicalTrials.gov and that trials are being registered completely and accurately. Conclusion In conclusion, there has been a decline in the number of trials being funded over time, explained in part by a relatively constant budget, increases in trial costs, or other factors that cannot be quantified. National Institutes of Health-funded trials are relatively small and tend to be single-centered. There are substantial differences in the number and types of trials done by Institutes and Centers within the National Institutes of Health.

Structural basis for drug-induced allosteric changes to human β-cardiac myosin motor activity

PubMed Central

Winkelmann, Donald A.; Forgacs, Eva; Miller, Matthew T.; Stock, Ann M.

2015-01-01

Omecamtiv Mecarbil (OM) is a small molecule allosteric effector of cardiac myosin that is in clinical trials for treatment of systolic heart failure. A detailed kinetic analysis of cardiac myosin has shown that the drug accelerates phosphate release by shifting the equilibrium of the hydrolysis step towards products, leading to a faster transition from weak to strong actin-bound states. The structure of the human β-cardiac motor domain (cMD) with OM bound reveals a single OM-binding site nestled in a narrow cleft separating two domains of the human cMD where it interacts with the key residues that couple lever arm movement to the nucleotide state. In addition, OM induces allosteric changes in three strands of the β-sheet that provides the communication link between the actin-binding interface and the nucleotide pocket. The OM-binding interactions and allosteric changes form the structural basis for the kinetic and mechanical tuning of cardiac myosin. PMID:26246073

Theta Oscillations Rapidly Convey Odor-Specific Content in Human Piriform Cortex.

PubMed

Jiang, Heidi; Schuele, Stephan; Rosenow, Joshua; Zelano, Christina; Parvizi, Josef; Tao, James X; Wu, Shasha; Gottfried, Jay A

2017-04-05

Olfactory oscillations are pervasive throughout vertebrate and invertebrate nervous systems. Such observations have long implied that rhythmic activity patterns play a fundamental role in odor coding. Using intracranial EEG recordings from rare patients with medically resistant epilepsy, we find that theta oscillations are a distinct electrophysiological signature of olfactory processing in the human brain. Across seven patients, odor stimulation enhanced theta power in human piriform cortex, with robust effects at the level of single trials. Importantly, classification analysis revealed that piriform oscillatory activity conveys olfactory-specific information that can be decoded within 110-518 ms of a sniff, and maximally within the theta frequency band. This temporal window was also associated with increased theta-specific phase coupling between piriform cortex and hippocampus. Together these findings suggest that human piriform cortex has access to olfactory content in the time-frequency domain and can utilize these signals to rapidly differentiate odor stimuli. Copyright © 2017 Elsevier Inc. All rights reserved.

Splicing Efficiently Couples Optical Fibers

NASA Technical Reports Server (NTRS)

Lutes, G. F.

1985-01-01

Method of splicing single-mode optical fibers results in very low transmission losses through joined fiber ends. Coupling losses between joined optical-fiber ends only 0.1 dB. Method needs no special operator training.

A theoretical and experimental benchmark study of core-excited states in nitrogen

DOE PAGES

Myhre, Rolf H.; Wolf, Thomas J. A.; Cheng, Lan; ...

2018-02-14

The high resolution near edge X-ray absorption fine structure spectrum of nitrogen displays the vibrational structure of the core-excited states. This makes nitrogen well suited for assessing the accuracy of different electronic structure methods for core excitations. We report high resolution experimental measurements performed at the SOLEIL synchrotron facility. These are compared with theoretical spectra calculated using coupled cluster theory and algebraic diagrammatic construction theory. The coupled cluster singles and doubles with perturbative triples model known as CC3 is shown to accurately reproduce the experimental excitation energies as well as the spacing of the vibrational transitions. In conclusion, the computationalmore » results are also shown to be systematically improved within the coupled cluster hierarchy, with the coupled cluster singles, doubles, triples, and quadruples method faithfully reproducing the experimental vibrational structure.« less

Calibration for single multi-mode fiber digital scanning microscopy imaging system

NASA Astrophysics Data System (ADS)

Yin, Zhe; Liu, Guodong; Liu, Bingguo; Gan, Yu; Zhuang, Zhitao; Chen, Fengdong

2015-11-01

Single multimode fiber (MMF) digital scanning imaging system is a development tendency of modern endoscope. We concentrate on the calibration method of the imaging system. Calibration method comprises two processes, forming scanning focused spots and calibrating the couple factors varied with positions. Adaptive parallel coordinate algorithm (APC) is adopted to form the focused spots at the multimode fiber (MMF) output. Compare with other algorithm, APC contains many merits, i.e. rapid speed, small amount calculations and no iterations. The ratio of the optics power captured by MMF to the intensity of the focused spots is called couple factor. We setup the calibration experimental system to form the scanning focused spots and calculate the couple factors for different object positions. The experimental result the couple factor is higher in the center than the edge.

Comparison of efficiency and feedback characteristics of techniques of coupling semiconductor lasers into single-mode fiber.

PubMed

Wenke, G; Zhu, Y

1983-12-01

The coupling of CSP lasers to single-mode fibers with different coupling structures made on the fiber face is investigated. In this case easy to make coupling arrangements such as tapers and microlenses, result in a high launching efficiency (approximately 2-dB loss), in contrast to launching from gain-guided lasers with strong astigmatism and a broader far-field pattern. Index-guiding lasers exhibit, however, a higher sensitivity to optical feedback. Laser output power and wavelength are changed due to reflections from the fiber tip. Critical distances exist which lead to a highly unstable laser spectrum. A comparison of the influence of various fiber faces on laser power and wavelength stability is presented. It is concluded that a tapered fiber end with a large working distance reduces the influence on the laser's performance.

Search for Production of Single Top Quarks Via tcg and tug Flavor-Changing-Neutral-Current Couplings

NASA Astrophysics Data System (ADS)

Abazov, V. M.; Abbott, B.; Abolins, M.; Acharya, B. S.; Adams, M.; Adams, T.; Aguilo, E.; Ahn, S. H.; Ahsan, M.; Alexeev, G. D.; Alkhazov, G.; Alton, A.; Alverson, G.; Alves, G. A.; Anastasoaie, M.; Ancu, L. S.; Andeen, T.; Anderson, S.; Andrieu, B.; Anzelc, M. S.; Arnoud, Y.; Arov, M.; Askew, A.; Åsman, B.; Assis Jesus, A. C. S.; Atramentov, O.; Autermann, C.; Avila, C.; Ay, C.; Badaud, F.; Baden, A.; Bagby, L.; Baldin, B.; Bandurin, D. V.; Banerjee, P.; Banerjee, S.; Barberis, E.; Barfuss, A.-F.; Bargassa, P.; Baringer, P.; Barnes, C.; Barreto, J.; Bartlett, J. F.; Bassler, U.; Bauer, D.; Beale, S.; Bean, A.; Begalli, M.; Begel, M.; Belanger-Champagne, C.; Bellantoni, L.; Bellavance, A.; Benitez, J. A.; Beri, S. B.; Bernardi, G.; Bernhard, R.; Berntzon, L.; Bertram, I.; Besançon, M.; Beuselinck, R.; Bezzubov, V. A.; Bhat, P. C.; Bhatnagar, V.; Binder, M.; Biscarat, C.; Blackler, I.; Blazey, G.; Blekman, F.; Blessing, S.; Bloch, D.; Bloom, K.; Boehnlein, A.; Boline, D.; Bolton, T. A.; Boos, E. E.; Borissov, G.; Bos, K.; Bose, T.; Brandt, A.; Brock, R.; Brooijmans, G.; Bross, A.; Brown, D.; Buchanan, N. J.; Buchholz, D.; Buehler, M.; Buescher, V.; Bunichev, V.; Burdin, S.; Burke, S.; Burnett, T. H.; Busato, E.; Buszello, C. P.; Butler, J. M.; Calfayan, P.; Calvet, S.; Cammin, J.; Caron, S.; Carvalho, W.; Casey, B. C. K.; Cason, N. M.; Castilla-Valdez, H.; Chakrabarti, S.; Chakraborty, D.; Chan, K.; Chan, K. M.; Chandra, A.; Charles, F.; Cheu, E.; Chevallier, F.; Cho, D. K.; Choi, S.; Choudhary, B.; Christofek, L.; Christoudias, T.; Claes, D.; Clément, B.; Clément, C.; Coadou, Y.; Cooke, M.; Cooper, W. E.; Corcoran, M.; Couderc, F.; Cousinou, M.-C.; Cox, B.; Crépé-Renaudin, S.; Cutts, D.; Ćwiok, M.; da Motta, H.; Das, A.; Davies, B.; Davies, G.; de, K.; de Jong, P.; de Jong, S. J.; de La Cruz-Burelo, E.; de Oliveira Martins, C.; Degenhardt, J. D.; Déliot, F.; Demarteau, M.; Demina, R.; Denisov, D.; Denisov, S. P.; Desai, S.; Diehl, H. T.; Diesburg, M.; Doidge, M.; Dominguez, A.; Dong, H.; Dudko, L. V.; Duflot, L.; Dugad, S. R.; Duggan, D.; Duperrin, A.; Dyer, J.; Dyshkant, A.; Eads, M.; Edmunds, D.; Ellison, J.; Elvira, V. D.; Enari, Y.; Eno, S.; Ermolov, P.; Evans, H.; Evdokimov, A.; Evdokimov, V. N.; Ferapontov, A. V.; Ferbel, T.; Fiedler, F.; Filthaut, F.; Fisher, W.; Fisk, H. E.; Ford, M.; Fortner, M.; Fox, H.; Fu, S.; Fuess, S.; Gadfort, T.; Galea, C. F.; Gallas, E.; Galyaev, E.; Garcia, C.; Garcia-Bellido, A.; Gavrilov, V.; Gay, P.; Geist, W.; Gelé, D.; Gerber, C. E.; Gershtein, Y.; Gillberg, D.; Ginther, G.; Gollub, N.; Gómez, B.; Goussiou, A.; Grannis, P. D.; Greenlee, H.; Greenwood, Z. D.; Gregores, E. M.; Grenier, G.; Gris, Ph.; Grivaz, J.-F.; Grohsjean, A.; Grünendahl, S.; Grünewald, M. W.; Guo, F.; Guo, J.; Gutierrez, G.; Gutierrez, P.; Haas, A.; Hadley, N. J.; Haefner, P.; Hagopian, S.; Haley, J.; Hall, I.; Hall, R. E.; Han, L.; Hanagaki, K.; Hansson, P.; Harder, K.; Harel, A.; Harrington, R.; Hauptman, J. M.; Hauser, R.; Hays, J.; Hebbeker, T.; Hedin, D.; Hegeman, J. G.; Heinmiller, J. M.; Heinson, A. P.; Heintz, U.; Hensel, C.; Herner, K.; Hesketh, G.; Hildreth, M. D.; Hirosky, R.; Hobbs, J. D.; Hoeneisen, B.; Hoeth, H.; Hohlfeld, M.; Hong, S. J.; Hooper, R.; Houben, P.; Hu, Y.; Hubacek, Z.; Hynek, V.; Iashvili, I.; Illingworth, R.; Ito, A. S.; Jabeen, S.; Jaffré, M.; Jain, S.; Jakobs, K.; Jarvis, C.; Jenkins, A.; Jesik, R.; Johns, K.; Johnson, C.; Johnson, M.; Jonckheere, A.; Jonsson, P.; Juste, A.; Käfer, D.; Kahn, S.; Kajfasz, E.; Kalinin, A. M.; Kalk, J. M.; Kalk, J. R.; Kappler, S.; Karmanov, D.; Kasper, J.; Kasper, P.; Katsanos, I.; Kau, D.; Kaur, R.; Kehoe, R.; Kermiche, S.; Khalatyan, N.; Khanov, A.; Kharchilava, A.; Kharzheev, Y. M.; Khatidze, D.; Kim, H.; Kim, T. J.; Kirby, M. H.; Klima, B.; Kohli, J. M.; Konrath, J.-P.; Kopal, M.; Korablev, V. M.; Kotcher, J.; Kothari, B.; Koubarovsky, A.; Kozelov, A. V.; Krop, D.; Kryemadhi, A.; Kuhl, T.; Kumar, A.; Kunori, S.; Kupco, A.; Kurča, T.; Kvita, J.; Lam, D.; Lammers, S.; Landsberg, G.; Lazoflores, J.; Lebrun, P.; Lee, W. M.; Leflat, A.; Lehner, F.; Lesne, V.; Leveque, J.; Lewis, P.; Li, J.; Li, L.; Li, Q. Z.; Lietti, S. M.; Lima, J. G. R.; Lincoln, D.; Linnemann, J.; Lipaev, V. V.; Lipton, R.; Liu, Z.; Lobo, L.; Lobodenko, A.; Lokajicek, M.; Lounis, A.; Love, P.; Lubatti, H. J.; Lynker, M.; Lyon, A. L.; Maciel, A. K. A.; Madaras, R. J.; Mättig, P.; Magass, C.; Magerkurth, A.; Makovec, N.; Mal, P. K.; Malbouisson, H. B.; Malik, S.; Malyshev, V. L.; Mao, H. S.; Maravin, Y.; Martin, B.; McCarthy, R.; Melnitchouk, A.; Mendes, A.; Mendoza, L.; Mercadante, P. G.; Merkin, M.; Merritt, K. W.; Meyer, A.; Meyer, J.; Michaut, M.; Miettinen, H.; Millet, T.; Mitrevski, J.; Molina, J.; Mommsen, R. K.; Mondal, N. K.; Monk, J.; Moore, R. W.; Moulik, T.; Muanza, G. S.; Mulders, M.; Mulhearn, M.; Mundal, O.; Mundim, L.; Nagy, E.; Naimuddin, M.; Narain, M.; Naumann, N. A.; Neal, H. A.; Negret, J. P.; Neustroev, P.; Nilsen, H.; Noeding, C.; Nomerotski, A.; Novaes, S. F.; Nunnemann, T.; O'Dell, V.; O'Neil, D. C.; Obrant, G.; Ochando, C.; Oguri, V.; Oliveira, N.; Onoprienko, D.; Oshima, N.; Osta, J.; Otec, R.; Otero Y Garzón, G. J.; Owen, M.; Padley, P.; Pangilinan, M.; Parashar, N.; Park, S.-J.; Park, S. K.; Parsons, J.; Partridge, R.; Parua, N.; Patwa, A.; Pawloski, G.; Perea, P. M.; Perfilov, M.; Peters, K.; Peters, Y.; Pétroff, P.; Petteni, M.; Piegaia, R.; Piper, J.; Pleier, M.-A.; Podesta-Lerma, P. L. M.; Podstavkov, V. M.; Pogorelov, Y.; Pol, M.-E.; Pompoš, A.; Pope, B. G.; Popov, A. V.; Potter, C.; Prado da Silva, W. L.; Prosper, H. B.; Protopopescu, S.; Qian, J.; Quadt, A.; Quinn, B.; Rangel, M. S.; Rani, K. J.; Ranjan, K.; Ratoff, P. N.; Renkel, P.; Reucroft, S.; Rijssenbeek, M.; Ripp-Baudot, I.; Rizatdinova, F.; Robinson, S.; Rodrigues, R. F.; Royon, C.; Rubinov, P.; Ruchti, R.; Sajot, G.; Sánchez-Hernández, A.; Sanders, M. P.; Santoro, A.; Savage, G.; Sawyer, L.; Scanlon, T.; Schaile, D.; Schamberger, R. D.; Scheglov, Y.; Schellman, H.; Schieferdecker, P.; Schmitt, C.; Schwanenberger, C.; Schwartzman, A.; Schwienhorst, R.; Sekaric, J.; Sengupta, S.; Severini, H.; Shabalina, E.; Shamim, M.; Shary, V.; Shchukin, A. A.; Shivpuri, R. K.; Shpakov, D.; Siccardi, V.; Sidwell, R. A.; Simak, V.; Sirotenko, V.; Skubic, P.; Slattery, P.; Smirnov, D.; Smith, R. P.; Snow, G. R.; Snow, J.; Snyder, S.; Söldner-Rembold, S.; Sonnenschein, L.; Sopczak, A.; Sosebee, M.; Soustruznik, K.; Souza, M.; Spurlock, B.; Stark, J.; Steele, J.; Stolin, V.; Stone, A.; Stoyanova, D. A.; Strandberg, J.; Strandberg, S.; Strang, M. A.; Strauss, M.; Ströhmer, R.; Strom, D.; Strovink, M.; Stutte, L.; Sumowidagdo, S.; Svoisky, P.; Sznajder, A.; Talby, M.; Tamburello, P.; Taylor, W.; Telford, P.; Temple, J.; Tiller, B.; Tissandier, F.; Titov, M.; Tokmenin, V. V.; Tomoto, M.; Toole, T.; Torchiani, I.; Trefzger, T.; Trincaz-Duvoid, S.; Tsybychev, D.; Tuchming, B.; Tully, C.; Tuts, P. M.; Unalan, R.; Uvarov, L.; Uvarov, S.; Uzunyan, S.; Vachon, B.; van den Berg, P. J.; van Eijk, B.; van Kooten, R.; van Leeuwen, W. M.; Varelas, N.; Varnes, E. W.; Vartapetian, A.; Vasilyev, I. A.; Vaupel, M.; Verdier, P.; Vertogradov, L. S.; Verzocchi, M.; Villeneuve-Seguier, F.; Vint, P.; Vlimant, J.-R.; von Toerne, E.; Voutilainen, M.; Vreeswijk, M.; Wahl, H. D.; Wang, L.; Wang, M. H. L. S.; Warchol, J.; Watts, G.; Wayne, M.; Weber, G.; Weber, M.; Weerts, H.; Wenger, A.; Wermes, N.; Wetstein, M.; White, A.; Wicke, D.; Wilson, G. W.; Wimpenny, S. J.; Wobisch, M.; Wood, D. R.; Wyatt, T. R.; Xie, Y.; Yacoob, S.; Yamada, R.; Yan, M.; Yasuda, T.; Yatsunenko, Y. A.; Yip, K.; Yoo, H. D.; Youn, S. W.; Yu, C.; Yu, J.; Yurkewicz, A.; Zatserklyaniy, A.; Zeitnitz, C.; Zhang, D.; Zhao, T.; Zhou, B.; Zhu, J.; Zielinski, M.; Zieminska, D.; Zieminski, A.; Zutshi, V.; Zverev, E. G.

2007-11-01

We search for the production of single top quarks via flavor-changing-neutral-current couplings of a gluon to the top quark and a charm (c) or up (u) quark. We analyze 230pb-1 of lepton+jets data from pp¯ collisions at a center of mass energy of 1.96 TeV collected by the D0 detector at the Fermilab Tevatron Collider. We observe no significant deviation from standard model predictions, and hence set upper limits on the anomalous coupling parameters κgc/Λ and κgu/Λ, where κg define the strength of tcg and tug couplings, and Λ defines the scale of new physics. The limits at 95% C.L. are κgc/Λ<0.15TeV-1 and κgu/Λ<0.037TeV-1.

A theoretical and experimental benchmark study of core-excited states in nitrogen

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

Myhre, Rolf H.; Wolf, Thomas J. A.; Cheng, Lan

The high resolution near edge X-ray absorption fine structure spectrum of nitrogen displays the vibrational structure of the core-excited states. This makes nitrogen well suited for assessing the accuracy of different electronic structure methods for core excitations. We report high resolution experimental measurements performed at the SOLEIL synchrotron facility. These are compared with theoretical spectra calculated using coupled cluster theory and algebraic diagrammatic construction theory. The coupled cluster singles and doubles with perturbative triples model known as CC3 is shown to accurately reproduce the experimental excitation energies as well as the spacing of the vibrational transitions. In conclusion, the computationalmore » results are also shown to be systematically improved within the coupled cluster hierarchy, with the coupled cluster singles, doubles, triples, and quadruples method faithfully reproducing the experimental vibrational structure.« less

Tunable semiconductor lasers

NASA Technical Reports Server (NTRS)

Taghavi-Larigani, Shervin (Inventor); Vanzyl, Jakob J. (Inventor); Yariv, Amnon (Inventor)

2006-01-01

Tunable semiconductor lasers are disclosed requiring minimized coupling regions. Multiple laser embodiments employ ring resonators or ring resonator pairs using only a single coupling region with the gain medium are detailed. Tuning can be performed by changing the phase of the coupling coefficient between the gain medium and a ring resonator of the laser. Another embodiment provides a tunable laser including two Mach-Zehnder interferometers in series and a reflector coupled to a gain medium.

Effects of Visual Complexity and Sublexical Information in the Occipitotemporal Cortex in the Reading of Chinese Phonograms: A Single-Trial Analysis with MEG

ERIC Educational Resources Information Center

Hsu, Chun-Hsien; Lee, Chia-Ying; Marantz, Alec

2011-01-01

We employ a linear mixed-effects model to estimate the effects of visual form and the linguistic properties of Chinese characters on M100 and M170 MEG responses from single-trial data of Chinese and English speakers in a Chinese lexical decision task. Cortically constrained minimum-norm estimation is used to compute the activation of M100 and M170…

Preliminary SP-100/Stirling Heat Exchanger Designs

NASA Astrophysics Data System (ADS)

Schmitz, Paul; Tower, Leonard; Dawson, Ronald; Blue, Brain; Dunn, Pat

1994-07-01

Analytic modeling of several heat exchanger concepts to couple the SP-100 nuclear reactor primary lithium loop and the Space Stirling Power Convertor(SSPC)was performed. Four 25 kWe SSPC's are used to produce the required 100 kW of electrical power. This design work focused on the interface between a single SSPC and the primary lithium loop. Manifolding to separate and collect the four channel flow was not modeled. This work modeled two separate types of heat exchanger interfaces (conductive coupling and radiative coupling) to explore their relative advantages and disadvantages. The minimum mass design of the conductively coupled concepts was 18 kg or 0.73 kg/kWe for a single 25 kWe convertor. The minimum mass radiatively coupled concept was 41 kg or 1.64 kg/kWe. The direct conduction heat exchanger provides a lighter weight system because of its ability to operate the Stirling convertor evaporator at higher heat fluxes than those attainable by the radiatively coupled systems. Additionally the conductively coupled concepts had relatively small volumes and provide potentially simpler assembly. Their disadvantages were the tight tolerances and material joining problems associated with this refractory to superalloy interface. The advantages of the radiatively coupled designs were the minimal material interface problems.

Preliminary SP-100/Stirling heat exchanger designs

NASA Astrophysics Data System (ADS)

Schmitz, Paul; Tower, Leonard; Dawson, Ronald; Blue, Brian; Dunn, Pat

1993-12-01

Analytic modeling of several heat exchanger concepts to couple the SP-100 nuclear reactor primary lithium loop and the Space Stirling Power Convertor (SSPC) was performed. Four 25 kWe SSPC's are used to produce the required 100 kW of electrical power. This design work focused on the interface between a single SSPC and the primary lithium loop. Manifolding to separate and collect the four channel flow was not modeled. This work modeled two separate types of heat exchanger interfaces (conductive coupling and radiative coupling) to explore their relative advantages and disadvantages. The minimum mass design of the conductively coupled concepts was 18 kg or 0.73 kg/kWe for a single 25 kWe convertor. The minimum mass radiatively coupled concept was 41 kg or 1.64 kg/kWe. The direct conduction heat exchanger provides a lighter weight system because of its ability to operate the Stirling convertor evaporator at higher heat fluxes than those attainable by the radiatively coupled systems. Additionally the conductively coupled concepts had relatively small volumes and provide potentially simpler assembly. Their disadvantages were the tight tolerances and material joining problems associated with this refractory to superalloy interface. The advantages of the radiatively coupled designs were the minimal material interface problems.

Preliminary SP-100/Stirling heat exchanger designs

NASA Technical Reports Server (NTRS)

Schmitz, Paul; Tower, Leonard; Dawson, Ronald; Blue, Brian; Dunn, Pat

1993-01-01

Analytic modeling of several heat exchanger concepts to couple the SP-100 nuclear reactor primary lithium loop and the Space Stirling Power Convertor (SSPC) was performed. Four 25 kWe SSPC's are used to produce the required 100 kW of electrical power. This design work focused on the interface between a single SSPC and the primary lithium loop. Manifolding to separate and collect the four channel flow was not modeled. This work modeled two separate types of heat exchanger interfaces (conductive coupling and radiative coupling) to explore their relative advantages and disadvantages. The minimum mass design of the conductively coupled concepts was 18 kg or 0.73 kg/kWe for a single 25 kWe convertor. The minimum mass radiatively coupled concept was 41 kg or 1.64 kg/kWe. The direct conduction heat exchanger provides a lighter weight system because of its ability to operate the Stirling convertor evaporator at higher heat fluxes than those attainable by the radiatively coupled systems. Additionally the conductively coupled concepts had relatively small volumes and provide potentially simpler assembly. Their disadvantages were the tight tolerances and material joining problems associated with this refractory to superalloy interface. The advantages of the radiatively coupled designs were the minimal material interface problems.

Methodological challenges for the evaluation of clinical effectiveness in the context of accelerated regulatory approval: an overview.

PubMed

Woolacott, Nerys; Corbett, Mark; Jones-Diette, Julie; Hodgson, Robert

2017-10-01

Regulatory authorities are approving innovative therapies with limited evidence. Although this level of data is sufficient for the regulator to establish an acceptable risk-benefit balance, it is problematic for downstream health technology assessment, where assessment of cost-effectiveness requires reliable estimates of effectiveness relative to existing clinical practice. Some key issues associated with a limited evidence base include using data, from nonrandomized studies, from small single-arm trials, or from single-center trials; and using surrogate end points. We examined these methodological challenges through a pragmatic review of the available literature. Methods to adjust nonrandomized studies for confounding are imperfect. The relative treatment effect generated from single-arm trials is uncertain and may be optimistic. Single-center trial results may not be generalizable. Surrogate end points, on average, overestimate treatment effects. Current methods for analyzing such data are limited, and effectiveness claims based on these suboptimal forms of evidence are likely to be subject to significant uncertainty. Assessments of cost-effectiveness, based on the modeling of such data, are likely to be subject to considerable uncertainty. This uncertainty must not be underestimated by decision makers: methods for its quantification are required and schemes to protect payers from the cost of uncertainty should be implemented. Crown Copyright © 2017. Published by Elsevier Inc. All rights reserved.

Single-solute and bisolute sorption of phenol and trichloroethylene from aqueous solution onto modified montmorillonite and application of sorption models.

PubMed

Wu, C D; Wang, L; Hu, C X; He, M H

2013-01-01

The single-solute and bisolute sorption behaviour of phenol and trichloroethylene, two organic compounds with different structures, onto cetyltrimethylammonium bromide (CTAB)-montmorillonite was studied. The monolayer Langmuir model (MLM) and empirical Freundlich model (EFM) were applied to the single-solute sorption of phenol or trichloroethylene from water onto monolayer or multilayer CTAB-montmorillonite. The parameters contained in the MLM and EFM were determined for each solute by fitting to the single-solute isotherm data, and subsequently utilized in binary sorption. The extended Langmuir model (ELM) coupled with the single-solute MLM and the ideal adsorbed solution theory (IAST) coupled with the single-solute EFM were used to predict the binary sorption of phenol and trichloroethylene onto CTAB-montmorillonite. It was found that the EFM was better than the MLM at describing single-solute sorption from water onto CTAB-montmorillonite, and the IAST was better than the ELM at describing the binary sorption from water onto CTAB-montmorillonite.

Ultrafast Room-Temperature Single Photon Emission from Quantum Dots Coupled to Plasmonic Nanocavities.

PubMed

Hoang, Thang B; Akselrod, Gleb M; Mikkelsen, Maiken H

2016-01-13

Efficient and bright single photon sources at room temperature are critical components for quantum information systems such as quantum key distribution, quantum state teleportation, and quantum computation. However, the intrinsic radiative lifetime of quantum emitters is typically ∼10 ns, which severely limits the maximum single photon emission rate and thus entanglement rates. Here, we demonstrate the regime of ultrafast spontaneous emission (∼10 ps) from a single quantum emitter coupled to a plasmonic nanocavity at room temperature. The nanocavity integrated with a single colloidal semiconductor quantum dot produces a 540-fold decrease in the emission lifetime and a simultaneous 1900-fold increase in the total emission intensity. At the same time, the nanocavity acts as a highly efficient optical antenna directing the emission into a single lobe normal to the surface. This plasmonic platform is a versatile geometry into which a variety of other quantum emitters, such as crystal color centers, can be integrated for directional, room-temperature single photon emission rates exceeding 80 GHz.

Single-atom cavity QED and optomicromechanics

NASA Astrophysics Data System (ADS)

Wallquist, M.; Hammerer, K.; Zoller, P.; Genes, C.; Ludwig, M.; Marquardt, F.; Treutlein, P.; Ye, J.; Kimble, H. J.

2010-02-01

In a recent publication [K. Hammerer, M. Wallquist, C. Genes, M. Ludwig, F. Marquardt, P. Treutlein, P. Zoller, J. Ye, and H. J. Kimble, Phys. Rev. Lett. 103, 063005 (2009)] we have shown the possibility to achieve strong coupling of the quantized motion of a micron-sized mechanical system to the motion of a single trapped atom. In the proposed setup the coherent coupling between a SiN membrane and a single atom is mediated by the field of a high finesse cavity and can be much larger than the relevant decoherence rates. This makes the well-developed tools of cavity quantum electrodynamics with single atoms available in the realm of cavity optomechanics. In this article we elaborate on this scheme and provide detailed derivations and technical comments. Moreover, we give numerical as well as analytical results for a number of possible applications for transfer of squeezed or Fock states from atom to membrane as well as entanglement generation, taking full account of dissipation. In the limit of strong-coupling the preparation and verification of nonclassical states of a mesoscopic mechanical system is within reach.

A noniterative asymmetric triple excitation correction for the density-fitted coupled-cluster singles and doubles method: Preliminary applications

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

Bozkaya, Uğur, E-mail: ugrbzky@gmail.com

2016-04-14

An efficient implementation of the asymmetric triples correction for the coupled-cluster singles and doubles [ΛCCSD(T)] method [S. A. Kucharski and R. J. Bartlett, J. Chem. Phys. 108, 5243 (1998); T. D. Crawford and J. F. Stanton, Int. J. Quantum Chem. 70, 601 (1998)] with the density-fitting [DF-ΛCCSD(T)] approach is presented. The computational time for the DF-ΛCCSD(T) method is compared with that of ΛCCSD(T). Our results demonstrate that the DF-ΛCCSD(T) method provide substantially lower computational costs than ΛCCSD(T). Further application results show that the ΛCCSD(T) and DF-ΛCCSD(T) methods are very beneficial for the study of single bond breaking problems as wellmore » as noncovalent interactions and transition states. We conclude that ΛCCSD(T) and DF-ΛCCSD(T) are very promising for the study of challenging chemical systems, where the coupled-cluster singles and doubles with perturbative triples method fails.« less

A randomised controlled trial of intra-uterine insemination versus in vitro fertilisation in patients with idiopathic or mild male infertility.

PubMed

Elzeiny, Hossam; Garrett, Claire; Toledo, Manuela; Stern, Kate; McBain, John; Baker, Hugh William Gordon

2014-04-01

The cause of infertility is unexplained or poorly explained in 30-40% of couples undergoing standard investigations, and treatment ranges from expectant management to IUI and IVF. The aim of this study was to compare the clinical pregnancy rates and costs of intra-uterine insemination (IUI) and in vitro fertilisation (IVF) in women where the same ovarian stimulation led to the development of two or three mature follicles. A randomised controlled clinical trial compared the efficacy of IUI and IVF in a tertiary fertility centre (ISRCTN28780587). Primary outcome measures were fetal heart positive pregnancy rate and cost per live birth. The selection criteria were age: females 18-42 years and males 18-60 years, infertility for one year or more, no IVF or IUI for 12 months prior to the trial, and no coital, tubal or ovulatory disorders, oligospermia, untreated endometriosis or contraindication for multiple pregnancy. All women (n = 102) had the same dose FSH stimulation protocol. Those who developed two or three preovulatory follicles were randomised 3:1 to IUI (n = 33) or IVF (n = 10). IUI or IVF was performed 36 h after hCG administration with single or double embryo transfer on day two. Clinical pregnancy rates (40% vs 12%, P = 0.04) and live birth rate (40% vs 6%, P = 0.01) were higher for IVF than IUI. The cost per live birth was AU$8735 for IVF compared with $42,487 for IUI. This study provides evidence that IVF is more successful and cost-effective than IUI using the same doses of FSH. Further confirmatory studies are required. © 2014 The Royal Australian and New Zealand College of Obstetricians and Gynaecologists.

Regional-scale geomechanical impact assessment of underground coal gasification by coupled 3D thermo-mechanical modeling

NASA Astrophysics Data System (ADS)

Otto, Christopher; Kempka, Thomas; Kapusta, Krzysztof; Stańczyk, Krzysztof

2016-04-01

Underground coal gasification (UCG) has the potential to increase the world-wide coal reserves by utilization of coal deposits not mineable by conventional methods. The UCG process involves combusting coal in situ to produce a high-calorific synthesis gas, which can be applied for electricity generation or chemical feedstock production. Apart from its high economic potentials, UCG may induce site-specific environmental impacts such as fault reactivation, induced seismicity and ground subsidence, potentially inducing groundwater pollution. Changes overburden hydraulic conductivity resulting from thermo-mechanical effects may introduce migration pathways for UCG contaminants. Due to the financial efforts associated with UCG field trials, numerical modeling has been an important methodology to study coupled processes considering UCG performance. Almost all previous UCG studies applied 1D or 2D models for that purpose, that do not allow to predict the performance of a commercial-scale UCG operation. Considering our previous findings, demonstrating that far-field models can be run at a higher computational efficiency by using temperature-independent thermo-mechanical parameters, representative coupled simulations based on complex 3D regional-scale models were employed in the present study. For that purpose, a coupled thermo-mechanical 3D model has been developed to investigate the environmental impacts of UCG based on a regional-scale of the Polish Wieczorek mine located in the Upper Silesian Coal Basin. The model size is 10 km × 10 km × 5 km with ten dipping lithological layers, a double fault and 25 UCG reactors. Six different numerical simulation scenarios were investigated, considering the transpressive stress regime present in that part of the Upper Silesian Coal Basin. Our simulation results demonstrate that the minimum distance between the UCG reactors is about the six-fold of the coal seam thickness to avoid hydraulic communication between the single UCG reactors. Fault reactivation resulting from fault shear and normal displacements is discussed under consideration of potentially induced seismicity. Here, the coupled simulation results indicate that seismic hazard during UCG operation remains negligible with a seismic moment magnitude of MW < 3.

Couple-focused human immunodeficiency virus prevention for young Latino parents: randomized clinical trial of efficacy and sustainability.

PubMed

Koniak-Griffin, Deborah; Lesser, Janna; Takayanagi, Sumiko; Cumberland, William G

2011-04-01

To evaluate the efficacy and sustainability of a couple-focused human immunodeficiency virus (HIV) prevention intervention in reducing unprotected sex and increasing intent to use condoms and knowledge about AIDS. Randomized controlled trial. Urban community settings in Southern California. Primarily Latino couples (168 couples; 336 individuals) who were aged 14 to 25 years, English or Spanish speaking, and coparenting a child at least 3 months of age. A 12-hour theory-based, couple-focused HIV prevention program culturally tailored for young Latino parents, with emphasis on family protection, skill building, and issues related to gender and power. The 1½-hour control condition provided basic HIV-AIDS information. Primary outcome measures included self-report of condom use during the past 3 months; secondary, intent to use condoms and knowledge about AIDS. The HIV prevention intervention reduced the proportion of unprotected sex episodes (odds ratio, 0.87 per month from baseline to 6 months; 95% confidence interval [CI], 0.82-0.93) and increased intent to use condoms (slope increase, 0.20; 95% CI, 0.04-0.37) at the 6-month follow-up; however, these effects were not sustained at 12 months. Knowledge about AIDS was increased in both groups from baseline to 6 months (slope estimate, 0.57; 95% CI, 0.47-0.67) and was maintained in the intervention group only through 12 months. Female participants in both groups had higher intent to use condoms and knowledge about AIDS than male participants (P ≤ .01). The couple-focused HIV prevention intervention reduced risky sexual behaviors and improved intent to use condoms among young Latino parents at the 6-month evaluation. A maintenance program is needed to improve the sustainability of effects over time.

Carraguard acceptability among men and women in a couples study in Thailand.

PubMed

Martin, Sarah; Blanchard, Kelly; Manopaiboon, Chomnad; Chaikummao, Supaporn; Schaffer, Kate; Friedland, Barbara; Kilmarx, Peter H

2010-08-01

The aim of this study is to evaluate the use and acceptability of Carraguard among men and women enrolled as couples in a microbicide trial. Focus groups were conducted with participants in a 6-month randomized, placebo-controlled trial that enrolled sexually active, low-risk couples in Thailand. Participants were blinded as to which gel they had received at the time of the discussions. Most men and women liked the gel and found it acceptable. The majority of men and women thought that using the gel increased sexual pleasure, although participants disagreed about whether using the gel increased sexual frequency. Drawbacks of gel use included that it was too wet or messy, and nearly all respondents thought that the applicator was too hard. Most men and women questioned the utility of using the gel among married couples since gel use was tied to perception of HIV/STI risk. However, those who perceived themselves to be at risk expressed interest in using the product as an alternative to condoms. Many women were particularly interested in a product that also had contraceptive properties. Gel use also raised issues of trust and fidelity among couples and questions about men's ability to detect women's use of the product. Men and women in this study found the gel acceptable and thought that it should be made available if it is found to be safe and effective. Strategies for marketing a potential microbicide product must take the target population into consideration. For married couples, key considerations may be partner dynamics and trust issues, whereas messages focusing on sexual pleasure or disease prevention may resonate more strongly with sex workers or other populations.

Clinical Trials in Dentistry: A Cross-sectional Analysis of World Health Organization-International Clinical Trial Registry Platform.

PubMed

Sivaramakrishnan, Gowri; Sridharan, Kannan

2016-06-01

Clinical trials are the back bone for evidence-based practice (EBP) and recently EBP has been considered the best source of treatment strategies available. Clinical trial registries serve as databases of clinical trials. As regards to dentistry in specific data on the number of clinical trials and their quality is lacking. Hence, the present study was envisaged. Clinical trials registered in WHO-ICTRP (http://apps.who.int/trialsearch/AdvSearch.aspx) in dental specialties were considered. The details assessed from the collected trials include: Type of sponsors; Health condition; Recruitment status; Study design; randomization, method of randomization and allocation concealment; Single or multi-centric; Retrospective or prospective registration; and Publication status in case of completed studies. A total of 197 trials were identified. Maximum trials were from United States (n = 30) and United Kingdom (n = 38). Seventy six trials were registered in Clinical Trials.gov, 54 from International Standards of Reporting Clinical Trials, 13 each from Australia and New Zealand Trial Register and Iranian Registry of Clinical Trials, 10 from German Clinical Trial Registry, eight each from Brazilian Clinical Trial Registry and Nederland's Trial Register, seven from Japan Clinical Trial Registry, six from Clinical Trial Registry of India and two from Hong Kong Clinical Trial Registry. A total of 78.7% studies were investigator-initiated and 64% were completed while 3% were terminated. Nearly four-fifths of the registered trials (81.7%) were interventional studies of which randomized were the large majority (94.4%) with 63.2% being open label, 20.4% using single blinding technique and 16.4% were doubled blinded. The number, methodology and the characteristics of clinical trials in dentistry have been noted to be poor especially in terms of being conducted multi-centrically, employing blinding and the method for randomization and allocation concealment. More emphasis has to be laid down on the quality of trials being conducted in order to provide justice in the name of EBP. Copyright © 2016 Elsevier Inc. All rights reserved.

Hybrid optical fiber add-drop filter based on wavelength dependent light coupling between micro/nano fiber ring and side-polished fiber

NASA Astrophysics Data System (ADS)

Yu, Jianhui; Jin, Shaoshen; Wei, Qingsong; Zang, Zhigang; Lu, Huihui; He, Xiaoli; Luo, Yunhan; Tang, Jieyuan; Zhang, Jun; Chen, Zhe

2015-01-01

In this paper, we report our experimental study on directly coupling a micro/nano fiber (MNOF) ring with a side-polished fiber(SPF). As a result of the study, the behavior of an add-drop filter was observed. The demonstrated add-drop filter explored the wavelength dependence of light coupling between a MNOF ring and a SPF. The characteristics of the filter and its performance dependence on the MNOF ring diameter were investigated experimentally. The investigation resulted in an empirically obtained ring diameter that showed relatively good filter performance. Since light coupling between a (MNOF) and a conventional single mode fiber has remained a challenge in the photonic integration community, the present study may provide an alternative way to couple light between a MNOF device and a conventional single mode fiber based device or system. The hybridization approach that uses a SPF as a platform to integrate a MNOF device may enable the realization of other all-fiber optical hybrid devices.

Hybrid optical fiber add-drop filter based on wavelength dependent light coupling between micro/nano fiber ring and side-polished fiber.

PubMed

Yu, Jianhui; Jin, Shaoshen; Wei, Qingsong; Zang, Zhigang; Lu, Huihui; He, Xiaoli; Luo, Yunhan; Tang, Jieyuan; Zhang, Jun; Chen, Zhe

2015-01-12

In this paper, we report our experimental study on directly coupling a micro/nano fiber (MNOF) ring with a side-polished fiber(SPF). As a result of the study, the behavior of an add-drop filter was observed. The demonstrated add-drop filter explored the wavelength dependence of light coupling between a MNOF ring and a SPF. The characteristics of the filter and its performance dependence on the MNOF ring diameter were investigated experimentally. The investigation resulted in an empirically obtained ring diameter that showed relatively good filter performance. Since light coupling between a (MNOF) and a conventional single mode fiber has remained a challenge in the photonic integration community, the present study may provide an alternative way to couple light between a MNOF device and a conventional single mode fiber based device or system. The hybridization approach that uses a SPF as a platform to integrate a MNOF device may enable the realization of other all-fiber optical hybrid devices.

Single trial discrimination of individual finger movements on one hand: A combined MEG and EEG study☆

PubMed Central

Quandt, F.; Reichert, C.; Hinrichs, H.; Heinze, H.J.; Knight, R.T.; Rieger, J.W.

2012-01-01

It is crucial to understand what brain signals can be decoded from single trials with different recording techniques for the development of Brain-Machine Interfaces. A specific challenge for non-invasive recording methods are activations confined to small spatial areas on the cortex such as the finger representation of one hand. Here we study the information content of single trial brain activity in non-invasive MEG and EEG recordings elicited by finger movements of one hand. We investigate the feasibility of decoding which of four fingers of one hand performed a slight button press. With MEG we demonstrate reliable discrimination of single button presses performed with the thumb, the index, the middle or the little finger (average over all subjects and fingers 57%, best subject 70%, empirical guessing level: 25.1%). EEG decoding performance was less robust (average over all subjects and fingers 43%, best subject 54%, empirical guessing level 25.1%). Spatiotemporal patterns of amplitude variations in the time series provided best information for discriminating finger movements. Non-phase-locked changes of mu and beta oscillations were less predictive. Movement related high gamma oscillations were observed in average induced oscillation amplitudes in the MEG but did not provide sufficient information about the finger's identity in single trials. Importantly, pre-movement neuronal activity provided information about the preparation of the movement of a specific finger. Our study demonstrates the potential of non-invasive MEG to provide informative features for individual finger control in a Brain-Machine Interface neuroprosthesis. PMID:22155040

Low efficacy of mebendazole against hookworm in Vietnam: two randomized controlled trials.

PubMed

Flohr, Carsten; Tuyen, Luc Nguyen; Lewis, Sarah; Minh, Truong Tan; Campbell, Jim; Britton, John; Williams, Hywel; Hien, Tran Tinh; Farrar, Jeremy; Quinnell, Rupert J

2007-04-01

Vietnam is participating in a global de-worming effort that aims to treat 650 million school children regularly by 2010. The treatment used in Vietnam is single dose oral mebendazole (Phardazone) 500 mg. We tested the efficacy of single dose mebendazole 500 mg in the therapy of hookworm infection in a randomized double-blind placebo-controlled trial among 271 Vietnamese schoolchildren. The treatment efficacy of single dose mebendazole in children did not differ significantly from placebo, with a reduction in mean eggs per gram of feces relative to placebo of 31% (95% CI -9 to 56%, P = 0.1). In light of these findings we then carried out a similar randomized trial comparing triple dose mebendazole, single dose albendazole, and triple dose albendazole against placebo in 209 adults in the same area. The estimated reduction in mean post-treatment eggs per gram of feces relative to placebo was 63% (95% CI 30-81%) for triple mebendazole, 75% (47-88%) for single albendazole, and 88% (58-97%) for triple albendazole. Our results suggest that single dose oral mebendazole has low efficacy against hookworm infection in Vietnam, and that it should be replaced by albendazole. These findings are of major public health relevance given the opportunity costs of treating entire populations with ineffective therapies. We recommend that efficacy of anti-helminth therapies is pilot tested before implementation of national gut worm control programs.