Priming effects under correct change detection and change blindness.

PubMed

Caudek, Corrado; Domini, Fulvio

2013-03-01

In three experiments, we investigated the priming effects induced by an image change on a successive animate/inanimate decision task. We studied both perceptual (Experiments 1 and 2) and conceptual (Experiment 3) priming effects, under correct change detection and change blindness (CB). Under correct change detection, we found larger positive priming effects on congruent trials for probes representing animate entities than for probes representing artifactual objects. Under CB, we found performance impairment relative to a "no-change" baseline condition. This inhibition effect induced by CB was modulated by the semantic congruency between the changed item and the probe in the case of probe images, but not for probe words. We discuss our results in the context of the literature on the negative priming effect. Copyright © 2012 Elsevier Inc. All rights reserved.

Do open label blinded outcome studies of novel anticoagulants versus warfarin have equivalent validity to those carried out under double-blind conditions?

PubMed

O'Neil, William M; Welner, Sharon A; Lip, Gregory Y H

2013-03-01

Recent anticoagulants for stroke prevention in AF have been tested in active comparator controlled studies versus warfarin using two designs: double-blind, double-dummy and prospective randomised, open blinded endpoint (PROBE). The former requires elaborate procedures to maintain blinding, while PROBE does not. Outcomes of double-blind and PROBE designed studies of novel anticoagulants for AF, focusing on warfarin controls, were explored. Major, Phase III warfarin-controlled trials for stroke prevention in AF were identified. Odds ratios (ORs) of key outcomes for active comparators versus VKA and event rates for VKA arms were compared between designs, in context of baseline demographics and inclusion criteria. Identified trials studied five novel anticoagulants in three each of PROBE and double-blind design. For ORs of results across studies and outcomes, there was little pattern differentiating the two designs. Among VKA-control subjects, event rates for the primary outcome (stroke or systemic embolism) in PROBE trials at 1.74 %/year (95% confidence interval: 1.54-1.95) was not significantly different from that in double-blind trials, at 1.88 (1.73-2.03). Among other outcomes, VKA-treated subjects in both trial designs had similar event rates, apart from higher all-cause mortality in ROCKET AF, and lower myocardial infarction rates among the PROBE study patients. Although there are differences in outcome between PROBE and double blind trials, they do not appear to be design-related. The exacting requirements of double-blinding in AF trials may not be necessary.

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

Diaz, Aaron A.; Chamberlin, Clyde E.; Edwards, Matthew K.

This section of the Joint summary technical letter report (TLR) describes work conducted at the Pacific Northwest National Laboratory (PNNL) during FY 2016 (FY16) on the under-sodium viewing (USV) PNNL project 58745, work package AT-16PN230102. This section of the TLR satisfies PNNL’s M3AT-16PN2301025 milestone and is focused on summarizing the design, development, and evaluation of two different phased-array ultrasonic testing (PA-UT) probe designs—a two-dimensional (2D) matrix phased-array probe, and two one-dimensional (1D) linear array probes, referred to as serial number 4 (SN4) engineering test units (ETUs). The 2D probe is a pulse-echo (PE), 32×2, 64-element matrix phased-array ETU. The 1Dmore » probes are 32×1 element linear array ETUs. This TLR also provides the results from a performance demonstration (PD) of in-sodium target detection trials at 260°C using both probe designs. This effort continues the iterative evolution supporting the longer term goal of producing and demonstrating a pre-manufacturing prototype ultrasonic probe that possesses the fundamental performance characteristics necessary to enable the development of a high-temperature sodium-cooled fast reactor (SFR) inspection system for in-sodium detection and imaging.« less

The match/mismatch of visuo-spatial cues between acquisition and retrieval contexts influences the expression of response vs. place memory in rats.

PubMed

Cassel, Raphaelle; Kelche, Christian; Lecourtier, Lucas; Cassel, Jean-Christophe

2012-05-01

Animals can perform goal-directed tasks by using response cues or place cues. The underlying memory systems are occasionally presented as competing. Using the double-H maze test (Pol-Bodetto et al.), we trained rats for response learning and, 24 h later, tested their memory in a 60-s probe trial using a new start place. A modest shift of the start place (translation: 60-cm to the left) provided a high misleading potential, whereas a marked shift (180° rotation; shift to the opposite) provided a low misleading potential. We analyzed each rat's first arm choice (to assess response vs. place memory retrieval) and its subsequent search for the former platform location (to assess the persistence in place memory or the shift from response to place memory). After the translation, response memory-based behavior was found in more than 90% rats (24/26). After the rotation, place memory-based behavior was observed in 50% rats, the others showing response memory or failing. Rats starting to use response cues were nevertheless able to subsequently shift to place ones. A posteriori behavioral analyses showed more and longer stops in rats starting their probe trial on the basis of place (vs. response) cues. These observations qualify the idea of competing memory systems for responses and places and are compatible with that of a cooperation between both systems according to principles of match/mismatch computation (at the start of a probe trial) and of error-driven adjustment (during the ongoing probe trial). Copyright © 2012 Elsevier B.V. All rights reserved.

Negative mood and mind wandering increase long-range temporal correlations in attention fluctuations.

PubMed

Irrmischer, Mona; van der Wal, C Natalie; Mansvelder, Huibert D; Linkenkaer-Hansen, Klaus

2018-01-01

There is growing evidence that the intermittent nature of mind wandering episodes and mood have a pronounced influence on trial-to-trial variability in performance. Nevertheless, the temporal dynamics and significance of such lapses in attention remains inadequately understood. Here, we hypothesize that the dynamics of fluctuations in sustained attention between external and internal sources of information obey so-called critical-state dynamics, characterized by trial-to-trial dependencies with long-range temporal correlations. To test this, we performed behavioral investigations measuring reaction times in a visual sustained attention task and cued introspection in probe-caught reports of mind wandering. We show that trial-to-trial variability in reaction times exhibit long-range temporal correlations in agreement with the criticality hypothesis. Interestingly, we observed the fastest responses in subjects with the weakest long-range temporal correlations and show the vital effect of mind wandering and bad mood on this response variability. The implications of these results stress the importance of future research to increase focus on behavioral variability.

Negative mood and mind wandering increase long-range temporal correlations in attention fluctuations

PubMed Central

van der Wal, C. Natalie; Mansvelder, Huibert D.; Linkenkaer-Hansen, Klaus

2018-01-01

There is growing evidence that the intermittent nature of mind wandering episodes and mood have a pronounced influence on trial-to-trial variability in performance. Nevertheless, the temporal dynamics and significance of such lapses in attention remains inadequately understood. Here, we hypothesize that the dynamics of fluctuations in sustained attention between external and internal sources of information obey so-called critical-state dynamics, characterized by trial-to-trial dependencies with long-range temporal correlations. To test this, we performed behavioral investigations measuring reaction times in a visual sustained attention task and cued introspection in probe-caught reports of mind wandering. We show that trial-to-trial variability in reaction times exhibit long-range temporal correlations in agreement with the criticality hypothesis. Interestingly, we observed the fastest responses in subjects with the weakest long-range temporal correlations and show the vital effect of mind wandering and bad mood on this response variability. The implications of these results stress the importance of future research to increase focus on behavioral variability. PMID:29746529

Exploring age differences in visual working memory capacity: is there a contribution of memory for configuration?

PubMed

Cowan, Nelson; Saults, J Scott; Clark, Katherine M

2015-07-01

Recent research has shown marked developmental increases in the apparent capacity of working memory. This recent research is based largely on performance on tasks in which a visual array is to be retained briefly for comparison with a subsequent probe display. Here we examined a possible theoretical alternative (or supplement) to a developmental increase in working memory in which children could improve in the ability to combine items in an array to form a coherent configuration. Elementary school children and adults received, on each trial, an array of colored spots to be remembered. On some trials, we provided structure in the probe display to facilitate the formation of a mental representation in which a coherent configuration is encoded. This stimulus structure in the probe display helped younger children, and thus reduced the developmental trend, but only on trials in which the participants were held responsible for the locations of items in the array. We conclude that, in addition to the development of the ability to form precise spatial configurations from items, the evidence is consistent with the existence of an actual developmental increase in working memory capacity for objects in an array. Copyright © 2015 Elsevier Inc. All rights reserved.

Attentional bias to emotional stimuli is altered during moderate- but not high-intensity exercise.

PubMed

Tian, Qu; Smith, J Carson

2011-12-01

Little is known regarding how attention to emotional stimuli is affected during simultaneously performed exercise. Attentional biases to emotional face stimuli were assessed in 34 college students (17 women) using the dot-probe task during counterbalanced conditions of moderate- (heart rate at 45% peak oxygen consumption) and high-intensity exercise (heart rate at 80% peak oxygen consumption) compared with seated rest. The dot-probe task consisted of 1 emotional face (pleasant or unpleasant) paired with a neutral face for 1,000 ms; 256 trials (128 trials for each valence) were presented during each condition. Each condition lasted approximately 10 min. Participants were instructed to perform each trial of the dot-probe task as quickly and accurately as possible during the exercise and rest conditions. During moderate-intensity exercise, participants exhibited significantly greater attentional bias scores to pleasant compared with unpleasant faces (p < .01), whereas attentional bias scores to emotional faces did not differ at rest or during high-intensity exercise (p > .05). In addition, the attentional bias to unpleasant faces was significantly reduced during moderate-intensity exercise compared with that during rest (p < .05). These results provide behavioral evidence that during exercise at a moderate intensity, there is a shift in attention allocation toward pleasant emotional stimuli and away from unpleasant emotional stimuli. Future work is needed to determine whether acute exercise may be an effective treatment approach to reduce negative bias or enhance positive bias in individuals diagnosed with mood or anxiety disorders, or whether attentional bias during exercise predicts adherence to exercise. (c) 2011 APA, all rights reserved.

Effects of Error Correction during Assessment Probes on the Acquisition of Sight Words for Students with Moderate Intellectual Disabilities

ERIC Educational Resources Information Center

Waugh, Rebecca E.

2010-01-01

Simultaneous prompting is an errorless learning strategy designed to reduce the number of errors students make; however, research has shown a disparity in the number of errors students make during instructional versus probe trials. This study directly examined the effects of error correction versus no error correction during probe trials on the…

Effects of Error Correction during Assessment Probes on the Acquisition of Sight Words for Students with Moderate Intellectual Disabilities

ERIC Educational Resources Information Center

Waugh, Rebecca E.; Alberto, Paul A.; Fredrick, Laura D.

2011-01-01

Simultaneous prompting is an errorless learning strategy designed to reduce the number of errors students make; however, research has shown a disparity in the number of errors students make during instructional versus probe trials. This study directly examined the effects of error correction versus no error correction during probe trials on the…

Comparison of Everyday and Every-Fourth-Day Probe Sessions with the Simultaneous Prompting Procedure

ERIC Educational Resources Information Center

Reichow, Brian; Wolery, Mark

2009-01-01

Simultaneous prompting is a response-prompting procedure requiring two daily sessions: an instructional session in which a controlling prompt is provided on all trials, and a probe session in which no prompt is provided on any trials. In this study, two schedules of conducting the probe sessions (daily vs. every fourth day) were compared using the…

Memory for Items and Relationships among Items Embedded in Realistic Scenes: Disproportionate Relational Memory Impairments in Amnesia

PubMed Central

Hannula, Deborah E.; Tranel, Daniel; Allen, John S.; Kirchhoff, Brenda A.; Nickel, Allison E.; Cohen, Neal J.

2014-01-01

Objective The objective of this study was to examine the dependence of item memory and relational memory on medial temporal lobe (MTL) structures. Patients with amnesia, who either had extensive MTL damage or damage that was relatively restricted to the hippocampus, were tested, as was a matched comparison group. Disproportionate relational memory impairments were predicted for both patient groups, and those with extensive MTL damage were also expected to have impaired item memory. Method Participants studied scenes, and were tested with interleaved two-alternative forced-choice probe trials. Probe trials were either presented immediately after the corresponding study trial (lag 1), five trials later (lag 5), or nine trials later (lag 9) and consisted of the studied scene along with a manipulated version of that scene in which one item was replaced with a different exemplar (item memory test) or was moved to a new location (relational memory test). Participants were to identify the exact match of the studied scene. Results As predicted, patients were disproportionately impaired on the test of relational memory. Item memory performance was marginally poorer among patients with extensive MTL damage, but both groups were impaired relative to matched comparison participants. Impaired performance was evident at all lags, including the shortest possible lag (lag 1). Conclusions The results are consistent with the proposed role of the hippocampus in relational memory binding and representation, even at short delays, and suggest that the hippocampus may also contribute to successful item memory when items are embedded in complex scenes. PMID:25068665

Laser speckle imaging to improve clinical outcomes for patients with trigeminal neuralgia undergoing radiofrequency thermocoagulation.

PubMed

Ringkamp, Matthias; Wooten, Matthew; Carson, Benjamin S; Lim, Michael; Hartke, Timothy; Guarnieri, Michael

2016-02-01

Percutaneous treatments for trigeminal neuralgia are safe, simple, and effective for achieving good pain control. Procedural risks could be minimized by using noninvasive imaging techniques to improve the placement of the radiofrequency thermocoagulation probe into the trigeminal ganglion. Positioning of a probe is crucial to maximize pain relief and to minimize unwanted side effects, such as denervation in unaffected areas. This investigation examined the use of laser speckle imaging during probe placement in an animal model. This preclinical safety study used nonhuman primates, Macaca nemestrina (pigtail monkeys), to examine whether real-time imaging of blood flow in the face during the positioning of a coagulation probe could monitor the location and guide the positioning of the probe within the trigeminal ganglion. Data from 6 experiments in 3 pigtail monkeys support the hypothesis that laser imaging is safe and improves the accuracy of probe placement. Noninvasive laser speckle imaging can be performed safely in nonhuman primates. Because improved probe placement may reduce morbidity associated with percutaneous rhizotomies, efficacy trials of laser speckle imaging should be conducted in humans.

Tracked ultrasound calibration studies with a phantom made of LEGO bricks

NASA Astrophysics Data System (ADS)

Soehl, Marie; Walsh, Ryan; Rankin, Adam; Lasso, Andras; Fichtinger, Gabor

2014-03-01

In this study, spatial calibration of tracked ultrasound was compared by using a calibration phantom made of LEGO® bricks and two 3-D printed N-wire phantoms. METHODS: The accuracy and variance of calibrations were compared under a variety of operating conditions. Twenty trials were performed using an electromagnetic tracking device with a linear probe and three trials were performed using varied probes, varied tracking devices and the three aforementioned phantoms. The accuracy and variance of spatial calibrations found through the standard deviation and error of the 3-D image reprojection were used to compare the calibrations produced from the phantoms. RESULTS: This study found no significant difference between the measured variables of the calibrations. The average standard deviation of multiple 3-D image reprojections with the highest performing printed phantom and those from the phantom made of LEGO® bricks differed by 0.05 mm and the error of the reprojections differed by 0.13 mm. CONCLUSION: Given that the phantom made of LEGO® bricks is significantly less expensive, more readily available, and more easily modified than precision-machined N-wire phantoms, it prompts to be a viable calibration tool especially for quick laboratory research and proof of concept implementations of tracked ultrasound navigation.

Context-specific control and the Stroop negative priming effect.

PubMed

Milliken, Bruce; Thomson, David R; Bleile, Karmen; MacLellan, Ellen; Giammarco, Maria

2012-01-01

The present study highlights the utility of context-specific learning for different probe types in accounting for the commonly observed dependence of negative priming on probe selection. Using a Stroop priming procedure, Experiments 1a and 1b offered a demonstration that Stroop priming effects can differ qualitatively for selection and no-selection probes when probe selection is manipulated between subjects, but not when it is manipulated randomly from trial to trial within subject (see also Moore, 1994). In Experiments 2 and 3, selection and no-selection probes served as two contexts that varied randomly from trial to trial, but for which proportion repeated was manipulated separately. A context-specific proportion repeated effect was observed in Experiment 2, characterized by modest quantitative shifts in the repetition effects as a function of the context-specific proportion repeated manipulation. However, with a longer intertrial interval in Experiment 3, a context-specific proportion repeated manipulation that focused on the no-selection probes changed the repetition effect qualitatively, from negative priming when the proportion repeated was .25 to positive priming when the proportion repeated was .75. The results are discussed with reference to the role of rapid, context-specific learning processes in the integration of prior experiences with current perception and action.

Doppler Endoscopic Probe Monitoring of Blood Flow Improves Risk Stratification and Outcomes of Patients With Severe Nonvariceal Upper Gastrointestinal Hemorrhage.

PubMed

Jensen, Dennis M; Kovacs, Thomas O G; Ohning, Gordon V; Ghassemi, Kevin; Machicado, Gustavo A; Dulai, Gareth S; Sedarat, Alireza; Jutabha, Rome; Gornbein, Jeffrey

2017-05-01

For 4 decades, stigmata of recent hemorrhage in patients with nonvariceal lesions have been used for risk stratification and endoscopic hemostasis. The arterial blood flow that underlies the stigmata rarely is monitored, but can be used to determine risk for rebleeding. We performed a randomized controlled trial to determine whether Doppler endoscopic probe monitoring of blood flow improves risk stratification and outcomes in patients with severe nonvariceal upper gastrointestinal hemorrhage. In a single-blind study performed at 2 referral centers we assigned 148 patients with severe nonvariceal upper gastrointestinal bleeding (125 with ulcers, 19 with Dieulafoy's lesions, and 4 with Mallory Weiss tears) to groups that underwent standard, visually guided endoscopic hemostasis (control, n = 76), or endoscopic hemostasis assisted by Doppler monitoring of blood flow under the stigmata (n = 72). The primary outcome was the rate of rebleeding after 30 days; secondary outcomes were complications, death, and need for transfusions, surgery, or angiography. There was a significant difference in the rates of lesion rebleeding within 30 days of endoscopic hemostasis in the control group (26.3%) vs the Doppler group (11.1%) (P = .0214). The odds ratio for rebleeding with Doppler monitoring was 0.35 (95% confidence interval, 0.143-0.8565) and the number needed to treat was 7. In a randomized controlled trial of patients with severe upper gastrointestinal hemorrhage from ulcers or other lesions, Doppler probe guided endoscopic hemostasis significantly reduced 30-day rates of rebleeding compared with standard, visually guided hemostasis. Guidelines for nonvariceal gastrointestinal bleeding should incorporate these results. ClinicalTrials.gov no: NCT00732212 (CLIN-013-07F). Copyright © 2017 AGA Institute. Published by Elsevier Inc. All rights reserved.

FY15 Status of Immersion Phased Array Ultrasonic Probe Development and Performance Demonstration Results for Under Sodium Viewing

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

Diaz, Aaron A.; Larche, Michael R.; Mathews, Royce

2015-09-01

This Technical Letter Report (TLR) describes work conducted at the Pacific Northwest National Laboratory (PNNL) during FY 2015 on the under-sodium viewing (USV) PNNL project 58745, Work Package AT-15PN230102. This TLR satisfies PNNL’s M3AT-15PN2301027 milestone, and is focused on summarizing the design, development, and evaluation of a two-dimensional matrix phased-array probe referred to as serial number 3 (SN3). In addition, this TLR also provides the results from a performance demonstration of in-sodium target detection trials at 260°C using a one-dimensional 22-element linear array developed in FY14 and referred to as serial number 2 (SN2).

System Design under Uncertainty: Evolutionary Optimization of the Gravity Probe-B Spacecraft

NASA Technical Reports Server (NTRS)

Pullen, Samuel P.; Parkinson, Bradford W.

1994-01-01

This paper discusses the application of evolutionary random-search algorithms (Simulated Annealing and Genetic Algorithms) to the problem of spacecraft design under performance uncertainty. Traditionally, spacecraft performance uncertainty has been measured by reliability. Published algorithms for reliability optimization are seldom used in practice because they oversimplify reality. The algorithm developed here uses random-search optimization to allow us to model the problem more realistically. Monte Carlo simulations are used to evaluate the objective function for each trial design solution. These methods have been applied to the Gravity Probe-B (GP-B) spacecraft being developed at Stanford University for launch in 1999, Results of the algorithm developed here for GP-13 are shown, and their implications for design optimization by evolutionary algorithms are discussed.

Ad-hoc and context-dependent adjustments of selective attention in conflict control: an ERP study with visual probes.

PubMed

Nigbur, R; Schneider, J; Sommer, W; Dimigen, O; Stürmer, B

2015-02-15

Cognitive conflict control in flanker tasks has often been described using the zoom-lens metaphor of selective attention. However, whether and how selective attention - in terms of suppression and enhancement - operates in this context has remained unclear. To examine the dynamic interplay of selective attention and cognitive control we used electrophysiological measures and presented task-irrelevant visual probe stimuli at foveal, parafoveal, and peripheral display positions. Target-flanker congruency varied either randomly from trial to trial (mixed-block) or block-wise (fixed-block) in order to induce reactive versus proactive control modes, respectively. Three EEG measures were used to capture ad-hoc adjustments within trials as well as effects of context-based predictions: the N1 component of the visual evoked potential (VEP) to probes, the VEP to targets, and the conflict-related midfrontal N2 component. Results from probe-VEPs indicate that enhanced processing of the foveal target rather than suppression of the peripheral flankers supports interference control. In incongruent mixed-block trials VEPs were larger to probes near the targets. In the fixed-blocks probe-VEPs were not modulated, but contrary to the mixed-block the preceding target-related VEP was affected by congruency. Results of the control-related N2 reveal largest amplitudes in the unpredictable context, which did not differentiate for stimulus and response incongruency. In contrast, in the predictable context, N2 amplitudes were reduced overall and differentiated between stimulus and response incongruency. Taken together these results imply that predictability alters interference control by a reconfiguration of stimulus processing. During unpredictable sequences participants adjust their attentional focus dynamically on a trial-by-trial basis as reflected in congruency-dependent probe-VEP-modulation. This reactive control mode also elicits larger N2 amplitudes. In contrast, when task demands are predictable, participants focus selective attention earlier as reflected in the target-related VEPs. This proactive control mode leads to smaller N2 amplitudes and absent probe effects. Copyright © 2014 Elsevier Inc. All rights reserved.

The Attentional White Bear Phenomenon: The Mandatory Allocation of Attention to Expected Distractor Locations

ERIC Educational Resources Information Center

Tsal, Yehoshua; Makovski, Tal

2006-01-01

The authors devised a prestimulus-probe method to assess the allocation of attention as a function of participants' top-down expectancies concerning distractor and target locations. Participants performed the flanker task, and distractor locations remained fixed. On some trials, instead of the flanker display, either 2 simultaneous dots or a…

Temporal Dynamics of Motivation-Cognitive Control Interactions Revealed by High-Resolution Pupillometry

PubMed Central

Chiew, Kimberly S.; Braver, Todd S.

2013-01-01

Motivational manipulations, such as the presence of performance-contingent reward incentives, can have substantial influences on cognitive control. Previous evidence suggests that reward incentives may enhance cognitive performance specifically through increased preparatory, or proactive, control processes. The present study examined reward influences on cognitive control dynamics in the AX-Continuous Performance Task (AX-CPT), using high-resolution pupillometry. In the AX-CPT, contextual cues must be actively maintained over a delay in order to appropriately respond to ambiguous target probes. A key feature of the task is that it permits dissociable characterization of preparatory, proactive control processes (i.e., utilization of context) and reactive control processes (i.e., target-evoked interference resolution). Task performance profiles suggested that reward incentives enhanced proactive control (context utilization). Critically, pupil dilation was also increased on reward incentive trials during context maintenance periods, suggesting trial-specific shifts in proactive control, particularly when context cues indicated the need to overcome the dominant target response bias. Reward incentives had both transient (i.e., trial-by-trial) and sustained (i.e., block-based) effects on pupil dilation, which may reflect distinct underlying processes. The transient pupillary effects were present even when comparing against trials matched in task performance, suggesting a unique motivational influence of reward incentives. These results suggest that pupillometry may be a useful technique for investigating reward motivational signals and their dynamic influence on cognitive control. PMID:23372557

Sensorimotor Learning during a Marksmanship Task in Immersive Virtual Reality

PubMed Central

Rao, Hrishikesh M.; Khanna, Rajan; Zielinski, David J.; Lu, Yvonne; Clements, Jillian M.; Potter, Nicholas D.; Sommer, Marc A.; Kopper, Regis; Appelbaum, Lawrence G.

2018-01-01

Sensorimotor learning refers to improvements that occur through practice in the performance of sensory-guided motor behaviors. Leveraging novel technical capabilities of an immersive virtual environment, we probed the component kinematic processes that mediate sensorimotor learning. Twenty naïve subjects performed a simulated marksmanship task modeled after Olympic Trap Shooting standards. We measured movement kinematics and shooting performance as participants practiced 350 trials while receiving trial-by-trial feedback about shooting success. Spatiotemporal analysis of motion tracking elucidated the ballistic and refinement phases of hand movements. We found systematic changes in movement kinematics that accompanied improvements in shot accuracy during training, though reaction and response times did not change over blocks. In particular, we observed longer, slower, and more precise ballistic movements that replaced effort spent on corrections and refinement. Collectively, these results leverage developments in immersive virtual reality technology to quantify and compare the kinematics of movement during early learning of full-body sensorimotor orienting. PMID:29467693

Contingency Training Alters Neurobiological Components of Emotional Resilience in Male and Female Rats.

PubMed

Kent, M; Scott, S; Lambert, S; Kirk, E; Terhune-Cotter, B; Thompson, B; Neal, S; Dozier, B; Bardi, M; Lambert, K

2018-06-19

Prior research with a rat model of behavioral therapy [i.e., effort-based reward (EBR) contingency training] suggests that strengthened associations between physical effort and desired outcomes enhance neurobiological indices of resilience. In the current study, male and female Long-Evans rats were exposed to either six weeks of EBR training or noncontingent training prior to 10 days of exposure to chronic unpredictable stress (CUS). Subsequently, all animals were exposed to a problem-solving task and then trained in a spatial learning/foraging task, the Dry Land Maze (DLM). Following habituation training and test trials, rats were assessed in a probe trial that generated a prediction error (cognitive uncertainty). Results indicated that, during CUS exposure, contingency-training enhanced dehydroepiandrosterone/corticosterone ratios (consistent with healthier stress responses), especially in male rats. Additionally, contingency training increased exploratory behaviors in the probe trial as well as differentially influenced on-task problem-solving performance in males and females. Following the probe trial, brains were exposed to histological analyses to determine the effects of sex and contingency training on various neurobiological markers. Contingency training decreased BDNF-immunoreactivity (ir) in the hippocampus CA1 and lateral habenula, implicating differential neuroplasticity responses in the training groups. Further, coordinated fos-ir activation in areas associated with emotional resilience (i.e., motivation-regulation) was observed in contingent-trained animals. In sum, the current findings confirm that behavioral training is associated with neurobiological markers of emotional resilience; however, further assessments are necessary to more accurately determine the therapeutic potential for the EBR contingency training model. Copyright © 2018 IBRO. Published by Elsevier Ltd. All rights reserved.

An oral health optimized diet can reduce gingival and periodontal inflammation in humans - a randomized controlled pilot study.

PubMed

Woelber, J P; Bremer, K; Vach, K; König, D; Hellwig, E; Ratka-Krüger, P; Al-Ahmad, A; Tennert, C

2016-07-26

The aim of this pilot study was to investigate the effects of four weeks of an oral health optimized diet on periodontal clinical parameters in a randomized controlled trial. The experimental group (n = 10) had to change to a diet low in carbohydrates, rich in Omega-3 fatty acids, and rich in vitamins C and D, antioxidants and fiber for four weeks. Participants of the control group (n = 5) did not change their dietary behavior. Plaque index, gingival bleeding, probing depths, and bleeding upon probing were assessed by a dentist with a pressure-sensitive periodontal probe. Measurements were performed after one and two weeks without a dietary change (baseline), followed by a two week transitional period, and finally performed weekly for four weeks. Despite constant plaque values in both groups, all inflammatory parameters decreased in the experimental group to approximately half that of the baseline values (GI: 1.10 ± 0.51 to 0.54 ± 0.30; BOP: 53.57 to 24.17 %; PISA: 638 mm(2) to 284 mm(2)). This reduction was significantly different compared to that of the control group. A diet low in carbohydrates, rich in Omega-3 fatty acids, rich in vitamins C and D, and rich in fibers can significantly reduce gingival and periodontal inflammation. German Clinical Trials Register; https://www.germanctr.de (DRKS00006301). Registered on 2015-02-21.

Place Learning in the Morris Water Task: Making the Memory Stick

ERIC Educational Resources Information Center

Bolding, Kevin; Rudy, Jerry W.

2006-01-01

Although the Morris water task has been used in hundreds of studies of place learning, there have been no systematic studies of retention of the place memory. We report that retention, as measured by selective search behavior on a probe trial, is excellent when the retention interval is short (5-10 min). However, performance rapidly deteriorates,…

Anticipatory versus reactive spatial attentional bias to threat.

PubMed

Gladwin, Thomas E; Möbius, Martin; McLoughlin, Shane; Tyndall, Ian

2018-05-10

Dot-probe or visual probe tasks (VPTs) are used extensively to measure attentional biases. A novel variant termed the cued VPT (cVPT) was developed to focus on the anticipatory component of attentional bias. This study aimed to establish an anticipatory attentional bias to threat using the cVPT and compare its split-half reliability with a typical dot-probe task. A total of 120 students performed the cVPT task and dot-probe tasks. Essentially, the cVPT uses cues that predict the location of pictorial threatening stimuli, but on trials on which probe stimuli are presented the pictures do not appear. Hence, actual presentation of emotional stimuli did not affect responses. The reliability of the cVPT was higher at most cue-stimulus intervals and was .56 overall. A clear anticipatory attentional bias was found. In conclusion, the cVPT may be of methodological and theoretical interest. Using visually neutral predictive cues may remove sources of noise that negatively impact reliability. Predictive cues are able to bias response selection, suggesting a role of predicted outcomes in automatic processes. © 2018 The British Psychological Society.

Visualization Improves Supraclavicular Access to the Subclavian Vein in a Mixed Reality Simulator.

PubMed

Sappenfield, Joshua Warren; Smith, William Brit; Cooper, Lou Ann; Lizdas, David; Gonsalves, Drew B; Gravenstein, Nikolaus; Lampotang, Samsun; Robinson, Albert R

2018-07-01

We investigated whether visual augmentation (3D, real-time, color visualization) of a procedural simulator improved performance during training in the supraclavicular approach to the subclavian vein, not as widely known or used as its infraclavicular counterpart. To train anesthesiology residents to access a central vein, a mixed reality simulator with emulated ultrasound imaging was created using an anatomically authentic, 3D-printed, physical mannequin based on a computed tomographic scan of an actual human. The simulator has a corresponding 3D virtual model of the neck and upper chest anatomy. Hand-held instruments such as a needle, an ultrasound probe, and a virtual camera controller are directly manipulated by the trainee and tracked and recorded with submillimeter resolution via miniature, 6 degrees of freedom magnetic sensors. After Institutional Review Board approval, 69 anesthesiology residents and faculty were enrolled and received scripted instructions on how to perform subclavian venous access using the supraclavicular approach based on anatomic landmarks. The volunteers were randomized into 2 cohorts. The first used real-time 3D visualization concurrently with trial 1, but not during trial 2. The second did not use real-time 3D visualization concurrently with trial 1 or 2. However, after trial 2, they observed a 3D visualization playback of trial 2 before performing trial 3 without visualization. An automated scoring system based on time, success, and errors/complications generated objective performance scores. Nonparametric statistical methods were used to compare the scores between subsequent trials, differences between groups (real-time visualization versus no visualization versus delayed visualization), and improvement in scores between trials within groups. Although the real-time visualization group demonstrated significantly better performance than the delayed visualization group on trial 1 (P = .01), there was no difference in gain scores, between performance on the first trial and performance on the final trial, that were dependent on group (P = .13). In the delayed visualization group, the difference in performance between trial 1 and trial 2 was not significant (P = .09); reviewing performance on trial 2 before trial 3 resulted in improved performance when compared to trial 1 (P < .0001). There was no significant difference in median scores (P = .13) between the real-time visualization and delayed visualization groups for the last trial after both groups had received visualization. Participants reported a significant improvement in confidence in performing supraclavicular access to the subclavian vein. Standard deviations of scores, a measure of performance variability, decreased in the delayed visualization group after viewing the visualization. Real-time visual augmentation (3D visualization) in the mixed reality simulator improved performance during supraclavicular access to the subclavian vein. No difference was seen in the final trial of the group that received real-time visualization compared to the group that had delayed visualization playback of their prior attempt. Training with the mixed reality simulator improved participant confidence in performing an unfamiliar technique.

Electrical high frequency stimulation in the dorsal striatum: Effects on response learning and on GABA levels in rats.

PubMed

Schumacher, Anett; de Vasconcelos, Anne Pereira; Lecourtier, Lucas; Moser, Andreas; Cassel, Jean-Christophe

2011-09-23

Electrical high frequency stimulation (HFS) has been used to treat various neurological and psychiatric diseases. The striatal area contributes to response learning and procedural memory. Therefore, we investigated the effect of striatal HFS application on procedural/declarative-like memory in rats. All rats were trained in a flooded Double-H maze for three days (4 trials/day) to swim to an escape platform hidden at a constant location. The starting place was the same for all trials. After each training session, HFS of the left dorsal striatum was performed over 4h in alternating 20 min periods (during rest time, 10a.m. to 3p.m.). Nineteen hours after the last HFS and right after a probe trial assessing the rats' strategy (procedural vs. declarative-like memory-based choice), animals were sacrificed and the dorsal striatum was quickly removed. Neurotransmitter levels were measured by HPLC. Stimulated rats did not differ from sham-operated and control rats in acquisition performance, but exhibited altered behavior during the probe trial (procedural memory responses being less frequent than in controls). In stimulated rats, GABA levels were significantly increased in the dorsal striatum on both sides. We suggest that HFS of the dorsal striatum does not alter learning behavior in rats but influences the strategy by which the rats solve the task. Given that the HFS-induced increase of GABA levels was found 19 h after stimulation, it can be assumed that HFS has consequences lasting for several hours and which are functionally significant at a behavioral level, at least under our stimulation (frequency, timing, location, side and strength of stimulation) and testing conditions. Copyright © 2011 Elsevier B.V. All rights reserved.

Behavioral Consequences of Neurotransmitter Regulation

DTIC Science & Technology

1988-09-01

C57BL mice and only, when administered before acquisition began. Likewise, chronic treatment with oxotremorine had a similar effect indicating that a...muscarinic agonist, oxotremorine (OXO). OXO also produces down- regulation of muscarinic receptors but via a direct mechanism, i.e., binding at the...hrs after their removal from oxotremorine t atment, oxotremorine -treated animals performed poorer than the saline-treateu controls in the probe trial

Visual landmarks facilitate rodent spatial navigation in virtual reality environments

PubMed Central

Youngstrom, Isaac A.; Strowbridge, Ben W.

2012-01-01

Because many different sensory modalities contribute to spatial learning in rodents, it has been difficult to determine whether spatial navigation can be guided solely by visual cues. Rodents moving within physical environments with visual cues engage a variety of nonvisual sensory systems that cannot be easily inhibited without lesioning brain areas. Virtual reality offers a unique approach to ask whether visual landmark cues alone are sufficient to improve performance in a spatial task. We found that mice could learn to navigate between two water reward locations along a virtual bidirectional linear track using a spherical treadmill. Mice exposed to a virtual environment with vivid visual cues rendered on a single monitor increased their performance over a 3-d training regimen. Training significantly increased the percentage of time avatars controlled by the mice spent near reward locations in probe trials without water rewards. Neither improvement during training or spatial learning for reward locations occurred with mice operating a virtual environment without vivid landmarks or with mice deprived of all visual feedback. Mice operating the vivid environment developed stereotyped avatar turning behaviors when alternating between reward zones that were positively correlated with their performance on the probe trial. These results suggest that mice are able to learn to navigate to specific locations using only visual cues presented within a virtual environment rendered on a single computer monitor. PMID:22345484

PET Probe-Guided Surgery in Patients with Breast Cancer: Proposal for a Methodological Approach.

PubMed

Orsaria, Paolo; Chiaravalloti, Agostino; Fiorentini, Alessandro; Pistolese, Chiara; Vanni, Gianluca; Granai, Alessandra Vittoria; Varvaras, Dimitrios; Danieli, Roberta; Schillaci, Orazio; Petrella, Giuseppe; Buonomo, Oreste Claudio

2017-01-02

Although it is valuable for detecting distant metastases, identifying recurrence, and evaluating responses to chemotherapy, the role of 18 F-fluorodeoxyglucose positron-emission tomography/computed tomography ( 18 F-FDG PET/CT) in assessing locoregional nodal status for initial staging of breast cancer has not yet been well-defined in clinical practice. In the current report, we describe a new PET probe-based clinical approach, with evaluation of the technical performance of a handheld high-energy gamma probe for intraoperative localization of breast carcinomas, and evaluation of lymph node metastases during radio-guided oncological surgery. Three patients underwent a PET/CT scan immediately prior to surgery following the standard clinical protocol. Intraoperatively, tumors were localized and resected with the assistance of a hand-held gamma probe. PET-guided assessment of the presence or absence of regional nodal spread of malignancy was compared with the reference standard of histopathological examination. In all three cases, perioperative 18 F-FDG PET/CT imaging and intraoperative gamma probe detection verified complete resection of the hypermetabolic lesions and demonstrated no additional suspicious occult disease. This innovative approach demonstrates great promise for providing real-time access to metabolic and morphological tumor information that may lead to an optimal disease-tailored approach. In carefully selected indications, a PET probe can be a useful adjunct in surgical practice, but further trials with a larger number of patients need to be performed to verify these findings. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

Hearing sensitivity during target presence and absence while a whale echolocates.

PubMed

Supin, Alexander Ya; Nachtigall, Paul E; Breese, Marlee

2008-01-01

Hearing sensitivity was measured in a false killer whale during echolocation. Sensitivity was measured using probe stimuli as sinusoidally amplitude modulated signals with a 22.5-kHz carrier frequency and recording auditory evoked potentials as envelope-following responses. The probes were presented and responses were recorded during short 2-s periods when the animal echolocated to detect the presence or absence of a target in a go/no-go paradigm. In the target-absent trials, a hearing threshold of 90.4 dB re 1 muPa was found; in the target-present trials, the threshold was 109.8 dB. Thus, a 19.4-dB difference was found between thresholds in the target-present and target-absent trials. To check the possibility that this difference was the result of different masking degree of the probe by the emitted sonar clicks, click statistics were investigated in similar trials. No indication was found that the energy of the emitted clicks was higher in the target-present than in target-absent trials; on the contrary, mean click level, mean number of clicks per train, and overall train energy was slightly higher in the target-absent trials. Thus the data indicate that the hearing sensitivity of the whale varied depending on target presence or absence.

Age-dependent effects of neonatal methamphetamine exposure on spatial learning

PubMed Central

Vorhees, Charles V.; Skelton, Matthew R.; Williams, Michael T.

2009-01-01

Neonatal rats exposed to (+)-methamphetamine (MA) display spatial learning and reference memory deficits in the Morris water maze. In separate experiments the emergence and permanence of these effects were determined. Twenty litters were used in each experiment, and two male/female pairs/litter received saline or MA (5 mg/kg four times a day) on postnatal days (P) 11–20. In experiment 1, one MA and one saline pair from each litter began testing on either P30 or P40, whereas in experiment 2, testing began on P180 or P360. Animals received trials in a straight swimming channel and then in the Morris maze (acquisition, reversal, and reduced platform phases). In both experiments, MA-treated groups showed impaired learning in the platform trials and impaired reference memory in the probe trials, which were largely independent of age. The P30 and P40 MA impairments were seen on acquisition and reduced platform trials but not on reversal. In the probe trials, MA effects were seen during all phases. The P180 and P360 MA-induced deficits were seen in all phases of the platform trials. In probe trials, deficits were only seen during the reversal and reduced platform phases. The results demonstrate that neonatal MA treatment induces spatial learning and reference memory deficits that emerge early and persist until at least 1 year of age, suggesting permanence. PMID:17762523

Optimising probe holder design for sentinel lymph node imaging using clinical photoacoustic system with Monte Carlo simulation

NASA Astrophysics Data System (ADS)

Sivasubramanian, Kathyayini; Periyasamy, Vijitha; Wen, Kew Kok; Pramanik, Manojit

2017-03-01

Photoacoustic tomography is a hybrid imaging modality that combines optical and ultrasound imaging. It is rapidly gaining attention in the field of medical imaging. The challenge is to translate it into a clinical setup. In this work, we report the development of a handheld clinical photoacoustic imaging system. A clinical ultrasound imaging system is modified to integrate photoacoustic imaging with the ultrasound imaging. Hence, light delivery has been integrated with the ultrasound probe. The angle of light delivery is optimized in this work with respect to the depth of imaging. Optimization was performed based on Monte Carlo simulation for light transport in tissues. Based on the simulation results, the probe holders were fabricated using 3D printing. Similar results were obtained experimentally using phantoms. Phantoms were developed to mimic sentinel lymph node imaging scenario. Also, in vivo sentinel lymph node imaging was done using the same system with contrast agent methylene blue up to a depth of 1.5 cm. The results validate that one can use Monte Carlo simulation as a tool to optimize the probe holder design depending on the imaging needs. This eliminates a trial and error approach generally used for designing a probe holder.

Long-term interference at the semantic level: Evidence from blocked-cyclic picture matching.

PubMed

Wei, Tao; Schnur, Tatiana T

2016-01-01

Processing semantically related stimuli creates interference across various domains of cognition, including language and memory. In this study, we identify the locus and mechanism of interference when retrieving meanings associated with words and pictures. Subjects matched a probe stimulus (e.g., cat) to its associated target picture (e.g., yarn) from an array of unrelated pictures. Across trials, probes were either semantically related or unrelated. To test the locus of interference, we presented probes as either words or pictures. If semantic interference occurs at the stage common to both tasks, that is, access to semantic representations, then interference should occur in both probe presentation modalities. Results showed clear semantic interference effects independent of presentation modality and lexical frequency, confirming a semantic locus of interference in comprehension. To test the mechanism of interference, we repeated trials across 4 presentation cycles and manipulated the number of unrelated intervening trials (zero vs. two). We found that semantic interference was additive across cycles and survived 2 intervening trials, demonstrating interference to be long-lasting as opposed to short-lived. However, interference was smaller with zero versus 2 intervening trials, which we interpret to suggest that short-lived facilitation counteracted the long-lived interference. We propose that retrieving meanings associated with words/pictures from the same semantic category yields both interference due to long-lasting changes in connection strength between semantic representations (i.e., incremental learning) and facilitation caused by short-lived residual activation. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Trial-to-trial carry-over of item- and relational-information in auditory short-term memory

PubMed Central

Visscher, Kristina M.; Kahana, Michael J.; Sekuler, Robert

2009-01-01

Using a short-term recognition memory task we evaluated the carry-over across trials of two types of auditory information: the characteristics of individual study sounds (item information), and the relationships between the study sounds (relational information). On each trial, subjects heard two successive broadband study sounds and then decided whether a subsequently presented probe sound had been in the study set. On some trials, the probe item's similarity to stimuli presented on the preceding trial was manipulated. This item information interfered with recognition, increasing false alarms from 0.4% to 4.4%. Moreover, the interference was tuned so that only stimuli very similar to each other interfered. On other trials, the relationship among stimuli was manipulated in order to alter the criterion subjects used in making recognition judgments. The effect of this manipulation was confined to the very trial on which the criterion change was generated, and did not affect the subsequent trial. These results demonstrate the existence of a sharply-tuned carry-over of auditory item information, but no carry-over of relational information. PMID:19210080

Intraoperative Cryoanalgesia for Reducing Post-Tonsillectomy Pain: A Systemic Review.

PubMed

Raggio, Blake S; Barton, Blair M; Grant, Maria C; McCoul, Edward D

2018-06-01

Summarize the effectiveness of intraoperative cryoanalgesia in the management of postoperative pain among patients undergoing palatine tonsillectomy. A systematic review of PubMED, MEDLINE, EMBASE, Google Scholar, and Cochrane trial registries was performed through January 2017 using the PRISMA standards. We included English-language randomized controlled trials evaluating patients of all age groups with benign pathology who underwent tonsillectomy with cryoanalgesia versus without. Three limited quality randomized controlled trials involving 153 participants (age range, 1-60 years) were included. Cryoanalgesia was performed with a cryotherapy probe (-56°C) in 1 trial and ice-water cooling (4°C to 10°C) in 2. In the 3 trials reviewed, patients who received cryoanalgesia reported 21.38%, 28.33%, and 31.53% less average relative postoperative pain than controls on the visual analog scale. Review of secondary outcomes suggested no significant difference in time to resume normal diet (2 studies) or postoperative bleeding (2 studies) between the 2 groups. Cryoanalgesia allowed patients to return to work 4 days earlier than controls in 1 study. Two studies reported a trend toward less postoperative analgesia use among the treatment group; however, no statistical conclusions could be drawn. The available evidence suggests that patients undergoing tonsillectomy with cryoanalgesia experience less average postoperative pain without additional complications.

Comparison of computer based instruction to behavior skills training for teaching staff implementation of discrete-trial instruction with an adult with autism.

PubMed

Nosik, Melissa R; Williams, W Larry; Garrido, Natalia; Lee, Sarah

2013-01-01

In the current study, behavior skills training (BST) is compared to a computer based training package for teaching discrete trial instruction to staff, teaching an adult with autism. The computer based training package consisted of instructions, video modeling and feedback. BST consisted of instructions, modeling, rehearsal and feedback. Following training, participants were evaluated in terms of their accuracy on completing critical skills for running a discrete trial program. Six participants completed training; three received behavior skills training and three received the computer based training. Participants in the BST group performed better overall after training and during six week probes than those in the computer based training group. There were differences across both groups between research assistant and natural environment competency levels. Copyright © 2012 Elsevier Ltd. All rights reserved.

Meta-analysis of five photodisinfection clinical trials for periodontitis

NASA Astrophysics Data System (ADS)

Andersen, Roger C.; Loebel, Nicolas G.; Andersen, Dane M.

2009-06-01

Photodynamic therapy(PDT) has been demonstrated to effectively kill human periopathogens in vitro. To evaluate the efficacy of PDT in vivo a series of clinical trials was carried out in multiple centers and populations. Clinical parameters including clinical attachment level, pocket probing depth and bleeding on probing were all evaluated. All groups received the standard of care, scaling and root planing, and the treatment group additionally received a single treatment of PDT. Of the total 309 patients and over 40,000 pockets treated in these 5 trials it was determined that photodynamic therapy provided a statistically significant improvement in clinical parameters over scaling and root planing alone.

A new cognitive evaluation battery for Down syndrome and its relevance for clinical trials

PubMed Central

de Sola, Susana; de la Torre, Rafael; Sánchez-Benavides, Gonzalo; Benejam, Bessy; Cuenca-Royo, Aida; del Hoyo, Laura; Rodríguez, Joan; Catuara-Solarz, Silvina; Sanchez-Gutierrez, Judit; Dueñas-Espin, Ivan; Hernandez, Gimena; Peña-Casanova, Jordi; Langohr, Klaus; Videla, Sebastia; Blehaut, Henry; Farre, Magi; Dierssen, Mara; Cuenca-Royo, Aida

2015-01-01

The recent prospect of pharmaceutical interventions for cognitive impairment of Down syndrome (DS) has boosted a number of clinical trials in this population. However, running the trials has raised some methodological challenges and questioned the prevailing methodology used to evaluate cognitive functioning of DS individuals. This is usually achieved by comparing DS individuals to matched healthy controls of the same mental age. We propose a new tool, the TESDAD Battery that uses comparison with age-matched typically developed adults. This is an advantageous method for probing the clinical efficacy of DS therapies, allowing the interpretation and prediction of functional outcomes in clinical trials. In our DS population the TESDAD battery permitted a quantitative assessment of cognitive defects, which indicated language dysfunction and deficits in executive function, as the most important contributors to other cognitive and adaptive behavior outcomes as predictors of functional change in DS. Concretely, auditory comprehension and functional academics showed the highest potential as end-point measures of therapeutic intervention for clinical trials: the former as a cognitive key target for therapeutic intervention, and the latter as a primary functional outcome measure of clinical efficacy. Our results also emphasize the need to explore the modulating effects of IQ, gender and age on cognitive enhancing treatments. Noticeably, women performed significantly better than men of the same age and IQ in most cognitive tests, with the most consistent differences occurring in memory and executive functioning and negative trends rarely emerged on quality of life linked to the effect of age after adjusting for IQ and gender. In sum, the TESDAD battery is a useful neurocognitive tool for probing the clinical efficacy of experimental therapies in interventional studies in the DS population suggesting that age-matched controls are advantageous for determining normalization of DS. PMID:26089807

The development of automaticity in short-term memory search: Item-response learning and category learning.

PubMed

Cao, Rui; Nosofsky, Robert M; Shiffrin, Richard M

2017-05-01

In short-term-memory (STM)-search tasks, observers judge whether a test probe was present in a short list of study items. Here we investigated the long-term learning mechanisms that lead to the highly efficient STM-search performance observed under conditions of consistent-mapping (CM) training, in which targets and foils never switch roles across trials. In item-response learning, subjects learn long-term mappings between individual items and target versus foil responses. In category learning, subjects learn high-level codes corresponding to separate sets of items and learn to attach old versus new responses to these category codes. To distinguish between these 2 forms of learning, we tested subjects in categorized varied mapping (CV) conditions: There were 2 distinct categories of items, but the assignment of categories to target versus foil responses varied across trials. In cases involving arbitrary categories, CV performance closely resembled standard varied-mapping performance without categories and departed dramatically from CM performance, supporting the item-response-learning hypothesis. In cases involving prelearned categories, CV performance resembled CM performance, as long as there was sufficient practice or steps taken to reduce trial-to-trial category-switching costs. This pattern of results supports the category-coding hypothesis for sufficiently well-learned categories. Thus, item-response learning occurs rapidly and is used early in CM training; category learning is much slower but is eventually adopted and is used to increase the efficiency of search beyond that available from item-response learning. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Transmit-receive eddy current probes for defect detection and sizing in steam generator tubes

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

Obrutsky, L.S.; Cecco, V.S.; Sullivan, S.P.

1997-02-01

Inspection of steam generator tubes in aging Nuclear Generating Stations is increasingly important. Defect detection and sizing, especially in defect prone areas such as the tubesheet, support plates and U-bend regions, are required to assess the fitness-for-service of the steam generators. Information about defect morphology is required to address operational integrity issues, i.e., risk of tube rupture, number of tubes at risk, consequential leakage. A major challenge continues to be the detection and sizing of circumferential cracks. Utilities around the world have experienced this type of tube failure. Conventional in-service inspection, performed with eddy current bobbin probes, is ineffectual inmore » detecting circumferential cracks in tubing. It has been demonstrated in CANDU steam generators, with deformation, magnetite and copper deposits that multi-channel probes with transmit-receive eddy current coils are superior to those using surface impedance coils. Transmit-receive probes have strong directional properties, permitting probe optimization according to crack orientation. They are less sensitive to lift-off noise and magnetite deposits and possess good discrimination to internal defects. A single pass C3 array transmit-receive probe developed by AECL can detect and size circumferential stress corrosion cracks as shallow as 40% through-wall. Since its first trial in 1992, it has been used routinely for steam generator in-service inspection of four CANDU plants, preventing unscheduled shutdowns due to leaking steam generator tubes. More recently, a need has surfaced for simultaneous detection of both circumferential and axial cracks. The C5 probe was designed to address this concern. It combines transmit-receive array probe technology for equal sensitivity to axial and circumferential cracks with a bobbin probe for historical reference. This paper will discuss the operating principles of transmit-receive probes, along with inspection results.« less

Fluctuating Minds: Spontaneous Psychophysical Variability during Mind-Wandering

PubMed Central

Henríquez, Rodrigo A.; Chica, Ana B.; Billeke, Pablo; Bartolomeo, Paolo

2016-01-01

Mind-wandering is the occasional distraction we experience while performing a cognitive task. It arises without any external precedent, varies over time, and interferes with the processing of sensory information. Here, we asked whether the transition from the on-task state to mind-wandering is a gradual process or an abrupt event. We developed a new experimental approach, based on the continuous, online assessment of individual psychophysical performance. Probe questions were asked whenever response times (RTs) exceeded 2 standard deviations from the participant’s average RT. Results showed that mind-wandering reports were generally preceded by slower RTs, as compared to trials preceding on-task reports. Mind-wandering episodes could be reliably predicted from the response time difference between the last and the second-to-last trials. Thus, mind-wandering reports follow an abrupt increase in behavioral variability, lasting between 2.5 and 10 seconds. PMID:26863144

Results of the NeuroBlate System first-in-humans Phase I clinical trial for recurrent glioblastoma: clinical article.

PubMed

Sloan, Andrew E; Ahluwalia, Manmeet S; Valerio-Pascua, Jose; Manjila, Sunil; Torchia, Mark G; Jones, Stephen E; Sunshine, Jeffrey L; Phillips, Michael; Griswold, Mark A; Clampitt, Mark; Brewer, Cathy; Jochum, Jennifer; McGraw, Mary V; Diorio, Dawn; Ditz, Gail; Barnett, Gene H

2013-06-01

Laser interstitial thermal therapy has been used as an ablative treatment for glioma; however, its development was limited due to technical issues. The NeuroBlate System incorporates several technological advances to overcome these drawbacks. The authors report a Phase I, thermal dose-escalation trial assessing the safety and efficacy of NeuroBlate in recurrent glioblastoma multiforme (rGBM). Adults with suspected supratentorial rGBM of 15- to 40-mm dimension and a Karnofsky Performance Status score of ≥ 60 were eligible. After confirmatory biopsy, treatment was delivered using a rigid, gas-cooled, side-firing laser probe. Treatment was monitored using real-time MRI thermometry, and proprietary software providing predictive thermal damage feedback was used by the surgeon, along with control of probe rotation and depth, to tailor tissue coagulation. An external data safety monitoring board determined if toxicity at lower levels justified dose escalation. Ten patients were treated at the Case Comprehensive Cancer Center (Cleveland Clinic and University Hospitals-Case Medical Center). Their average age was 55 years (range 34-69 years) and the median preoperative Karnofsky Performance Status score was 80 (range 70-90). The mean tumor volume was 6.8 ± 5 cm(3) (range 2.6-19 cm(3)), the percentage of tumor treated was 78% ± 12% (range 57%-90%), and the conformality index was 1.21 ± 0.33 (range 1.00-2.04). Treatment-related necrosis was evident on MRI studies at 24 and 48 hours. The median survival was 316 days (range 62-767 days). Three patients improved neurologically, 6 remained stable, and 1 worsened. Steroid-responsive treatment-related edema occurred in all patients but one. Three had Grade 3 adverse events at the highest dose. NeuroBlate represents new technology for delivering laser interstitial thermal therapy, allowing controlled thermal ablation of deep hemispheric rGBM. CLINICAL TRIAL REGISTRATION NO.: NCT00747253 ( ClinicalTrials.gov ).

Investigation of left and right lateral fluid percussion injury in C57BL6/J mice: In vivo functional consequences

PubMed Central

Schurman, Lesley D.; Smith, Terry L.; Morales, Anthony J.; Lee, Nancy N.; Reeves, Thomas M.; Phillips, Linda L.; Lichtman, Aron H.

2017-01-01

Although rodent models of traumatic brain injury (TBI) reliably produce cognitive and motor disturbances, behavioral characterization resulting from left and right hemisphere injuries remains unexplored. Here we examined the functional consequences of targeting the left versus right parietal cortex in lateral fluid percussion injury, on Morris water maze (MWM) spatial memory tasks (fixed platform and reversal) and neurological motor deficits (neurological severity score and rotarod). In the MWM fixed platform task, right lateral injury produced a small delay in acquisition rate compared to left. However, injury to either hemisphere resulted in probe trial deficits. In the MWM reversal task, left-right performance deficits were not evident, though left lateral injury produced mild acquisition and probe trial deficits compared to sham controls. Additionally, left and right injury produced similar neurological motor task deficits, impaired righting times, and lesion volumes. Injury to either hemisphere also produced robust ipsilateral, and modest contralateral, morphological changes in reactive microglia and astrocytes. In conclusion, left and right lateral TBI impaired MWM performance, with mild fixed platform acquisition rate differences, despite similar motor deficits, histological damage, and glial cell reactivity. Thus, while both left and right lateral TBI produce cognitive deficits, laterality in mouse MWM learning and memory merits consideration in the investigation of TBI-induced cognitive consequences. PMID:28527714

Investigation of left and right lateral fluid percussion injury in C57BL6/J mice: In vivo functional consequences.

PubMed

Schurman, Lesley D; Smith, Terry L; Morales, Anthony J; Lee, Nancy N; Reeves, Thomas M; Phillips, Linda L; Lichtman, Aron H

2017-07-13

Although rodent models of traumatic brain injury (TBI) reliably produce cognitive and motor disturbances, behavioral characterization resulting from left and right hemisphere injuries remains unexplored. Here we examined the functional consequences of targeting the left versus right parietal cortex in lateral fluid percussion injury, on Morris water maze (MWM) spatial memory tasks (fixed platform and reversal) and neurological motor deficits (neurological severity score and rotarod). In the MWM fixed platform task, right lateral injury produced a small delay in acquisition rate compared to left. However, injury to either hemisphere resulted in probe trial deficits. In the MWM reversal task, left-right performance deficits were not evident, though left lateral injury produced mild acquisition and probe trial deficits compared to sham controls. Additionally, left and right injury produced similar neurological motor task deficits, impaired righting times, and lesion volumes. Injury to either hemisphere also produced robust ipsilateral, and modest contralateral, morphological changes in reactive microglia and astrocytes. In conclusion, left and right lateral TBI impaired MWM performance, with mild fixed platform acquisition rate differences, despite similar motor deficits, histological damage, and glial cell reactivity. Thus, while both left and right lateral TBI produce cognitive deficits, laterality in mouse MWM learning and memory merits consideration in the investigation of TBI-induced cognitive consequences. Copyright © 2017. Published by Elsevier B.V.

The effect of zirconia or titanium as abutment material on soft peri-implant tissues: a systematic review and meta-analysis.

PubMed

Linkevicius, Tomas; Vaitelis, Julius

2015-09-01

The objective of this review was to analyze research with regard to the effect of zirconia or titanium as abutment material on soft peri-implant tissues. Clinical studies were selected via electronic and hand searches in English language journals until December 1, 2014. Only randomized clinical trials (RCTs) and prospective controlled clinical trials (CCTs) showing direct comparison between zirconia (Zr) and titanium (Ti) abutments in the same patient were considered. The outcome measures were (1) soft tissue color, (2) soft tissue recession, (3) peri-implant probing, (4) bleeding on probing, (5) esthetic indexes, (6) patient-reported outcome, (7) marginal bone level, and (8) biological complications. Nine relevant studies (11 papers) were identified: 4 RCTs and 5 CCTs. Due to heterogeneity in the study design, statistical methods, and reported results, a meta-analysis of the data was feasible only for soft tissue color. The outcome was found to be significantly superior for Zr abutments. For the other outcome measures, a qualitative analysis of the selected articles was performed. The studies did not show any statistically significant differences between Zr and Ti abutments on soft tissue recession, probing depths, bleeding on probing, marginal bone level, and patient-reported outcome. One study reported significantly higher pink esthetic score (PES) scores at Zr implants with Zr abutments, compared to metal implants and Ti abutments. Overall, the research does not support any obvious advantage of Ti or Zr abutments over each other. However, there is a significant tendency in Zr abutments evoking better color response of peri-implant mucosa and superior esthetic outcome measured by PES score. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Accuracy of pulse oximetry in detection of oxygen saturation in patients admitted to the intensive care unit of heart surgery: comparison of finger, toe, forehead and earlobe probes.

PubMed

Seifi, Sohila; Khatony, Alireza; Moradi, Gholamreza; Abdi, Alireza; Najafi, Farid

2018-01-01

Heart surgery patients are more at risk of poor peripheral perfusion, and peripheral capillary oxygen saturation (SpO2) measurement is regular care for continuous analysis of blood oxygen saturation in these patients. With regard to controversial studies on accuracy of the current pulse oximetry probes and lack of data related to patients undergoing heart surgery, the present study was conducted to determine accuracy of pulse oximetry probes of finger, toe, forehead and earlobe in detection of oxygen saturation in patients admitted to intensive care units for coronary artery bypass surgery. In this clinical trial, 67 patients were recruited based on convenience sampling method among those admitted to intensive care units for coronary artery bypass surgery. The SpO2 value was measured using finger, toe, forehead and earlobe probes and then compared with the standard value of arterial oxygen saturation (SaO2). Data were entered into STATA-11 software and analyzed using descriptive, inferential and Bland-Altman statistical analyses. Highest and lowest correlational mean values of SpO2 and SaO2 were related to finger and earlobe probes, respectively. The highest and lowest agreement of SpO2 and SaO2 were related to forehead and earlobe probes. The SpO2 of earlobe probes due to lesser mean difference, more limited confidence level and higher agreement ration with SaO2 resulted by arterial blood gas (ABG) analysis had higher accuracy. Thus, it is suggested to use earlobe probes in patients admitted to the intensive care unit for coronary artery bypass surgery. Registration of this trial protocol has been approved in Iranian Registry of Clinical Trials at 2018-03-19 with reference IRCT20100913004736N22. "Retrospectively registered."

Acquisition and long-term retention of spatial learning in the human immunodeficiency virus-1 transgenic rat: Effects of repeated nicotine treatment

PubMed Central

Vigorito, Michael; Cao, Junran; Li, Ming D.; Chang, Sulie L.

2013-01-01

The HIV-1 transgenic (HIV-1Tg) rat shows a deficit in learning to locate a submerged platform in a multiple-trial water maze task compared to transgenic littermate and F344 control rats (Vigorito et al. 2008; Lashomb et al. 2009). Nicotine is known to have neuroprotective effects possibly by minimizing cytotoxic effects of glutamate or by modulating a cholinergic anti-inflammatory pathway. Nicotine also improves performance in a variety of learning tasks by enhancing attention and short-term memory (STM). The purpose of this study was to determine if the learning deficit in HIV-1Tg is ameliorated by repeated nicotine treatment independent of its effects on STM. HIV-1Tg and F344 rats were treated (subcutaneous) with nicotine (0.25mg/kg/injection) or saline twice daily and tested in a single-trial-per-day procedure which precludes the impact of STM on the acquisition of the spatial learning task. HIV-1Tg rats showed a deficit in the acquisition of the task and in the long-term retention for the platform location in a probe test. Nicotine did not ameliorate the deficit in HIV-1Tg rats and slightly worsened performance during acquisition. Analysis of individual differences in performance during the probe test suggested that nicotine improved performance in some F344 rats but not in HIV-1Tg rats. These results indicate that a deficit in the consolidation of long-term memory (LTM) contributes to the acquisition deficit of HIV1-Tg rats. The results, however, do not provide any evidence of the amelioration of the learning deficit observed in this behavioral model at least with the nicotine dose tested. PMID:23456952

Frontal lobe activation during object alternation acquisition.

PubMed

Zald, David H; Curtis, Clayton; Chernitsky, Laura A; Pardo, José V

2005-01-01

Object alternation (OA) tasks are increasingly used as probes of ventral prefrontal functioning in humans. In the most common variant of the OA task, subjects must deduce the task rule through trial-and-error learning. To examine the neural correlates of OA acquisition, the authors measured regional cerebral blood flow with positron emission tomography while subjects acquired an OA task, performed a sensorimotor control condition, or performed already learned and practiced OA. As expected, activations emerged in the ventral prefrontal cortex. However, activation of the presupplemental motor area was more closely associated with successful task performance. The authors suggest that areas beyond the ventral prefrontal cortex are critically involved in OA acquisition. 2005 APA

Retroactive interference in short-term memory and the word-length effect.

PubMed

Campoy, Guillermo

2011-09-01

Two experiments investigated the possibility that the word-length effect in short-term memory (STM) is a consequence of long words generating a greater level of retroactive interference than shorter words. In Experiment 1, six-word lists were auditorily presented under articulatory suppression for immediate serial reconstruction of only the first three words. These three words were always drawn from a single set of middle-length words, whereas the last three positions were occupied by either short or long interfering words. The results showed worse memory performance when the to-be-remembered words were followed by long words. In Experiment 2, a recent-probes task was used, in which recent negative probes matched a target word in trial n-2. The results showed lower levels of proactive interference when trial n-1 involved long words instead of short words, suggesting that long words displaced previous STM content to a greater extent. By two different experimental approaches, therefore, this study shows that long words produce more retroactive interference than short words, supporting an interference-based account for the word-length effect. Copyright © 2011 Elsevier B.V. All rights reserved.

What is the Most Sensitive Measure of Water Maze Probe Test Performance?

PubMed Central

Maei, Hamid R.; Zaslavsky, Kirill; Teixeira, Cátia M.; Frankland, Paul W.

2009-01-01

The water maze is commonly used to assay spatial cognition, or, more generally, learning and memory in experimental rodent models. In the water maze, mice or rats are trained to navigate to a platform located below the water's surface. Spatial learning is then typically assessed in a probe test, where the platform is removed from the pool and the mouse or rat is allowed to search for it. Performance in the probe test may then be evaluated using either occupancy-based (percent time in a virtual quadrant [Q] or zone [Z] centered on former platform location), error-based (mean proximity to former platform location [P]) or counting-based (platform crossings [X]) measures. While these measures differ in their popularity, whether they differ in their ability to detect group differences is not known. To address this question we compiled five separate databases, containing more than 1600 mouse probe tests. Random selection of individual trials from respective databases then allowed us to simulate experiments with varying sample and effect sizes. Using this Monte Carlo-based method, we found that the P measure consistently outperformed the Q, Z and X measures in its ability to detect group differences. This was the case regardless of sample or effect size, and using both parametric and non-parametric statistical analyses. The relative superiority of P over other commonly used measures suggests that it is the most appropriate measure to employ in both low- and high-throughput water maze screens. PMID:19404412

Comparison between single-diode low-level laser therapy (LLLT) and LED multi-diode (cluster) therapy (LEDT) applications before high-intensity exercise.

PubMed

Leal Junior, Ernesto Cesar Pinto; Lopes-Martins, Rodrigo Alvaro Brandão; Baroni, Bruno Manfredini; De Marchi, Thiago; Rossi, Rafael Paolo; Grosselli, Douglas; Generosi, Rafael Abeche; de Godoi, Vanessa; Basso, Maira; Mancalossi, José Luis; Bjordal, Jan Magnus

2009-08-01

There is anecdotal evidence that low-level laser therapy (LLLT) may affect the development of muscular fatigue, minor muscle damage, and recovery after heavy exercises. Although manufacturers claim that cluster probes (LEDT) maybe more effective than single-diode lasers in clinical settings, there is a lack of head-to-head comparisons in controlled trials. This study was designed to compare the effect of single-diode LLLT and cluster LEDT before heavy exercise. This was a randomized, placebo-controlled, double-blind cross-over study. Young male volleyball players (n = 8) were enrolled and asked to perform three Wingate cycle tests after 4 x 30 sec LLLT or LEDT pretreatment of the rectus femoris muscle with either (1) an active LEDT cluster-probe (660/850 nm, 10/30 mW), (2) a placebo cluster-probe with no output, and (3) a single-diode 810-nm 200-mW laser. The active LEDT group had significantly decreased post-exercise creatine kinase (CK) levels (-18.88 +/- 41.48 U/L), compared to the placebo cluster group (26.88 +/- 15.18 U/L) (p < 0.05) and the active single-diode laser group (43.38 +/- 32.90 U/L) (p < 0.01). None of the pre-exercise LLLT or LEDT protocols enhanced performance on the Wingate tests or reduced post-exercise blood lactate levels. However, a non-significant tendency toward lower post-exercise blood lactate levels in the treated groups should be explored further. In this experimental set-up, only the active LEDT probe decreased post-exercise CK levels after the Wingate cycle test. Neither performance nor blood lactate levels were significantly affected by this protocol of pre-exercise LEDT or LLLT.

Human factors flight trial analysis for 3D SVS: part II

NASA Astrophysics Data System (ADS)

Schiefele, Jens; Howland, Duncan; Maris, John; Pschierer, Christian; Wipplinger, Patrick; Meuter, Michael

2005-05-01

This paper describes flight trials performed in Centennial, CO using a Piper Cheyenne owned and operated by Marinvent. The goal of the flight trial was to evaluate the objective performance of pilots using conventional paper charts or a 3D SVS display. Six pilots flew thirty-six approaches to the Colorado Springs airport to accomplish this goal. As dependent variables, positional accuracy and situational awareness probe (SAP) statistics were measured while analysis was conducted by an ANOVA test. In parallel, all pilots answered subjective Cooper-Harper, NASA TLX, situation awareness rating technique (SART), Display Readability Rating, Display Flyability Rating and debriefing questionnaires. Three different settings (paper chart, electronic navigation chart, 3D SVS display) were evaluated in a totally randomized manner. This paper describes the comparison between the conventional paper chart and the 3D SVS display. The 3D SVS primary flight display provides a depiction of primary flight data as well as a 3D depiction of airports, terrain and obstacles. In addition, a 3D dynamic channel visualizing the selected approach procedure can be displayed. The result shows that pilots flying the 3D SVS display perform no worse than pilots with the conventional paper chart. Flight technical error and workload are lower, situational awareness is equivalent with conventional paper charts.

Change perception and change interference within and across feature dimensions.

PubMed

Pilling, Michael; Barrett, Doug J K

2018-06-04

The ability to perceive a change in a visual object is reduced when that change is presented in competition with other changes which are task-irrelevant. We performed two experiments which investigate the basis of this change interference effect. We tested whether change interference occurs as a consequence of some form of attentional capture, or whether the interference occurs at a stage prior to attentional selection of the task-relevant change. A modified probe-detection task was used to explore this issue. Observers were required to report the presence/absence of a specified change-type (colour, shape) in the probe, in a context in which - on certain trials - irrelevant changes occur in non-probe items. There were two key variables in these experiments: the attentional state of the observer, and the dimensional congruence of changes in the probe and non-probe items. Change interference was strongest when the irrelevant changes were the same as those on the report dimension. However the interference pattern persisted even when observers did not know the report dimension at the time the changes occurred. These results seem to rule out attention as a factor. Our results fit best with an interpretation in which change interference produces feature-specific sensory noise which degrades the signal quality of the target change. Copyright © 2018 Elsevier B.V. All rights reserved.

Neural circuitry of emotional and cognitive conflict revealed through facial expressions.

PubMed

Chiew, Kimberly S; Braver, Todd S

2011-03-09

Neural systems underlying conflict processing have been well studied in the cognitive realm, but the extent to which these overlap with those underlying emotional conflict processing remains unclear. A novel adaptation of the AX Continuous Performance Task (AX-CPT), a stimulus-response incompatibility paradigm, was examined that permits close comparison of emotional and cognitive conflict conditions, through the use of affectively-valenced facial expressions as the response modality. Brain activity was monitored with functional magnetic resonance imaging (fMRI) during performance of the emotional AX-CPT. Emotional conflict was manipulated on a trial-by-trial basis, by requiring contextually pre-cued facial expressions to emotional probe stimuli (IAPS images) that were either affectively compatible (low-conflict) or incompatible (high-conflict). The emotion condition was contrasted against a matched cognitive condition that was identical in all respects, except that probe stimuli were emotionally neutral. Components of the brain cognitive control network, including dorsal anterior cingulate cortex (ACC) and lateral prefrontal cortex (PFC), showed conflict-related activation increases in both conditions, but with higher activity during emotion conditions. In contrast, emotion conflict effects were not found in regions associated with affective processing, such as rostral ACC. These activation patterns provide evidence for a domain-general neural system that is active for both emotional and cognitive conflict processing. In line with previous behavioural evidence, greatest activity in these brain regions occurred when both emotional and cognitive influences additively combined to produce increased interference.

Neural Circuitry of Emotional and Cognitive Conflict Revealed through Facial Expressions

PubMed Central

Chiew, Kimberly S.; Braver, Todd S.

2011-01-01

Background Neural systems underlying conflict processing have been well studied in the cognitive realm, but the extent to which these overlap with those underlying emotional conflict processing remains unclear. A novel adaptation of the AX Continuous Performance Task (AX-CPT), a stimulus-response incompatibility paradigm, was examined that permits close comparison of emotional and cognitive conflict conditions, through the use of affectively-valenced facial expressions as the response modality. Methodology/Principal Findings Brain activity was monitored with functional magnetic resonance imaging (fMRI) during performance of the emotional AX-CPT. Emotional conflict was manipulated on a trial-by-trial basis, by requiring contextually pre-cued facial expressions to emotional probe stimuli (IAPS images) that were either affectively compatible (low-conflict) or incompatible (high-conflict). The emotion condition was contrasted against a matched cognitive condition that was identical in all respects, except that probe stimuli were emotionally neutral. Components of the brain cognitive control network, including dorsal anterior cingulate cortex (ACC) and lateral prefrontal cortex (PFC), showed conflict-related activation increases in both conditions, but with higher activity during emotion conditions. In contrast, emotion conflict effects were not found in regions associated with affective processing, such as rostral ACC. Conclusions/Significance These activation patterns provide evidence for a domain-general neural system that is active for both emotional and cognitive conflict processing. In line with previous behavioural evidence, greatest activity in these brain regions occurred when both emotional and cognitive influences additively combined to produce increased interference. PMID:21408006

Healing of Postextraction Sockets Preserved With Autologous Platelet Concentrates. A Systematic Review and Meta-Analysis.

PubMed

Del Fabbro, Massimo; Bucchi, Cristina; Lolato, Alessandra; Corbella, Stefano; Testori, Tiziano; Taschieri, Silvio

2017-08-01

The true benefit of autologous platelet concentrates (APCs) for enhancing the healing of postextraction sites is still a matter of debate, and in recent years several clinical trials have addressed this issue. The purpose of this study was to determine the effectiveness of an APC adjunct in the preservation of fresh extraction sockets. An electronic search was performed on Medline, Embase, Scopus, and the Cochrane Central Register of Controlled Trials. Only controlled clinical trials or randomized clinical trials were included. Selected articles underwent risk-of-bias assessment. The outcomes were complications and adverse events, discomfort and quality of life, bone healing and remodeling assessed by histologic and radiographic techniques, and soft tissue healing. Thirty-three comparative studies were included. Nine articles had a parallel design and 24 had a split-mouth design. Twenty studies were considered to have a low risk of bias and 13 were considered to have a high risk. Overall, 1,193 teeth were extracted from 911 patients. Meta-analysis showed that soft tissue healing, probing depth at 3 months, and bone density at 1, 3, and 6 months were statistically better for the APC group. Qualitative analysis suggested that APCs might be associated with a decrease in swelling and trismus. However, no relevant difference among groups was found for probing depth at 1 month, incidence of alveolar osteitis, acute inflammation or infection, percentage of new bone, and indirect measurement of bone metabolism. APCs should be used in postextraction sites to improve clinical and radiographic outcomes such as bone density and soft tissue healing and postoperative symptoms. The actual benefit of APCs on decreasing pain in extraction sockets is still not quantifiable. Copyright © 2017 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Irreversible Electroporation (IRE) Fails to Demonstrate Efficacy in a Prospective Multicenter Phase II Trial on Lung Malignancies: The ALICE Trial

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

Ricke, Jens, E-mail: jens.ricke@med.ovgu.de; Jürgens, Julian H. W., E-mail: julian.juergens@med.ovgu.de; Deschamps, Frederic

2015-04-15

PurposeTo assess safety and efficacy of irreversible electroporation (IRE) of lung malignancies.Materials and MethodsPatients with primary and secondary lung malignancies and preserved lung function were included in this prospective single arm trial. Primary and secondary endpoints were safety and efficacy. Recruitment goal was 36 subjects in 2 centers. Patients underwent IRE under general anesthesia with probe placement performed in Fluoroscopy-CT. The IRE system employed was NanoKnife{sup ®} (Angiodynamics). System settings for the ablation procedure followed the manufacturer’s recommendations. The Mann–Whitney U test was used to evaluate the correlation of nine technical parameters with local tumor control. Median follow up wasmore » 12 months.ResultsThe expected efficacy was not met at interim analysis and the trial was stopped prematurely after inclusion of 23 patients (13/10 between both centers). The dominant tumor entity was colorectal (n = 13). The median tumor diameter was 16 mm (8–27 mm). Pneumothoraces were observed in 11 of 23 patients with chest tubes required in 8 (35 %). Frequently observed alveolar hemorrhage never led to significant hemoptysis. 14/23 showed progressive disease (61 %). Stable disease was found in 1 (4 %), partial remission in 1 (4 %) and complete remission in 7 (30 %) patients. The relative increase of the current during ablation was significantly higher in the group treated successfully as compared to the group presenting local recurrence (p < 0.05). Needle tract seeding was found in three cases (13 %).ConclusionsIRE is not effective for the treatment of lung malignancies. We hypothesize that the energy deposition with current IRE probes is highly sensitive to air exposure.« less

Learning and processing of nonverbal symbolic information in bilinguals and monolinguals

PubMed Central

Blumenfeld, Henrike K.; Adams, Ashley M.

2014-01-01

Bilinguals have been shown to outperform monolinguals on word learning and on inhibition tasks that require competition resolution. Yet the scope of such bilingual advantages remains underspecified. We compared bilinguals and monolinguals on nonverbal symbolic learning and on competition resolution while processing newly-learned material. Participants were trained on 12 tone-to-symbol mappings, combining timbre, pitch, and duration of tones. During subsequent processing, participants viewed a display with four symbols, and were instructed to identify the symbol that matched a simultaneously-presented tone. On competition trials, two symbols matched the tone in timbre and pitch, but only one matched the tone on timbre, pitch, and duration. No learning differences emerged between 27 Spanish-English bilinguals and 27 English monolinguals, and more successful learners performed better on the Peabody Picture Vocabulary task. During the processing task, competition trials yielded responses with lower accuracies and longer latencies than control trials. Further, in both groups, more successful learning of tone-to-symbol mappings was associated with more successful retrieval during processing. In monolinguals, English receptive vocabulary scores also influenced retrieval efficiency during processing, with English/Spanish vocabulary less related to the novel processing task in bilinguals. Finally, to examine inhibition of competing stimuli, priming probes were presented after each tone-symbol processing trial. These probes suggested that bilinguals, and to a lesser extent monolinguals, showed residual inhibition of competitors at 200 ms post-target identification. Together, findings suggest that learning of novel symbolic information may depend in part on previous linguistic knowledge (not bilingualism per se), and that, during processing of newly-learned material, subtle differences in retrieval and competition resolution may emerge between bilinguals and monolinguals. PMID:25360125

Spatial and reversal learning in the Morris water maze are largely resistant to six hours of REM sleep deprivation following training

PubMed Central

Walsh, Christine M.; Booth, Victoria; Poe, Gina R.

2011-01-01

This first test of the role of REM (rapid eye movement) sleep in reversal spatial learning is also the first attempt to replicate a much cited pair of papers reporting that REM sleep deprivation impairs the consolidation of initial spatial learning in the Morris water maze. We hypothesized that REM sleep deprivation following training would impair both hippocampus-dependent spatial learning and learning a new target location within a familiar environment: reversal learning. A 6-d protocol was divided into the initial spatial learning phase (3.5 d) immediately followed by the reversal phase (2.5 d). During the 6 h following four or 12 training trials/day of initial or reversal learning phases, REM sleep was eliminated and non-REM sleep left intact using the multiple inverted flowerpot method. Contrary to our hypotheses, REM sleep deprivation during four or 12 trials/day of initial spatial or reversal learning did not affect training performance. However, some probe trial measures indicated REM sleep-deprivation–associated impairment in initial spatial learning with four trials/day and enhancement of subsequent reversal learning. In naive animals, REM sleep deprivation during normal initial spatial learning was followed by a lack of preference for the subsequent reversal platform location during the probe. Our findings contradict reports that REM sleep is essential for spatial learning in the Morris water maze and newly reveal that short periods of REM sleep deprivation do not impair concurrent reversal learning. Effects on subsequent reversal learning are consistent with the idea that REM sleep serves the consolidation of incompletely learned items. PMID:21677190

Development of a Multi-Sensor Cancer Detection Probe Final Report CRADA No. TC-2026-01

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

Marion, J.; Hular, R.

This collaboration continued work started under a previous CRADA (TSB-2023-00) to take a detailed concept specification for a multi-sensor needle/probe suitable for breast cancer analysis and produce a prototype system suitable for human FDA trials.

Clinical effect of azithromycin as an adjunct to non-surgical treatment of chronic periodontitis: a meta-analysis of randomized controlled clinical trials.

PubMed

Zhang, Z; Zheng, Y; Bian, X

2016-06-01

The results of recent published studies focusing on the effect of azithromycin as an adjunct to scaling and root planing (SRP) in the treatment of chronic periodontitis are inconsistent. We conducted a meta-analysis of randomized controlled clinical trials to examine the effect of azithromycin combined with SRP on periodontal clinical parameters as compared to SRP alone. An electronic search was carried out on Pubmed, Embase and the Cochrane Central Register of Controlled Trials from their earliest records through December 28, 2014 to identify studies that met pre-stated inclusion criteria. Reference lists of retrieved articles were also reviewed. Data were extracted independently by two authors. Either a fixed- or random-effects model was used to calculate the overall effect sizes of azithromycin on probing depth, attachment level (AL) and bleeding on probing (BOP). Heterogeneity was evaluated using the Q test and I(2) statistic. Publication bias was evaluated by Begg's test and Egger's test. A total of 14 trials were included in the meta-analysis. Compared with SRP alone, locally delivered azithromycin plus SRP statistically significantly reduced probing depth by 0.99 mm (95% CI 0.42-1.57) and increased AL by 1.12 mm (95% CI 0.31-1.92). In addition, systemically administered azithromycin plus SRP statistically significantly reduced probing depth by 0.21 mm (95% CI 0.12-0.29), BOP by 4.50% (95% CI 1.45-7.56) and increased AL by 0.23 mm (95% CI 0.07-0.39). Sensitivity analysis yielded similar results. No evidence of publication bias was observed. The additional benefit of systemic azithromycin was shown at the initially deep probing depth sites, but not at shallow or moderate sites. The overall effect sizes of systemic azithromycin showed a tendency to decrease with time, and meta-regression analysis suggested a negative relation between the length of follow-up and net change in probing depth (r = -0.05, p = 0.02). This meta-analysis provides further evidence that azithromycin used as an adjunct to SRP significantly improves the efficacy of non-surgical periodontal therapy on reducing probing depth, BOP and improving AL, particularly at the initially deep probing depth sites. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

A Probe Intermix Procedure for Fading Response Prompts.

ERIC Educational Resources Information Center

Billingsley, Felix F.

1987-01-01

A prompt fading method was employed to teach an eight-year-old student with severe behavior disorders the self-paced use of a functional behavior (requesting rather than grabbing food items). Initial pairing of prompts and natural cues was followed by a mix of prompted and probe (unprompted) trials. (Author/JW)

Memory-guided selective attention: Single experiences with conflict have long-lasting effects on cognitive control.

PubMed

Brosowsky, Nicholaus P; Crump, Matthew J C

2018-05-17

Adjustments in cognitive control, as measured by congruency sequence effects, are thought to be influenced by both external stimuli and internal goals. However, this dichotomy has often overshadowed the potential contribution of past experience stored in memory. Here, we examine the role of long-term episodic memory in guiding selective attention. Our aim was to demonstrate new evidence that selective attention can be modulated by long-term retrieval of stimulus-specific attentional control settings. All the experiments used a modified flanker task involving multiple unique stimuli. Critically, each stimulus was only presented twice during the experiment: first as a prime, and second as a probe. Experiments 1 and 2 varied the number of intervening trials between prime and probe and manipulated the amount of conflict using a secondary task. Experiment 3 ensured that specific colors assigned to prime stimuli were not repeated when presented as probes. Across both Experiments 1 and 2, we consistently found smaller congruency effects on probe trials when its associated prime trial was incongruent compared with congruent, demonstrating long-term congruency sequence effects. However, Experiment 3 showed no evidence for long-term effects. These findings suggest long-term preservation of selective attention processing at the episodic level, and implicate a role for memory in updating cognitive control. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Uremic Solute-Aryl Hydrocarbon Receptor-Tissue Factor Axis Associates with Thrombosis after Vascular Injury in Humans.

PubMed

Kolachalama, Vijaya B; Shashar, Moshe; Alousi, Faisal; Shivanna, Sowmya; Rijal, Keshab; Belghasem, Mostafa E; Walker, Joshua; Matsuura, Shinobu; Chang, Gary H; Gibson, C Michael; Dember, Laura M; Francis, Jean M; Ravid, Katya; Chitalia, Vipul C

2018-03-01

Individuals with CKD are particularly predisposed to thrombosis after vascular injury. Using mouse models, we recently described indoxyl sulfate, a tryptophan metabolite retained in CKD and an activator of tissue factor (TF) through aryl hydrocarbon receptor (AHR) signaling, as an inducer of thrombosis across the CKD spectrum. However, the translation of findings from animal models to humans is often challenging. Here, we investigated the uremic solute-AHR-TF thrombosis axis in two human cohorts, using a targeted metabolomics approach to probe a set of tryptophan products and high-throughput assays to measure AHR and TF activity. Analysis of baseline serum samples was performed from 473 participants with advanced CKD from the Dialysis Access Consortium Clopidogrel Prevention of Early AV Fistula Thrombosis trial. Participants with subsequent arteriovenous thrombosis had significantly higher levels of indoxyl sulfate and kynurenine, another uremic solute, and greater activity of AHR and TF, than those without thrombosis. Pattern recognition analysis using the components of the thrombosis axis facilitated clustering of the thrombotic and nonthrombotic groups. We further validated these findings using 377 baseline samples from participants in the Thrombolysis in Myocardial Infarction II trial, many of whom had CKD stage 2-3. Mechanistic probing revealed that kynurenine enhances thrombosis after vascular injury in an animal model and regulates thrombosis in an AHR-dependent manner. This human validation of the solute-AHR-TF axis supports further studies probing its utility in risk stratification of patients with CKD and exploring its role in other diseases with heightened risk of thrombosis. Copyright © 2018 by the American Society of Nephrology.

Variability of acute extracellular action potential measurements with multisite silicon probes

PubMed Central

Scott, Kimberly M.; Du, Jiangang; Lester, Henry A.; Masmanidis, Sotiris C.

2012-01-01

Device miniaturization technologies have led to significant advances in sensors for extracellular measurements of electrical activity in the brain. Multisite, silicon-based probes containing implantable electrode arrays afford greater coverage of neuronal activity than single electrodes and therefore potentially offer a more complete view of how neuronal ensembles encode information. However, scaling up the number of sites is not sufficient to ensure capture of multiple neurons, as action potential signals from extracellular electrodes may vary due to numerous factors. In order to understand the large-scale recording capabilities and potential limitations of multisite probes, it is important to quantify this variability, and to determine whether certain key device parameters influence the recordings. Here we investigate the effect of four parameters, namely, electrode surface, width of the structural support shafts, shaft number, and position of the recording site relative to the shaft tip. This study employs acutely implanted silicon probes containing up to 64 recording sites, whose performance is evaluated by the metrics of noise, spike amplitude, and spike detection probability. On average, we find no significant effect of device geometry on spike amplitude and detection probability but we find significant differences among individual experiments, with the likelihood of detecting spikes varying by a factor of approximately three across trials. PMID:22971352

Memory for sequences of events impaired in typical aging.

PubMed

Allen, Timothy A; Morris, Andrea M; Stark, Shauna M; Fortin, Norbert J; Stark, Craig E L

2015-03-01

Typical aging is associated with diminished episodic memory performance. To improve our understanding of the fundamental mechanisms underlying this age-related memory deficit, we previously developed an integrated, cross-species approach to link converging evidence from human and animal research. This novel approach focuses on the ability to remember sequences of events, an important feature of episodic memory. Unlike existing paradigms, this task is nonspatial, nonverbal, and can be used to isolate different cognitive processes that may be differentially affected in aging. Here, we used this task to make a comprehensive comparison of sequence memory performance between younger (18-22 yr) and older adults (62-86 yr). Specifically, participants viewed repeated sequences of six colored, fractal images and indicated whether each item was presented "in sequence" or "out of sequence." Several out of sequence probe trials were used to provide a detailed assessment of sequence memory, including: (i) repeating an item from earlier in the sequence ("Repeats"; e.g., AB A: DEF), (ii) skipping ahead in the sequence ("Skips"; e.g., AB D: DEF), and (iii) inserting an item from a different sequence into the same ordinal position ("Ordinal Transfers"; e.g., AB 3: DEF). We found that older adults performed as well as younger controls when tested on well-known and predictable sequences, but were severely impaired when tested using novel sequences. Importantly, overall sequence memory performance in older adults steadily declined with age, a decline not detected with other measures (RAVLT or BPS-O). We further characterized this deficit by showing that performance of older adults was severely impaired on specific probe trials that required detailed knowledge of the sequence (Skips and Ordinal Transfers), and was associated with a shift in their underlying mnemonic representation of the sequences. Collectively, these findings provide unambiguous evidence that the capacity to remember sequences of events is fundamentally affected by typical aging. © 2015 Allen et al.; Published by Cold Spring Harbor Laboratory Press.

Memory for sequences of events impaired in typical aging

PubMed Central

Allen, Timothy A.; Morris, Andrea M.; Stark, Shauna M.; Fortin, Norbert J.

2015-01-01

Typical aging is associated with diminished episodic memory performance. To improve our understanding of the fundamental mechanisms underlying this age-related memory deficit, we previously developed an integrated, cross-species approach to link converging evidence from human and animal research. This novel approach focuses on the ability to remember sequences of events, an important feature of episodic memory. Unlike existing paradigms, this task is nonspatial, nonverbal, and can be used to isolate different cognitive processes that may be differentially affected in aging. Here, we used this task to make a comprehensive comparison of sequence memory performance between younger (18–22 yr) and older adults (62–86 yr). Specifically, participants viewed repeated sequences of six colored, fractal images and indicated whether each item was presented “in sequence” or “out of sequence.” Several out of sequence probe trials were used to provide a detailed assessment of sequence memory, including: (i) repeating an item from earlier in the sequence (“Repeats”; e.g., ABADEF), (ii) skipping ahead in the sequence (“Skips”; e.g., ABDDEF), and (iii) inserting an item from a different sequence into the same ordinal position (“Ordinal Transfers”; e.g., AB3DEF). We found that older adults performed as well as younger controls when tested on well-known and predictable sequences, but were severely impaired when tested using novel sequences. Importantly, overall sequence memory performance in older adults steadily declined with age, a decline not detected with other measures (RAVLT or BPS-O). We further characterized this deficit by showing that performance of older adults was severely impaired on specific probe trials that required detailed knowledge of the sequence (Skips and Ordinal Transfers), and was associated with a shift in their underlying mnemonic representation of the sequences. Collectively, these findings provide unambiguous evidence that the capacity to remember sequences of events is fundamentally affected by typical aging. PMID:25691514

Human sex differences in solving a virtual navigation problem.

PubMed

Astur, Robert S; Purton, Andrea J; Zaniewski, Melanie J; Cimadevilla, Jose; Markus, Etan J

2016-07-15

The current study examined sex differences in initial and subsequent strategies in solving a navigational problem within a virtual reality environment. We tested 163 undergraduates on a virtual T-maze task that included probe trials designed to assess whether participants were responding using either a place or response strategy. Participants were also tested on a mental rotation task and memory of the details of the virtual room. There were no differences between the sexes in copying or recalling a map of the room or on first trial performance of the T-maze. However, at trial two, males show a significant advantage in solving the task, and approximately 80% of the males adopt a place strategy to solve the T-maze whereas females at that point showed no strategy preference. Across all testing, both males and females preferentially used a place strategy. We discuss how factors such as spatial priming affect strategy preferences and how such factors may differentially affect males and females. Copyright © 2016 Elsevier B.V. All rights reserved.

Trial-by-trial analysis of intermanual transfer during visuomotor adaptation

PubMed Central

Wojaczynski, Greg J.; Ivry, Richard B.

2011-01-01

Studies of intermanual transfer have been used to probe representations formed during skill acquisition. We employ a new method that provides a continuous assay of intermanual transfer, intermixing right- and left-hand trials while limiting visual feedback to right-hand movements. We manipulated the degree of awareness of the visuomotor rotation, introducing a 22.5° perturbation in either an abrupt single step or gradually in ∼1° increments every 10 trials. Intermanual transfer was observed with the direction of left-hand movements shifting in the opposite direction of the rotation over the course of training. The transfer on left-hand trials was less than that observed in the right hand. Moreover, the magnitude of transfer was larger in our mixed-limb design compared with the standard blocked design in which transfer is only probed at the end of training. Transfer was similar in the abrupt and gradual groups, suggesting that awareness of the perturbation has little effect on intermanual transfer. In a final experiment, participants were provided with a strategy to offset an abrupt rotation, a method that has been shown to increase error over the course of training due to the operation of sensorimotor adaptation. This deterioration was also observed on left-hand probe trials, providing further support that awareness has little effect on intermanual transfer. These results indicate that intermanual transfer is not dependent on the implementation of cognitively assisted strategies that participants might adopt when they become aware that the visuomotor mapping has been perturbed. Rather, the results indicate that the information available to processes involved in adaptation entails some degree of effector independence. PMID:21917998

Effects of Housing on Methamphetamine-Induced Neurotoxicity and Spatial Learning and Memory.

PubMed

Gutierrez, Arnold; Jablonski, Sarah A; Amos-Kroohs, Robyn M; Barnes, Anna C; Williams, Michael T; Vorhees, Charles V

2017-07-19

Severe stress potentiates methamphetamine (MA) neurotoxicity. However, whether moderate stress increases or decreases the neurotoxic effects of MA is unknown. We assessed the effects of MA (4 × 10 mg/kg at 2 h intervals) in combination with prior barren-cage housing in adult male Sprague-Dawley rats on monoamines and glial fibrillary acid protein (GFAP) in one cohort and spatial learning and memory in the Morris water maze in another cohort. MA reduced dopamine (DA) and serotonin (5-HT) in the neostriatum and nucleus accumbens, 5-HT in the hippocampus, and increased GFAP in neostriatum and nucleus accumbens compared with saline controls. In neostriatum, barren-cage housing protected against MA-induced increases in GFAP, but it did not prevent DA and 5-HT reductions, although it did increase hippocampal norepinephrine. MA impaired spatial learning during acquisition, reversal, and shift phases and impaired reference memory on reversal and shift probe trials. Barren-cage housing enhanced performance during acquisition but not during reversal or shift or on probe trials. The data indicate that prior barren-cage housing moderates MA-induced neostriatal astrogliosis and initial spatial learning, but has no protective effect when the platform is smaller and relocated and therefore requires cognitive flexibility in relearning.

Backward masked fearful faces enhance contralateral occipital cortical activity for visual targets within the spotlight of attention

PubMed Central

Reinke, Karen S.; LaMontagne, Pamela J.; Habib, Reza

2011-01-01

Spatial attention has been argued to be adaptive by enhancing the processing of visual stimuli within the ‘spotlight of attention’. We previously reported that crude threat cues (backward masked fearful faces) facilitate spatial attention through a network of brain regions consisting of the amygdala, anterior cingulate and contralateral visual cortex. However, results from previous functional magnetic resonance imaging (fMRI) dot-probe studies have been inconclusive regarding a fearful face-elicited contralateral modulation of visual targets. Here, we tested the hypothesis that the capture of spatial attention by crude threat cues would facilitate processing of subsequently presented visual stimuli within the masked fearful face-elicited ‘spotlight of attention’ in the contralateral visual cortex. Participants performed a backward masked fearful face dot-probe task while brain activity was measured with fMRI. Masked fearful face left visual field trials enhanced activity for spatially congruent targets in the right superior occipital gyrus, fusiform gyrus and lateral occipital complex, while masked fearful face right visual field trials enhanced activity in the left middle occipital gyrus. These data indicate that crude threat elicited spatial attention enhances the processing of subsequent visual stimuli in contralateral occipital cortex, which may occur by lowering neural activation thresholds in this retinotopic location. PMID:20702500

Bayesian hierarchical modeling for subject-level response classification in peptide microarray immunoassays

PubMed Central

Imholte, Gregory; Gottardo, Raphael

2017-01-01

Summary The peptide microarray immunoassay simultaneously screens sample serum against thousands of peptides, determining the presence of antibodies bound to array probes. Peptide microarrays tiling immunogenic regions of pathogens (e.g. envelope proteins of a virus) are an important high throughput tool for querying and mapping antibody binding. Because of the assay’s many steps, from probe synthesis to incubation, peptide microarray data can be noisy with extreme outliers. In addition, subjects may produce different antibody profiles in response to an identical vaccine stimulus or infection, due to variability among subjects’ immune systems. We present a robust Bayesian hierarchical model for peptide microarray experiments, pepBayes, to estimate the probability of antibody response for each subject/peptide combination. Heavy-tailed error distributions accommodate outliers and extreme responses, and tailored random effect terms automatically incorporate technical effects prevalent in the assay. We apply our model to two vaccine trial datasets to demonstrate model performance. Our approach enjoys high sensitivity and specificity when detecting vaccine induced antibody responses. A simulation study shows an adaptive thresholding classification method has appropriate false discovery rate control with high sensitivity, and receiver operating characteristics generated on vaccine trial data suggest that pepBayes clearly separates responses from non-responses. PMID:27061097

Markers of preparatory attention predict visual short-term memory performance.

PubMed

Murray, Alexandra M; Nobre, Anna C; Stokes, Mark G

2011-05-01

Visual short-term memory (VSTM) is limited in capacity. Therefore, it is important to encode only visual information that is most likely to be relevant to behaviour. Here we asked which aspects of selective biasing of VSTM encoding predict subsequent memory-based performance. We measured EEG during a selective VSTM encoding task, in which we varied parametrically the memory load and the precision of recall required to compare a remembered item to a subsequent probe item. On half the trials, a spatial cue indicated that participants only needed to encode items from one hemifield. We observed a typical sequence of markers of anticipatory spatial attention: early attention directing negativity (EDAN), anterior attention directing negativity (ADAN), late directing attention positivity (LDAP); as well as of VSTM maintenance: contralateral delay activity (CDA). We found that individual differences in preparatory brain activity (EDAN/ADAN) predicted cue-related changes in recall accuracy, indexed by memory-probe discrimination sensitivity (d'). Importantly, our parametric manipulation of memory-probe similarity also allowed us to model the behavioural data for each participant, providing estimates for the quality of the memory representation and the probability that an item could be retrieved. We found that selective encoding primarily increased the probability of accurate memory recall; that ERP markers of preparatory attention predicted the cue-related changes in recall probability. Copyright © 2011. Published by Elsevier Ltd.

When does a good working memory counteract proactive interference? Surprising evidence from a probe recognition task.

PubMed

Cowan, Nelson; Saults, J Scott

2013-02-01

It is often proposed that individuals with high working memory span overcome proactive interference (PI) from previous trials, saving working memory for task-relevant items. We examined this hypothesis in word-list probe recognition. We found no difference in PI related to span. Instead, ex-gaussian analysis of reaction time showed speed advantages for high spans specific to short lists (3 or 4 items) but absent from longer lists (6 or 8 items). We suggest that high-span advantages in reaction time are based on finesse during easy trials, not on overcoming PI. 2013 APA, all rights reserved

The contribution of the androgen receptor (AR) in human spatial learning and memory: A study in women with complete androgen insensitivity syndrome (CAIS).

PubMed

Mueller, S C; Verwilst, T; Van Branteghem, A; T'Sjoen, G; Cools, M

2016-02-01

Few studies have examined the impact of androgen insensitivity on human spatial learning and memory. In the present study, we tested 11 women with complete androgen insensitivity syndrome (CAIS), a rare genetic disorder characterized by complete absence of AR activity, and compared their performance against 20 comparison males and 19 comparison females on a virtual analog of the Morris Water Maze task. The results replicated a main sex effect showing that men relative to women were faster in finding the hidden platform and had reduced heading error. Furthermore, findings indicated that mean performance of women with CAIS was between control women and control men, though the differences were not statistically significant. Effect size estimates (and corresponding confidence intervals) of spatial learning trials showed little difference between women with CAIS and control women but CAIS women differed from men, but not women, on two variables, latency to find the platform and first-move latency. No differences between groups were present during visible platform trials or the probe trial, a measure of spatial memory. Moreover, groups also did not differ on estimates of IQ and variability of performance. The findings are discussed in relation to androgen insensitivity in human spatial learning and memory. Copyright © 2015 Elsevier Inc. All rights reserved.

Investigating Inhibitory Control in Children with Epilepsy: An fMRI Study

PubMed Central

Triplett, Regina L.; Velanova, Katerina; Luna, Beatriz; Padmanabhan, Aarthi; Gaillard, William D.; Asato, Miya R.

2014-01-01

SUMMARY Objective Deficits in executive function are increasingly noted in children with epilepsy and have been associated with poor academic and psychosocial outcomes. Impaired inhibitory control contributes to executive dysfunction in children with epilepsy; however, its neuroanatomic basis has not yet been investigated. We used functional Magnetic Resonance Imaging (fMRI) to probe the integrity of activation in brain regions underlying inhibitory control in children with epilepsy. Methods This cross-sectional study consisted of 34 children aged 8 to 17 years: 17 with well-controlled epilepsy and 17 age-and sex-matched controls. Participants performed the antisaccade (AS) task, representative of inhibitory control, during fMRI scanning. We compared AS performance during neutral and reward task conditions and evaluated task-related blood-oxygen level dependent (BOLD) activation. Results Children with epilepsy demonstrated impaired AS performance compared to controls during both neutral (non-reward) and reward trials, but exhibited significant task improvement during reward trials. Post-hoc analysis revealed that younger patients made more errors than older patients and all controls. fMRI results showed preserved activation in task-relevant regions in patients and controls, with the exception of increased activation in the left posterior cingulate gyrus in patients specifically with generalized epilepsy across neutral and reward trials. Significance Despite impaired inhibitory control, children with epilepsy accessed typical neural pathways as did their peers without epilepsy. Children with epilepsy showed improved behavioral performance in response to the reward condition, suggesting potential benefits of the use of incentives in cognitive remediation. PMID:25223606

Ridge preservation using a composite bone graft and a bioabsorbable membrane with and without primary wound closure: a comparative clinical trial.

PubMed

Engler-Hamm, Daniel; Cheung, Wai S; Yen, Alec; Stark, Paul C; Griffin, Terrence

2011-03-01

The aim of this single-masked, randomized controlled clinical trial is to compare hard and soft tissue changes after ridge preservation performed with (control, RPc) and without (test, RPe) primary soft tissue closure in a split-mouth design. Eleven patients completed this 6-month trial. Extraction and ridge preservation were performed using a composite bone graft of inorganic bovine-derived hydroxyapatite matrix and cell binding peptide P-15 (ABM/P-15), demineralized freeze-dried bone allograft, and a copolymer bioabsorbable membrane. Primary wound closure was achieved on the control sites (RPc), whereas test sites (RPe) left the membrane exposed. Pocket probing depth on adjacent teeth, repositioning of the mucogingival junction, bone width, bone fill, and postoperative discomfort were assessed. Bone cores were obtained for histological examination. Intragroup analyses for both groups demonstrated statistically significant mean reductions in probing depth (RPc: 0.42 mm, P = 0.012; RPe: 0.25 mm, P = 0.012) and bone width (RPc: 3 mm, P = 0.002; RPe: 3.42 mm, P <0.001). However, intergroup analysis did not find these parameters to be statistically different at 6 months. The test group showed statistically significant mean change in bone fill (7.21 mm; P <0.001). Compared to the control group, the test group showed statistically significant lower mean postoperative discomfort (RPc 4 versus RPe 2; P = 0.002). Histomorphometric analysis showed presence of 0% to 40% of ABM/P-15 and 5% to 20% of new bone formation in both groups. Comparison of clinical variables between the two groups at 6 months revealed that the mucogingival junction was statistically significantly more coronally displaced in the control group than in the test group, with a mean of 3.83 mm versus 1.21 mm (P = 0.002). Ridge preservation without flap advancement preserves more keratinized tissue and has less postoperative discomfort and swelling. Although ridge preservation is performed with either method, ≈27% to 30% of bone width is lost.

Stokes polarimetry probe for skin lesion evaluation: preliminary results

NASA Astrophysics Data System (ADS)

Louie, Daniel C.; Tchvialeva, Lioudmilla; Kalia, Sunil; Lui, Harvey; Lee, Tim K.

2018-02-01

This paper reports on the design of a prototype in-vivo Stokes polarimetry probe for skin lesion evaluation, and preliminary results from skin phantom and clinical trials of this device. The probe releases a single millisecond-long pulse from a laser diode with either linear or circular polarization. It then captures the resulting backscattered far-field polarization speckle and calculates the Stokes parameters. This probe was designed with three novel innovations in mind. First, the Stokes vector is captured quickly, using low-cost components without the use of moving parts. Second, a compact collimated laser diode was used as the light source. Third, the device and detector geometry were designed to produce and capture a uniform speckle field. In the first clinical trial of this device, measurements were taken from a variety of skin lesions, both cancerous and benign. The Stokes vector was measured and used to calculate the degree of polarization (DOP), the azimuth angle, and the ellipticity angle of the polarization ellipse for two input light polarizations. Among other findings, the DOP for circular polarized input light was consistently lower than the DOP for linear polarized input light. These findings indicate the potential for a fast and low-cost in-vivo skin cancer screening tool, and encourages the continuing development of this probe's techniques.

Photobiomodulation in human muscle tissue: an advantage in sports performance?

PubMed Central

Ferraresi, Cleber; Huang, Ying-Ying; Hamblin, Michael R.

2016-01-01

Photobiomodulation (PBM) describes the use of red or near-infrared (NIR) light to vstimulate, heal, and regenerate damaged tissue. Both pre-conditioning (light delivered to muscles before exercise) and PBM applied after exercise can increase sports performance in athletes. This review covers the effects of PBM on human muscle tissue in clinical trials in volunteers related to sports performance and in athletes. The parameters used were categorized into those with positive effects or no effects on muscle performance and recovery. Randomized controlled trials and case-control studies in both healthy trained and untrained participants, and elite athletes were retrieved from MEDLINE up to 2016. Performance metrics included fatigue, number of repetitions, torque, hypertrophy; measures of muscle damage and recovery such as creatine kinase and delayed onset muscle soreness. Searches retrieved 533 studies, of which 46 were included in the review (n=1045 participants). Studies used single laser probes, cluster of laser-diodes, LED-clusters, mixed clusters (lasers and LEDs), and flexible LED arrays. Both red, NIR, and red/NIR mixtures were used. PBM can increase muscle mass gained after training, and decrease inflammation and oxidative stress in muscle biopsies. We raise the question of whether PBM should be permitted in athletic competition by international regulatory authorities. PMID:27874264

The spatial learning and memory performance in methamphetamine–sensitized and withdrawn rats

PubMed Central

Bigdeli, Imanollah; Asia, Masomeh Nikfarjam- Haft; Miladi-Gorji, Hossein; Fadaei, Atefeh

2015-01-01

Objective(s): There is controversial evidence about the effect of methamphetamine (METH) on spatial memory. We tested the time- dependent effects of METH on spatial short-term (working) and long-term (reference) memory in METH –sensitized and withdrawn rats in the Morris water maze. Materials and Methods: Rats were sensitized to METH (2 mg/kg, daily/5 days, SC). Rats were trained in water maze (4 trials/day/for 5 days). Probe test was performed 24 hr after training. Two days after probe test, working memory training (2 trials/day/for 5 days) was conducted. Acquisition–retention interval was 75 min. The treatment was continued per day 30 and 120 min before the test. Two groups of METH –sensitized rats were trained in reference memory after a longer period of withdrawal (30 days). Results: Sensitized rats exhibited significantly longer escape latencies on the training, spent significantly less time in the target zone (all, P<0.05), and their working memory impaired 30 min after injection. While, METH has no effect on the spatial learning process 120 min after injection, and rats spent significantly less time in the target zone (P<0.05), as well it has no effect on working memory. Also, impairment of reference memory persisted after prolonged abstinence. Conclusion: Our findings indicated that METH impaired spatial learning and memory 30 min after injection, but spared spatial learning, either acquisition or retention of spatial working, but partially impaired retention of spatial reference memory following 120 min after injection in sensitized rats, which persisted even after prolonged abstinence. PMID:25945235

Optimizing Equivalence-Based Instruction: Effects of Training Protocols on Equivalence Class Formation

ERIC Educational Resources Information Center

Fienup, Daniel M.; Wright, Nicole A.; Fields, Lanny

2015-01-01

Two experiments evaluated the effects of the simple-to-complex and simultaneous training protocols on the formation of academically relevant equivalence classes. The simple-to-complex protocol intersperses derived relations probes with training baseline relations. The simultaneous protocol conducts all training trials and test trials in separate…

Hypothesis Sampling Systems among Preoperational and Concrete Operational Kindergarten Children

ERIC Educational Resources Information Center

Gholson, Barry; And Others

1976-01-01

Preoperational and concrete operational kindergarten children received stimulus differentiation training, either with or without feedback, and then a series of discrimination learning problems in which a blank trial probe was used to detect a child's hypothesis after each feedback trial. Piagetian stage theory requires elaboration to account…

Temporal Expectations Guide Dynamic Prioritization in Visual Working Memory through Attenuated α Oscillations.

PubMed

van Ede, Freek; Niklaus, Marcel; Nobre, Anna C

2017-01-11

Although working memory is generally considered a highly dynamic mnemonic store, popular laboratory tasks used to understand its psychological and neural mechanisms (such as change detection and continuous reproduction) often remain relatively "static," involving the retention of a set number of items throughout a shared delay interval. In the current study, we investigated visual working memory in a more dynamic setting, and assessed the following: (1) whether internally guided temporal expectations can dynamically and reversibly prioritize individual mnemonic items at specific times at which they are deemed most relevant; and (2) the neural substrates that support such dynamic prioritization. Participants encoded two differently colored oriented bars into visual working memory to retrieve the orientation of one bar with a precision judgment when subsequently probed. To test for the flexible temporal control to access and retrieve remembered items, we manipulated the probability for each of the two bars to be probed over time, and recorded EEG in healthy human volunteers. Temporal expectations had a profound influence on working memory performance, leading to faster access times as well as more accurate orientation reproductions for items that were probed at expected times. Furthermore, this dynamic prioritization was associated with the temporally specific attenuation of contralateral α (8-14 Hz) oscillations that, moreover, predicted working memory access times on a trial-by-trial basis. We conclude that attentional prioritization in working memory can be dynamically steered by internally guided temporal expectations, and is supported by the attenuation of α oscillations in task-relevant sensory brain areas. In dynamic, everyday-like, environments, flexible goal-directed behavior requires that mental representations that are kept in an active (working memory) store are dynamic, too. We investigated working memory in a more dynamic setting than is conventional, and demonstrate that expectations about when mnemonic items are most relevant can dynamically and reversibly prioritize these items in time. Moreover, we uncover a neural substrate of such dynamic prioritization in contralateral visual brain areas and show that this substrate predicts working memory retrieval times on a trial-by-trial basis. This places the experimental study of working memory, and its neuronal underpinnings, in a more dynamic and ecologically valid context, and provides new insights into the neural implementation of attentional prioritization within working memory. Copyright © 2017 van Ede et al.

Caecal microbiota of chickens fed diets containing propolis.

PubMed

Eyng, C; Murakami, A E; Pedroso, A A; Duarte, C R A; Picoli, K P

2017-06-01

The present study aimed to evaluate the effect of different levels of ethanolic extract of propolis (EEP) and raw propolis (RP) on broiler performance and on selected bacterial groups in caecal microbiota using fluorescent in situ hybridization (FISH) measured by fluorescent activated cell sorting. Two experiments were conducted with 120 male chicks from 1 to 21 days of age for each, raised in cages and distributed in a completely randomized experimental design; there were five replicates with four birds per experimental unit and six treatments for each experiment (trial 1 - EEP - 0, 1000, 2000, 3000, 4000 and 5000 ppm and trial 2 - RP - 0, 100, 200, 300, 400 and 500 ppm). Fluorescent probes were used against the bacterial groups in caecal samples collected at 21 days of age. The data were subjected to one-way anova followed by Tukey's and regression analyses were used to assess the relationship between dietary levels of EEP or RP on performance and intestinal microbiota (p < 0.05). In the trial 1, results showed that the EEP did not cause any significant (p > 0.05) modification in the performance and caecal microbiota. In the trial 2, RP inclusion did not affect the performance but changed the bacterial composition (p < 0.05). Clostridiaceae, Gammaproteobacteria excluding Enterobacteriaceae and Lactobacillus spp. showed a quadratic response (p < 0.05), with the lowest value predicted to occur at 240 ppm, 221 ppm and 213 ppm of RP respectively. The proportion of Bacteroidaceae and Gammaproteobacteria did not differ (p > 0.05) among the experimental groups. The inclusion of ethanolic extract of propolis did not affect the performance and intestinal microbiota, whereas the supplementation of raw propolis modulates the caecal microbiota composition without any effects on chicken performance. Journal of Animal Physiology and Animal Nutrition © 2016 Blackwell Verlag GmbH.

Open access chemical probes for epigenetic targets

PubMed Central

Brown, Peter J; Müller, Susanne

2015-01-01

Background High attrition rates in drug discovery call for new approaches to improve target validation. Academia is filling gaps, but often lacks the experience and resources of the pharmaceutical industry resulting in poorly characterized tool compounds. Discussion The SGC has established an open access chemical probe consortium, currently encompassing ten pharmaceutical companies. One of its mandates is to create well-characterized inhibitors (chemical probes) for epigenetic targets to enable new biology and target validation for drug development. Conclusion Epigenetic probe compounds have proven to be very valuable and have not only spurred a plethora of novel biological findings, but also provided starting points for clinical trials. These probes have proven to be critical complementation to traditional genetic targeting strategies and provided sometimes surprising results. PMID:26397018

The Patient Reported Outcomes, Burdens and Experiences (PROBE) Project: development and evaluation of a questionnaire assessing patient reported outcomes in people with haemophilia.

PubMed

Skinner, M W; Chai-Adisaksopha, C; Curtis, R; Frick, N; Nichol, M; Noone, D; O'Mahony, B; Page, D; Stonebraker, J S; Iorio, A

2018-01-01

The interest of health care agencies, private payers and policy makers for patient-reported outcomes (PRO) is continuously increasing. There is a substantial need to improve capacity to collect and interpret relevant PRO data to support implementation of patient-centered research and optimal care in haemophilia. The Patient Reported Outcomes, Burdens and Experiences (PROBE) Project aims to develop a patient-led research network, to develop a standardized questionnaire to gather patient-reported outcomes and to perform a feasibility study of implementing the PROBE questionnaire. A pilot questionnaire was developed using focus group methodology. Content and face validity were assessed by a pool of persons living with haemophilia (PWH) and content experts through interactive workshops. The PROBE questionnaire was translated with the forward-backward approach. PROBE recruited national haemophilia patient non-governmental organizations (NGOs) to administer the questionnaire to people with and without haemophilia. PROBE measured the time to complete the questionnaire and gathered feedback on its content and clarity; staff time and cost required to implement the questionnaire were also collected. The PROBE questionnaire is comprised of four major sections (demographic data, general health problems, haemophilia-related health problems and health-related quality of life using EQ-5D-5L and EQ-VAS). Seventeen NGOs participated in the pilot study of the PROBE Project, recruiting 656 participants. Of these, 71% completed the questionnaire within 15 min, and all participants completed within 30 min. The median total staff and volunteer time required for the NGOs to carry out the study within their country was 9 h (range 2 to 40 h). NGO costs ranged from $22.00 to $543.00 USD per country, with printing and postage being the most commonly reported expenditures. The PROBE questionnaire assesses patient-important reported outcomes in PWH and control participants, with a demonstrated short completion time. PROBE proved the feasibility to engage diverse patient communities in the structured generation of real-world outcome research at all stages. Trial registration: NCT02439710.

Understanding of visual attention by adult humans (Homo sapiens): a partial replication of Povinelli, Bierschwale, and Cech (1999).

PubMed

Thomas, Emily; Murphy, Mary; Pitt, Rebecca; Rivers, Angela; Leavens, David A

2008-11-01

Povinelli, Bierschwale, and Cech (1999) reported that when tested on a visual attention task, the behavior of juvenile chimpanzees did not support a high-level understanding of visual attention. This study replicates their research using adult humans and aims to investigate the validity of their experimental design. Participants were trained to respond to pointing cues given by an experimenter, and then tested on their ability to locate hidden objects from visual cues. Povinelli et al.'s assertion that the generalization of pointing to gaze is indicative of a high-level framework was not supported by our findings: Training improved performance only on initial probe trials when the experimenter's gaze was not directed at the baited cup. Furthermore, participants performed above chance on such trials, the same result exhibited by chimpanzees and used as evidence by Povinelli et al. to support a low-level framework. These findings, together with the high performance of participants in an incongruent condition, in which the experimenter pointed to or gazed at an unbaited container, challenge the validity of their experimental design. (PsycINFO Database Record (c) 2008 APA, all rights reserved).

Treatment of vulvar/vaginal condyloma by HPV: developed instrumentation and clinical report

NASA Astrophysics Data System (ADS)

Inada, N. M.; Kurachi, C.; Ferreira, J.; Ribeiro, E. S.; Guimarães, O. C. C.; Quintana, S. M.; Lombardi, W.; Bagnato, V. S.

2009-06-01

Human papillomavirus (HPVs) are a family of sexually viruses with over 100 different genotypes identified till date. They are associated in 99% of cervical cancers, with HPV16 found in about 50% of cases. They are a cause of the second most common female cancer worldwide. PDT may constitute an alternative treatment for condyloma by HPV. In this work we present the development of a PDT device specifically designed for the treatment of vulvar and vaginal lesions induced by HPV. This equipment has been used in a clinical protocol and it is optically based on 640 nm LED (light emitting diodes) arrays. There are three illumination probes available that were anatomically designed for specific site applications: a 30 mm x 115 mm diffuser cylinder for intravaginal illumination and uniform irradiance of 42 mW/cm2; a 36 mm circular probe with 118 mW/cm2 and a 74 mm circular probe with 57 mW/cm2, both for external illumination. The 10% aminolevulinic acid cream is topically placed over the lesions and 4-6 hours after the application the illumination is performed. The illumination time is set depending on the chosen probe and treatment area to achieve a fluence of 200 J/cm2. In this presentation, the preliminary results of this clinical trial will be presented.

Effects of Contextual Similarity and Target-Repetition Proportion on Negative Priming in RT Distributional Analyses

ERIC Educational Resources Information Center

Tse, Chi-Shing; Hutchison, Keith A.; Li, Yongna

2011-01-01

Participants' reaction time (RT) data in a prime-probe flanker task (e.g., ABA-CAC) were analyzed in terms of the characteristics of RT distribution to examine possible mechanisms that produce negative priming. When the prime and probe were presented in the same context and the proportion of repetition-target trials (TRP) was 0.33, negative…

When Does a Good Working Memory Counteract Proactive Interference? Surprising Evidence from a Probe Recognition Task

ERIC Educational Resources Information Center

Cowan, Nelson; Saults, J. Scott

2013-01-01

It is often proposed that individuals with high working memory span overcome proactive interference (PI) from previous trials, saving working memory for task-relevant items. We examined this hypothesis in word-list probe recognition. We found no difference in PI related to span. Instead, ex-Gaussian analysis of reaction time showed speed…

Teaching Basic First-Aid Skills against Home Accidents to Children with Autism through Video Modeling

ERIC Educational Resources Information Center

Ergenekon, Yasemin

2012-01-01

It is known that children with DD can learn first-aid skills and use whenever needed. Applying first-aid skills was taught to three inclusion students with autism through "first-aid skills training package". In the study multiple probe design with probe trials across behaviors was used. The findings indicated that first-aid skills…

Attention Training in Individuals with Generalized Social Phobia: A Randomized Controlled Trial

ERIC Educational Resources Information Center

Amir, Nader; Beard, Courtney; Taylor, Charles T.; Klumpp, Heide; Elias, Jason; Burns, Michelle; Chen, Xi

2009-01-01

The authors conducted a randomized, double-blind placebo-controlled trial to examine the efficacy of an attention training procedure in reducing symptoms of social anxiety in 44 individuals diagnosed with generalized social phobia (GSP). Attention training comprised a probe detection task in which pictures of faces with either a threatening or…

Clinical utility of a DNA probe to 17p11.2 in screening of patients with a peripheral neuropathy

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

Blancato, J.; Precht, K.; Meck, J.

1994-09-01

We assessed the usefulness of in situ hybridization with a DNA probe to the area of chromosome 17 at p11.2 as a diagnostic tool for screening for Charcot Marte Tooth 1A (CMT 1A). In situ hybridization with a probe to 17p11.2 was performed on fixed lymphocytes from the following groups of individuals: (1) normal controls; (2) patients evoking a strong clinical suspicion of CMT 1A; and (3) 3 families with an apparent autosomal dominant peripheral neuropathy of unknown diagnoses. Group 2 patients had evidence of demyelination as defined by nerve conduction of less that 50% of the normal mean ormore » terminal latency greater than 50% of the normal mean in conduction studies. Analysis of interphase cells hybridized with a cosmid DNA probe to 17p11.2 requires inclusion of a normal control with each trial and masked observer. Due to the size of the target DNA and the nature of the centromeric heterochromatin, the scoring of this probe is more subjective than centromere probes. For example, if the two 17 chromosomes are decondensed as in interphase, two tandem signals may be visualized as one. Results from duplication positive patients demonstrate a large proportion of cells with two closely aligned, but separate, signals with an additional single signal. Normal results demonstrate a majority of cells with two separate signals representing both normal homologues. None of the 3 families with questionable diagnosis revealed a duplication at the region, reinforcing our belief that a clinical diagnosis is the most discriminating tool available for diagnosis of CMT 1A. We concur with Boylan that molecular analysis for CMT 1A is useful for establishing a diagnosis of CMT 1A, but is not a primary differential diagnostic test. The yield in screening patients without physiologic evidence of demyelination is likely to be low. We further find that the use of in situ hybridization is a simple method of performing the duplication analysis.« less

Attending to unrelated targets boosts short-term memory for color arrays.

PubMed

Makovski, Tal; Swallow, Khena M; Jiang, Yuhong V

2011-05-01

Detecting a target typically impairs performance in a second, unrelated task. It has been recently reported however, that detecting a target in a stream of distractors can enhance long-term memory of faces and scenes that were presented concurrently with the target (the attentional boost effect). In this study we ask whether target detection also enhances performance in a visual short-term memory task, where capacity limits are severe. Participants performed two tasks at once: a one shot, color change detection task and a letter-detection task. In Experiment 1, a central letter appeared at the same time as 3 or 5 color patches (memory display). Participants encoded the colors and pressed the spacebar if the letter was a T (target). After a short retention interval, a probe display of color patches appeared. Performance on the change detection task was enhanced when a target, rather than a distractor, appeared with the memory display. This effect was not modulated by memory load or the frequency of trials in which a target appeared. However, there was no enhancement when the target appeared at the same time as the probe display (Experiment 2a) or during the memory retention interval (Experiment 2b). Together these results suggest that detecting a target facilitates the encoding of unrelated information into visual short-term memory. Copyright © 2010 Elsevier Ltd. All rights reserved.

Effectiveness of Mechanical Debridement Combined With Adjunctive Therapies for Nonsurgical Treatment of Periimplantitis: A Systematic Review.

PubMed

de Almeida, Juliano Milanezi; Matheus, Henrique Rinaldi; Rodrigues Gusman, David Jonathan; Faleiros, Paula Lazilha; Januário de Araújo, Nathália; Noronha Novaes, Vivian Cristina

2017-02-01

This study aimed to perform a systematic review of the effectiveness of nonsurgical treatment associated with different adjuvant therapies on periimplantitis. Different individuals, following a research process, performed a network research of controlled and randomized controlled clinical trials on PubMed, Embase/MEDLINE, with 20 years' time constraint and the last search in January 2016. From 108 articles found by the first search, they analyzed 10 full texts, and in none did they find a standard control group. When compared, mechanical therapies combined with adjuvant therapy decreased prevalence of periimplant ratios; however, some groups showed unsatisfactory results, mainly related to the probing depth and bleeding index. When comparing debridement with other nonsurgical therapies (Er:YAG, Vector, air abrasive with amino acid glycine powder), increased periimplant levels were noticed in the test and control groups, although in different periods. Despite the improvement in the periimplant indices, there is no sufficient evidence to score the best results or even to choose the best association for nonsurgical treatment of periimplantitis; hence, more trials are necessary to answer this question.

Investigations of timing during the schedule and reinforcement intervals with wheel-running reinforcement.

PubMed

Belke, Terry W; Christie-Fougere, Melissa M

2006-11-01

Across two experiments, a peak procedure was used to assess the timing of the onset and offset of an opportunity to run as a reinforcer. The first experiment investigated the effect of reinforcer duration on temporal discrimination of the onset of the reinforcement interval. Three male Wistar rats were exposed to fixed-interval (FI) 30-s schedules of wheel-running reinforcement and the duration of the opportunity to run was varied across values of 15, 30, and 60s. Each session consisted of 50 reinforcers and 10 probe trials. Results showed that as reinforcer duration increased, the percentage of postreinforcement pauses longer than the 30-s schedule interval increased. On probe trials, peak response rates occurred near the time of reinforcer delivery and peak times varied with reinforcer duration. In a second experiment, seven female Long-Evans rats were exposed to FI 30-s schedules leading to 30-s opportunities to run. Timing of the onset and offset of the reinforcement period was assessed by probe trials during the schedule interval and during the reinforcement interval in separate conditions. The results provided evidence of timing of the onset, but not the offset of the wheel-running reinforcement period. Further research is required to assess if timing occurs during a wheel-running reinforcement period.

Modulation of the attentional span by foveal and parafoveal task load: An ERP study using attentional probes.

PubMed

Kornrumpf, Benthe; Sommer, Werner

2015-09-01

Due to capacity limitation, visual attention must be focused to a limited region of the visual field. Nevertheless, it is assumed that the size of that region may vary with task demands. We aimed to obtain direct evidence for the modulation of visuospatial attention as a function of foveal and parafoveal task load. Participants were required to fixate the center word of word triplets. In separate task blocks, either just the fixated word or both the fixated and the parafoveal word to the right should be semantically classified. The spatiotemporal distribution of attention was assessed with task-irrelevant probes flashed briefly at center or parafoveal positions, during or in between word presentation trials. The N1 component of the ERP elicited by intertrial probes at possible target positions increased with task demands within a block. These results suggest the recruitment of additional attentional resources rather than a redistribution of a fixed resource pool, which persists across trials. © 2015 Society for Psychophysiological Research.

Rapid feature-driven changes in the attentional window.

PubMed

Leonard, Carly J; Lopez-Calderon, Javier; Kreither, Johanna; Luck, Steven J

2013-07-01

Spatial attention must adjust around an object of interest in a manner that reflects the object's size on the retina as well as the proximity of distracting objects, a process often guided by nonspatial features. This study used ERPs to investigate how quickly the size of this type of "attentional window" can adjust around a fixated target object defined by its color and whether this variety of attention influences the feedforward flow of subsequent information through the visual system. The task involved attending either to a circular region at fixation or to a surrounding annulus region, depending on which region contained an attended color. The region containing the attended color varied randomly from trial to trial, so the spatial distribution of attention had to be adjusted on each trial. We measured the initial sensory ERP response elicited by an irrelevant probe stimulus that appeared in one of the two regions at different times after task display onset. This allowed us to measure the amount of time required to adjust spatial attention on the basis of the location of the task-relevant feature. We found that the probe-elicited sensory response was larger when the probe occurred within the region of the attended dots, and this effect required a delay of approximately 175 msec between the onset of the task display and the onset of the probe. Thus, the window of attention is rapidly adjusted around the point of fixation in a manner that reflects the spatial extent of a task-relevant stimulus, leading to changes in the feedforward flow of subsequent information through the visual system.

Conflicting Demands of Abstract and Specific Visual Object Processing Resolved by Fronto-Parietal Networks

PubMed Central

McMenamin, Brenton W.; Marsolek, Chad J.; Morseth, Brianna K.; Speer, MacKenzie F.; Burton, Philip C.; Burgund, E. Darcy

2016-01-01

Object categorization and exemplar identification place conflicting demands on the visual system, yet humans easily perform these fundamentally contradictory tasks. Previous studies suggest the existence of dissociable visual processing subsystems to accomplish the two abilities – an abstract category (AC) subsystem that operates effectively in the left hemisphere, and a specific exemplar (SE) subsystem that operates effectively in the right hemisphere. This multiple subsystems theory explains a range of visual abilities, but previous studies have not explored what mechanisms exist for coordinating the function of multiple subsystems and/or resolving the conflicts that would arise between them. We collected functional MRI data while participants performed two variants of a cue-probe working memory task that required AC or SE processing. During the maintenance phase of the task, the bilateral intraparietal sulcus (IPS) exhibited hemispheric asymmetries in functional connectivity consistent with exerting proactive control over the two visual subsystems: greater connectivity to the left hemisphere during the AC task, and greater connectivity to the right hemisphere during the SE task. Moreover, probe-evoked activation revealed activity in a broad fronto-parietal network (containing IPS) associated with reactive control when the two visual subsystems were in conflict, and variations in this conflict signal across trials was related to the visual similarity of the cue/probe stimulus pairs. Although many studies have confirmed the existence of multiple visual processing subsystems, this study is the first to identify the mechanisms responsible for coordinating their operations. PMID:26883940

Conflicting demands of abstract and specific visual object processing resolved by frontoparietal networks.

PubMed

McMenamin, Brenton W; Marsolek, Chad J; Morseth, Brianna K; Speer, MacKenzie F; Burton, Philip C; Burgund, E Darcy

2016-06-01

Object categorization and exemplar identification place conflicting demands on the visual system, yet humans easily perform these fundamentally contradictory tasks. Previous studies suggest the existence of dissociable visual processing subsystems to accomplish the two abilities-an abstract category (AC) subsystem that operates effectively in the left hemisphere and a specific exemplar (SE) subsystem that operates effectively in the right hemisphere. This multiple subsystems theory explains a range of visual abilities, but previous studies have not explored what mechanisms exist for coordinating the function of multiple subsystems and/or resolving the conflicts that would arise between them. We collected functional MRI data while participants performed two variants of a cue-probe working memory task that required AC or SE processing. During the maintenance phase of the task, the bilateral intraparietal sulcus (IPS) exhibited hemispheric asymmetries in functional connectivity consistent with exerting proactive control over the two visual subsystems: greater connectivity to the left hemisphere during the AC task, and greater connectivity to the right hemisphere during the SE task. Moreover, probe-evoked activation revealed activity in a broad frontoparietal network (containing IPS) associated with reactive control when the two visual subsystems were in conflict, and variations in this conflict signal across trials was related to the visual similarity of the cue-probe stimulus pairs. Although many studies have confirmed the existence of multiple visual processing subsystems, this study is the first to identify the mechanisms responsible for coordinating their operations.

Stock Versus CAD/CAM Customized Zirconia Implant Abutments – Clinical and Patient‐Based Outcomes in a Randomized Controlled Clinical Trial

PubMed Central

Meijer, Henny J.A.; Kerdijk, Wouter; Raghoebar, Gerry M.; Cune, Marco

2016-01-01

Abstract Background Single‐tooth replacement often requires a prefabricated dental implant and a customized crown. The benefits of individualization of the abutment remain unclear. Purpose This randomized controlled clinical trial aims to study potential benefits of individualization of zirconia implant abutments with respect to preservation of marginal bone level and several clinical and patient‐based outcome measures. Material and Methods Fifty participants with a missing premolar were included and randomly assigned to standard (ZirDesign, DentsplySirona Implants, Mölndal, Sweden) or computer aided design/computer aided manufacturing (CAD/CAM) customized (Atlantis, DentsplySirona Implants, Mölndal, Sweden) zirconia abutment therapy. Peri‐implant bone level (primary outcome), Plaque‐index, calculus formation, bleeding on probing, gingiva index, probing pocket depth, recession, appearance of soft tissues and patients' contentment were assessed shortly after placement and one year later. Results No implants were lost and no complications related to the abutments were observed. Statistically significant differences between stock and CAD/CAM customized zirconia abutments could not be demonstrated for any of the operationalized variables. Conclusion The use of a CAD/CAM customized zirconia abutment in single tooth replacement of a premolar is not associated with an improvement in clinical performance or patients' contentment when compared to the use of a stock zirconia abutment. PMID:27476829

Pattern of eyelid motion predictive of decision errors during drowsiness: oculomotor indices of altered states.

PubMed

Lobb, M L; Stern, J A

1986-08-01

Sequential patterns of eye and eyelid motion were identified in seven subjects performing a modified serial probe recognition task under drowsy conditions. Using simultaneous EOG and video recordings, eyelid motion was divided into components above, within, and below the pupil and the durations in sequence were recorded. A serial probe recognition task was modified to allow for distinguishing decision errors from attention errors. Decision errors were found to be more frequent following a downward shift in the gaze angle which the eyelid closing sequence was reduced from a five element to a three element sequence. The velocity of the eyelid moving over the pupil during decision errors was slow in the closing and fast in the reopening phase, while on decision correct trials it was fast in closing and slower in reopening. Due to the high variability of eyelid motion under drowsy conditions these findings were only marginally significant. When a five element blink occurred, the velocity of the lid over pupil motion component of these endogenous eye blinks was significantly faster on decision correct than on decision error trials. Furthermore, the highly variable, long duration closings associated with the decision response produced slow eye movements in the horizontal plane (SEM) which were more frequent and significantly longer in duration on decision error versus decision correct responses.

Stock Versus CAD/CAM Customized Zirconia Implant Abutments - Clinical and Patient-Based Outcomes in a Randomized Controlled Clinical Trial.

PubMed

Schepke, Ulf; Meijer, Henny J A; Kerdijk, Wouter; Raghoebar, Gerry M; Cune, Marco

2017-02-01

Single-tooth replacement often requires a prefabricated dental implant and a customized crown. The benefits of individualization of the abutment remain unclear. This randomized controlled clinical trial aims to study potential benefits of individualization of zirconia implant abutments with respect to preservation of marginal bone level and several clinical and patient-based outcome measures. Fifty participants with a missing premolar were included and randomly assigned to standard (ZirDesign, DentsplySirona Implants, Mölndal, Sweden) or computer aided design/computer aided manufacturing (CAD/CAM) customized (Atlantis, DentsplySirona Implants, Mölndal, Sweden) zirconia abutment therapy. Peri-implant bone level (primary outcome), Plaque-index, calculus formation, bleeding on probing, gingiva index, probing pocket depth, recession, appearance of soft tissues and patients' contentment were assessed shortly after placement and one year later. No implants were lost and no complications related to the abutments were observed. Statistically significant differences between stock and CAD/CAM customized zirconia abutments could not be demonstrated for any of the operationalized variables. The use of a CAD/CAM customized zirconia abutment in single tooth replacement of a premolar is not associated with an improvement in clinical performance or patients' contentment when compared to the use of a stock zirconia abutment. © 2016 The Authors. Clinical Implant Dentistry and Related Research Published by Wiley Periodicals, Inc.

Reversible online control of habitual behavior by optogenetic perturbation of medial prefrontal cortex

PubMed Central

Smith, Kyle S.; Virkud, Arti; Deisseroth, Karl; Graybiel, Ann M.

2012-01-01

Habits tend to form slowly but, once formed, can have great stability. We probed these temporal characteristics of habitual behaviors by intervening optogenetically in forebrain habit circuits as rats performed well-ingrained habitual runs in a T-maze. We trained rats to perform a maze habit, confirmed the habitual behavior by devaluation tests, and then, during the maze runs (ca. 3 s), we disrupted population activity in a small region in the medial prefrontal cortex, the infralimbic cortex. In accordance with evidence that this region is necessary for the expression of habits, we found that this cortical disruption blocked habitual behavior. Notably, however, this blockade of habitual performance occurred on line, within an average of three trials (ca. 9 s of inhibition), and as soon as during the first trial (<3 s). During subsequent weeks of training, the rats acquired a new behavioral pattern. When we again imposed the same cortical perturbation, the rats regained the suppressed maze-running that typified the original habit, and, simultaneously, the more recently acquired habit was blocked. These online changes occurred within an average of two trials (ca. 6 s of infralimbic inhibition). Measured changes in generalized performance ability and motivation to consume reward were unaffected. This immediate toggling between breaking old habits and returning to them demonstrates that even semiautomatic behaviors are under cortical control and that this control occurs online, second by second. These temporal characteristics define a framework for uncovering cellular transitions between fixed and flexible behaviors, and corresponding disturbances in pathologies. PMID:23112197

A quantitative method for determining spatial discriminative capacity.

PubMed

Zhang, Zheng; Tannan, Vinay; Holden, Jameson K; Dennis, Robert G; Tommerdahl, Mark

2008-03-10

The traditional two-point discrimination (TPD) test, a widely used tactile spatial acuity measure, has been criticized as being imprecise because it is based on subjective criteria and involves a number of non-spatial cues. The results of a recent study showed that as two stimuli were delivered simultaneously, vibrotactile amplitude discrimination became worse when the two stimuli were positioned relatively close together and was significantly degraded when the probes were within a subject's two-point limen. The impairment of amplitude discrimination with decreasing inter-probe distance suggested that the metric of amplitude discrimination could possibly provide a means of objective and quantitative measurement of spatial discrimination capacity. A two alternative forced-choice (2AFC) tracking procedure was used to assess a subject's ability to discriminate the amplitude difference between two stimuli positioned at near-adjacent skin sites. Two 25 Hz flutter stimuli, identical except for a constant difference in amplitude, were delivered simultaneously to the hand dorsum. The stimuli were initially spaced 30 mm apart, and the inter-stimulus distance was modified on a trial-by-trial basis based on the subject's performance of discriminating the stimulus with higher intensity. The experiment was repeated via sequential, rather than simultaneous, delivery of the same vibrotactile stimuli. Results obtained from this study showed that the performance of the amplitude discrimination task was significantly degraded when the stimuli were delivered simultaneously and were near a subject's two-point limen. In contrast, subjects were able to correctly discriminate between the amplitudes of the two stimuli when they were sequentially delivered at all inter-probe distances (including those within the two-point limen), and improved when an adapting stimulus was delivered prior to simultaneously delivered stimuli. Subjects' capacity to discriminate the amplitude difference between two vibrotactile stimulations was degraded as the inter-stimulus distance approached the limit of their two-point spatial discriminative capacity. This degradation of spatial discriminative capacity lessened when an adapting stimulus was used. Performance of the task, as well as improvement on the task with adaptation, would most likely be impaired if the cortical information processing capacity of a subject or subject population were systemically altered, and thus, the methods described could be effective measures for use in clinical or clinical research applications.

Human strategies for solving a time-place learning task: the role of counting and following verbal cues.

PubMed

García-Gallardo, Daniel; Aguilar, Francisco; Armenta, Benjamín; Carpio, Claudio

2015-04-01

Two experiments were conducted to assess the emergence of time-place learning in humans. In experiment 1, a computer based software was designed in which participants had to choose to enter one of four rooms in an abandoned house search for a zombie every 3-15s. Zombies could be found in only one of these rooms every trial in 3 min periods during the 12 min sessions. After 4 training sessions, participants were exposed to a probe session in which zombies could be found in any room on every trial. Almost all participants behaved as if they were timing the availability intervals: they anticipated the changes in the location of the zombie and they persisted in their performance patterns during the probe session; however, verbal reports revealed that they were counting the number of trials in each period in order to decide when to switch between rooms. In the second experiment, the task was modified in two ways: counting was made harder by using three different intertrial ranges within each session: 2-6s, 2-11s and 2-16s. Second, labels were displaced during the final session to assess whether participants learned to click on a given place or to follow a set of verbal cues. We found that participants did not notice the label changes suggesting that they learned to click on a given place, and that a win/stay-lose/shift strategy was clearly used to decide when to switch rooms in the second experiment. The implications of verbal behavior when assessing time-place learning with humans and the possible differences in this process between humans and animals are discussed. Copyright © 2015 Elsevier B.V. All rights reserved.

Comments on "J. Vera et. al., Soil water balance trial involving capacitance and neutron probe measurements"

USDA-ARS?s Scientific Manuscript database

Vera et al. (2009) compared estimates of soil profile water content (mm) to a depth of 0.8 m made with the neutron moisture meter (NMM) and a multi-depth capacitance probe (MDCP), using measurements replicated in four drainage lysimeters (5 m x 5 m x 1.5-m deep). The NMM estimates of water content w...

Vision 20/20: Molecular-guided surgical oncology based upon tumor metabolism or immunologic phenotype: Technological pathways for point of care imaging and intervention

PubMed Central

Paulsen, Keith D.; Samkoe, Kimberley S.; Elliott, Jonathan T.; Hasan, Tayyaba; Strong, Theresa V.; Draney, Daniel R.; Feldwisch, Joachim

2016-01-01

Surgical guidance with fluorescence has been demonstrated in individual clinical trials for decades, but the scientific and commercial conditions exist today for a dramatic increase in clinical value. In the past decade, increased use of indocyanine green based visualization of vascular flow, biliary function, and tissue perfusion has spawned a robust growth in commercial systems that have near-infrared emission imaging and video display capabilities. This recent history combined with major preclinical innovations in fluorescent-labeled molecular probes, has the potential for a shift in surgical practice toward resection guidance based upon molecular information in addition to conventional visual and palpable cues. Most surgical subspecialties already have treatment management decisions partially based upon the immunohistochemical phenotype of the cancer, as assessed from molecular pathology of the biopsy tissue. This phenotyping can inform the surgical resection process by spatial mapping of these features. Further integration of the diagnostic and therapeutic value of tumor metabolism sensing molecules or immune binding agents directly into the surgical process can help this field mature. Maximal value to the patient would come from identifying the spatial patterns of molecular expression in vivo that are well known to exist. However, as each molecular agent is advanced into trials, the performance of the imaging system can have a critical impact on the success. For example, use of pre-existing commercial imaging systems are not well suited to image receptor targeted fluorophores because of the lower concentrations expected, requiring orders of magnitude more sensitivity. Additionally the imaging system needs the appropriate dynamic range and image processing features to view molecular probes or therapeutics that may have nonspecific uptake or pharmacokinetic issues which lead to limitations in contrast. Imaging systems need to be chosen based upon objective performance criteria, and issues around calibration, validation, and interpretation need to be established before a clinical trial starts. Finally, as early phase trials become more established, the costs associated with failures can be crippling to the field, and so judicious use of phase 0 trials with microdose levels of agents is one viable paradigm to help the field advance, but this places high sensitivity requirements on the imaging systems used. Molecular-guided surgery has truly transformative potential, and several key challenges are outlined here with the goal of seeing efficient advancement with ideal choices. The focus of this vision 20/20 paper is on the technological aspects that are needed to be paired with these agents. PMID:27277060

Vision 20/20: Molecular-guided surgical oncology based upon tumor metabolism or immunologic phenotype: Technological pathways for point of care imaging and intervention.

PubMed

Pogue, Brian W; Paulsen, Keith D; Samkoe, Kimberley S; Elliott, Jonathan T; Hasan, Tayyaba; Strong, Theresa V; Draney, Daniel R; Feldwisch, Joachim

2016-06-01

Surgical guidance with fluorescence has been demonstrated in individual clinical trials for decades, but the scientific and commercial conditions exist today for a dramatic increase in clinical value. In the past decade, increased use of indocyanine green based visualization of vascular flow, biliary function, and tissue perfusion has spawned a robust growth in commercial systems that have near-infrared emission imaging and video display capabilities. This recent history combined with major preclinical innovations in fluorescent-labeled molecular probes, has the potential for a shift in surgical practice toward resection guidance based upon molecular information in addition to conventional visual and palpable cues. Most surgical subspecialties already have treatment management decisions partially based upon the immunohistochemical phenotype of the cancer, as assessed from molecular pathology of the biopsy tissue. This phenotyping can inform the surgical resection process by spatial mapping of these features. Further integration of the diagnostic and therapeutic value of tumor metabolism sensing molecules or immune binding agents directly into the surgical process can help this field mature. Maximal value to the patient would come from identifying the spatial patterns of molecular expression in vivo that are well known to exist. However, as each molecular agent is advanced into trials, the performance of the imaging system can have a critical impact on the success. For example, use of pre-existing commercial imaging systems are not well suited to image receptor targeted fluorophores because of the lower concentrations expected, requiring orders of magnitude more sensitivity. Additionally the imaging system needs the appropriate dynamic range and image processing features to view molecular probes or therapeutics that may have nonspecific uptake or pharmacokinetic issues which lead to limitations in contrast. Imaging systems need to be chosen based upon objective performance criteria, and issues around calibration, validation, and interpretation need to be established before a clinical trial starts. Finally, as early phase trials become more established, the costs associated with failures can be crippling to the field, and so judicious use of phase 0 trials with microdose levels of agents is one viable paradigm to help the field advance, but this places high sensitivity requirements on the imaging systems used. Molecular-guided surgery has truly transformative potential, and several key challenges are outlined here with the goal of seeing efficient advancement with ideal choices. The focus of this vision 20/20 paper is on the technological aspects that are needed to be paired with these agents.

Discrete Trial Instruction vs. Mand Training for Teaching Children with Autism to Make Requests

ERIC Educational Resources Information Center

Jennett, Heather K.; Harris, Sandra L.; Delmolino, Lara

2008-01-01

The present study compared the effects of discrete trial instruction (DTI) and mand training on the acquisition of independent requests in 6 children with autism. Two multiple-probe designs across participants were conducted with 3 participants receiving mand training followed by DTI and the other 3 receiving DTI followed by mand training. Eye…

A Replication and Extension of the Antisymmetry Effect in Pigeons

ERIC Educational Resources Information Center

Urcuioli, Peter J.; Swisher, Melissa

2012-01-01

Pigeons trained on successive AB symbolic matching show emergent BA antisymmetry if they are also trained on successive AA oddity and BB identity (Urcuioli, 2008, Experiment 4). In other words, when tested on BA probe trials following training, they respond more to the comparisons on the reverse of the nonreinforced AB baseline trials than on the…

The NASA Smart Probe Project for real-time multiple microsensor tissue recognition

NASA Technical Reports Server (NTRS)

Andrews, Russell J.; Mah, Robert W.

2003-01-01

BACKGROUND: Remote surgery requires automated sensors, effectors and sensor-effector communication. The NASA Smart Probe Project has focused on the sensor aspect. METHODS: The NASA Smart Probe uses neural networks and data from multiple microsensors for a unique tissue signature in real time. Animal and human trials use several probe configurations: (1) 8-microsensor probe (2.5 mm in diameter) for rodent studies (normal and subcutaneous mammary tumor tissues), and (2) 21-gauge needle probe with 3 spectroscopic fibers and an impedance microelectrode for breast cancer diagnosis in humans. Multisensor data are collected in real time (update 100 times/s) using PCs. RESULTS: Human data (collected by NASA licensee BioLuminate) from 15 women undergoing breast biopsy distinguished normal tissue from both benign tumors and breast carcinoma. Tumor margins and necrosis are rapidly detected. CONCLUSION: Real-time tissue identification is achievable. Potential applications, including probes incorporating nanoelectrode arrays, are presented. Copyright 2003 S. Karger AG, Basel.

The Impact of Residual Subgingival Cement on Biological Complications Around Dental Implants: A Systematic Review.

PubMed

Quaranta, Alessandro; Lim, Zhuo Wei; Tang, Joyce; Perrotti, Vittoria; Leichter, Jonathan

2017-06-01

To perform a systematic review on the impact of residual subgingival cement on peri-implant diseases and crestal bone loss. MEDLINE, SCOPUS, ISI Web of Knowledge and Cochrane Central Register of Controlled Trials (CENTRAL) databases were used to identify articles published without time limits. A total of 6 articles were selected for a total of 389 patients (687 implants). The studies were heterogeneous and had a moderate-to-high risk of bias, but met the inclusion criteria. Four of 6 studies were published by the same research group and assessed similar populations over time. A positive relationship between residual cement and peri-implant inflammation was observed. Data on peri-implant probing depths and crestal bone loss were reported in 1 study. Residual subgingival cement seems to be strongly associated with peri-implant mucositis which is a risk factor for increased probing depths crestal bone loss and peri-implantitis. Zinc oxide eugenol cements should be preferred to resin cements especially in patients with a history of periodontitis.

Virtual Morris task responses in individuals in an abstinence phase from alcohol.

PubMed

Ceccanti, Mauro; Coriale, Giovanna; Hamilton, Derek A; Carito, Valentina; Coccurello, Roberto; Scalese, Bruna; Ciafrè, Stefania; Codazzo, Claudia; Messina, Marisa Patrizia; Chaldakov, George N; Fiore, Marco

2018-02-01

The present study was aimed at examining spatial learning and memory, in 33 men and 12 women with alcohol use disorder (AUD) undergoing ethanol detoxification, by using a virtual Morris task. As controls, we recruited 29 men and 10 women among episodic drinkers without a history of alcohol addiction or alcohol-related diseases. Elevated latency to the first movement in all trials was observed only in AUD persons; furthermore, control women had longer latencies compared with control men. Increased time spent to reach the hidden platform in the learning phase was found for women of both groups compared with men, in particular during trial 3. As predicted, AUD persons (more evident in men) spent less time in the target quadrant during the probe trial; however, AUD women had longer latencies to reach the platform in the visible condition during trials 6 and 7 that resulted in a greater distance moved. As for the probe trial, men of both groups showed increased virtual locomotion compared with the women of both groups. The present investigation confirms and extends previous studies showing (i) different gender responses in spatial learning tasks, (ii) some alterations due to alcohol addiction in virtual spatial learning, and (iii) differences between AUD men and AUD women in spatial-behaviour-related paradigms.

The effects of anxiety upon attention allocation to affective stimuli.

PubMed

Waters, Allison M; Nitz, Ashley B; Craske, Michelle G; Johnson, Chris

2007-04-01

Pictures of emotionally aversive, neutral, and pleasant scenes were presented for 500 ms, followed by a probe presented in the same location (valid trials) or an alternate location (invalid trials) as the picture. Response-times to the probes were recorded in low (N=20) and high (N=27) trait anxious participants. Results revealed an overall negative cue validity effect of shorter reaction times (RTs) on invalid than valid trials, suggestive of an inhibition of return effect. Moreover, high trait anxious females showed a reduced negative cue validity effect for aversive pictures in comparison with neutral and pleasant pictures, suggestive of selective interference by the unpleasant material. By contrast, low trait anxious females showed an enhanced negative cue validity effect for aversive pictures relative to neutral and pleasant pictures, suggestive of attentional avoidance of the aversive content. The emotional content of picture cues did not significantly affect RTs in males, regardless of anxiety status. The results suggest that biased attention processes for aversive stimuli may contribute to the greater female propensity for anxiety disorders.

Recent advances in high-performance fluorescent and bioluminescent RNA imaging probes.

PubMed

Xia, Yuqiong; Zhang, Ruili; Wang, Zhongliang; Tian, Jie; Chen, Xiaoyuan

2017-05-22

RNA plays an important role in life processes. Imaging of messenger RNAs (mRNAs) and micro-RNAs (miRNAs) not only allows us to learn the formation and transcription of mRNAs and the biogenesis of miRNAs involved in various life processes, but also helps in detecting cancer. High-performance RNA imaging probes greatly expand our view of life processes and enhance the cancer detection accuracy. In this review, we summarize the state-of-the-art high-performance RNA imaging probes, including exogenous probes that can image RNA sequences with special modification and endogeneous probes that can directly image endogenous RNAs without special treatment. For each probe, we review its structure and imaging principle in detail. Finally, we summarize the application of mRNA and miRNA imaging probes in studying life processes as well as in detecting cancer. By correlating the structures and principles of various probes with their practical uses, we compare different RNA imaging probes and offer guidance for better utilization of the current imaging probes and the future design of higher-performance RNA imaging probes.

Early results of an in vivo trial of ESS in thyroid cancer

NASA Astrophysics Data System (ADS)

Rosen, Jennifer E.; Goukassian, Ilona D.; A'Amar, Ousama M.; Bigio, Irving J.; Lee, Stephanie L.

2012-02-01

Introduction: Thyroid cancer is the most common endocrine malignancy. The current gold standard for diagnosis, fine-needle aspiration (FNA) biopsy, yields 10-25% of indeterminate cytology results, leading to patients undergoing thyroidectomy for diagnosis. We assessed the technical potential of a miniaturized in vivo ESS (elastic light scattering spectroscopy) probe, built into an FNA needle assembly, to differentiate benign from malignant thyroid nodules. Methods: Under IRB approval, 15 patients in the endocrine clinic undergoing FNAB of a thyroid nodule had collection of ESS data using our novel miniaturized FNA probe. Using final surgical pathology as our gold standard, data post processing and visual inspection was completed. Results: 225 spectra were grouped and analyzed (120 benign, 30 malignant and 75 from indeterminate cytology). ESS probes demonstrated excellent reproducibility in use. Initial analysis of these preliminary data is promising, indicating distinction of spectral ESS features between malignant and benign conditions. Conclusion(s): An in vivo trial of an invasive miniaturized integrated ESS biopsy probe is acceptable to patients, and collection of ESS data is feasible and reliable. With development of a disease-specific algorithm, ESS could potentially be used as an in-situ real time intra-operative diagnostic tool or as a minimally invasive adjunct to conventional FNA cytology.

Auditory enhancement of increments in spectral amplitude stems from more than one source.

PubMed

Carcagno, Samuele; Semal, Catherine; Demany, Laurent

2012-10-01

A component of a test sound consisting of simultaneous pure tones perceptually "pops out" if the test sound is preceded by a copy of itself with that component attenuated. Although this "enhancement" effect was initially thought to be purely monaural, it is also observable when the test sound and the precursor sound are presented contralaterally (i.e., to opposite ears). In experiment 1, we assessed the magnitude of ipsilateral and contralateral enhancement as a function of the time interval between the precursor and test sounds (10, 100, or 600 ms). The test sound, randomly transposed in frequency from trial to trial, was followed by a probe tone, either matched or mismatched in frequency to the test sound component which was the target of enhancement. Listeners' ability to discriminate matched probes from mismatched probes was taken as an index of enhancement magnitude. The results showed that enhancement decays more rapidly for ipsilateral than for contralateral precursors, suggesting that ipsilateral enhancement and contralateral enhancement stem from at least partly different sources. It could be hypothesized that, in experiment 1, contralateral precursors were effective only because they provided attentional cues about the target tone frequency. In experiment 2, this hypothesis was tested by presenting the probe tone before the precursor sound rather than after the test sound. Although the probe tone was then serving as a frequency cue, contralateral precursors were again found to produce enhancement. This indicates that contralateral enhancement cannot be explained by cuing alone and is a genuine sensory phenomenon.

Measures of skin conductance and heart rate in alcoholic men and women during memory performance

PubMed Central

Poey, Alan; Ruiz, Susan Mosher; Marinkovic, Ksenija; Oscar-Berman, Marlene

2015-01-01

We examined abnormalities in physiological responses to emotional stimuli associated with long-term chronic alcoholism. Skin conductance responses (SCR) and heart rate (HR) responses were measured in 32 abstinent alcoholic (ALC) and 30 healthy nonalcoholic (NC) men and women undergoing an emotional memory task in an MRI scanner. The task required participants to remember the identity of two emotionally-valenced faces presented at the onset of each trial during functional magnetic resonance imaging (fMRI) scanning. After viewing the faces, participants saw a distractor image (an alcoholic beverage, nonalcoholic beverage, or scrambled image) followed by a single probe face. The task was to decide whether the probe face matched one of the two encoded faces. Skin conductance measurements (before and after the encoded faces, distractor, and probe) were obtained from electrodes on the index and middle fingers on the left hand. HR measurements (beats per minute before and after the encoded faces, distractor, and probe) were obtained by a pulse oximeter placed on the little finger on the left hand. We expected that, relative to NC participants, the ALC participants would show reduced SCR and HR responses to the face stimuli, and that we would identify greater reactivity to the alcoholic beverage stimuli than to the distractor stimuli unrelated to alcohol. While the beverage type did not differentiate the groups, the ALC group did have reduced skin conductance and HR responses to elements of the task, as compared to the NC group. PMID:26020002

Rapid prototyping of flexible intrafascicular electrode arrays by picosecond laser structuring.

PubMed

Mueller, Matthias; de la Oliva, Natalia; Del Valle, Jaume; Delgado-Martínez, Ignacio; Navarro, Xavier; Stieglitz, Thomas

2017-12-01

Interfacing the peripheral nervous system can be performed with a large variety of electrode arrays. However, stimulating and recording a nerve while having a reasonable amount of channels limits the number of available systems. Translational research towards human clinical trial requires device safety and biocompatibility but would benefit from design flexibility in the development process to individualize probes. We selected established medical grade implant materials like precious metals and Parylene C to develop a rapid prototyping process for novel intrafascicular electrode arrays using a picosecond laser structuring. A design for a rodent animal model was developed in conjunction with an intrafascicular implantation strategy. Electrode characterization and optimization was performed first in saline solution in vitro before performance and biocompatibility were validated in sciatic nerves of rats in chronic implantation. The novel fabrication process proved to be suitable for prototyping and building intrafascicular electrode arrays. Electrochemical properties of the electrode sites were enhanced and tested for long-term stability. Chronic implantation in the sciatic nerve of rats showed good biocompatibility, selectivity and stable stimulation thresholds. Established medical grade materials can be used for intrafascicular nerve electrode arrays when laser structuring defines structure size in the micro-scale. Design flexibility reduces re-design cycle time and material certificates are beneficial support for safety studies on the way to clinical trials.

Manual versus sonic-powered toothbrushing for plaque reduction in patients with dental implants: an explanatory randomised controlled trial.

PubMed

Swierkot, Katrin; Brusius, Manuel; Leismann, Diana; Nonnenmacher, Claudia; Nüsing, Rolf; Lubbe, Dirk; Schade-Brittinger, Carmen; Mengel, Reiner

2013-01-01

The aim of the present study was to investigate plaque levels following sonic-powered and manual toothbrushing in subjects with dental implants. This study included 36 male and 47 female partially edentulous patients (age range 45-78 years, mean age 59.8 years) that were randomly assigned to one of two treatment groups: the sonic toothbrush group (n = 42; Philips Sonicare FlexCare® toothbrush) or the manual toothbrush group (n = 41; Oral-B P40®). Clinical, microbiological and immunological examinations were performed blinded at baseline and after 3, 6, 9 and 12 months. Microbiological analyses were performed by real-time polymerase chain reaction. Immunological analyses (prostaglandin E2) were performed by chromatography-electrospray spectrometry. The plaque index difference between baseline and 12 months at implants showed no significant difference between sonic or manual toothbrushing in a two-sided Mann-Whitney test (W = 773.5, P = 0.426, 95% CI -0.64 to 0.20). At the end of the study, there were no significant changes in plaque index, bleeding on probing, gingival index, pocket probing depth, gingival recession, clinical attachment level or the microbiological and immunological outcomes at implants or teeth in either group. This study uncovered no significant difference between sonic and manual toothbrushing for plaque reduction at implants and teeth. Both toothbrushes maintain healthy peri-implant soft tissue.

Handheld Automated Microsurgical Instrumentation for Intraocular Laser Surgery

PubMed Central

Yang, Sungwook; Lobes, Louis A.; Martel, Joseph N.; Riviere, Cameron N.

2016-01-01

Background and Objective Laser photocoagulation is a mainstay or adjuvant treatment for a variety of common retinal diseases. Automated laser photocoagulation during intraocular surgery has not yet been established. The authors introduce an automated laser photocoagulation system for intraocular surgery, based on a novel handheld instrument. The goals of the system are to enhance accuracy and efficiency and improve safety. Materials and Methods Triple-ring patterns are introduced as a typical arrangement for the treatment of proliferative retinopathy and registered to a preoperative fundus image. In total, 32 target locations are specified along the circumferences of three rings having diameters of 1, 2, and 3 mm, with a burn spacing of 600 μm. Given the initial system calibration, the retinal surface is reconstructed using stereo vision, and the targets specified on the preoperative image are registered with the control system. During automated operation, the laser probe attached to the manipulator of the active handheld instrument is deflected as needed via visual servoing in order to correct the error between the aiming beam and a specified target, regardless of any erroneous handle motion by the surgeon. A constant distance of the laser probe from the retinal surface is maintained in order to yield consistent size of burns and ensure safety during operation. Real-time tracking of anatomical features enables compensation for any movement of the eye. A graphical overlay system within operating microscope provides the surgeon with guidance cues for automated operation. Two retinal surgeons performed automated and manual trials in an artificial model of the eye, with each trial repeated three times. For the automated trials, various targeting thresholds (50–200 μm) were used to automatically trigger laser firing. In manual operation, fixed repetition rates were used, with frequencies of 1.0–2.5 Hz. The power of the 532 nm laser was set at 3.0 W with a duration of 20 ms. After completion of each trial, the speed of operation and placement error of burns were measured. The performance of the automated laser photocoagulation was compared with manual operation, using interpolated data for equivalent firing rates from 1.0 to 1.75 Hz. Results In automated trials, average error increased from 45 ± 27 to 60 ± 37 μm as the targeting threshold varied from 50 to 200 μm, while average firing rate significantly increased from 0.69 to 1.71 Hz. The average error in the manual trials increased from 102 ± 67 to 174 ± 98 μm as firing rate increased from 1.0 to 2.5 Hz. Compared to the manual trials, the average error in the automated trials was reduced by 53.0–56.4%, resulting in statistically significant differences (P ≤ 10−20) for all equivalent frequencies (1.0–1.75 Hz). The depth of the laser tip in the automated trials was consistently maintained within 18 ± 2 μm root-mean-square (RMS) of its initial position, whereas it significantly varied in the manual trials, yielding an error of 296 ± 30 μm RMS. At high firing rates in manual trials, such as at 2.5 Hz, laser photocoagulation is marginally attained, yielding failed burns of 30% over the entire pattern, whereas no failed burns are found in automated trials. Relatively regular burn sizes are attained in the automated trials by the depth servoing of the laser tip, while burn sizes in the manual trials vary considerably. Automated avoidance of blood vessels was also successfully demonstrated, utilizing the retina-tracking feature to identify avoidance zones. Conclusion Automated intraocular laser surgery can improve the accuracy of photocoagulation while ensuring safety during operation. This paper provides an initial demonstration of the technique under reasonably realistic laboratory conditions; development of a clinically applicable system requires further work. PMID:26287813

DIAGNOdent Pen versus tactile sense for detection of subgingival calculus: an in vitro study.

PubMed

Shakibaie, Fardad; Walsh, Laurence J

2015-10-01

The objective of this study is to compare the performance of the DIAGNOdent laser fluorescence (LF) Pen to conventional periodontal probing for detection of subgingival calculus under defined laboratory conditions. Extracted teeth with various levels of subgingival deposits of calculus were mounted anatomically in stone casts, and an impression material was used to replicate periodontal soft tissues. The casts were examined for the presence of subgingival calculus at eight surfaces per tooth (240 sites) using LF and a periodontal probe. Sites were rescored after 1 and 3 weeks. Direct imaging of the root surfaces under magnification was the gold standard. As a result, for an experienced operator, LF was more accurate than tactile assessment (across all sites, 84.0% vs. 59.8%). The performance difference was greater for multi-rooted teeth (85.8% vs. 56.9%) than single-rooted teeth (77.2% vs. 66.7%). The performance of LF in this laboratory trial was influenced strongly by clinician skill and experience. When used by an experienced operator, LF was more sensitive (75.1% vs. 69.2%), specific (92.6% vs. 86.3%), and accurate (84% vs. 77.9%) than for an inexperienced operator. In conclusion, under the defined laboratory conditions used, LF had better performance than tactile examination, particularly for multi-rooted teeth. This method may have value clinically as an adjunct for detecting subgingival deposits of calculus in clinical practice. The usefulness of the method improves with operator experience.

Spatial Memory: Behavioral Determinants of Persistence in the Watermaze Delayed Matching-to-Place Task

ERIC Educational Resources Information Center

da Silva, Bruno M.; Bast, Tobias; Morris, Richard G. M.

2014-01-01

The watermaze delayed matching-to-place (DMP) task was modified to include probe trials, to quantify search preference for the correct place. Using a zone analysis of search preference, a gradual decay of one-trial memory in rats was observed over 24 h with weak memory consistently detected at a retention interval of 6 h, but unreliably at 24 h.…

Safety and Effectiveness of a Longer Focal Beam and Burst Duration in Ultrasonic Propulsion for Repositioning Urinary Stones and Fragments.

PubMed

Janssen, Karmon M; Brand, Timothy C; Cunitz, Bryan W; Wang, Yak-Nam; Simon, Julianna C; Starr, Frank; Liggitt, H Denny; Thiel, Jeff; Sorensen, Mathew D; Harper, Jonathan D; Bailey, Michael R; Dunmire, Barbrina

2017-08-01

In the first-in-human trial of ultrasonic propulsion, subjects passed collections of residual stone fragments repositioned with a C5-2 probe. Here, effectiveness and safety in moving multiple fragments are compared between the C5-2 and a custom (SC-50) probe that produces a longer focal beam and burst duration. Effectiveness was quantified by the number of stones expelled from a calyx phantom consisting of a 30-mm deep, water-filled well in a block of tissue mimicking material. Each probe was positioned below the phantom to move stones against gravity. Single propulsion bursts of 50 ms or 3 s duration were applied to three separate targets: 10 fragments of 2 different sizes (1-2 and 2-3 mm) and a single 4 × 7 mm human stone. Safety studies consisted of porcine kidneys exposed to an extreme dose of 10-minute burst duration, including a 7-day survival study and acute studies with surgically implanted stones. Although successful in the clinical trial, the shorter focal beam and maximum 50 ms burst duration of the C5-2 probe moved stones, but did not expel any stones from the phantom's 30-mm deep calyx. The results were similar with the SC-50 probe under the same 50 ms burst duration. Longer (3 s) bursts available with the SC-50 probe expelled all stones at both 4.5 and 9.5 cm "skin-to-stone" depths with lower probe heating compared to the C5-2. No abnormal behavior, urine chemistry, serum chemistry, or histological findings were observed within the kidney or surrounding tissues for the 10 min burst duration used in the animal studies. A longer focal beam and burst duration improved expulsion of a stone and multiple stone fragments from a phantom over a broad range of clinically relevant penetration depths and did not cause kidney injury in animal studies.

The role of the central histaminergic receptors in the exercise-induced improvements of the spatial learning and memory in rats.

PubMed

Taati, Majid; Moghaddasi, Mehrnoush; Esmaeili, Masoumeh; Pourkhodadad, Soheila; Nayebzadeh, Hassan

2014-10-31

While it is well known that exercise can improve cognitive performance, the underlying mechanisms are not fully understood. There is now evidence that histamine can modulate learning and memory in different types of behavioral tasks. The present study was designed to examine the possible role of central histamine H1 and H2 receptors in forced treadmill running-induced enhancement of learning and memory in rats. For this purpose the animals received intracerebroventricularly chlorpheniramine (H1 receptor blocker) and cimetidine (H2 receptor blocker) before each day of fifteen consecutive days of exercise. Then their learning and memory were tested on the water maze task using a four-trial-per-day for 4 consecutive days. A probe trial was performed after the last training day. Our data showed that cimetidine reversed the exercise-induced improvement in learning and memory in rats; however, this was not the case regarding chlorpheniramine. Our findings indicate that central histamine H2 receptors play an important role in mediating the beneficial effects of forced exercise on learning and memory. Copyright © 2014 Elsevier B.V. All rights reserved.

Activation of intentional mechanisms through utilization of nonsymbolic movements in aphasia rehabilitation.

PubMed

Richards, Katherine; Singletary, Floris; Rothi, Leslie J Gonzalez; Koehler, Shirley; Crosson, Bruce

2002-01-01

Intentional mechanisms play an important role in complex self-initiated actions, such as language and gesturing. Deficits demonstrated in nonfluent aphasia may be a result of a disconnection between or damage to the initiation (intention) and production mechanisms in the left hemisphere. In chronic nonfluent aphasias, damaged language production mechanisms in the left hemisphere may switch to homologous regions in the right hemisphere while the initiation mechanisms remain active in the left hemisphere. A treatment was developed to prime right-hemisphere initiation mechanisms with movements of the nondominant hand, thereby bringing initiation into the right hemisphere where the language production mechanisms have been shifted. Three subjects with stable, chronic nonfluent aphasias were trained in daily sessions with a therapist to perform a complex nonsymbolic movement sequence with their nondominant hand to initiate naming trials of simple line drawings. Naming probes were administered during pre treatment baseline sessions and before each treatment session. All three subjects demonstrated a stable baseline and a significant increase over baseline performance in the percentage correct on naming probes during the treatment. Findings indicate that more extensive investigations of this newly developed treatment are justified and suggest that activation of right-hemisphere initiation mechanisms may enhance word production accuracy in stable, chronic nonfluent aphasias.

Monkey prefrontal neurons during Sternberg task performance: full contents of working memory or most recent item?

PubMed

Konecky, R O; Smith, M A; Olson, C R

2017-06-01

To explore the brain mechanisms underlying multi-item working memory, we monitored the activity of neurons in the dorsolateral prefrontal cortex while macaque monkeys performed spatial and chromatic versions of a Sternberg working-memory task. Each trial required holding three sequentially presented samples in working memory so as to identify a subsequent probe matching one of them. The monkeys were able to recall all three samples at levels well above chance, exhibiting modest load and recency effects. Prefrontal neurons signaled the identity of each sample during the delay period immediately following its presentation. However, as each new sample was presented, the representation of antecedent samples became weak and shifted to an anomalous code. A linear classifier operating on the basis of population activity during the final delay period was able to perform at approximately the level of the monkeys on trials requiring recall of the third sample but showed a falloff in performance on trials requiring recall of the first or second sample much steeper than observed in the monkeys. We conclude that delay-period activity in the prefrontal cortex robustly represented only the most recent item. The monkeys apparently based performance of this classic working-memory task on some storage mechanism in addition to the prefrontal delay-period firing rate. Possibilities include delay-period activity in areas outside the prefrontal cortex and changes within the prefrontal cortex not manifest at the level of the firing rate. NEW & NOTEWORTHY It has long been thought that items held in working memory are encoded by delay-period activity in the dorsolateral prefrontal cortex. Here we describe evidence contrary to that view. In monkeys performing a serial multi-item working memory task, dorsolateral prefrontal neurons encode almost exclusively the identity of the sample presented most recently. Information about earlier samples must be encoded outside the prefrontal cortex or represented within the prefrontal cortex in a cryptic code. Copyright © 2017 the American Physiological Society.

Bilingualism influences inhibitory control in auditory comprehension

PubMed Central

Blumenfeld, Henrike K.; Marian, Viorica

2013-01-01

Bilinguals have been shown to outperform monolinguals at suppressing task-irrelevant information. The present study aimed to identify how processing linguistic ambiguity during auditory comprehension may be associated with inhibitory control. Monolinguals and bilinguals listened to words in their native language (English) and identified them among four pictures while their eye-movements were tracked. Each target picture (e.g., hamper) appeared together with a similar-sounding within-language competitor picture (e.g., hammer) and two neutral pictures. Following each eye-tracking trial, priming probe trials indexed residual activation of target words, and residual inhibition of competitor words. Eye-tracking showed similar within-language competition across groups; priming showed stronger competitor inhibition in monolinguals than in bilinguals, suggesting differences in how inhibitory control was used to resolve within-language competition. Notably, correlation analyses revealed that inhibition performance on a nonlinguistic Stroop task was related to linguistic competition resolution in bilinguals but not in monolinguals. Together, monolingual-bilingual comparisons suggest that cognitive control mechanisms can be shaped by linguistic experience. PMID:21159332

Cognitive correlates of spatial navigation: Associations between executive functioning and the virtual Morris Water Task.

PubMed

Korthauer, L E; Nowak, N T; Frahmand, M; Driscoll, I

2017-01-15

Although effective spatial navigation requires memory for objects and locations, navigating a novel environment may also require considerable executive resources. The present study investigated associations between performance on the virtual Morris Water Task (vMWT), an analog version of a nonhuman spatial navigation task, and neuropsychological tests of executive functioning and spatial performance in 75 healthy young adults. More effective vMWT performance (e.g., lower latency and distance to reach hidden platform, greater distance in goal quadrant on a probe trial, fewer path intersections) was associated with better verbal fluency, set switching, response inhibition, and ability to mentally rotate objects. Findings also support a male advantage in spatial navigation, with sex moderating several associations between vMWT performance and executive abilities. Overall, we report a robust relationship between executive functioning and navigational skill, with some evidence that men and women may differentially recruit cognitive abilities when navigating a novel environment. Copyright © 2016 Elsevier B.V. All rights reserved.

Anger and aggression problems in veterans are associated with an increased acoustic startle reflex.

PubMed

Heesink, Lieke; Kleber, Rolf; Häfner, Michael; van Bedaf, Laury; Eekhout, Iris; Geuze, Elbert

2017-02-01

Anger and aggression are frequent problems in deployed military personnel. A lowered threshold of perceiving and responding to threat can trigger impulsive aggression. This can be indicated by an exaggerated startle response. Fifty-two veterans with anger and aggression problems (Anger group) and 50 control veterans were tested using a startle experiment with 10 startle probes and 10 prepulse trials, presented in a random order and with a random interval between the trials. Predictors (demographics, Trait Anger, State Anger, Harm Avoidance and Anxious Arousal) for the startle response within the Anger group were tested. Increased EMG responses were found to the startle probes in the Anger Group compared to the Control group, but not to the prepulse trials. Furthermore, Harm Avoidance and State Anger predicted the increased startle reflex within the Anger group, whereas Trait Anger was negatively related to the startle reflex. These findings indicate that threat reactivity is increased in anger and aggression problems. These problems are not only caused by an anxious predisposition, the degree of anger also predicts the startle reflex. Copyright © 2016 Elsevier B.V. All rights reserved.

Less is more: Patient-level meta-analysis reveals paradoxical dose-response effects of a computer-based social anxiety intervention targeting attentional bias.

PubMed

Price, Rebecca B; Kuckertz, Jennie M; Amir, Nader; Bar-Haim, Yair; Carlbring, Per; Wallace, Meredith L

2017-12-01

The past decade of research has seen considerable interest in computer-based approaches designed to directly target cognitive mechanisms of anxiety, such as attention bias modification (ABM). By pooling patient-level datasets from randomized controlled trials of ABM that utilized a dot-probe training procedure, we assessed the impact of training "dose" on relevant outcomes among a pooled sample of 693 socially anxious adults. A paradoxical effect of the number of training trials administered was observed for both posttraining social anxiety symptoms and behavioral attentional bias (AB) toward threat (the target mechanism of ABM). Studies administering a large (>1,280) number of training trials showed no benefit of ABM over control conditions, while those administering fewer training trials showed significant benefit for ABM in reducing social anxiety (P = .02). These moderating effects of dose were not better explained by other examined variables and previously identified moderators, including patient age, training setting (laboratory vs. home), or type of anxiety assessment (clinician vs. self-report). Findings inform the optimal dosing for future dot-probe style ABM applications in both research and clinical settings, and suggest several novel avenues for further research. © 2017 Wiley Periodicals, Inc.

Use of a cyanine dye probe to estimate the composition of the vitreous body after enzymatic treatment

NASA Astrophysics Data System (ADS)

Panova, Ina G.; Tatikolov, Alexander S.; Sharova, Natalia P.

2010-02-01

The aim of this work was to study the effect of enzymes such as proteinase K, trypsin, collagenase with hyaluronidase, as well as a mixture of all these enzymes, on albumin and collagens incorporated in the vitreous body, using a cyanine dye as a spectral-fluorescent probe. We studied the vitreous body of the eyes of 19/20-week human fetuses, in which, as we showed earlier, the concentration of albumin in the vitreous body is sufficiently high. Proteinase K steeply decreased the albumin content in the vitreous body, whereas trypsin and hyaluronidase with collagenase had no effect on the albumin content. Collagen was not subjected to proteinase K. Enzymatic digestion of collagen occurred under the action of collagenase with hyaluronidase. The content of albumin and collagen sharply decreased in the system after treatment of the vitreous body with mixture of all enzymes. Hence, the results obtained showed that, even being in the mixture, these enzymes have a selective effect on albumin and collagens. The possibility to study the dose-dependent character of enzymatic vitreolysis using a cyanine dye probe has been shown. The spectral-fluorescent probe for albumin and collagens proved to be useful for experimental approaches at screening the enzymatic mixtures possessing the selective action. The study performed is considered as a preclinical trial, and the method presented as promising for the further research in this field. The effect of the enzymes used for therapeutic purposes on the functional conditions of the vitreous body should be studied.

Nuclear micro-probe analysis of Arabidopsis thaliana leaves

NASA Astrophysics Data System (ADS)

Ager, F. J.; Ynsa, M. D.; Domínguez-Solís, J. R.; López-Martín, M. C.; Gotor, C.; Romero, L. C.

2003-09-01

Phytoremediation is a cost-effective plant-based approach for remediation of soils and waters which takes advantage of the remarkable ability of some plants to concentrate elements and compounds from the environment and to metabolize various molecules in their tissues, such as toxic heavy metals and organic pollutants. Nowadays, phytoremediation technology is becoming of paramount importance when environmental decontamination is concerned, due to the emerging knowledge of its physiological and molecular mechanisms and the new biological and engineering strategies designed to optimize and improve it. In addition, the feasibility of using plants for environmental cleanup has been confirmed by many different trials around the world. Arabidopsis thaliana plants can be used for basic studies to improve the technology on phytoremediation. Making use of nuclear microscopy techniques, in this paper we study leaves of wild type and transgenic A. thaliana plants grown in a cadmium-rich environment under different conditions. Micro-PIXE, RBS and SEM analyses, performed on the scanning proton micro-probe at the CNA in Seville (Spain), prove that cadmium is preferentially sequestered in the central region of epidermal trichome and allow comparing the effects of genetic modifications.

Colorimetric DNA detection of transgenic plants using gold nanoparticles functionalized with L-shaped DNA probes

NASA Astrophysics Data System (ADS)

Nourisaeid, Elham; Mousavi, Amir; Arpanaei, Ayyoob

2016-01-01

In this study, a DNA colorimetric detection system based on gold nanoparticles functionalized with L-shaped DNA probes was prepared and evaluated. We investigated the hybridization efficiency of the L-shaped probes and studied the effect of nanoparticle size and the L-shaped DNA probe length on the performance of the as-prepared system. Probes were attached to the surface of gold nanoparticles using an adenine sequence. An optimal sequence of 35S rRNA gene promoter from the cauliflower mosaic virus, which is frequently used in the development of transgenic plants, and the two complementary ends of this gene were employed as model target strands and probe molecules, respectively. The spectrophotometric properties of the as-prepared systems indicated that the large NPs show better changes in the absorption spectrum and consequently present a better performance. The results of this study revealed that the probe/Au-NPs prepared using a vertical spacer containing 5 thymine oligonucleotides exhibited a stronger spectrophotometric response in comparison to that of larger probes. These results in general indicate the suitable performance of the L-shaped DNA probe-functionalized Au-NPs, and in particular emphasize the important role of the gold nanoparticle size and length of the DNA probes in enhancing the performance of such a system.

Sonography of the chest using linear-array versus sector transducers: Correlation with auscultation, chest radiography, and computed tomography.

PubMed

Tasci, Ozlem; Hatipoglu, Osman Nuri; Cagli, Bekir; Ermis, Veli

2016-07-08

The primary purpose of our study was to compare the efficacies of two sonographic (US) probes, a high-frequency linear-array probe and a lower-frequency phased-array sector probe in the diagnosis of basic thoracic pathologies. The secondary purpose was to compare the diagnostic performance of thoracic US with auscultation and chest radiography (CXR) using thoracic CT as a gold standard. In total, 55 consecutive patients scheduled for thoracic CT were enrolled in this prospective study. Four pathologic entities were evaluated: pneumothorax, pleural effusion, consolidation, and interstitial syndrome. A portable US scanner was used with a 5-10-MHz linear-array probe and a 1-5-MHz phased-array sector probe. The first probe used was chosen randomly. US, CXR, and auscultation results were compared with the CT results. The linear-array probe had the highest performance in the identification of pneumothorax (83% sensitivity, 100% specificity, and 99% diagnostic accuracy) and pleural effusion (100% sensitivity, 97% specificity, and 98% diagnostic accuracy); the sector probe had the highest performance in the identification of consolidation (89% sensitivity, 100% specificity, and 95% diagnostic accuracy) and interstitial syndrome (94% sensitivity, 93% specificity, and 94% diagnostic accuracy). For all pathologies, the performance of US was superior to those of CXR and auscultation. The linear probe is superior to the sector probe for identifying pleural pathologies, whereas the sector probe is superior to the linear probe for identifying parenchymal pathologies. Thoracic US has better diagnostic performance than CXR and auscultation for the diagnosis of common pathologic conditions of the chest. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 44:383-389, 2016. © 2016 Wiley Periodicals, Inc.

Novel temperature-controlled RFA probe for treatment of blocked metal biliary stents in patients with pancreaticobiliary cancers: initial experience.

PubMed

Nayar, Manu K; Oppong, Kofi W; Bekkali, Noor L H; Leeds, John S

2018-05-01

 Radiofrequency ablation (RFA) is used to treat blocked biliary stents in patients with pancreaticobiliary (PB) tumors with varying results. We report our experience with a novel temperature-controlled probe for treatment of blocked metal stents.  Patients with histologically proven PB cancers and a blocked biliary stents were treated using ELRATM electrode (Taewoong Medical) under fluoroscopic guidance. Demographics, clinical outcome, stricture diameter improvements, complications and mortality at 30 days were prospectively recorded.  Nine procedures were performed on seven patients (4 male, 3 female); mean age 65.33 (range 56 - 82 years). Mean stricture diameter prior to RFA was 1.13 mm (SD ± 0.54) and 4.42 mm (SD ± 1.54) following RFA ( P  < 0.0001). Five of seven patients (71 %) required additional stents to ensure optimal drainage. There were no procedure-related complications. Mean follow-up was 193.55 days (range 31 - 540) and three of nine patients (33 %) died due to terminal cancer. These are the first reported data on use of a temperature-controlled RFA catheter in humans to treat blocked metal biliary stents. The device is safe but further randomized trials are required to establish the efficacy and survival benefits of this probe.

Attention Training in Individuals with Generalized Social Phobia: A Randomized Controlled Trial

PubMed Central

Amir, Nader; Beard, Courtney; Taylor, Charles T.; Klumpp, Heide; Elias, Jason; Burns, Michelle; Chen, Xi

2009-01-01

We conducted a randomized, double-blind placebo-controlled trial to examine the efficacy of an attention training procedure in reducing symptoms of social anxiety in forty-four individuals diagnosed with Generalized Social Phobia (GSP). Attention training comprised a probe detection task where pictures of faces with either a threatening or neutral emotional expression cued different locations on the computer screen. In the Attention Modification Program (AMP), participants responded to a probe that always followed neutral faces when paired with a threatening face, thereby directing attention away from threat. In the Attention Control Condition (ACC), the probe appeared with equal frequency in the position of the threat and neutral faces. Results revealed that the AMP facilitated attention disengagement from threat from pre- to post-assessment, and reduced clinician- and self-reported symptoms of social anxiety relative to the ACC. Participants no longer meeting DSM-IV criteria for GSP at post-assessment were 50% in the AMP and 14% in the ACC. Symptom reduction in the AMP group was maintained during four-month follow-up assessment. These results suggest that computerized attention training procedures may be beneficial for treating social phobia. PMID:19803575

Standard Practices for Usage of Inductive Magnetic Field Probes with Application to Electric Propulsion Testing

NASA Technical Reports Server (NTRS)

Polzin, Kurt A.; Hill, Carrie S.; Turchi, Peter J.; Burton, Rodney L.; Messer, Sarah; Lovberg, Ralph H.; Hallock, Ashley K.

2013-01-01

Inductive magnetic field probes (also known as B-dot probes and sometimes as B-probes or magnetic probes) are often employed to perform field measurements in electric propulsion applications where there are time-varying fields. Magnetic field probes provide the means to measure these magnetic fields and can even be used to measure the plasma current density indirectly through the application of Ampere's law. Measurements of this type can yield either global information related to a thruster and its performance or detailed, local data related to the specific physical processes occurring in the plasma. Results of the development of a standard for B-dot probe measurements are presented, condensing the available literature on the subject into an accessible set of rules, guidelines, and techniques to standardize the performance and presentation of future measurements.

Caloric restriction and spatial learning in old mice.

PubMed

Bellush, L L; Wright, A M; Walker, J P; Kopchick, J; Colvin, R A

1996-08-01

Spatial learning in old mice (19 or 24 months old), some of which had been calorically restricted beginning at 14 weeks of age, was compared to that of young mice, in two separate experiments using a Morris water maze. In the first experiment, only old mice reaching criterion performance on a cued learning task were tested in a subsequent spatial task. Thus, all old mice tested for spatial learning had achieved escape latencies equivalent to those of young controls. Despite equivalent swimming speeds, only about half the old mice in each diet group achieved criterion performance in the spatial task. In the second experiment, old and young mice all received the same number of training trials in a cued task and then in a spatial task. Immediately following spatial training, they were given a 60-s probe trial, with no platform in the pool. Both groups of old mice spent significantly less time in the quadrant where the platform had been and made significantly fewer direct crosses over the previous platform location than did the young control group. As in Experiment 1, calorie restriction failed to provide protection against aging-related deficits. However, in both experiments, some individual old mice evidenced performance in spatial learning indistinguishable from that of young controls. Separate comparisons of "age-impaired" and "age-unimpaired" old mice with young controls may facilitate the identification of neurobiological mechanisms underlying age-related cognitive decline.

Rapid prototyping of flexible intrafascicular electrode arrays by picosecond laser structuring

NASA Astrophysics Data System (ADS)

Mueller, Matthias; de la Oliva, Natalia; del Valle, Jaume; Delgado-Martínez, Ignacio; Navarro, Xavier; Stieglitz, Thomas

2017-12-01

Objective. Interfacing the peripheral nervous system can be performed with a large variety of electrode arrays. However, stimulating and recording a nerve while having a reasonable amount of channels limits the number of available systems. Translational research towards human clinical trial requires device safety and biocompatibility but would benefit from design flexibility in the development process to individualize probes. Approach. We selected established medical grade implant materials like precious metals and Parylene C to develop a rapid prototyping process for novel intrafascicular electrode arrays using a picosecond laser structuring. A design for a rodent animal model was developed in conjunction with an intrafascicular implantation strategy. Electrode characterization and optimization was performed first in saline solution in vitro before performance and biocompatibility were validated in sciatic nerves of rats in chronic implantation. Main results. The novel fabrication process proved to be suitable for prototyping and building intrafascicular electrode arrays. Electrochemical properties of the electrode sites were enhanced and tested for long-term stability. Chronic implantation in the sciatic nerve of rats showed good biocompatibility, selectivity and stable stimulation thresholds. Significance. Established medical grade materials can be used for intrafascicular nerve electrode arrays when laser structuring defines structure size in the micro-scale. Design flexibility reduces re-design cycle time and material certificates are beneficial support for safety studies on the way to clinical trials.

Dissociable contributions of dorsal and ventral striatal regions on a rodent cost/benefit decision-making task requiring cognitive effort.

PubMed

Silveira, Mason M; Tremblay, Melanie; Winstanley, Catharine A

2018-04-24

Cognitive effort is a ubiquitous process, yet surprisingly little is known about the brain mechanisms responsible for evaluating it. Here, we utilize the rat Cognitive Effort Task (rCET) to probe the striatum's role in deciding between options that vary in the amount of cognitive effort required for success. In the rCET, animals choose to perform either an easy trial, in which the attentional demand is low but the potential reward is small, or a difficult trial which is more attentionally demanding but can yield twice the sugar pellets. Twenty-six male Long Evans rats were trained on the rCET and the effects of pharmacologically inactivating the dorsomedial striatum (DMS) and core region of the nucleus accumbens were determined. Temporary inactivation of the DMS decreased all animals' choice of the high-effort, high-reward option, impaired attentional accuracy, and robustly increased premature responding without impairing general indices of motor ability. The DMS therefore appears necessary for the integration of cognitive signals required for optimal performance. In stark contrast, following temporary inactivation of the ventral striatum, subjects were fundamentally unable to perform the task, as reflected by a drastic decrease in the number of trials initiated and an increase in omitted responses. Together, these data suggest the striatum is likely part of a larger cortico-limbic-striatal network whose function is to optimize decisions requiring cognitive effort costs, at least in the attentional domain, and that striatal subregions have dissociable roles in the adjudication and application of this form of cognitive effort. Copyright © 2018 Elsevier Ltd. All rights reserved.

Dissociation of spatial navigation and visual guidance performance in Purkinje cell degeneration (pcd) mutant mice.

PubMed

Goodlett, C R; Hamre, K M; West, J R

1992-04-10

Spatial learning in rodents requires normal functioning of hippocampal and cortical structures. Recent data suggest that the cerebellum may also be essential. Neurological mutant mice with dysgenesis of the cerebellum provide useful models to examine the effects of abnormal cerebellar function. Mice with one such mutation, Purkinje cell degeneration (pcd), in which Purkinje cells degenerate between the third and fourth postnatal weeks, were evaluated for performance of spatial navigation learning and visual guidance learning in the Morris maze swim-escape task. Unaffected littermates and C57BL/6J mice served as controls. Separate groups of pcd and control mice were tested at 30, 50 and 110 days of age. At all ages, pcd mice had severe deficits in distal-cue (spatial) navigation, failing to decrease path lengths over training and failing to express appropriate spatial biases on probe trials. On the proximal-cue (visual guidance) task, whenever performance differences between groups did occur, they were limited to the initial trials. The ability of the pcd mice to perform the proximal-cue but not the distal-cue task indicates that the massive spatial navigation deficit was not due simply to motor dysfunction. Histological evaluations confirmed that the pcd mutation resulted in Purkinje cell loss without significant depletion of cells in the hippocampal formation. These data provide further evidence that the cerebellum is vital for the expression of behavior directed by spatial cognitive processes.

Evaluation of acute effect of light-emitting diode (LED) phototherapy on muscle deoxygenation and pulmonary oxygen uptake kinetics in patients with diabetes mellitus: study protocol for a randomized controlled trial.

PubMed

Francisco, Cristina de Oliveira; Beltrame, Thomas; Ferraresi, Cleber; Parizotto, Nivaldo Antonio; Bagnato, Vanderlei Salvador; Borghi Silva, Audrey; Benze, Benedito Galvão; Porta, Alberto; Catai, Aparecida Maria

2015-12-15

Type 2 diabetes mellitus (DM) is responsible for a significant reduction in the quality of life due to its negative impact on functional capacity. Cardiopulmonary fitness impairment in DM patients has been associated with limited tissue oxygenation. Phototherapy is widely utilized to treat several disorders due to expected light-tissue interaction. This type of therapy may help to improve muscular oxygenation, thereby increasing aerobic fitness and functional capacity. This study is a randomized, double-blind, placebo-controlled crossover trial approved by the Ethics Committee of the Federal University of São Carlos and registered at ClinicalTrials.gov. Four separate tests will be performed to evaluate the acute effect of phototherapy. All participants will receive both interventions in random order: light-emitting diode therapy (LEDT) and placebo, with a minimum 14-day interval between sessions (washout period). Immediately after the intervention, participants will perform moderate constant workload cycling exercise corresponding to 80 % of the pulmonary oxygen uptake [Formula: see text] during the gas exchange threshold (GET). LEDT will be administered with a multidiode cluster probe (50 GaAIA LEDs, 850 ηm, 75 mW each diode, and 3 J per point) before each exercise session. Pulmonary oxygen uptake, muscle oxygenation, heart rate, and arterial pressure will be measured using a computerized metabolic cart, a near-infrared spectrometer, an electrocardiogram, and a photoplethysmography system, respectively. The main objective of this study is to evaluate the acute effects of muscular pre-conditioning using LED phototherapy on pulmonary oxygen uptake, muscle oxygenation, heart rate, and arterial pressure dynamics during dynamic moderate exercise. We hypothesize that phototherapy may be beneficial to optimize aerobic fitness in the DM population. Data will be published after the study is completed. Registered at ClinicalTrials.gov under trial number NCT01889784 (date of registration 5 June 2013).

Pump-probe Kelvin-probe force microscopy: Principle of operation and resolution limits

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

Murawski, J.; Graupner, T.; Milde, P., E-mail: peter.milde@tu-dresden.de

Knowledge on surface potential dynamics is crucial for understanding the performance of modern-type nanoscale devices. We describe an electrical pump-probe approach in Kelvin-probe force microscopy that enables a quantitative measurement of dynamic surface potentials at nanosecond-time and nanometer-length scales. Also, we investigate the performance of pump-probe Kelvin-probe force microscopy with respect to the relevant experimental parameters. We exemplify a measurement on an organic field effect transistor that verifies the undisturbed functionality of our pump-probe approach in terms of simultaneous and quantitative mapping of topographic and electronic information at a high lateral and temporal resolution.

Slope-based and geometric encoding of a goal location by the terrestrial toad (Rhinella arenarum).

PubMed

Sotelo, María Inés; Bingman, Verner P; Muzio, Rubén N

2017-11-01

The current study was designed to test for the ability of terrestrial toads, Rhinella arenarum , to use slope as source of spatial information to locate a goal, and investigate the relative importance of slope and geometric information for goal localization. Toads were trained to locate a single, water-reward goal location in a corner of a rectangular arena placed on an incline. Once the toads learned the task, 3 types of probe trials were carried out to determine the relative use of slope and geometric information for goal localization. The probe trials revealed that the toads were able to independently use slope, and as previously reported, geometry to locate the goal. However, the boundary geometry of the experimental arena was found to be preferentially used by the toads when geometric and slope information were set in conflict. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Optimisation of readout performance of phase-change probe memory in terms of capping layer and probe tip

NASA Astrophysics Data System (ADS)

Wang, Lei; Wright, C. David; Aziz, Mustafa. M.; Yang, Ci Hui; Yang, Guo Wei

2014-11-01

The capping layer and the probe tip that serve as the protective layer and the recording tool, respectively, for phase-change probe memory play an important role on the writing performance of phase-change probe memory, thus receiving considerable attention. On the other hand, their influence on the readout performance of phasechange probe memory has rarely been reported before. A three-dimensional parametric study based on the Laplace equation was therefore conducted to investigate the effect of the capping layer and the probe tip on the resulting reading contrast for the two cases of reading a crystalline bit from an amorphous matrix and reading an amorphous bit from a crystalline matrix. The results indicated that a capping layer with a thickness of 2 nm and an electrical conductivity of 50 Ω-1m-1 is able to provide an appropriate reading contrast for both the cases, while satisfying the previous writing requirement, particularly with the assistance of a platinum silicide probe tip.

Effect of intranasal manganese administration on neurotransmission and spatial learning in rats

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

Blecharz-Klin, Kamilla; Piechal, Agnieszka; Joniec-Maciejak, Ilona

2012-11-15

The effect of intranasal manganese chloride (MnCl{sub 2}·4H{sub 2}O) exposure on spatial learning, memory and motor activity was estimated in Morris water maze task in adult rats. Three-month-old male Wistar rats received for 2 weeks MnCl{sub 2}·4H{sub 2}O at two doses the following: 0.2 mg/kg b.w. (Mn0.2) or 0.8 mg/kg b.w. (Mn0.8) per day. Control (Con) and manganese-exposed groups were observed for behavioral performance and learning in water maze. ANOVA for repeated measurements did not show any significant differences in acquisition in the water maze between the groups. However, the results of the probe trial on day 5, exhibited spatialmore » memory deficits following manganese treatment. After completion of the behavioral experiment, the regional brain concentrations of neurotransmitters and their metabolites were determined via HPLC in selected brain regions, i.e. prefrontal cortex, hippocampus and striatum. ANOVA demonstrated significant differences in the content of monoamines and metabolites between the treatment groups compared to the controls. Negative correlations between platform crossings on the previous platform position in Southeast (SE) quadrant during the probe trial and neurotransmitter turnover suggest that impairment of spatial memory and cognitive performance after manganese (Mn) treatment is associated with modulation of the serotonergic, noradrenergic and dopaminergic neurotransmission in the brain. These findings show that intranasally applied Mn can impair spatial memory with significant changes in the tissue level and metabolism of monoamines in several brain regions. -- Highlights: ► Intranasal exposure to manganese in rats impairs spatial memory in the water maze. ► Regional changes in levels of neurotransmitters in the brain have been identified. ► Cognitive disorder correlates with modulation of 5-HT, NA and DA neurotransmission.« less

Fluorescence-guided surgery for cancer patients: a proof of concept study on human xenografts in mice and spontaneous tumors in pets

PubMed Central

Mery, Eliane; Golzio, Muriel; Guillermet, Stephanie; Lanore, Didier; Naour, Augustin Le; Thibault, Benoît; Tilkin-Mariamé, Anne Françoise; Bellard, Elizabeth; Delord, Jean Pierre; Querleu, Denis; Ferron, Gwenael; Couderc, Bettina

2017-01-01

Surgery is often the first treatment option for patients with cancer. Patient survival essentially depends on the completeness of tumor resection. This is a major challenge, particularly in cases of peritoneal carcinomatosis, where tumors are widely disseminated in the large peritoneal cavity. Any development to help surgeons visualize these residual cells would improve the completeness of the surgery. For non-disseminated tumors, imaging could be used to ensure that the tumor margins and the draining lymph nodes are free of tumor deposits. Near-infrared fluorescence imaging has been shown to be one of the most convenient imaging modalities. Our aim was to evaluate the efficacy of a near-infrared fluorescent probe targeting the αvβ3 integrins (Angiostamp™) for intraoperative detection of tumors using the Fluobeam® device. We determined whether different human tumor nodules from various origins could be detected in xenograft mouse models using both cancer cell lines and patient-derived tumor cells. We found that xenografts could be imaged by fluorescent staining irrespective of their integrin expression levels. This suggests imaging of the associated angiogenesis of the tumor and a broader potential utilization of Angiostamp™. We therefore performed a veterinary clinical trial in cats and dogs with local tumors or with spontaneous disseminated peritoneal carcinomatosis. Our results demonstrate that the probe can specifically visualize both breast and ovarian nodules, and suggest that Angiostamp™ is a powerful fluorescent contrast agent that could be used in both human and veterinary clinical trials for intraoperative detection of tumors. PMID:29312629

Benefits of flexible prioritization in working memory can arise without costs.

PubMed

Myers, Nicholas E; Chekroud, Sammi R; Stokes, Mark G; Nobre, Anna C

2018-03-01

Most recent models conceptualize working memory (WM) as a continuous resource, divided up according to task demands. When an increasing number of items need to be remembered, each item receives a smaller chunk of the memory resource. These models predict that the allocation of attention to high-priority WM items during the retention interval should be a zero-sum game: improvements in remembering cued items come at the expense of uncued items because resources are dynamically transferred from uncued to cued representations. The current study provides empirical data challenging this model. Four precision retrocueing WM experiments assessed cued and uncued items on every trial. This permitted a test for trade-off of the memory resource. We found no evidence for trade-offs in memory across trials. Moreover, robust improvements in WM performance for cued items came at little or no cost to uncued items that were probed afterward, thereby increasing the net capacity of WM relative to neutral cueing conditions. An alternative mechanism of prioritization proposes that cued items are transferred into a privileged state within a response-gating bottleneck, in which an item uniquely controls upcoming behavior. We found evidence consistent with this alternative. When an uncued item was probed first, report of its orientation was biased away from the cued orientation to be subsequently reported. We interpret this bias as competition for behavioral control in the output-driving bottleneck. Other items in WM did not bias each other, making this result difficult to explain with a shared resource model. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Development and implementation of a three-choice serial reaction time task for zebrafish (Danio rerio).

PubMed

Parker, Matthew O; Millington, Mollie E; Combe, Fraser J; Brennan, Caroline H

2012-02-01

Zebrafish are an established and widely utilized developmental genetic model system, but limitations in developed behavioral assays have meant that their potential as a model in behavioral neuroscience has yet to be fully realized. Here, we describe the development of a novel operant behavioral assay to examine a variety of aspects of stimulus control in zebrafish using a 3 choice serial reaction time task (3 CSRTT). Fish were briefly exposed to three spatially distinct, but perceptually identical stimuli, presented in a random order after a fixed-time inter-trial interval (ITI). Entries to the correct response aperture either during the stimulus presentation, or within a brief limited hold period following presentation, were reinforced with illumination of the magazine light and delivery of a small food reward. Following training, premature responding was probed with a long-ITI session three times; once at baseline, once following a saline injection and once following an injection of a low dose of amphetamine (AMPH; 0.025 mg/kg). We predicted that if premature responding was related to impulsivity (as in rodents) it would be reduced following the AMPH injection. Results confirmed that zebrafish could learn to perform a complex operant task similar to tasks developed for rodents which are used to probe sustained attention and impulsivity, but the results from the AMPH trials were inconclusive. This study provides the foundations for development and further validation of this species as a model for some aspects of human attentional and impulse control disorders, such as substance abuse disorder. Copyright © 2011 Elsevier B.V. All rights reserved.

Adjunctive clinical effect of a water-cooled Nd:YAG laser in a periodontal maintenance care programme: a randomized controlled trial.

PubMed

Slot, Dagmar E; Timmerman, Mark F; Versteeg, Paula A; van der Velden, Ubele; van der Weijden, Fridus A

2012-12-01

Various laser systems are currently available for intra-oral use. Neodymium:Yttrium-Aluminium Garnet lasers(Nd:YAG) have been approved by the US Food and Drug Administration for soft tissue treatment in the oral cavity. The aim of this study was to test whether the use of a water-cooled Nd:YAG laser during a maintenance care programme as an adjunct to supragingival and subgingival debridement (scaling and root planing, SRP) with hand and ultrasonic instruments results in clinical improvement compared with SRP alone. This study was an examiner-blind, randomized and controlled clinical trial using a split-mouth design. Thirty subjects were selected, originally diagnosed with moderate to severe generalized periodontitis, following a periodontal maintenance care programme (PMC). Immediately after SRP in two randomly assigned contra-lateral quadrants, all pockets ≥5 mm were additionally treated with a Nd:YAG laser (1064 nm, 4W, 250-μsec pulse). Clinical assessments [probing pocket depth PPD, bleeding on pocket probing (BOPP)] were performed pre-treatment and at 6 months. Based on these assessments, the periodontal inflamed surface area (PISA) was calculated. At 6 months, the clinical parameters had significantly improved for both regimens. No statistically significant differences between treatment modalities were observed for PPD and BOPP scores at any time. PISA scores supported these findings. In residual pockets ≥5 mm, treated in a PMC, the adjunctive use of an Nd:YAG laser does not provide a clinically significant additional advantage. © 2012 John Wiley & Sons A/S.

Feasibility and repeatability of cold and mechanical quantitative sensory testing in normal dogs

PubMed Central

Briley, Jessica D.; Williams, Morika D.; Freire, Mila; Griffith, Emily H.; Lascelles, B. Duncan X.

2015-01-01

Feasibility and inter-session repeatability of cold and mechanical quantitative sensory testing (QST) were assessed in 24 normal dogs. Cold thermal latencies were evaluated using a thermal probe (0 °C) applied to three pelvic limb sites. Mechanical thresholds were measured using an electronic von Frey anesthesiometer (EVF) and a blunt-probed pressure algometer (PA) applied to the dorsal aspect of the metatarsus. All QST trials were performed with dogs in lateral recumbency. Collection of cold QST data was easy (feasible) in 19/24 (79%) dogs. However, only 18.4%, 18.9% and 13.2% of cold QST trials elicited a response at the medial tibia, third digital pad and plantar metatarsal regions, respectively. Collection of mechanical QST data was easy (feasible) in 20/24 (83%) dogs for both EVF and PA. At consecutive sampling times, approximately 2 weeks apart, the average EVF sensory thresholds were 414 ± 186 g and 379 ± 166 g, respectively, and the average PA sensory thresholds were 1089 ± 414 g and 1028 ± 331 g, respectively. There was no significant difference in inter-session or inter-limb threshold values for either mechanical QST device. The cold QST protocol in this study was achievable, but did not provide consistently quantifiable results. Both mechanical QST devices tested provided repeatable, reliable sensory threshold measurements in normal, client-owned dogs. These findings contribute to the validation of the EVF and PA as tools to obtain repeated QST data over time in dogs to assess somatosensory processing changes. PMID:24268475

High-speed femtosecond pump-probe spectroscopy with a smart pixel detector array.

PubMed

Bourquin, S; Prasankumar, R P; Kärtner, F X; Fujimoto, J G; Lasser, T; Salathé, R P

2003-09-01

A new femtosecond pump-probe spectroscopy technique is demonstrated that permits the high-speed, parallel acquisition of pump-probe measurements at multiple wavelengths. This is made possible by use of a novel, two-dimensional smart pixel detector array that performs amplitude demodulation in real time on each pixel. This detector array can not only achieve sensitivities comparable with lock-in amplification but also simultaneously performs demodulation of probe transmission signals at multiple wavelengths, thus permitting rapid time- and wavelength-resolved femtosecond pump-probe spectroscopy. Measurements on a thin sample of bulk GaAs are performed across 58 simultaneous wavelengths. Differential probe transmission changes as small as approximately 2 x 10(-4) can be measured over a 5-ps delay scan in only approximately 3 min. This technology can be applied to a wide range of pump-probe measurements in condensed matter, chemistry, and biology.

Similarity-based distortion of visual short-term memory is due to perceptual averaging.

PubMed

Dubé, Chad; Zhou, Feng; Kahana, Michael J; Sekuler, Robert

2014-03-01

A task-irrelevant stimulus can distort recall from visual short-term memory (VSTM). Specifically, reproduction of a task-relevant memory item is biased in the direction of the irrelevant memory item (Huang & Sekuler, 2010a). The present study addresses the hypothesis that such effects reflect the influence of neural averaging under conditions of uncertainty about the contents of VSTM (Alvarez, 2011; Ball & Sekuler, 1980). We manipulated subjects' attention to relevant and irrelevant study items whose similarity relationships were held constant, while varying how similar the study items were to a subsequent recognition probe. On each trial, subjects were shown one or two Gabor patches, followed by the probe; their task was to indicate whether the probe matched one of the study items. A brief cue told subjects which Gabor, first or second, would serve as that trial's target item. Critically, this cue appeared either before, between, or after the study items. A distributional analysis of the resulting mnemometric functions showed an inflation in probability density in the region spanning the spatial frequency of the average of the two memory items. This effect, due to an elevation in false alarms to probes matching the perceptual average, was diminished when cues were presented before both study items. These results suggest that (a) perceptual averages are computed obligatorily and (b) perceptual averages are relied upon to a greater extent when item representations are weakened. Implications of these results for theories of VSTM are discussed. Copyright © 2014 Elsevier Ltd. All rights reserved.

Improving the psychometric properties of dot-probe attention measures using response-based computation.

PubMed

Evans, Travis C; Britton, Jennifer C

2018-09-01

Abnormal threat-related attention in anxiety disorders is most commonly assessed and modified using the dot-probe paradigm; however, poor psychometric properties of reaction-time measures may contribute to inconsistencies across studies. Typically, standard attention measures are derived using average reaction-times obtained in experimentally-defined conditions. However, current approaches based on experimentally-defined conditions are limited. In this study, the psychometric properties of a novel response-based computation approach to analyze dot-probe data are compared to standard measures of attention. 148 adults (19.19 ± 1.42 years, 84 women) completed a standardized dot-probe task including threatening and neutral faces. We generated both standard and response-based measures of attention bias, attentional orientation, and attentional disengagement. We compared overall internal consistency, number of trials necessary to reach internal consistency, test-retest reliability (n = 72), and criterion validity obtained using each approach. Compared to standard attention measures, response-based measures demonstrated uniformly high levels of internal consistency with relatively few trials and varying improvements in test-retest reliability. Additionally, response-based measures demonstrated specific evidence of anxiety-related associations above and beyond both standard attention measures and other confounds. Future studies are necessary to validate this approach in clinical samples. Response-based attention measures demonstrate superior psychometric properties compared to standard attention measures, which may improve the detection of anxiety-related associations and treatment-related changes in clinical samples. Copyright © 2018 Elsevier Ltd. All rights reserved.

Study on a New Ultraviolet Sterilizer to the Surface Disinfection of the Ultrasound Probe.

PubMed

Chen, Gui Qiu; Chen, Yu Hao; Yi, Liang; Yin, Jin; Gao, Qiong; Song, Jiang Nan; Li, Shi Kang; Chen, Pei Hou; Guo, Gui Ping

2018-02-01

We studied the disinfection effect of a new ultraviolet (UV) sterilizer and its utilization on ultrasound probe surfaces. Carrier quantitative germicidal tests, simulated on-the-spot trials, and organic substance influence tests were used to carry out experimental observation. Artificially infected probes were disinfected using the sterilizer or a germicidal lamp for comparison. The total number and types of bacteria were determined and identified. Our results demonstrated the sterilizer had the best disinfection effect among three different disinfection methods in hospital. The sterilizer has been used in a hospital setting for 2 years with no notable damage to the ultrasound probe instrument. It has the advantages of fast disinfection, high disinfection effect, and good compatibility with the ultrasound instrument, worthy of being a promoted application in medical institutions. Copyright © 2018 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

Selective Maintenance in Visual Working Memory Does Not Require Sustained Visual Attention

PubMed Central

Hollingworth, Andrew; Maxcey-Richard, Ashleigh M.

2012-01-01

In four experiments, we tested whether sustained visual attention is required for the selective maintenance of objects in VWM. Participants performed a color change-detection task. During the retention interval, a valid cue indicated the item that would be tested. Change detection performance was higher in the valid-cue condition than in a neutral-cue control condition. To probe the role of visual attention in the cuing effect, on half of the trials, a difficult search task was inserted after the cue, precluding sustained attention on the cued item. The addition of the search task produced no observable decrement in the magnitude of the cuing effect. In a complementary test, search efficiency was not impaired by simultaneously prioritizing an object for retention in VWM. The results demonstrate that selective maintenance in VWM can be dissociated from the locus of visual attention. PMID:23067118

Selective maintenance in visual working memory does not require sustained visual attention.

PubMed

Hollingworth, Andrew; Maxcey-Richard, Ashleigh M

2013-08-01

In four experiments, we tested whether sustained visual attention is required for the selective maintenance of objects in visual working memory (VWM). Participants performed a color change-detection task. During the retention interval, a valid cue indicated the item that would be tested. Change-detection performance was higher in the valid-cue condition than in a neutral-cue control condition. To probe the role of visual attention in the cuing effect, on half of the trials, a difficult search task was inserted after the cue, precluding sustained attention on the cued item. The addition of the search task produced no observable decrement in the magnitude of the cuing effect. In a complementary test, search efficiency was not impaired by simultaneously prioritizing an object for retention in VWM. The results demonstrate that selective maintenance in VWM can be dissociated from the locus of visual attention. 2013 APA, all rights reserved

Two-probe STM experiments at the atomic level.

PubMed

Kolmer, Marek; Olszowski, Piotr; Zuzak, Rafal; Godlewski, Szymon; Joachim, Christian; Szymonski, Marek

2017-11-08

Direct characterization of planar atomic or molecular scale devices and circuits on a supporting surface by multi-probe measurements requires unprecedented stability of single atom contacts and manipulation of scanning probes over large, nanometer scale area with atomic precision. In this work, we describe the full methodology behind atomically defined two-probe scanning tunneling microscopy (STM) experiments performed on a model system: dangling bond dimer wire supported on a hydrogenated germanium (0 0 1) surface. We show that 70 nm long atomic wire can be simultaneously approached by two independent STM scanners with exact probe to probe distance reaching down to 30 nm. This allows direct wire characterization by two-probe I-V characteristics at distances below 50 nm. Our technical results presented in this work open a new area for multi-probe research, which can be now performed with precision so far accessible only by single-probe scanning probe microscopy (SPM) experiments.

Design of piezoelectric probe for measurement of longitudinal and shear components of elastic wave

NASA Astrophysics Data System (ADS)

Aoyanagi, Masafumi; Wakatsuki, Naoto; Mizutani, Koichi; Ebihara, Tadashi

2017-07-01

We focus on ultrasonic probes for nondestructive tests and evaluation. Transient characteristics of probes are important for nondestructive tests such as the pulse echo method. We previously reported the principle of measurement using a piezoelectric probe with triaxial sensitivities. In the results, it was calculated that the probe could transmit and receive particle displacement which contains normal and tangential components. It was confirmed that the probe had sensitivities in triaxial directions. However, its performance in terms of frequency and transient characteristics has not been evaluated. The purpose of this study is to design a probe by changing its shape to obtain better performance. The transient characteristics of probes in longitudinal and shear driving were evaluated by the inverse Fourier transformation of frequency responses of longitudinal and shear components, using the two-dimensional finite element method. As a result, the sensitivities at the dips of frequency characteristics increased when using our probe compared with those measured using conventional probes in longitudinal and shear driving. Hence, the performance in terms of the frequency response was improved by more than 3 dB under the conditions in this simulation. Also, the pulse width of impulse response was decreased by half compared with that of probes with conventional shapes.

Neural substrates of approach-avoidance conflict decision-making

PubMed Central

Aupperle, Robin L.; Melrose, Andrew J.; Francisco, Alex; Paulus, Martin P.; Stein, Murray B.

2014-01-01

Animal approach-avoidance conflict paradigms have been used extensively to operationalize anxiety, quantify the effects of anxiolytic agents, and probe the neural basis of fear and anxiety. Results from human neuroimaging studies support that a frontal-striatal-amygdala neural circuitry is important for approach-avoidance learning. However, the neural basis of decision-making is much less clear in this context. Thus, we combined a recently developed human approach-avoidance paradigm with functional magnetic resonance imaging (fMRI) to identify neural substrates underlying approach-avoidance conflict decision-making. Fifteen healthy adults completed the approach-avoidance conflict (AAC) paradigm during fMRI. Analyses of variance were used to compare conflict to non-conflict (avoid-threat and approach-reward) conditions and to compare level of reward points offered during the decision phase. Trial-by-trial amplitude modulation analyses were used to delineate brain areas underlying decision-making in the context of approach/avoidance behavior. Conflict trials as compared to the non-conflict trials elicited greater activation within bilateral anterior cingulate cortex (ACC), anterior insula, and caudate, as well as right dorsolateral prefrontal cortex. Right caudate and lateral PFC activation was modulated by level of reward offered. Individuals who showed greater caudate activation exhibited less approach behavior. On a trial-by-trial basis, greater right lateral PFC activation related to less approach behavior. Taken together, results suggest that the degree of activation within prefrontal-striatal-insula circuitry determines the degree of approach versus avoidance decision-making. Moreover, the degree of caudate and lateral PFC activation is related to individual differences in approach-avoidance decision-making. Therefore, the AAC paradigm is ideally suited to probe anxiety-related processing differences during approach-avoidance decision-making. PMID:25224633

Neural substrates of approach-avoidance conflict decision-making.

PubMed

Aupperle, Robin L; Melrose, Andrew J; Francisco, Alex; Paulus, Martin P; Stein, Murray B

2015-02-01

Animal approach-avoidance conflict paradigms have been used extensively to operationalize anxiety, quantify the effects of anxiolytic agents, and probe the neural basis of fear and anxiety. Results from human neuroimaging studies support that a frontal-striatal-amygdala neural circuitry is important for approach-avoidance learning. However, the neural basis of decision-making is much less clear in this context. Thus, we combined a recently developed human approach-avoidance paradigm with functional magnetic resonance imaging (fMRI) to identify neural substrates underlying approach-avoidance conflict decision-making. Fifteen healthy adults completed the approach-avoidance conflict (AAC) paradigm during fMRI. Analyses of variance were used to compare conflict to nonconflict (avoid-threat and approach-reward) conditions and to compare level of reward points offered during the decision phase. Trial-by-trial amplitude modulation analyses were used to delineate brain areas underlying decision-making in the context of approach/avoidance behavior. Conflict trials as compared to the nonconflict trials elicited greater activation within bilateral anterior cingulate cortex, anterior insula, and caudate, as well as right dorsolateral prefrontal cortex (PFC). Right caudate and lateral PFC activation was modulated by level of reward offered. Individuals who showed greater caudate activation exhibited less approach behavior. On a trial-by-trial basis, greater right lateral PFC activation related to less approach behavior. Taken together, results suggest that the degree of activation within prefrontal-striatal-insula circuitry determines the degree of approach versus avoidance decision-making. Moreover, the degree of caudate and lateral PFC activation related to individual differences in approach-avoidance decision-making. Therefore, the approach-avoidance conflict paradigm is ideally suited to probe anxiety-related processing differences during approach-avoidance decision-making. © 2014 Wiley Periodicals, Inc.

Deconstructing events: The neural bases for space, time, and causality

PubMed Central

Kranjec, Alexander; Cardillo, Eileen R.; Lehet, Matthew; Chatterjee, Anjan

2013-01-01

Space, time, and causality provide a natural structure for organizing our experience. These abstract categories allow us to think relationally in the most basic sense; understanding simple events require one to represent the spatial relations among objects, the relative durations of actions or movements, and links between causes and effects. The present fMRI study investigates the extent to which the brain distinguishes between these fundamental conceptual domains. Participants performed a one-back task with three conditions of interest (SPACE, TIME and CAUSALITY). Each condition required comparing relations between events in a simple verbal narrative. Depending on the condition, participants were instructed to either attend to the spatial, temporal, or causal characteristics of events, but between participants, each particular event relation appeared in all three conditions. Contrasts compared neural activity during each condition against the remaining two and revealed how thinking about events is deconstructed neurally. Space trials recruited neural areas traditionally associated with visuospatial processing, primarily bilateral frontal and occipitoparietal networks. Causality trials activated areas previously found to underlie causal thinking and thematic role assignment, such as left medial frontal, and left middle temporal gyri, respectively. Causality trials also produced activations in SMA, caudate, and cerebellum; cortical and subcortical regions associated with the perception of time at different timescales. The TIME contrast however, produced no significant effects. This pattern, indicating negative results for TIME trials, but positive effects for CAUSALITY trials in areas important for time perception, motivated additional overlap analyses to further probe relations between domains. The results of these analyses suggest a closer correspondence between time and causality than between time and space. PMID:21861674

Fiber optic tracheal detection device

NASA Astrophysics Data System (ADS)

Souhan, Brian E.; Nawn, Corinne D.; Shmel, Richard; Watts, Krista L.; Ingold, Kirk A.

2017-02-01

Poorly performed airway management procedures can lead to a wide variety of adverse events, such as laryngeal trauma, stenosis, cardiac arrest, hypoxemia, or death as in the case of failed airway management or intubation of the esophagus. Current methods for confirming tracheal placement, such as auscultation, direct visualization or capnography, may be subjective, compromised due to clinical presentation or require additional specialized equipment that is not always readily available during the procedure. Consequently, there exists a need for a non-visual detection mechanism for confirming successful airway placement that can give the provider rapid feedback during the procedure. Based upon our previously presented work characterizing the reflectance spectra of tracheal and esophageal tissue, we developed a fiber-optic prototype to detect the unique spectral characteristics of tracheal tissue. Device performance was tested by its ability to differentiate ex vivo samples of tracheal and esophageal tissue. Pig tissue samples were tested with the larynx, trachea and esophagus intact as well as excised and mounted on cork. The device positively detected tracheal tissue 18 out of 19 trials and 1 false positive out of 19 esophageal trials. Our proof of concept device shows great promise as a potential mechanism for rapid user feedback during airway management procedures to confirm tracheal placement. Ongoing studies will investigate device optimizations of the probe for more refined sensing and in vivo testing.

Word boundaries affect visual attention in Chinese reading.

PubMed

Li, Xingshan; Ma, Guojie

2012-01-01

In two experiments, we explored attention deployment during the reading of Chinese words using a probe detection task. In both experiments, Chinese readers saw four simplified Chinese characters briefly, and then a probe was presented at one of the character positions. The four characters constituted either one word or two words of two characters each. Reaction time was shorter when the probe was at the character 2 position than the character 3 position in the two-word condition, but not in the one-word condition. In Experiment 2, there were more trials and the materials were more carefully controlled, and the results replicated that of Experiment 1. These results suggest that word boundary information affects attentional deployment in Chinese reading.

Decomposing decision components in the Stop-signal task: A model-based approach to individual differences in inhibitory control

PubMed Central

White, Corey N.; Congdon, Eliza; Mumford, Jeanette A.; Karlsgodt, Katherine H.; Sabb, Fred W.; Freimer, Nelson B.; London, Edythe D.; Cannon, Tyrone D.; Bilder, Robert M.; Poldrack, Russell A.

2014-01-01

The Stop-signal task (SST), in which participants must inhibit prepotent responses, has been used to identify neural systems that vary with individual differences in inhibitory control. To explore how these differences relate to other aspects of decision-making, a drift diffusion model of simple decisions was fitted to SST data from Go trials to extract measures of caution, motor execution time, and stimulus processing speed for each of 123 participants. These values were used to probe fMRI data to explore individual differences in neural activation. Faster processing of the Go stimulus correlated with greater activation in the right frontal pole for both Go and Stop trials. On Stop trials stimulus processing speed also correlated with regions implicated in inhibitory control, including the right inferior frontal gyrus, medial frontal gyrus, and basal ganglia. Individual differences in motor execution time correlated with activation of the right parietal cortex. These findings suggest a robust relationship between the speed of stimulus processing and inhibitory processing at the neural level. This model-based approach provides novel insight into the interrelationships among decision components involved in inhibitory control, and raises interesting questions about strategic adjustments in performance and inhibitory deficits associated with psychopathology. PMID:24405185

The Influence of Working Memory Load on Expectancy-Based Strategic Processes in the Stroop-Priming Task.

PubMed

Ortells, Juan J; Álvarez, Dolores; Noguera, Carmen; Carmona, Encarna; de Fockert, Jan W

2017-01-01

The present study investigated whether a differential availability of cognitive control resources as a result of varying working memory (WM) load could affect the capacity for expectancy-based strategic actions. Participants performed a Stroop-priming task in which a prime word (GREEN or RED) was followed by a colored target (red vs. green) that participants had to identify. The prime was incongruent or congruent with the target color on 80 and 20% of the trials, respectively, and participants were informed about the differential proportion of congruent vs. incongruent trials. This task was interleaved with a WM task, such that the prime word was preceded by a sequence of either a same digit repeated five times (low load) or five different random digits (high load), which should be retained by participants. After two, three, or four Stroop trials, they had to decide whether or not a probe digit was a part of the memory set. The key finding was a significant interaction between prime-target congruency and WM load: Whereas a strategy-dependent (reversed Stroop) effect was found under low WM load, a standard Stroop interference effect was observed under high WM load. These findings demonstrate that the availability of WM is crucial for implementing expectancy-based strategic actions.

Mechanical Validation of an MRI Compatible Stereotactic Neurosurgery Robot in Preparation for Pre-Clinical Trials.

PubMed

Nycz, Christopher J; Gondokaryono, Radian; Carvalho, Paulo; Patel, Nirav; Wartenberg, Marek; Pilitsis, Julie G; Fischer, Gregory S

2017-09-01

The use of magnetic resonance imaging (MRI) for guiding robotic surgical devices has shown great potential for performing precisely targeted and controlled interventions. To fully realize these benefits, devices must work safely within the tight confines of the MRI bore without negatively impacting image quality. Here we expand on previous work exploring MRI guided robots for neural interventions by presenting the mechanical design and assessment of a device for positioning, orienting, and inserting an interstitial ultrasound-based ablation probe. From our previous work we have added a 2 degree of freedom (DOF) needle driver for use with the aforementioned probe, revised the mechanical design to improve strength and function, and performed an evaluation of the mechanism's accuracy and effect on MR image quality. The result of this work is a 7-DOF MRI robot capable of positioning a needle tip and orienting it's axis with accuracy of 1.37 ± 0.06 mm and 0.79° ± 0.41°, inserting it along it's axis with an accuracy of 0.06 ± 0.07 mm , and rotating it about it's axis to an accuracy of 0.77° ± 1.31°. This was accomplished with no significant reduction in SNR caused by the robot's presence in the MRI bore, ≤ 10.3% reduction in SNR from running the robot's motors during a scan, and no visible paramagnetic artifacts.

Characterizing the performance of eddy current probes using photoinductive field-mapping

NASA Astrophysics Data System (ADS)

Moulder, John C.; Nakagawa, Norio

1992-12-01

We present a new method for characterizing the performance of eddy current probes by mapping their electromagnetic fields. The technique is based on the photoinductive effect, the change in the impedance of an eddy current probe induced by laser heating of the material under the probe. The instrument we developed maps a probe's electric field distribution by scanning an infrared laser beam over a thin film of gold lying underneath the probe. Measurements of both photoinductive signals and flaw signals for a series of similar probes demonstrates that the impedance change caused by an electrical-discharge-machined notch or a fatigue crack is proportional to the strength of the photoinductive signal. Thus, photoinductive measurements can supplant the use of artifact standards to calibrate eddy current probes.

Equivalence of litmus paper and intragastric pH probes for intragastric pH monitoring in the intensive care unit.

PubMed

Levine, R L; Fromm, R E; Mojtahedzadeh, M; Baghaie, A A; Opekun, A R

1994-06-01

To compare the accuracy of litmus paper-determined gastric pH to a nasogastric graphite antimony pH probe. A prospective clinical trial of gastric pH determination in patients enrolled in a study of histamine-2-receptor (H2) antagonists. The medical intensive care unit (ICU) of a 450-bed county hospital. Critically ill ICU patients requiring stress ulcer prophylaxis. Using a crossover design, the patients were randomized to initially receive an H2 antagonist by continuous infusion or intravenous bolus, and subsequently were crossed over to the other limb of the study. Gastric pH was determined using pH-sensitive litmus paper at the initiation of each limb of the study and at 1, 2, 4, and 8 hrs after the initiation of H2 receptor antagonist therapy. In addition, gastric pH was continuously determined over the same time period utilizing a graphite antimony pH probe. Gastric pH measurements determined with litmus paper and intragastric pH probes demonstrated an excellent correlation (r2 = .93, p < .001). McNemar's test of correlated proportions could not demonstrate a significant difference between the two monitoring methods (chi-square = 0.5, p > .47), and the kappa statistic (0.95, p < .001) demonstrated excellent concordance. Bias measurement was 0.01 (95% confidence interval = -0.155 to 0.176). Measurement of intragastric pH, using pH-sensitive litmus paper, is both sensitive and specific when utilizing a graphite antimony nasogastric pH probe as a reference standard. Litmus paper-determined gastric pH testing is both easy to perform and inexpensive. Therefore, based on the current data, we believe this technique (i.e., litmus paper determined gastric pH testing) to be the method of choice for determination of intragastric pH in patients at risk for stress gastric ulcers in the medical ICU.

Mechanically assisted 3D ultrasound for pre-operative assessment and guiding percutaneous treatment of focal liver tumors

NASA Astrophysics Data System (ADS)

Sadeghi Neshat, Hamid; Bax, Jeffery; Barker, Kevin; Gardi, Lori; Chedalavada, Jason; Kakani, Nirmal; Fenster, Aaron

2014-03-01

Image-guided percutaneous ablation is the standard treatment for focal liver tumors deemed inoperable and is commonly used to maintain eligibility for patients on transplant waitlists. Radiofrequency (RFA), microwave (MWA) and cryoablation technologies are all delivered via one or a number of needle-shaped probes inserted directly into the tumor. Planning is mostly based on contrast CT/MRI. While intra-procedural CT is commonly used to confirm the intended probe placement, 2D ultrasound (US) remains the main, and in some centers the only imaging modality used for needle guidance. Corresponding intraoperative 2D US with planning and other intra-procedural imaging modalities is essential for accurate needle placement. However, identification of matching features of interest among these images is often challenging given the limited field-of-view (FOV) and low quality of 2D US images. We have developed a passive tracking arm with a motorized scan-head and software tools to improve guiding capabilities of conventional US by large FOV 3D US scans that provides more anatomical landmarks that can facilitate registration of US with both planning and intra-procedural images. The tracker arm is used to scan the whole liver with a high geometrical accuracy that facilitates multi-modality landmark based image registration. Software tools are provided to assist with the segmentation of the ablation probes and tumors, find the 2D view that best shows the probe(s) from a 3D US image, and to identify the corresponding image from planning CT scans. In this paper, evaluation results from laboratory testing and a phase 1 clinical trial for planning and guiding RFA and MWA procedures using the developed system will be presented. Early clinical results show a comparable performance to intra-procedural CT that suggests 3D US as a cost-effective alternative with no side-effects in centers where CT is not available.

Load-Dependent Increases in Delay-Period Alpha-Band Power Track the Gating of Task-Irrelevant Inputs to Working Memory.

PubMed

Heinz, Andrew J; Johnson, Jeffrey S

2017-01-01

Studies exploring the role of neural oscillations in cognition have revealed sustained increases in alpha-band power (ABP) during the delay period of verbal and visual working memory (VWM) tasks. There have been various proposals regarding the functional significance of such increases, including the inhibition of task-irrelevant cortical areas as well as the active retention of information in VWM. The present study examines the role of delay-period ABP in mediating the effects of interference arising from on-going visual processing during a concurrent VWM task. Specifically, we reasoned that, if set-size dependent increases in ABP represent the gating out of on-going task-irrelevant visual inputs, they should be predictive with respect to some modulation in visual evoked potentials resulting from a task-irrelevant delay period probe stimulus. In order to investigate this possibility, we recorded the electroencephalogram while subjects performed a change detection task requiring the retention of two or four novel shapes. On a portion of trials, a novel, task-irrelevant bilateral checkerboard probe was presented mid-way through the delay. Analyses focused on examining correlations between set-size dependent increases in ABP and changes in the magnitude of the P1, N1 and P3a components of the probe-evoked response and how such increases might be related to behavior. Results revealed that increased delay-period ABP was associated with changes in the amplitude of the N1 and P3a event-related potential (ERP) components, and with load-dependent changes in capacity when the probe was presented during the delay. We conclude that load-dependent increases in ABP likely play a role in supporting short-term retention by gating task-irrelevant sensory inputs and suppressing potential sources of disruptive interference.

Load-Dependent Increases in Delay-Period Alpha-Band Power Track the Gating of Task-Irrelevant Inputs to Working Memory

PubMed Central

Heinz, Andrew J.; Johnson, Jeffrey S.

2017-01-01

Studies exploring the role of neural oscillations in cognition have revealed sustained increases in alpha-band power (ABP) during the delay period of verbal and visual working memory (VWM) tasks. There have been various proposals regarding the functional significance of such increases, including the inhibition of task-irrelevant cortical areas as well as the active retention of information in VWM. The present study examines the role of delay-period ABP in mediating the effects of interference arising from on-going visual processing during a concurrent VWM task. Specifically, we reasoned that, if set-size dependent increases in ABP represent the gating out of on-going task-irrelevant visual inputs, they should be predictive with respect to some modulation in visual evoked potentials resulting from a task-irrelevant delay period probe stimulus. In order to investigate this possibility, we recorded the electroencephalogram while subjects performed a change detection task requiring the retention of two or four novel shapes. On a portion of trials, a novel, task-irrelevant bilateral checkerboard probe was presented mid-way through the delay. Analyses focused on examining correlations between set-size dependent increases in ABP and changes in the magnitude of the P1, N1 and P3a components of the probe-evoked response and how such increases might be related to behavior. Results revealed that increased delay-period ABP was associated with changes in the amplitude of the N1 and P3a event-related potential (ERP) components, and with load-dependent changes in capacity when the probe was presented during the delay. We conclude that load-dependent increases in ABP likely play a role in supporting short-term retention by gating task-irrelevant sensory inputs and suppressing potential sources of disruptive interference. PMID:28555099

In vivo MRI cell tracking using perfluorocarbon probes and fluorine-19 detection

PubMed Central

Ahrens, Eric T.; Zhong, Jia

2013-01-01

This article is a brief survey of preclinical in vivo cell tracking methods and applications using perfluorocarbon (PFC) probes and fluorine-19 (19F) MRI detection. Detection of the 19F signal offers high cell specificity and quantification abilities in spin-density weighted MR images. We discuss the compositions of matter, methods, and applications of PFC-based cell tracking using ex vivo and in situ PFC labeling in preclinical studies of inflammation and cellular therapeutics. We will also address potential applicability of 19F cell tracking to clinical trials. PMID:23606473

Development of a combined OCT-Raman probe for the prospective in vivo clinical melanoma skin cancer screening

NASA Astrophysics Data System (ADS)

Mazurenka, M.; Behrendt, L.; Meinhardt-Wollweber, M.; Morgner, U.; Roth, B.

2017-10-01

A combined optical coherence tomography (OCT)-Raman probe was designed and built into a spectral domain OCT head, and its performance was evaluated and compared to the most common Raman probe setups, based on a fiber bundle and confocal free space optics. Due to the use of the full field of view of an OCT scanning lens, the combined probe has a superior performance within maximum permissible exposure limits, compared to the other two probes. Skin Raman spectra, recorded in vivo, further prove the feasibility of the OCT-Raman probe for the future in vivo clinical applications in skin cancer screening.

Validity and reliability of temperature measurement by heat flow thermistors, flexible thermocouple probes and thermistors in a stirred water bath.

PubMed

Versey, Nathan G; Gore, Christopher J; Halson, Shona L; Plowman, Jamie S; Dawson, Brian T

2011-09-01

We determined the validity and reliability of heat flow thermistors, flexible thermocouple probes and general purpose thermistors compared with a calibrated reference thermometer in a stirred water bath. Validity (bias) was defined as the difference between the observed and criterion values, and reliability as the repeatability (standard deviation or typical error) of measurement. Data were logged every 5 s for 10 min at water temperatures of 14, 26 and 38 °C for ten heat flow thermistors and 24 general purpose thermistors, and at 35, 38 and 41 °C for eight flexible thermocouple probes. Statistical analyses were conducted using spreadsheets for validity and reliability, where an acceptable bias was set at ±0.1 °C. None of the heat flow thermistors, 17% of the flexible thermocouple probes and 71% of the general purpose thermistors met the validity criterion for temperature. The inter-probe reliabilities were 0.03 °C for heat flow thermistors, 0.04 °C for flexible thermocouple probes and 0.09 °C for general purpose thermistors. The within trial intra-probe reliability of all three temperature probes was 0.01 °C. The results suggest that these temperature sensors should be calibrated individually before use at relevant temperatures and the raw data corrected using individual linear regression equations.

Proactive interference and item similarity in working memory.

PubMed

Bunting, Michael

2006-03-01

Proactive interference (PI) may influence the predictive utility of working memory span tasks. Participants in one experiment (N=70) completed Ravens Advanced Progressive Matrices (RAPM) and multiple versions of operation span and probed recall, modified for the type of memoranda (digits or words). Changing memoranda within- or across-trials released PI, but not doing so permitted PI buildup. Scores from PI-build trials, but not PI-release trials, correlated with RAPM and accounted for as much variance in RAPM as unmodified tasks. These results are consistent with controlled attention and inhibition accounts of working memory, and they elucidate a fundamental component of working memory span tasks.

Effects of salt loading and flow blockage on the WIPP shrouded probe

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

Chandra, S.; Ortiz, C.A.; McFarland, A.R.

1993-08-01

The shrouded probes at the WIPP site operate in a salt aerosol environment that can cause a buildup of salt deposits on exposed surfaces of the probes that, in turn, could produce changes in the sampling performance of the probes. At Station A, three probes had been operated for a period of approximately 2 1/2 years when they were inspected with a remote television camera. There were visible deposits of unknown thickness on the probes, so WIPP removed the probes for inspection and cleanup. Measurements were made on the probes and they showed the buildups to be approximately 2.5 mmmore » thick on the most critical dimension of a shrouded probe, which is the inside diameter of the inner probe. For reference, the diameter of a clean probe is 30 mm. The sampling performance of this particular shrouded probe had been previously evaluated in a wind tunnel at Aerosol Technology Laboratory (ATL) of Texas A&M University for two free stream velocities (14 and 21 m/s) and three particle sizes (5, 10 and 15 {mu}m AED).« less

Design and Application of Hybrid Magnetic Field-Eddy Current Probe

NASA Technical Reports Server (NTRS)

Wincheski, Buzz; Wallace, Terryl; Newman, Andy; Leser, Paul; Simpson, John

2013-01-01

The incorporation of magnetic field sensors into eddy current probes can result in novel probe designs with unique performance characteristics. One such example is a recently developed electromagnetic probe consisting of a two-channel magnetoresistive sensor with an embedded single-strand eddy current inducer. Magnetic flux leakage maps of ferrous materials are generated from the DC sensor response while high-resolution eddy current imaging is simultaneously performed at frequencies up to 5 megahertz. In this work the design and optimization of this probe will be presented, along with an application toward analysis of sensory materials with embedded ferromagnetic shape-memory alloy (FSMA) particles. The sensory material is designed to produce a paramagnetic to ferromagnetic transition in the FSMA particles under strain. Mapping of the stray magnetic field and eddy current response of the sample with the hybrid probe can thereby image locations in the structure which have experienced an overstrain condition. Numerical modeling of the probe response is performed with good agreement with experimental results.

Monoclonal antibodies reactive with human breast or ovarian carcinoma: In vivo applications

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

Thor, A.D.; Edgerton, S.M.

Monoclonal antibodies (MoAbs) are unique and useful bioprobes that allow in vivo targeting of membrane-associated or circulating antigens. Most of the clinical trials to date have used low dosages of radiolabeled MoAb given in a single dose. Newer studies have included antibody fragments, repeated injections, intraperitoneal (IP) administration, and other labels such as 90Y. Clinical MoAb trials are often arduous, expensive, and time-consuming to perform. Before human use, animal studies and extensive MoAb characterization are required. The production of pharmaceutical grade, radiolabeled MoAb is technically difficult and costly. Clinical trials require administrative and patient consent as well as extensive writtenmore » protocols. These studies necessitate interdepartmental and intradepartmental cooperation and coordination. Furthermore, the use of in vivo radiolabeled probes impacts many levels of health care providers from janitorial, nursing, and technical staff to laboratories and physicians. Simple blood tests or disposal of body excretions may concern nursing or technical staff with the possibility of radiation exposure. The responsibility for study design, personnel involvement, and prospective use in patients without a definitive cancer diagnosis ultimately rests with the physician. While many issues have been addressed, additional clinical trials, consideration of safety issues, and standardization between institutions will be necessary before the use of radiolabeled MoAb for diagnosis, management, or therapy of human tumors becomes routine. Continued cooperation and funding should ensure its achievement. 136 references.« less

Financial incentive does not affect P300 (in response to certain episodic and semantic probe stimuli) in the Complex Trial Protocol (CTP) version of the Concealed Information Test (CIT) in detection of malingering.

PubMed

Rosenfeld, J Peter; Labkovsky, Elena; Davydova, Elena; Ward, Anne; Rosenfeld, Lauren

2017-05-01

Previous research indicated that the skin conductance response of the autonomic nervous system in the Concealed Information Test (CIT) is typically increased in subjects who are financially and otherwise incentivized to defeat the CIT (the paradoxical "motivational impairment" effect). This is not the case for RT-based CITs, nor P300 tests based on the three-stimulus protocol for detection of cognitive malingering (although these are not the same as CITs). The present report is the first attempt to study the effect of financial motivation on the P300-based Complex Trial Protocol using both episodic and semantic memory probe and irrelevant stimuli. The Test of Memory Malingering (TOMM) was used to validate behavioral differences between the two groups we created by offering one (paid) group but not another (unpaid) group a financial reward for beating our tests. Group behavioral differences on the TOMM did confirm group manipulations. Probe-minus-irrelevant P300 differences did not differ between groups, although as previously, semantic memory-evoked P300s were larger than episodic memory-evoked P300s. © 2017 Society for Psychophysiological Research.

Transport of pulmonary secretions by asymmetric high frequency oscillation

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

Gruenauer, L.M.

1987-01-01

Asymmetric high frequency oscillation (AHFO) was investigated as a mechanism for augmenting the clearance of excess pulmonary secretions from the airways of the lungs. In vitro and in vivo models were developed to test its ability to predictably transport pulmonary secretions. The augmentation of mucus transport by 10 Hz AHFO was investigated in the canine trachea. Ventilation of eight dogs (2 studies each) was performed with three AHFO power settings in random order and conventional mechanical ventilation (CMV) before or after the AHFO trials. Prior to each trial, 35-45 ..mu..l of canine muscus mixed with a radiotagged colloid (/sup 99/Tc/supmore » m/) was instilled in the distal trachea. As the radiotagged mixture traveled up the trachea, tracheal muscus velocities (TMV) were recorded on six channels with a multidetector probe. CMV mean TMVs before and after AHFO were not significantly different. The mean TMV of 6.3 +/- 2.6 mm/min at 30% power AHFO was faster than the CMV mean TVM of 4.1 +/- 2.1 mm/min (p <0.05).« less

Bilingualism influences inhibitory control in auditory comprehension.

PubMed

Blumenfeld, Henrike K; Marian, Viorica

2011-02-01

Bilinguals have been shown to outperform monolinguals at suppressing task-irrelevant information. The present study aimed to identify how processing linguistic ambiguity during auditory comprehension may be associated with inhibitory control. Monolinguals and bilinguals listened to words in their native language (English) and identified them among four pictures while their eye-movements were tracked. Each target picture (e.g., hamper) appeared together with a similar-sounding within-language competitor picture (e.g., hammer) and two neutral pictures. Following each eye-tracking trial, priming probe trials indexed residual activation of target words, and residual inhibition of competitor words. Eye-tracking showed similar within-language competition across groups; priming showed stronger competitor inhibition in monolinguals than in bilinguals, suggesting differences in how inhibitory control was used to resolve within-language competition. Notably, correlation analyses revealed that inhibition performance on a nonlinguistic Stroop task was related to linguistic competition resolution in bilinguals but not in monolinguals. Together, monolingual-bilingual comparisons suggest that cognitive control mechanisms can be shaped by linguistic experience. Copyright © 2010 Elsevier B.V. All rights reserved.

D-region blunt probe data analysis using hybrid computer techniques

NASA Technical Reports Server (NTRS)

Burkhard, W. J.

1973-01-01

The feasibility of performing data reduction techniques with a hybrid computer was studied. The data was obtained from the flight of a parachute born probe through the D-region of the ionosphere. A presentation of the theory of blunt probe operation is included with emphasis on the equations necessary to perform the analysis. This is followed by a discussion of computer program development. Included in this discussion is a comparison of computer and hand reduction results for the blunt probe launched on 31 January 1972. The comparison showed that it was both feasible and desirable to use the computer for data reduction. The results of computer data reduction performed on flight data acquired from five blunt probes are also presented.

Study of new systems concepts for a Titan atmospheric probe

NASA Technical Reports Server (NTRS)

Bernard, Doug; Citron, Todd; Drean, Robert; Lewis, Scott; Lo, Martin; Mccarthy, John; Soderblom, Robert; Steffy, Dave; Vargas, Tina; Wolff, Marty

1986-01-01

Results of a systems concepts study for a Titan Probe were examined. The key tradeoffs performed are described in detail. Mass breakdown of each Probe subsystem or major element were given. The mission analysis performed to determine compliance with the high altitude sampling and descent time requirements are described. The baseline Descent Module design was derived. The element of the Probe System left on the Carrier after separation were described.

Effects of high Z probe on plasma behavior in HT-6M tokamak

NASA Astrophysics Data System (ADS)

Li, J.; Gong, X.; Luo, L.; Yin, F. X.; Noda, N.; Wan, B.; Xu, W.; Gao, X.; Yin, F.; Jiang, J. G.; Wu, Z.; Zhao, J. Y.; Wu, M.; Liu, S.; Han, Y.

1997-02-01

Molybdenum and tungsten probes have been tested in HT-6M tokamak under various discharge conditions aiming to find out the conditions in which high Z PFC can be used without serious degradation of core plasma performance. In normal OH discharges, the degradation of core plasma performance was found only when the probe was inserted beyond 3.0 cm inside the last closed flux surface (LCFS). The plasma performance did not change with positive biasing to the probe, whereas central Te degraded during negative biasing of -100 V. The insertion of the Mo probe to 1.5 cm inside the LCFS made a change in the threshold power of the L-H transition in EOH discharges. These results suggest a certain operation range of the H-mode in the EOH discharge with the Mo probe in HT-6M.

A Randomized Controlled Trial Evaluating the See, Tilt, Align, and Rotate (STAR) Maneuver on Skill Acquisition for Simulated Ultrasound-Guided Interventional Procedures.

PubMed

Lam, Nicholas C K; Fishburn, Steven J; Hammer, Angie R; Petersen, Timothy R; Gerstein, Neal S; Mariano, Edward R

2015-06-01

Achieving the best view of the needle and target anatomy when performing ultrasound-guided interventional procedures requires technical skill, which novices may find difficult to learn. We hypothesized that teaching novice performers to use 4 sequential steps (see, tilt, align, and rotate [STAR] method) to identify the needle under ultrasound guidance is more efficient than training with the commonly described probe movements of align, rotate, and tilt (ART). This study compared 2 instructional methods for transducer manipulation including alignment of a probe and needle by novices during a simulated ultrasound-guided nerve block. Right-handed volunteers between the ages of 18 and 55 years who had no previous ultrasound experience were recruited and randomized to 1 of 2 groups; one group was trained to troubleshoot misalignment with the ART method, and the other was trained with the new STAR maneuver. Participants performed the task, consisting of directing a needle in plane to 3 targets in a standardized gelatin phantom 3 times. The performance assessor and data analyst were blinded to group assignment. Thirty-five participants were recruited. The STAR group was able to complete the task more quickly (P < .001) and visualized the needle in a greater proportion of the procedure time (P = .004) compared to the ART group. All STAR participants were able to complete the task, whereas 41% of ART participants abandoned the task (P = .003). Novices are able to complete a simulated ultrasound-guided nerve block more quickly and efficiently when trained with the 4-step STAR maneuver compared to the ART method. © 2015 by the American Institute of Ultrasound in Medicine.

Effects of low-level laser therapy (LLLT) in the development of exercise-induced skeletal muscle fatigue and changes in biochemical markers related to postexercise recovery.

PubMed

Leal Junior, Ernesto Cesar Pinto; Lopes-Martins, Rodrigo Alvaro Brandão; Frigo, Lucio; De Marchi, Thiago; Rossi, Rafael Paolo; de Godoi, Vanessa; Tomazoni, Shaiane Silva; Silva, Daniela Perin; Basso, Maira; Filho, Pedro Lotti; de Valls Corsetti, Francisco; Iversen, Vegard V; Bjordal, Jan Magnus

2010-08-01

Randomized crossover double-blinded placebo-controlled trial. To investigate if low-level laser therapy (LLLT) can affect biceps muscle performance, fatigue development, and biochemical markers of postexercise recovery. Cell and animal studies have suggested that LLLT can reduce oxidative stress and inflammatory responses in muscle tissue. But it remains uncertain whether these findings can translate into humans in sport and exercise situations. Nine healthy male volleyball players participated in the study. They received either active LLLT (cluster probe with 5 laser diodes; lambda = 810 nm; 200 mW power output; 30 seconds of irradiation, applied in 2 locations over the biceps of the nondominant arm; 60 J of total energy) or placebo LLLT using an identical cluster probe. The intervention or placebo were applied 3 minutes before the performance of exercise. All subjects performed voluntary elbow flexion repetitions with a workload of 75% of their maximal voluntary contraction force until exhaustion. Active LLLT increased the number of repetitions by 14.5% (mean +/- SD, 39.6 +/- 4.3 versus 34.6 +/- 5.6; P = .037) and the elapsed time before exhaustion by 8.0% (P = .034), when compared to the placebo treatment. The biochemical markers also indicated that recovery may be positively affected by LLLT, as indicated by postexercise blood lactate levels (P<.01), creatine kinase activity (P = .017), and C-reactive protein levels (P = .047), showing a faster recovery with LLLT application prior to the exercise. We conclude that pre-exercise irradiation of the biceps with an LLLT dose of 6 J per application location, applied in 2 locations, increased endurance for repeated elbow flexion against resistance and decreased postexercise levels of blood lactate, creatine kinase, and C-reactiveprotein. Performance enhancement, level 1b.

The development of real-time stability supports visual working memory performance: Young children's feature binding can be improved through perceptual structure.

PubMed

Simmering, Vanessa R; Wood, Chelsey M

2017-08-01

Working memory is a basic cognitive process that predicts higher-level skills. A central question in theories of working memory development is the generality of the mechanisms proposed to explain improvements in performance. Prior theories have been closely tied to particular tasks and/or age groups, limiting their generalizability. The cognitive dynamics theory of visual working memory development has been proposed to overcome this limitation. From this perspective, developmental improvements arise through the coordination of cognitive processes to meet demands of different behavioral tasks. This notion is described as real-time stability, and can be probed through experiments that assess how changing task demands impact children's performance. The current studies test this account by probing visual working memory for colors and shapes in a change detection task that compares detection of changes to new features versus swaps in color-shape binding. In Experiment 1, 3- to 4-year-old children showed impairments specific to binding swaps, as predicted by decreased real-time stability early in development; 5- to 6-year-old children showed a slight advantage on binding swaps, but 7- to 8-year-old children and adults showed no difference across trial types. Experiment 2 tested the proposed explanation of young children's binding impairment through added perceptual structure, which supported the stability and precision of feature localization in memory-a process key to detecting binding swaps. This additional structure improved young children's binding swap detection, but not new-feature detection or adults' performance. These results provide further evidence for the cognitive dynamics and real-time stability explanation of visual working memory development. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

The Role of Cognitive Load in Intentional Forgetting Using the Think/No-Think Task.

PubMed

Noreen, Saima; de Fockert, Jan W

2017-01-01

We investigated the role of cognitive control in intentional forgetting by manipulating working memory load during the think/no-think task. In two experiments, participants learned a series of cue-target word pairs and were asked to recall the target words associated with some cues or to avoid thinking about the target associated with other cues. In addition to this, participants also performed a modified version of the n-back task which required them to respond to the identity of a single target letter present in the currently presented cue word (n = 0 condition, low working memory load), and in either the previous cue word (n = 1 condition, high working memory load, Experiment 1) or the cue word presented two trials previously (n = 2 condition, high working memory load, Experiment 2). Participants' memory for the target words was subsequently tested using same and novel independent probes. In both experiments it was found that although participants were successful at forgetting on both the same and independent-probe tests in the low working memory load condition, they were only successful at forgetting on the same-probe test in the high working memory load condition. We argue that our findings suggest that the high load working memory task diverted attention from direct suppression and acted as an interference-based strategy. Thus, when cognitive resources are limited participants can switch between the strategies they use to prevent unwanted memories from coming to mind.

A comparison of dentifrices for clinical relief from dentin hypersensitivity using the Jay Sensitivity Sensor Probe.

PubMed

Hegde, Shashikanth; Rao, B H Sripathi; Kakar, Ravish Chander; Kakar, Ashish

2013-05-01

To evaluate the clinical relief from dentin hypersensitivity among subjects provided with a dentifrice formulated with 8% arginine, calcium carbonate and 1,000 ppm fluoride [sodium monofluorophosphate (MFP)] in comparison to those issued a commercially available dentifrice containing 1,000 ppm fluoride [as sodium monofluorophosphate (MFP)]. Clinical evaluations for hypersensitivity were performed with a novel tactile hypersensitivity measuring instrument--the Jay Sensitivity Sensor (Jay) Probe--in conjunction with evaporative triggers by air blast (Schiff scale) and Visual Analog Scores (VAS). Qualified adults from the Mangalore, India area who presented two teeth with dentin hypersensitivity were enrolled for this double-blind, randomized, parallel, controlled clinical trial conducted in an outpatient clinical setting. At baseline, dentin hypersensitivity was evaluated by the Jay Probe (tactile), air blast and VAS methods. Subjects were randomly issued a study dentifrice and instructed to brush their teeth for 1 minute twice daily with the provided dentifrice. Clinical evaluations for hypersensitivity were repeated after 2, 4 and 8 weeks of product use. 86 subjects (35 males and 51 females) complied with the study protocol and completed the entire study. At each recall visit, both treatment groups demonstrated significant reductions in dentin hypersensitivity from their corresponding baselines (P < 0.05). Subjects assigned the 8% arginine, calcium carbonate and 1,000 ppm fluoride dentifrice demonstrated statistically significant reductions in responses to tactile stimuli, air blast, and VAS responses in comparison to those using the dentifrice containing 1,000 ppm fluoride after 2, 4, and 8 weeks, respectively.

Performance Evaluation of Particle Sampling Probes for Emission Measurements of Aircraft Jet Engines

NASA Technical Reports Server (NTRS)

Lee, Poshin; Chen, Da-Ren; Sanders, Terry (Technical Monitor)

2001-01-01

Considerable attention has been recently received on the impact of aircraft-produced aerosols upon the global climate. Sampling particles directly from jet engines has been performed by different research groups in the U.S. and Europe. However, a large variation has been observed among published data on the conversion efficiency and emission indexes of jet engines. The variation results surely from the differences in test engine types, engine operation conditions, and environmental conditions. The other factor that could result in the observed variation is the performance of sampling probes used. Unfortunately, it is often neglected in the jet engine community. Particle losses during the sampling, transport, and dilution processes are often not discussed/considered in literatures. To address this issue, we evaluated the performance of one sampling probe by challenging it with monodisperse particles. A significant performance difference was observed on the sampling probe evaluated under different temperature conditions. Thermophoretic effect, nonisokinetic sampling and turbulence loss contribute to the loss of particles in sampling probes. The results of this study show that particle loss can be dramatic if the sampling probe is not well designed. Further, the result allows ones to recover the actual size distributions emitted from jet engines.

The rapid distraction of attentional resources toward the source of incongruent stimulus input during multisensory conflict.

PubMed

Donohue, Sarah E; Todisco, Alexandra E; Woldorff, Marty G

2013-04-01

Neuroimaging work on multisensory conflict suggests that the relevant modality receives enhanced processing in the face of incongruency. However, the degree of stimulus processing in the irrelevant modality and the temporal cascade of the attentional modulations in either the relevant or irrelevant modalities are unknown. Here, we employed an audiovisual conflict paradigm with a sensory probe in the task-irrelevant modality (vision) to gauge the attentional allocation to that modality. ERPs were recorded as participants attended to and discriminated spoken auditory letters while ignoring simultaneous bilateral visual letter stimuli that were either fully congruent, fully incongruent, or partially incongruent (one side incongruent, one congruent) with the auditory stimulation. Half of the audiovisual letter stimuli were followed 500-700 msec later by a bilateral visual probe stimulus. As expected, ERPs to the audiovisual stimuli showed an incongruency ERP effect (fully incongruent versus fully congruent) of an enhanced, centrally distributed, negative-polarity wave starting ∼250 msec. More critically here, the sensory ERP components to the visual probes were larger when they followed fully incongruent versus fully congruent multisensory stimuli, with these enhancements greatest on fully incongruent trials with the slowest RTs. In addition, on the slowest-response partially incongruent trials, the P2 sensory component to the visual probes was larger contralateral to the preceding incongruent visual stimulus. These data suggest that, in response to conflicting multisensory stimulus input, the initial cognitive effect is a capture of attention by the incongruent irrelevant-modality input, pulling neural processing resources toward that modality, resulting in rapid enhancement, rather than rapid suppression, of that input.

Toward Automated Intraocular Laser Surgery Using a Handheld Micromanipulator

PubMed Central

Yang, Sungwook; MacLachlan, Robert A.; Riviere, Cameron N.

2014-01-01

This paper presents a technique for automated intraocular laser surgery using a handheld micromanipulator known as Micron. The novel handheld manipulator enables the automated scanning of a laser probe within a cylinder of 4 mm long and 4 mm in diameter. For the automation, the surface of the retina is reconstructed using a stereomicroscope, and then preplanned targets are placed on the surface. The laser probe is precisely located on the target via visual servoing of the aiming beam, while maintaining a specific distance above the surface. In addition, the system is capable of tracking the surface of the eye in order to compensate for any eye movement introduced during the operation. We compared the performance of the automated scanning using various control thresholds, in order to find the most effective threshold in terms of accuracy and speed. Given the selected threshold, we conducted the handheld operation above a fixed target surface. The average error and execution time are reduced by 63.6% and 28.5%, respectively, compared to the unaided trials. Finally, the automated laser photocoagulation was demonstrated also in an eye phantom, including compensation for the eye movement. PMID:25893135

The role of probiotic bacteria in managing periodontal disease: a systematic review.

PubMed

Matsubara, Victor Haruo; Bandara, H M H N; Ishikawa, Karin Hitomi; Mayer, Marcia Pinto Alves; Samaranayake, Lakshman Perera

2016-07-01

The frequent recolonization of treated sites by periodontopathogens and the emergence of antibiotic resistance have led to a call for new therapeutic approaches for managing periodontal diseases. As probiotics are considered a new tool for combating infectious diseases, we systematically reviewed the evidences for their effectiveness in the management of periodontitis. An electronic search was performed in the MEDLINE, SCOPUS and Cochrane Library databases up to March 2016 using the terms 'periodontitis', 'chronic periodontitis', 'probiotic(s)', 'prebiotic(s)', 'symbiotic(s)', 'Bifidobacterium and 'Lactobacillus'. Only randomized controlled trials (RCTs) were included in the present study. Analysis of 12 RCTs revealed that in general, oral administration of probiotics improved the recognized clinical signs of chronic and aggressive periodontitis such as probing pocket depth, bleeding on probing, and attachment loss, with a concomitant reduction in the levels of major periodontal pathogens. Continuous probiotic administration, laced mainly with Lactobacillus species, was necessary to maintain these benefits. Expert commentary: Oral administration of probiotics is a safe and effective adjunct to conventional mechanical treatment (scaling) in the management of periodontitis, specially the chronic disease entity. Their adjunctive use is likely to improve disease indices and reduce the need for antibiotics.

Convergent Synthesis of Two Fluorescent Ebselen-Coumarin Heterodimers.

PubMed

Küppers, Jim; Schulz-Fincke, Anna Christina; Palus, Jerzy; Giurg, Mirosław; Skarżewski, Jacek; Gütschow, Michael

2016-07-08

The organo-seleniumdrug ebselen exhibits a wide range of pharmacological effects that are predominantly due to its interference with redox systems catalyzed by seleno enzymes, e.g., glutathione peroxidase and thioredoxin reductase. Moreover, ebselen can covalently interact with thiol groups of several enzymes. According to its pleiotropic mode of action, ebselen has been investigated in clinical trials for the prevention and treatment of different ailments. Fluorescence-labeled probes containing ebselen are expected to be suitable for further biological and medicinal studies. We therefore designed and synthesized two coumarin-tagged activity-based probes bearing the ebselen warhead. The heterodimers differ by the nature of the spacer structure, for which-in the second compound-a PEG/two-amide spacer was introduced. The interaction of this probe and of ebselen with two cysteine proteases was investigated.

Is all motivation good for learning? Dissociable influences of approach and avoidance motivation in declarative memory.

PubMed

Murty, Vishnu P; LaBar, Kevin S; Hamilton, Derek A; Adcock, R Alison

2011-01-01

The present study investigated the effects of approach versus avoidance motivation on declarative learning. Human participants navigated a virtual reality version of the Morris water task, a classic spatial memory paradigm, adapted to permit the experimental manipulation of motivation during learning. During this task, participants were instructed to navigate to correct platforms while avoiding incorrect platforms. To manipulate motivational states participants were either rewarded for navigating to correct locations (approach) or punished for navigating to incorrect platforms (avoidance). Participants' skin conductance levels (SCLs) were recorded during navigation to investigate the role of physiological arousal in motivated learning. Behavioral results revealed that, overall, approach motivation enhanced and avoidance motivation impaired memory performance compared to nonmotivated spatial learning. This advantage was evident across several performance indices, including accuracy, learning rate, path length, and proximity to platform locations during probe trials. SCL analysis revealed three key findings. First, within subjects, arousal interacted with approach motivation, such that high arousal on a given trial was associated with performance deficits. In addition, across subjects, high arousal negated or reversed the benefits of approach motivation. Finally, low-performing, highly aroused participants showed SCL responses similar to those of avoidance-motivation participants, suggesting that for these individuals, opportunities for reward may evoke states of learning similar to those typically evoked by threats of punishment. These results provide a novel characterization of how approach and avoidance motivation influence declarative memory and indicate a critical and selective role for arousal in determining how reinforcement influences goal-oriented learning.

Is all motivation good for learning? Dissociable influences of approach and avoidance motivation in declarative memory

PubMed Central

Murty, Vishnu P.; LaBar, Kevin S.; Hamilton, Derek A.; Adcock, R. Alison

2011-01-01

The present study investigated the effects of approach versus avoidance motivation on declarative learning. Human participants navigated a virtual reality version of the Morris water task, a classic spatial memory paradigm, adapted to permit the experimental manipulation of motivation during learning. During this task, participants were instructed to navigate to correct platforms while avoiding incorrect platforms. To manipulate motivational states participants were either rewarded for navigating to correct locations (approach) or punished for navigating to incorrect platforms (avoidance). Participants’ skin conductance levels (SCLs) were recorded during navigation to investigate the role of physiological arousal in motivated learning. Behavioral results revealed that, overall, approach motivation enhanced and avoidance motivation impaired memory performance compared to nonmotivated spatial learning. This advantage was evident across several performance indices, including accuracy, learning rate, path length, and proximity to platform locations during probe trials. SCL analysis revealed three key findings. First, within subjects, arousal interacted with approach motivation, such that high arousal on a given trial was associated with performance deficits. In addition, across subjects, high arousal negated or reversed the benefits of approach motivation. Finally, low-performing, highly aroused participants showed SCL responses similar to those of avoidance–motivation participants, suggesting that for these individuals, opportunities for reward may evoke states of learning similar to those typically evoked by threats of punishment. These results provide a novel characterization of how approach and avoidance motivation influence declarative memory and indicate a critical and selective role for arousal in determining how reinforcement influences goal-oriented learning. PMID:22021253

Human factors analysis for a 2D enroute moving map application

NASA Astrophysics Data System (ADS)

Pschierer, Christian; Wipplinger, Patrick; Schiefele, Jens; Cromer, Scot; Laurin, John; Haffner, Skip

2005-05-01

The paper describes flight trials performed in Centennial, CO with a Piper Cheyenne from Marinvent. Six pilots flew the Cheyenne in twelve enroute segments between Denver Centennial and Colorado Springs. Two different settings (paper chart, enroute moving map) were evaluated with randomized settings. The flight trial goal was to evaluate the objective performance of pilots compared among the different settings. As dependent variables, positional accuracy and situational awareness probe (SAP) were measured. Analysis was conducted by an ANOVA test. In parallel, all pilots answered subjective Cooper-Harper, NASA TLX, situation awareness rating technique (SART), Display Readability Rating and debriefing questionnaires. The tested enroute moving map application has Jeppesen chart compliant symbologies for high-enroute and low-enroute. It has a briefing mode were all information found on today"s enroute paper chart together with a loaded flight plan are displayed in a north-up orientation. The execution mode displays a loaded flight plan routing together with only pertinent flight route relevant information in either a track up or north up orientation. Depiction of an own ship symbol is possible in both modes. All text and symbols are deconflicted. Additional information can be obtained by clicking on symbols. Terrain and obstacle data can be displayed for enhanced situation awareness. The result shows that pilots flying the 2D enroute moving map display perform no worse than pilots with conventional systems. Flight technical error and workload are equivalent or lower, situational awareness is higher than on conventional paper charts.

Coding performance of the Probe-Orbiter-Earth communication link

NASA Technical Reports Server (NTRS)

Divsalar, D.; Dolinar, S.; Pollara, F.

1993-01-01

The coding performance of the Probe-Orbiter-Earth communication link is analyzed and compared for several cases. It is assumed that the coding system consists of a convolutional code at the Probe, a quantizer and another convolutional code at the Orbiter, and two cascaded Viterbi decoders or a combined decoder on the ground.

Monte Carlo analysis on probe performance for endoscopic diffuse optical spectroscopy of tubular organ

NASA Astrophysics Data System (ADS)

Zhang, Yunyao; Zhu, Jingping; Cui, Weiwen; Nie, Wei; Li, Jie; Xu, Zhenghong

2015-03-01

We investigated the performance of endoscopic diffuse optical spectroscopy probes with circular or linear fiber arrangements for tubular organ cancer detection. Probe performance was measured by penetration depth. A Monte Carlo model was employed to simulate light transport in the hollow cylinder that both emits and receives light from the inner boundary of the sample. The influence of fiber configurations and tissue optical properties on penetration depth was simulated. The results show that under the same condition, probes with circular fiber arrangement penetrate deeper than probes with linear fiber arrangement, and the difference between the two probes' penetration depth decreases with an increase in the 'distance between source and detector (SD)' and the radius of the probe. Other results show that the penetration depths and their differences both decrease with an increase in the absorption coefficient and the reduced scattering coefficient but remain constant with changes in the anisotropy factor. Moreover, the penetration depth was more affected by the absorption coefficient than the reduced scattering coefficient. It turns out that in NIR band, probes with linear fiber arrangements are more appropriate for diagnosing superficial cancers, whereas probes with circular fiber arrangements should be chosen for diagnosing adenocarcinoma. But in UV-VIS band, the two probe configurations exhibit nearly the same. These results are useful in guiding endoscopic diffuse optical spectroscopy-based diagnosis for esophageal, cervical, colorectal and other cancers.

Initial laboratory experience with a novel ultrasound probe for standard and single-port robotic kidney surgery: increasing console surgeon autonomy and minimizing instrument clashing.

PubMed

Yakoubi, Rachid; Autorino, Riccardo; Laydner, Humberto; Guillotreau, Julien; White, Michael A; Hillyer, Shahab; Spana, Gregory; Khanna, Rakesh; Isaac, Wahib; Haber, Georges-Pascal; Stein, Robert J; Kaouk, Jihad H

2012-06-01

The aim of this study was to evaluate a novel ultrasound probe specifically developed for robotic surgery by determining its efficiency in identifying renal tumors. The study was carried out using the Da Vinci™ surgical system in one female pig. Renal tumor targets were created by percutaneous injection of a tumor mimic mixture. Single-port and standard robotic partial nephrectomy were performed. Intraoperative ultrasound was performed using both standard laparoscopic probe and the new ProART™ Robotic probe. Probe maneuverability and ease of handling for tumor localization were recorded. The standard laparoscopic probe was guided by the assistant. Significant clashing with robotic arms was noted during the single-port procedure. The novel robotic probe was easily introduced through the assistant trocar, and held by the console surgeon using the robotic Prograsp™ with no registered clashing in the external operative field. The average time for grasping the new robotic probe was less than 10 s. Once inserted and grasped, no limitation was found in terms of instrument clashing during the single-port procedure. This novel ultrasound probe developed for robotic surgery was noted to be user-friendly when performing porcine standard and especially single-port robotic partial nephrectomy. Copyright © 2011 John Wiley & Sons, Ltd.

Allocation of attentional resources during habituation and dishabituation of male sexual arousal.

PubMed

Koukounas, E; Over, R

1999-12-01

A secondary-task probe (tone) was presented intermittently while men viewed erotic film segments across a session involving 18 trials with the same film segment (habituation), then 2 trials with different film segments (novelty) and 2 trials with reinstatement of the original segment (dishabituation). Reaction time to the tone (an index of the extent processing resources were being committed to the erotic stimulus) shifted during the session in parallel with changes that occurred in penile tumescence and subjective sexual arousal. The decrease in sexual arousal over the first 18 trials in the session was accompanied by a progressively faster reaction to the tone, novel stimulation led to recovery of sexual arousal and a slower reaction to the tone, and on trials 21 and 22 sexual arousal and reaction time levels were above the values that prevailed immediately prior to novel stimulation. Results are discussed with reference to the relationship between habituation and attention.

Working memory component processes: isolating BOLD signal changes.

PubMed

Motes, Michael A; Rypma, Bart

2010-01-15

The chronology of the component processes subserving working memory (WM) and hemodynamic response lags has hindered the use of fMRI for exploring neural substrates of WM. In the present study, however, participants completed full trials that involved encoding two or six letters, maintaining the memory set over a delay, and then deciding whether a probe was in the memory set or not. Additionally, they completed encode-only, encode-and-maintain, and encode-and-decide partial trials intermixed with the full trials. The inclusion of partial trials allowed for the isolation of BOLD signal changes to the different trial periods. The results showed that only lateral and medial prefrontal cortex regions differentially responded to the 2- and 6-letter memory sets over the trial periods, showing greater activation to 6-letter sets during the encode and maintain trial periods. Thus, the data showed the differential involvement of PFC in the encoding and maintenance of supra- and sub-capacity memory sets and show the efficacy of using fMRI partial trial methods to study WM component processes.

Working Memory Component Processes: Isolating BOLD Signal-Changes

PubMed Central

Motes, Michael A.; Rypma, Bart

2009-01-01

The chronology of the component processes subserving working memory (WM) and hemodynamic response lags have hindered the use of fMRI for exploring neural substrates of WM. In the present study, however, participants completed full trials that involved encoding two or six letters, maintaining the memory-set over a delay, and then deciding whether a probe was in the memory-set or not. Additionally, they completed encode only, encode and maintain, and encode and decide partial-trials intermixed with the full-trials. The inclusion of partial-trials allowed for the isolation of BOLD signal-changes to the different trial-periods. The results showed that only lateral and medial prefrontal cortex regions differentially responded to the 2- and 6-letter memory-sets over the trial-periods, showing greater activation to 6-letter sets during the encode and maintain trial-periods. Thus, the data showed the differential involvement of PFC in the encoding and maintenance of supra- and sub-capacity memory-sets and show the efficacy of using fMRI partial-trial methods to study WM component processes. PMID:19732840

Task-switching cost and repetition priming: two overlooked confounds in the first-set procedure of the Sternberg paradigm and how they affect memory set-size effects.

PubMed

Jou, Jerwen

2014-10-01

Subjects performed Sternberg-type memory recognition tasks (Sternberg paradigm) in four experiments. Category-instance names were used as learning and testing materials. Sternberg's original experiments demonstrated a linear relation between reaction time (RT) and memory-set size (MSS). A few later studies found no relation, and other studies found a nonlinear relation (logarithmic) between the two variables. These deviations were used as evidence undermining Sternberg's serial scan theory. This study identified two confounding variables in the fixed-set procedure of the paradigm (where multiple probes are presented at test for a learned memory set) that could generate a MSS RT function that was either flat or logarithmic rather than linearly increasing. These two confounding variables were task-switching cost and repetition priming. The former factor worked against smaller memory sets and in favour of larger sets whereas the latter factor worked in the opposite way. Results demonstrated that a null or a logarithmic RT-to-MSS relation could be the artefact of the combined effects of these two variables. The Sternberg paradigm has been used widely in memory research, and a thorough understanding of the subtle methodological pitfalls is crucial. It is suggested that a varied-set procedure (where only one probe is presented at test for a learned memory set) is a more contamination-free procedure for measuring the MSS effects, and that if a fixed-set procedure is used, it is worthwhile examining the RT function of the very first trials across the MSSs, which are presumably relatively free of contamination by the subsequent trials.

[Efficacy and problems of bladder volume measurement using portable three dimensional ultrasound scanning device--in particular, on measuring bladder volume lower than 100ml].

PubMed

Oh-Oka, Hitoshi; Nose, Ryuichiro

2005-09-01

Using a portable three dimensional ultrasound scanning device (The Bladder Scan BVI6100, Diagnostic Ultrasound Corporation), we examined measured values of bladder volume, especially focusing on volume lower than 100 ml. A total of 100 patients (male: 66, female: 34) were enrolled in the study. We made a comparison study between the measured value (the average of three measurements of bladder urine volume after a trial in male and female modes) using BVI6100, and the actual measured value of the sample obtained by urethral catheterization in each patient. We examined the factors which could increase the error rate. We also introduced the effective techniques to reduce measurement errors. The actual measured values in all patients correlated well with the average value of three measurements after a trial in a male mode of the BVI6100. The correlation coefficient was 0.887, the error rate was--4.6 +/- 24.5%, and the average coefficient of variation was 15.2. It was observed that the measurement result using the BVI6100 is influenced by patient side factors (extracted edges between bladder wall and urine, thickened bladder wall, irregular bladder wall, flattened rate of bladder, mistaking prostate for bladder in male, mistaking bladder for uterus in a female mode, etc.) or examiner side factors (angle between BVI and abdominal wall, compatibility between abdominal wall and ultrasound probe, controlling deflection while using probe, etc). When appropriate patients are chosen and proper measurement is performed, BVI6100 provides significantly higher accuracy in determining bladder volume, compared with existing abdominal ultrasound methods. BVI6100 is a convenient and extremely effective device also for the measurement of bladder urine over 100 ml.

Antibiotic therapy as an adjunct to scaling and root planing in smokers: a systematic review and meta-analysis.

PubMed

Assem, Naida Zanini; Alves, Márcio Luiz Ferro; Lopes, Alessandra Barreto; Gualberto, Erivan Clementino; Garcia, Valdir Gouveia; Theodoro, Letícia Helena

2017-07-03

The aim of this study was to perform a systematic review and meta-analysis to examine the effect of systemic antibiotics in the periodontal treatment of smokers. The selection criteria were as follows: controlled randomized clinical trials; studies published in English; studies with smoker patients diagnosed with chronic periodontitis; patients without systemic diseases; studies that used systemic antibiotic therapy associated with periodontal treatment; studies that presented results for the test and control groups and assessments of clinical periodontal parameters, such as probing depth (PD), bleeding on probing (BOP), and clinical attachment level (CAL). The differences in average weights were calculated with a confidence interval (CI) of 95% for PD reduction, CAL gain and BOP. The means of the periodontal clinical parameters were compared between the baseline and post-treatment periods between the test groups and the control groups. The heterogeneity was assessed using the Cochran Q test (Q (df = 3), α = 5%). A total of 67 articles were found, and after the selection process, three randomized controlled trials were included in the meta-analysis. The results indicate that SRP associated with systemic antibiotics promoted additional benefits when compared to SRP alone, with a greater reduction of PD (p = 0.0359, CI = -0.42, -0.01) and a gain of CAL (p = 0.0161, CI = -0.39, -0.04). There was a modest PD reduction (PD, DM -0.21) and a modest CAL gain (CAL, DM -0.22). The results of our meta-analysis reveal the clinical benefits of systemic antibiotics as an adjunct to the non-surgical periodontal treatment of smokers. These clinical improvements, although statistically significant, appeared to be of little clinical relevance.

Clinical Comparison of Autogenous Bone Graft with and without Plasma Rich in Growth Factors in the Treatment of Grade II Furcation Involvement of Mandibular Molars

PubMed Central

Lafzi, Ardeshir; Shirmohammadi, Adileh; Faramarzi, Masoumeh; Jabali, Sahar; Shayan, Arman

2013-01-01

Background and aims Plasma rich in growth factors (PRGF) is a concentrated suspension of growth factors, which is used to promote periodontal tissue regeneration. The aim of this randomized, controlled, clinical trial was to evaluate of the treatment of grade II mandibular molar furcation involvement using autogenous bone graft with and without PRGF. Materials and methods In this double-blind clinical trial, thirty mandibular molars with grade II furcation involvement in 30 patients were selected. The test group received bone graft combined with PRGF, while the control group was treated with bone graft only. Clinical parameters included clinical probing depth (CPD), vertical clinical attachment level (V-CAL), horizontal clinical attachment level (H-CAL), location of gingival margin (LGM), surgically exposed horizontal probing depth of bony defect (E-HPD), vertical depth of bone crest (V-DBC), vertical depth of the base of bony defect (V-DBD), and length of the intrabony defect (LID). After six months, a re-entry surgery was performed. Data were analyzed by SPSS 14, using Kolmogorov, Mann-Whitney U, and paired t-test. Results After 6 months, both treatment methods led to significant improvement in V-CAL and H-CAL and significant decreases in CPD, E-HPD, V-DBD and LID; there was no significant difference in LGM and V-DBC in any of the treated groups compared to the baseline values. Also, none of the parameters showed significant differences between the study groups. Conclusion Although autogenous bone grafts, with or without PRGF, were successful in treating grade II furcation involvement, no differences between the study groups were observed. PMID:23486928

Teaching Spontaneous Responses to Young Children with Autism

ERIC Educational Resources Information Center

Jones, Emily A.; Feeley, Kathleen M.; Takacs, Jennifer

2007-01-01

Using a multiple probe design across responses, we demonstrated the effectiveness of intensive intervention in establishing spontaneous verbal responses to 2 3-year-old children with autism with generalization to novel settings involving novel persons. Intervention involved discrete-trial instruction (i.e., repeated instructional opportunities…

Effect of visuomotor-map uncertainty on visuomotor adaptation.

PubMed

Saijo, Naoki; Gomi, Hiroaki

2012-03-01

Vision and proprioception contribute to generating hand movement. If a conflict between the visual and proprioceptive feedback of hand position is given, reaching movement is disturbed initially but recovers after training. Although previous studies have predominantly investigated the adaptive change in the motor output, it is unclear whether the contributions of visual and proprioceptive feedback controls to the reaching movement are modified by visuomotor adaptation. To investigate this, we focused on the change in proprioceptive feedback control associated with visuomotor adaptation. After the adaptation to gradually introduce visuomotor rotation, the hand reached the shifted position of the visual target to move the cursor to the visual target correctly. When the cursor feedback was occasionally eliminated (probe trial), the end point of the hand movement was biased in the visual-target direction, while the movement was initiated in the adapted direction, suggesting the incomplete adaptation of proprioceptive feedback control. Moreover, after the learning of uncertain visuomotor rotation, in which the rotation angle was randomly fluctuated on a trial-by-trial basis, the end-point bias in the probe trial increased, but the initial movement direction was not affected, suggesting a reduction in the adaptation level of proprioceptive feedback control. These results suggest that the change in the relative contribution of visual and proprioceptive feedback controls to the reaching movement in response to the visuomotor-map uncertainty is involved in visuomotor adaptation, whereas feedforward control might adapt in a manner different from that of the feedback control.

Visual search by chimpanzees (Pan): assessment of controlling relations.

PubMed Central

Tomonaga, M

1995-01-01

Three experimentally sophisticated chimpanzees (Pan), Akira, Chloe, and Ai, were trained on visual search performance using a modified multiple-alternative matching-to-sample task in which a sample stimulus was followed by the search display containing one target identical to the sample and several uniform distractors (i.e., negative comparison stimuli were identical to each other). After they acquired this task, they were tested for transfer of visual search performance to trials in which the sample was not followed by the uniform search display (odd-item search). Akira showed positive transfer of visual search performance to odd-item search even when the display size (the number of stimulus items in the search display) was small, whereas Chloe and Ai showed a transfer only when the display size was large. Chloe and Ai used some nonrelational cues such as perceptual isolation of the target among uniform distractors (so-called pop-out). In addition to the odd-item search test, various types of probe trials were presented to clarify the controlling relations in multiple-alternative matching to sample. Akira showed a decrement of accuracy as a function of the display size when the search display was nonuniform (i.e., each "distractor" stimulus was not the same), whereas Chloe and Ai showed perfect performance. Furthermore, when the sample was identical to the uniform distractors in the search display, Chloe and Ai never selected an odd-item target, but Akira selected it when the display size was large. These results indicated that Akira's behavior was controlled mainly by relational cues of target-distractor oddity, whereas an identity relation between the sample and the target strongly controlled the performance of Chloe and Ai. PMID:7714449

Investigating the neural bases for intra-subject cognitive efficiency changes using functional magnetic resonance imaging

PubMed Central

Rao, Neena K.; Motes, Michael A.; Rypma, Bart

2014-01-01

Several fMRI studies have examined brain regions mediating inter-subject variability in cognitive efficiency, but none have examined regions mediating intra-subject variability in efficiency. Thus, the present study was designed to identify brain regions involved in intra-subject variability in cognitive efficiency via participant-level correlations between trial-level reaction time (RT) and trial-level fMRI BOLD percent signal change on a processing speed task. On each trial, participants indicated whether a digit-symbol probe-pair was present or absent in an array of nine digit-symbol probe-pairs while fMRI data were collected. Deconvolution analyses, using RT time-series models (derived from the proportional scaling of an event-related hemodynamic response function model by trial-level RT), were used to evaluate relationships between trial-level RTs and BOLD percent signal change. Although task-related patterns of activation and deactivation were observed in regions including bilateral occipital, bilateral parietal, portions of the medial wall such as the precuneus, default mode network regions including anterior cingulate, posterior cingulate, bilateral temporal, right cerebellum, and right cuneus, RT-BOLD correlations were observed in a more circumscribed set of regions. Positive RT-BOLD correlations, where fast RTs were associated with lower BOLD percent signal change, were observed in regions including bilateral occipital, bilateral parietal, and the precuneus. RT-BOLD correlations were not observed in the default mode network indicating a smaller set of regions associated with intra-subject variability in cognitive efficiency. The results are discussed in terms of a distributed area of regions that mediate variability in the cognitive efficiency that might underlie processing speed differences between individuals. PMID:25374527

Investigating the neural bases for intra-subject cognitive efficiency changes using functional magnetic resonance imaging.

PubMed

Rao, Neena K; Motes, Michael A; Rypma, Bart

2014-01-01

Several fMRI studies have examined brain regions mediating inter-subject variability in cognitive efficiency, but none have examined regions mediating intra-subject variability in efficiency. Thus, the present study was designed to identify brain regions involved in intra-subject variability in cognitive efficiency via participant-level correlations between trial-level reaction time (RT) and trial-level fMRI BOLD percent signal change on a processing speed task. On each trial, participants indicated whether a digit-symbol probe-pair was present or absent in an array of nine digit-symbol probe-pairs while fMRI data were collected. Deconvolution analyses, using RT time-series models (derived from the proportional scaling of an event-related hemodynamic response function model by trial-level RT), were used to evaluate relationships between trial-level RTs and BOLD percent signal change. Although task-related patterns of activation and deactivation were observed in regions including bilateral occipital, bilateral parietal, portions of the medial wall such as the precuneus, default mode network regions including anterior cingulate, posterior cingulate, bilateral temporal, right cerebellum, and right cuneus, RT-BOLD correlations were observed in a more circumscribed set of regions. Positive RT-BOLD correlations, where fast RTs were associated with lower BOLD percent signal change, were observed in regions including bilateral occipital, bilateral parietal, and the precuneus. RT-BOLD correlations were not observed in the default mode network indicating a smaller set of regions associated with intra-subject variability in cognitive efficiency. The results are discussed in terms of a distributed area of regions that mediate variability in the cognitive efficiency that might underlie processing speed differences between individuals.

Greater Working Memory Load Results in Greater Medial Temporal Activity at Retrieval

PubMed Central

Quiroz, Yakeel T.; Hasselmo, Michael E.; Stern, Chantal E.

2009-01-01

Most functional magnetic resonance imaging (fMRI) studies examining working memory (WM) load have focused on the prefrontal cortex (PFC) and have demonstrated increased prefrontal activity with increased load. Here we examined WM load effects in the medial temporal lobe (MTL) using an fMRI Sternberg task with novel complex visual scenes. Trials consisted of 3 sequential events: 1) sample presentation (encoding), 2) delay period (maintenance), and 3) probe period (retrieval). During sample encoding, subjects saw either 2 or 4 pictures consecutively. During retrieval, subjects indicated whether the probe picture matched one of the sample pictures. Results revealed that activity in the left anterior hippocampal formation, bilateral retrosplenial area, and left amygdala was greater at retrieval for trials with larger memory load, whereas activity in the PFC was greater at encoding for trials with larger memory load. There was no load effect during the delay. When encoding, maintenance, and retrieval periods were compared with fixation, activity was present in the hippocampal body/tail and fusiform gyrus bilaterally during encoding and retrieval, but not maintenance. Bilateral dorsolateral prefrontal activity was present during maintenance, but not during encoding or retrieval. The results support models of WM predicting that activity in the MTL should be modulated by WM load. PMID:19224975

Interference Resolution in Emotional Working Memory as a Function of Alexithymia.

PubMed

Colligan, Sean M; Koven, Nancy S

2015-01-01

Although alexithymia is recognized as a set of traitlike deficits in emotion processing, research suggests there are concomitant cognitive issues as well, including what appears to be an unusual pattern of enhanced working memory (WM) despite broader executive dysfunction. It is unknown whether this enhancement includes the executive elements of WM and whether executive control of WM in alexithymia differs for emotional and neutral stimuli. This study examined how alexithymia moderates patterns of interference resolution in WM with valenced and nonvalenced stimuli. Participants (N = 93) completed the Toronto Alexithymia Scale and a recency probes WM task containing positive, negative, and neutral stimuli, with some trials containing proactive interference from previous trials. The reaction time difference between interference and noninterference trials indexed degree of interference resolution. Toronto Alexithymia Scale score moderated a within-subject effect such that, when valenced probes were used, there was less proactive interference in the positive relative to negative valence condition; this valence-based interference discrepancy was significant for a subset of highly alexithymic participants. Alexithymia did not moderate proactive interference to negative or neutral stimuli or accuracy of responses. These results suggest that, although alexithymia does not influence executive control in WM for nonemotional items, alexithymic people demonstrate an idiosyncratic response to positive stimuli that might indicate blunted reactivity.

Facial expression movement enhances the measurement of temporal dynamics of attentional bias in the dot-probe task.

PubMed

Caudek, Corrado; Ceccarini, Francesco; Sica, Claudio

2017-08-01

The facial dot-probe task is one of the most common experimental paradigms used to assess attentional bias toward emotional information. In recent years, however, the psychometric properties of this paradigm have been questioned. In the present study, attentional bias to emotional face stimuli was measured with dynamic and static images of realistic human faces in 97 college students (63 women) who underwent either a positive or a negative mood-induction prior to the experiment. We controlled the bottom-up salience of the stimuli in order to dissociate the top-down orienting of attention from the effects of the bottom-up physical properties of the stimuli. A Bayesian analysis of our results indicates that 1) the traditional global attentional bias index shows a low reliability, 2) reliability increases dramatically when biased attention is analyzed by extracting a series of bias estimations from trial-to-trial (Zvielli, Bernstein, & Koster, 2015), 3) dynamic expression of emotions strengthens biased attention to emotional information, and 4) mood-congruency facilitates the measurement of biased attention to emotional stimuli. These results highlight the importance of using ecologically valid stimuli in attentional bias research, together with the importance of estimating biased attention at the trial level. Copyright © 2017 Elsevier Ltd. All rights reserved.

Implicit learning in a serial choice visual discrimination task in the operant 9-hole box by intact and striatal lesioned mice.

PubMed

Trueman, Rebecca C; Brooks, Simon P; Dunnett, Stephen B

2005-04-30

Within a broader programme developing murine models of Huntington's disease (HD), we have sought to develop a test of implicit learning for the mouse. Mice were trained in a novel serial visual discrimination task in the '9-hole box' operant test apparatus, followed by retesting after either bilateral quinolinic acid striatal lesions or sham lesions. In the task, each trial involves two sequential responses: an initial light stimulus is presented randomly in one of five holes, to which a nose-poke response results in the first light being extinguished and a second light is illuminated in a different hole. Response to the second light results in food reward, followed by a brief interval before the next trial. When the first light was in one of three of the five holes, the location of the second light was unpredictable in any of the remaining four holes; by contrast, if the first light occurred in one of the other two of the five holes, then the location of the second light was entirely predictable, being the hole two steps to the left or to the right, respectively. Reaction times and accuracy of responding were recorded to both stimuli. The mice learned the task with a degree of accuracy, and they demonstrated clear implicit learning, as measured by increased accuracy and reduced latency to respond to the presentation of the predictable stimulus. Striatal lesions disrupted performance, reducing accuracy for both the first and second stimuli and increasing response latencies for the second stimuli. The decrease in accuracy by the lesioned animals was accompanied by increases in perseverative nose-poking and inappropriate magazine entries throughout the trials, but the lesioned mice still showed a similar benefit (albeit, against a lower baseline of performance) from the implicit knowledge provided on predictable trials. The data validates the task as a sensitive probe for determining implicit learning deficits in the mouse, and suggests that the consequences of striatal lesions, while disrupting performance of skilled stimulus-response habits, are not selective to the process underlying implicit learning.

Toward Fourier interferometry fluorescence excitation/emission imaging of malignant cells combined with photoacoustic microscopy

NASA Astrophysics Data System (ADS)

Kohen, Elli; Hirschberg, Joseph G.; Berry, John P.; Ozkutuk, Nuri; Ornek, Ceren; Monti, Marco; Leblanc, Roger M.; Schachtschabel, Dietrich O.; Haroon, Sumaira

2003-10-01

Dual excitation fluorescence imaging has been used as a first step towards multi-wavelength excitation/emission fluorescence spectral imaging. Target cells are transformed keratinocytes, and other osteosarcoma, human breast and color cancer cells. Mitochondrial membrane potential probes, e.g. TMRM (tetramethylrhodamine methyl ester), Mitotracker Green (Molecular Probes, Inc., Eugene OR,USA; a recently synthesized mitochondrial oxygen probe, [PRE,P1"- pyrene butyl)-2-rhodamine ester] allow dual excitation in the UV plus in teh blue-green spectral regions. Also, using the natural endogenous probe NAD(P)H, preliminary results indicate mitochondrial responses to metabolic challenges (e.g. glucose addition), plus changes in mitochonrial distribution and morphology. In terms of application to biomedicine (for diagnostiscs, prognostsics and drug trials) three parameters have been selected in addition to the natural probe NAD(P)H, i.e. vital fluorescence probing of mitochondria, lysosomes and Golgi apparatus. It is hoped that such a multiparameter approach will allow malignant cell characterization and grading. A new area being introduced is the use of similar methodology for biotechnical applications such as the study of the hydrogen-producing alga Chlamydomonas Reinhardtii, and possible agricultural applications, such as Saccharomyces yeast for oenology. Complementation by Photoacoustic Microscopy is also contemplated, to study the internal conversion component which follows the excitation by photons.

A high-temperature superconducting Helmholtz probe for microscopy at 9.4 T.

PubMed

Hurlston, S E; Brey, W W; Suddarth, S A; Johnson, G A

1999-05-01

The design and operation of a high-temperature superconducting (HTS) probe for magnetic resonance microscopy (MRM) at 400 MHz are presented. The design of the probe includes a Helmholtz coil configuration and a stable open-cycle cooling mechanism. Characterization of coil operating parameters is presented to demonstrate the suitability of cryo-cooled coils for MRM. Specifically, the performance of the probe is evaluated by comparison of signal-to-noise (SNR) performance with that of a copper Helmholtz pair, analysis of B1 field homogeneity, and quantification of thermal stability. Images are presented to demonstrate the SNR advantage of the probe for typical MRM applications.

Evaluation of fluorophores for optimal performance in localization-based super-resolution imaging

PubMed Central

Dempsey, Graham T.; Vaughan, Joshua C.; Chen, Kok Hao; Bates, Mark; Zhuang, Xiaowei

2011-01-01

One approach to super-resolution fluorescence imaging uses sequential activation and localization of individual fluorophores to achieve high spatial resolution. Essential to this technique is the choice of fluorescent probes — the properties of the probes, including photons per switching event, on/off duty cycle, photostability, and number of switching cycles, largely dictate the quality of super-resolution images. While many probes have been reported, a systematic characterization of the properties of these probes and their impact on super-resolution image quality has been described in only a few cases. Here, we quantitatively characterized the switching properties of 26 organic dyes and directly related these properties to the quality of super-resolution images. This analysis provides a set of guidelines for characterization of super-resolution probes and a resource for selecting probes based on performance. Our evaluation identified several photoswitchable dyes with good to excellent performance in four independent spectral ranges, with which we demonstrated low crosstalk, four-color super-resolution imaging. PMID:22056676

Networks on the Edge of Forever: Examining the Feasibility of using Meteor Burst (MB) Communication Networks on Mars

NASA Astrophysics Data System (ADS)

Charania, A.

2002-01-01

The envisioned future may include continuous operating outposts and networks on other worlds supporting human and robotic exploration. Given this possibility, a feasibility analysis is performed of a communications architecture based upon reflection of ion trails from meteors in planetary atmospheres. Meteor Burst (MB) communication systems use meteoritic impacts on planetary atmospheres as two-way, short burst communication nodes. MB systems consist of semi-continuous, low bandwidth networks. These systems possess both long distance capability (hundred of kilometers) and have lower susceptibility to atmospheric perturbations. Every day millions of meteors come into Earth's upper atmosphere with enough energy to ionize gas molecules suitably to reflect radio waves and facilitate communications beyond line of site. The ionized trail occurs at altitudes of 100 km with lengths reaching 30 km. The trial sustains itself long enough to support typical network distances of 1800 km. The initial step to use meteors in this fashion includes detection of a usable ionic trail. A probe signal is sent from one station to another in the network. If there is a meteor trail present, the probe signal is reflected to a receiving station. When another station receives the probe signal, it sends an acknowledgement to the originating station to proceed with transfer on that trail in a high-speed digital data burst. This probe-main signal handshaking occurs each time a burst of data is sent and can occur several times over the course of just one useable meteor trail. Given the need for non-data sending probe signals and error correcting bits; typical transmission data rates vary from a few kilobits per second to over 100 kilobits per second. On Earth, MB links open up hundreds of time per hour depending upon daily and seasonal variations. Meteor bursts were first noticed in detail in the 1930s. With the capabilities of modern computer processing, MB systems have become both technically feasible and commercially viable for selected applications on Earth. Terrestrial applications currently include weather monitoring, river monitoring, transport tracking, emergency detection, two-way messaging, and vehicle performance monitoring. Translation of such a system beyond Earth requires an atmosphere; therefore Martian analogues of such a system are presented. Such systems could support planetary mobility (for humans and robots), weather stations, and emergency communications while minimizing the need for massive orbital telecommunication constellations. For this investigation, a conceptual Meteor Burst (MB) communication architecture is developed to assess potential viability in supporting planetary exploration missions on Mars. Current terrestrial systems are extrapolated to generate candidate network architectures for selected science applications. Technology road mapping activities are also performed on these architectures.

Intracellular probes for imaging oxygen concentration: how good are they?

NASA Astrophysics Data System (ADS)

Dmitriev, Ruslan I.; Papkovsky, Dmitri B.

2015-09-01

In the last decade a number of cell-permeable phosphorescence based probes for imaging of (intra)cellular oxygen (icO2) have been described. These small molecule, supramolecular and nanoparticle structures, although allowing analysis of hypoxia, local gradients and fluctuations in O2, responses to stimulation and drug treatment at sub-cellular level with high spatial and temporal resolution, differ significantly in their operational performance and applicability to different cell and tissue models. Here we discuss and compare these probes with respect to their staining efficiency, brightness, photostability, toxicity, cell specificity, compatibility with different cell and tissue models, and analytical performance. Merits and limitations of particular probes are highlighted and strategies for development of new high-performance O2 imaging probes defined. Key application areas in hypoxia research, stem cells, cancer biology and tissue physiology are also discussed.

Preston Probe Calibrations at High Reynolds Number

NASA Technical Reports Server (NTRS)

Smits, Alexander J.

1998-01-01

The overall goal of the research effort is to study the performance of two Preston probes designed by NASA Langley Research Center across an unprecedented range of Reynolds number (based on friction velocity and probe diameter), and perform an accurate calibration over the same Reynolds number range. Using the Superpipe facility in Princeton, two rounds of experiments were performed. In each round of experiments for each Reynolds number, the pressure gradient, static pressure from the Preston probes and the total pressure from the Preston probes were measured. In the first round, 3 Preston probes having outer diameters of 0.058 inches, 0.083 inches and 0.203 inches were tested over a large range of pipe Reynolds numbers. Two data reduction methods were employed: first, the static pressure measured on the Preston probe was used to calculate P (modified Preston probe configuration), and secondly, the static pressure measured at the reference pressure tap was used to calculate P (un-modified Preston probe configuration). For both methods, the static pressure was adjusted to correspond with the static pressure at the Preston probe tip using the pressure gradient. The measurements for Preston probes with diameters of 0.058 inches, and 0.083 inches respectively were performed in the test pipe before it was polished a second time. Therefore, the measurements at high pipe Reynolds numbers may have been affected by roughness. In the second round of experiments the 0.058 inches and 0.083 inches diameter, un-modified probes were tested after the pipe was polished and prepared to ensure that the surface was smooth. The average velocity was estimated by assuming that the connection between the centerline velocity and the average velocity was known, and by using a Pitot tube to measure the centerline velocity. A preliminary error estimate suggests that it is possible to introduce a 1% to 2% error in estimating the average velocity using this approach. The evidence on the errors attending the second data set is somewhat circumstantial, and the measurements have not been repeated using a better approach, it seems probable that the correlation given applies to un-modified Preston probes over the range 6.4 less than x* less than 11.3.

Spatiotemporal oscillatory dynamics of visual selective attention during a flanker task.

PubMed

McDermott, Timothy J; Wiesman, Alex I; Proskovec, Amy L; Heinrichs-Graham, Elizabeth; Wilson, Tony W

2017-08-01

The flanker task is a test of visual selective attention that has been widely used to probe error monitoring, response conflict, and related constructs. However, to date, few studies have focused on the selective attention component of this task and imaged the underlying oscillatory dynamics serving task performance. In this study, 21 healthy adults successfully completed an arrow-based version of the Eriksen flanker task during magnetoencephalography (MEG). All MEG data were pre-processed and transformed into the time-frequency domain. Significant oscillatory brain responses were imaged using a beamforming approach, and voxel time series were extracted from the peak responses to identify the temporal dynamics. Across both congruent and incongruent flanker conditions, our results indicated robust decreases in alpha (9-12Hz) activity in medial and lateral occipital regions, bilateral parietal cortices, and cerebellar areas during task performance. In parallel, increases in theta (3-7Hz) oscillatory activity were detected in dorsal and ventral frontal regions, and the anterior cingulate. As per conditional effects, stronger alpha responses (i.e., greater desynchronization) were observed in parietal, occipital, and cerebellar cortices during incongruent relative to congruent trials, whereas the opposite pattern emerged for theta responses (i.e., synchronization) in the anterior cingulate, left dorsolateral prefrontal, and ventral prefrontal cortices. Interestingly, the peak latency of theta responses in these latter brain regions was significantly correlated with reaction time, and may partially explain the amplitude difference observed between congruent and incongruent trials. Lastly, whole-brain exploratory analyses implicated the frontal eye fields, right temporoparietal junction, and premotor cortices. These findings suggest that regions of both the dorsal and ventral attention networks contribute to visual selective attention processes during incongruent trials, and that such differential processes are transient and fully completed shortly after the behavioral response in most trials. Copyright © 2017 Elsevier Inc. All rights reserved.

Measurements With a Split-Fiber Probe in Complex Unsteady Flows

NASA Technical Reports Server (NTRS)

Lepicovsky, Jan

2004-01-01

A split-fiber probe was used to acquire unsteady data in a research compressor. A calibration method was devised for a split-fiber probe, and a new algorithm was developed to decompose split-fiber probe signals into velocity magnitude and direction. The algorithm is based on the minimum value of a merit function that is built over the entire range of flow velocities for which the probe was calibrated. The split-fiber probe performance and signal decomposition was first verified in a free-jet facility by comparing the data from three thermo-anemometric probes, namely a single-wire, a single-fiber, and the split-fiber probe. All three probes performed extremely well as far as the velocity magnitude was concerned. However, there are differences in the peak values of measured velocity unsteadiness in the jet shear layer. The single-wire probe indicates the highest unsteadiness level, followed closely by the split-fiber probe. The single-fiber probe indicates a noticeably lower level of velocity unsteadiness. Experiments in the NASA Low Speed Axial Compressor facility revealed similar results. The mean velocities agreed well, and differences in the velocity unsteadiness are similar to the case of a free jet. A reason for these discrepancies is in the different frequency response characteristics of probes used. It follows that the single-fiber probe has the slowest frequency response. In summary, the split-fiber probe worked reliably during the entire program. The acquired data averaged in time followed closely data acquired by conventional pneumatic probes.

Spatial-scanning hyperspectral imaging probe for bio-imaging applications

NASA Astrophysics Data System (ADS)

Lim, Hoong-Ta; Murukeshan, Vadakke Matham

2016-03-01

The three common methods to perform hyperspectral imaging are the spatial-scanning, spectral-scanning, and snapshot methods. However, only the spectral-scanning and snapshot methods have been configured to a hyperspectral imaging probe as of today. This paper presents a spatial-scanning (pushbroom) hyperspectral imaging probe, which is realized by integrating a pushbroom hyperspectral imager with an imaging probe. The proposed hyperspectral imaging probe can also function as an endoscopic probe by integrating a custom fabricated image fiber bundle unit. The imaging probe is configured by incorporating a gradient-index lens at the end face of an image fiber bundle that consists of about 50 000 individual fiberlets. The necessary simulations, methodology, and detailed instrumentation aspects that are carried out are explained followed by assessing the developed probe's performance. Resolution test targets such as United States Air Force chart as well as bio-samples such as chicken breast tissue with blood clot are used as test samples for resolution analysis and for performance validation. This system is built on a pushbroom hyperspectral imaging system with a video camera and has the advantage of acquiring information from a large number of spectral bands with selectable region of interest. The advantages of this spatial-scanning hyperspectral imaging probe can be extended to test samples or tissues residing in regions that are difficult to access with potential diagnostic bio-imaging applications.

The positional-specificity effect reveals a passive-trace contribution to visual short-term memory.

PubMed

Postle, Bradley R; Awh, Edward; Serences, John T; Sutterer, David W; D'Esposito, Mark

2013-01-01

The positional-specificity effect refers to enhanced performance in visual short-term memory (VSTM) when the recognition probe is presented at the same location as had been the sample, even though location is irrelevant to the match/nonmatch decision. We investigated the mechanisms underlying this effect with behavioral and fMRI studies of object change-detection performance. To test whether the positional-specificity effect is a direct consequence of active storage in VSTM, we varied memory load, reasoning that it should be observed for all objects presented in a sub-span array of items. The results, however, indicated that although robust with a memory load of 1, the positional-specificity effect was restricted to the second of two sequentially presented sample stimuli in a load-of-2 experiment. An additional behavioral experiment showed that this disruption wasn't due to the increased load per se, because actively processing a second object--in the absence of a storage requirement--also eliminated the effect. These behavioral findings suggest that, during tests of object memory, position-related information is not actively stored in VSTM, but may be retained in a passive tag that marks the most recent site of selection. The fMRI data were consistent with this interpretation, failing to find location-specific bias in sustained delay-period activity, but revealing an enhanced response to recognition probes that matched the location of that trial's sample stimulus.

Mechanical Validation of an MRI Compatible Stereotactic Neurosurgery Robot in Preparation for Pre-Clinical Trials

PubMed Central

Nycz, Christopher J; Gondokaryono, Radian; Carvalho, Paulo; Patel, Nirav; Wartenberg, Marek; Pilitsis, Julie G; Fischer, Gregory S

2018-01-01

The use of magnetic resonance imaging (MRI) for guiding robotic surgical devices has shown great potential for performing precisely targeted and controlled interventions. To fully realize these benefits, devices must work safely within the tight confines of the MRI bore without negatively impacting image quality. Here we expand on previous work exploring MRI guided robots for neural interventions by presenting the mechanical design and assessment of a device for positioning, orienting, and inserting an interstitial ultrasound-based ablation probe. From our previous work we have added a 2 degree of freedom (DOF) needle driver for use with the aforementioned probe, revised the mechanical design to improve strength and function, and performed an evaluation of the mechanism’s accuracy and effect on MR image quality. The result of this work is a 7-DOF MRI robot capable of positioning a needle tip and orienting it’s axis with accuracy of 1.37 ± 0.06mm and 0.79° ± 0.41°, inserting it along it’s axis with an accuracy of 0.06 ± 0.07mm, and rotating it about it’s axis to an accuracy of 0.77° ± 1.31°. This was accomplished with no significant reduction in SNR caused by the robot’s presence in the MRI bore, ≤ 10.3% reduction in SNR from running the robot’s motors during a scan, and no visible paramagnetic artifacts. PMID:29696097

The PKC-β selective inhibitor, Enzastaurin, impairs memory in middle-aged rats.

PubMed

Willeman, Mari N; Mennenga, Sarah E; Siniard, Ashley L; Corneveaux, Jason J; De Both, Matt; Hewitt, Lauren T; Tsang, Candy W S; Caselli, Jason; Braden, B Blair; Bimonte-Nelson, Heather A; Huentelman, Matthew J

2018-01-01

Enzastaurin is a Protein Kinase C-β selective inhibitor that was developed to treat cancers. Protein Kinase C-β is an important enzyme for a variety of neuronal functions; in particular, previous rodent studies have reported deficits in spatial and fear-conditioned learning and memory with lower levels of Protein Kinase C-β. Due to Enzastaurin's mechanism of action, the present study investigated the consequences of Enzastaurin exposure on learning and memory in 12-month-old Fischer-344 male rats. Rats were treated daily with subcutaneous injections of either vehicle or Enzastaurin, and behaviorally tested using the spatial reference memory Morris Water Maze. Rats treated with Enzastaurin exhibited decreased overnight retention and poorer performance on the latter testing day, indicating a mild, but significant, memory impairment. There were no differences during the probe trial indicating that all animals were able to spatially localize the platform to the proper quadrant by the end of testing. RNA isolated from the hippocampus was analyzed using Next Generation Sequencing (Illumina). No statistically significant transcriptional differences were noted. Our findings suggest that acute Enzastaurin treatment can impair hippocampal-based learning and memory performance, with no effects on transcription in the hippocampus. We propose that care should be taken in future clinical trials that utilize Protein Kinase C-ß inhibitors, to monitor for possible cognitive effects, future research should examine if these effects are fully reversible.

Comparison of immediate implant placement in infected and non-infected extraction sockets: a systematic review and meta-analysis.

PubMed

Lee, Jungwon; Park, Dueun; Koo, Ki-Tae; Seol, Yang-Jo; Lee, Yong-Moo

2018-04-03

This review aimed to investigate the feasibility of immediate implant placement in infected extraction sockets. We performed electronic and manual searches up to March 2017 to obtain data from randomized controlled trials (RCTs) and nonrandomized controlled clinical trials (CCTs). Using a fixed-effects model to assess the difference in survival rate (primary outcome), we evaluated the risk difference for immediate implant placement in infected and non-infected sites. We estimated the weighted mean differences (WMDs) of the change in marginal bone loss (MBL), probing depth (PD), modified bleeding index (mBI), marginal gingival level (MGL) and width of keratinized gingiva (WKG) at baseline and latest follow-up. In total, five studies (0 RCT, five CCTs) were included in the systematic review and three studies were included in the meta-analysis. The risk difference for immediate implant placement in an infected extraction socket compared with that in a non-infected socket was -0.02. WMDs for MBL, PD, mBI, MGL and WKG between the two groups were 0.32, 0.12, 0.07, -0.06, 0.20 and 0.51, respectively. No statistical differences were observed between the two groups, except for the change in WKG. Implants can be placed in infected extraction sockets after thorough socket debridement. For aesthetics, WKG should be considered when performing immediate implant placement in infected sites.

Blueberry supplementation improves memory in middle-aged mice fed a high-fat diet.

PubMed

Carey, Amanda N; Gomes, Stacey M; Shukitt-Hale, Barbara

2014-05-07

Consuming a high-fat diet may result in behavioral deficits similar to those observed in aging animals. It has been demonstrated that blueberry supplementation can allay age-related behavioral deficits. To determine if supplementation of a high-fat diet with blueberries offers protection against putative high-fat diet-related declines, 9-month-old C57Bl/6 mice were maintained on low-fat (10% fat calories) or high-fat (60% fat calories) diets with and without 4% freeze-dried blueberry powder. Novel object recognition memory was impaired by the high-fat diet; after 4 months on the high-fat diet, mice spent 50% of their time on the novel object in the testing trial, performing no greater than chance performance. Blueberry supplementation prevented recognition memory deficits after 4 months on the diets, as mice on this diet spent 67% of their time on the novel object. After 5 months on the diets, mice consuming the high-fat diet passed through the platform location less often than mice on low-fat diets during probe trials on days 2 and 3 of Morris water maze testing, whereas mice consuming the high-fat blueberry diet passed through the platform location as often as mice on the low-fat diets. This study is a first step in determining if incorporating more nutrient-dense foods into a high-fat diet can allay cognitive dysfunction.

"Life-span development of visual working memory: When is feature binding difficult?": Correction to Cowan et al. (2006).

PubMed

2016-10-01

Reports an error in "Life-span development of visual working memory: When is feature binding difficult?" by Nelson Cowan, Moshe Naveh-Benjamin, Angela Kilb and J. Scott Saults ( Developmental Psychology , 2006[Nov], Vol 42[6], 1089-1102). In the article, there were two errors in experiment 1a. The mean for color item information in older adults was incorrectly calculated. As a result, Figure 3 shows a mean of over .70. The true mean was .63 ( SEM =.04). This change diminishes the magnitude of the aging deficit for associative information, although this deficit still appears to remain, to a smaller extent. (For a conceptual replication see Peterson & Naveh-Benjamin, 2016). There also was an error in the experimental procedure of Experiment 1a. The older adults in that experiment received only half the number of trials specified in the methods section, and half as much as the other groups. For all groups, when there were 4 or 6 items and the probe was a binding change, the probed location was matched by the same color at 1 other location but, when there were 8 or 10 squares, the probed location was matched by the same color at 1, 2, or 3 other locations. For 8 squares the number of trials was identical for these three trial subtypes whereas, for 10 squares, most of the trials had the same color at just 1 other location. These errors suggest that the experiment should be taken as only preliminary evidence that there is an aging deficit in color-location binding in visual working memory when color and binding trials are mixed in the same trial blocks. (The following abstract of the original article appeared in record 2006-20488-009.) We asked whether the ability to keep in working memory the binding between a visual object and its spatial location changes with development across the life span more than memory for item information. Paired arrays of colored squares were identical or differed in the color of one square, and in the latter case, the changed color was unique on that trial (item change) or was duplicated elsewhere in the array (color-location binding change). Children (8-10 and 11-12 years old) and older adults (65-85 years old) showed deficits relative to young adults. These were only partly simulated by dividing attention in young adults. The older adults had an additional deficiency, specifically in binding information, which was evident only when item- and binding-change trials were mixed together. In that situation, the older adults often overlooked the more subtle, binding-type changes. Some working memory processes related to binding undergo life-span development in an inverted-U shape, whereas other, bias- and salience-related processes that influence the use of binding information seem to develop monotonically. PsycINFO Database Record (c) 2016 APA, all rights reserved

Attention Diversion Improves Response Inhibition of Immediate Reward, But Only When it Is Beneficial: An fMRI Study

PubMed Central

Scalzo, Franco; O’Connor, David A.; Orr, Catherine; Murphy, Kevin; Hester, Robert

2016-01-01

Deficits of self-control are associated with a number of mental state disorders. The ability to direct attention away from an alluring stimulus appears to aid inhibition of an impulsive response. However, further functional imaging research is required to assess the impact of shifts in attention on self-regulating processes. We varied the level of attentional disengagement in an functional magnetic resonance imaging (fMRI)-based Go/No-go task to probe whether diversion of attention away from alluring stimuli facilitates response inhibition. We used the attention-grabbing characteristic of faces to exogenously direct attention away from stimuli and investigated the relative importance of attention and response inhibition mechanisms under different delayed reward scenarios [i.e., where forgoing an immediate reward ($1) led to a higher ($10) or no payoff in the future]. We found that diverting attention improved response inhibition performance, but only when resistance to an alluring stimulus led to delayed reward. Region of interest analyses indicated significant increased activity in posterior right inferior frontal gyrus during successful No-go trials for delayed reward trials compared to no delayed reward trials, and significant reduction in activity in the superior temporal gyri and left caudate in contexts of high attentional diversion. Our findings imply that strategies that increase the perceived benefits of response inhibition might assist individuals in abstaining from problematic impulsive behaviors. PMID:27616988

21 CFR 884.4120 - Gynecologic electrocautery and accessories.

Code of Federal Regulations, 2011 CFR

2011-04-01

... electrically heated probe. It is used to excise cervical lesions, perform biopsies, or treat chronic cervicitis... electrical generator, a probe, and electrical cables. (b) Classification. Class II (performance standards). ...

21 CFR 884.4120 - Gynecologic electrocautery and accessories.

Code of Federal Regulations, 2014 CFR

2014-04-01

... electrically heated probe. It is used to excise cervical lesions, perform biopsies, or treat chronic cervicitis... electrical generator, a probe, and electrical cables. (b) Classification. Class II (performance standards). ...

21 CFR 884.4120 - Gynecologic electrocautery and accessories.

Code of Federal Regulations, 2012 CFR

2012-04-01

... electrically heated probe. It is used to excise cervical lesions, perform biopsies, or treat chronic cervicitis... electrical generator, a probe, and electrical cables. (b) Classification. Class II (performance standards). ...

21 CFR 884.4120 - Gynecologic electrocautery and accessories.

Code of Federal Regulations, 2013 CFR

2013-04-01

... electrically heated probe. It is used to excise cervical lesions, perform biopsies, or treat chronic cervicitis... electrical generator, a probe, and electrical cables. (b) Classification. Class II (performance standards). ...

A Pan-GTPase Inhibitor as a Molecular Probe

PubMed Central

Hong, Lin; Guo, Yuna; BasuRay, Soumik; Agola, Jacob O.; Romero, Elsa; Simpson, Denise S.; Schroeder, Chad E.; Simons, Peter; Waller, Anna; Garcia, Matthew; Carter, Mark; Ursu, Oleg; Gouveia, Kristine; Golden, Jennifer E.; Aubé, Jeffrey; Wandinger-Ness, Angela; Sklar, Larry A.

2015-01-01

Overactive GTPases have often been linked to human diseases. The available inhibitors are limited and have not progressed far in clinical trials. We report here a first-in-class small molecule pan-GTPase inhibitor discovered from a high throughput screening campaign. The compound CID1067700 inhibits multiple GTPases in biochemical, cellular protein and protein interaction, as well as cellular functional assays. In the biochemical and protein interaction assays, representative GTPases from Rho, Ras, and Rab, the three most generic subfamilies of the GTPases, were probed, while in the functional assays, physiological processes regulated by each of the three subfamilies of the GTPases were examined. The chemical functionalities essential for the activity of the compound were identified through structural derivatization. The compound is validated as a useful molecular probe upon which GTPase-targeting inhibitors with drug potentials might be developed. PMID:26247207

Peripheral laser assisted angioplasty: results, complications and follow-up.

PubMed

Owen, E R; Moussa, S A; Lewis, J D; Wilkins, R A

1990-04-01

Detailed results including complications and ultimate outcome of 24 laser assisted angioplasties in 22 patients are presented. Despite the enthusiasm expressed in other published reports, we remain sceptical of the value of laser using a 1.5 mm 'hot-tip' probe for assisting angioplasty of peripheral occlusions. The tendency for this type of probe to damage the vessel wall and in so doing prohibit the use of subsequent balloon dilatation is a major problem. In this small series the long-term patency was not improved compared with conventional angioplasty. We have established the relative safety of this laser technique and further advances in probe design may lead to greater success in crossing long lesions. Long-term maintenance of patency in these diseased arteries will need further advances in technique and assessment preferably by a controlled trial.

Mechanisms underlying interlimb transfer of visuomotor rotations

PubMed Central

Wang, Jinsung; Sainburg, Robert L.

2013-01-01

We previously reported that opposite arm training improved the initial direction of dominant arm movements, whereas it only improved the final position accuracy of non-dominant arm movements. We now ask whether each controller accesses common, or separate, short-term memory resources. To address this question, we investigated interlimb transfer of learning for visuomotor rotations that were directed oppositely [clockwise (CW)/counterclockwise (CCW)] for the two arms. We expected that if information obtained by initial training was stored in the same short-term memory space for both arms, opposite arm training of a CW rotation would interfere with subsequent adaptation to a CCW rotation. All subjects first adapted to a 30° rotation (CW) in the visual display during reaching movements. Following this, they adapted to a 30° rotation in the opposite direction (CCW) with the other arm. In contrast to our previous findings for interlimb transfer of same direction rotations (CCW/CCW), no effects of opposite arm adaptation were indicated in the initial trials performed. This indicates that interlimb transfer is not obligatory, and suggests that short-term memory resources for the two limbs are independent. Through single trial analysis, we found that the direction and final position errors of the first trial of movement, following opposite arm training, were always the same as those of naive performance. This was true whether the opposite arm was trained with the same or the opposing rotation. When trained with the same rotation, transfer of learning did not occur until the second trial. These findings suggest that the selective use of opposite arm information is dependent on the first trial to probe current movement conditions. Interestingly, the final extent of adaptation appeared to be reduced by opposite arm training of opposing rotations. Thus, the extent of adaptation, but not initial information transfer, appears obligatorily affected by prior opposite arm adaptation. According to our findings, it is plausible that the initiation and the final extent of adaptation involve two independent neural processes. Theoretical implications of these findings are discussed. PMID:12677333

Evaluation of a flow direction probe and a pitot-static probe on the F-14 airplane at high angles of attack and sideslip

NASA Technical Reports Server (NTRS)

Larson, T. J.

1984-01-01

The measurement performance of a hemispherical flow-angularity probe and a fuselage-mounted pitot-static probe was evaluated at high flow angles as part of a test program on an F-14 airplane. These evaluations were performed using a calibrated pitot-static noseboom equipped with vanes for reference flow direction measurements, and another probe incorporating vanes but mounted on a pod under the fuselage nose. Data are presented for angles of attack up to 63, angles of sideslip from -22 deg to 22 deg, and for Mach numbers from approximately 0.3 to 1.3. During maneuvering flight, the hemispherical flow-angularity probe exhibited flow angle errors that exceeded 2 deg. Pressure measurements with the pitot-static probe resulted in very inaccurate data above a Mach number of 0.87 and exhibited large sensitivities with flow angle.

Flexible poly(methyl methacrylate)-based neural probe: An affordable implementation

NASA Astrophysics Data System (ADS)

Gasemi, Pejman; Veladi, Hadi; Shahabi, Parviz; Khalilzadeh, Emad

2018-03-01

This research presents a novel technique used to fabricate a deep brain stimulation probe based on a commercial poly(methyl methacrylate) (PMMA) polymer. This technique is developed to overcome the high cost of available probes crucial for chronic stimulation and recording in neural disorders such as Parkinson’s disease and epilepsy. The probe is made of PMMA and its mechanical properties have been customized by controlling the reaction conditions. The polymer is adjusted to be stiff enough to be easily inserted and, on the other hand, soft enough to perform required movements. As cost is one of the issues in the use of neural probes, a simple process is proposed for the production of PMMA neural probes without using expensive equipment and operations, and without compromising performance and quality. An in vivo animal test was conducted to observe the recording capability of a PMMA probe.

Empirical Recommendations for Improving the Stability of the Dot-Probe Task in Clinical Research

PubMed Central

Price, Rebecca B.; Kuckertz, Jennie M.; Siegle, Greg J.; Ladouceur, Cecile D.; Silk, Jennifer S.; Ryan, Neal D.; Dahl, Ronald E.; Amir, Nader

2014-01-01

The dot-probe task has been widely used in research to produce an index of biased attention based on reaction times (RTs). Despite its popularity, very few published studies have examined psychometric properties of the task, including test-retest reliability, and no previous study has examined reliability in clinically anxious samples or systematically explored the effects of task design and analysis decisions on reliability. In the current analysis, we utilized dot-probe data from three studies where attention bias towards threat-related faces was assessed at multiple (≥5) timepoints. Two of the studies were similar (adults with Social Anxiety Disorder, similar design features) while one was much more disparate (pediatric healthy volunteers, distinct task design). We explored the effects of analysis choices (e.g., bias score calculation formula, methods for outlier handling) on reliability and searched for convergence of findings across the three studies. We found that, when considering the three studies concurrently, the most reliable RT bias index utilized data from dot-bottom trials, comparing congruent to incongruent trials, with rescaled outliers, particularly after averaging across more than one assessment point. Although reliability of RT bias indices was moderate to low under most circumstances, within-session variability in bias (attention bias variability; ABV), a recently proposed RT index, was more reliable across sessions. Several eyetracking-based indices of attention bias (available in the pediatric healthy sample only) showed reliability that matched the optimal RT index (ABV). On the basis of these findings, we make specific recommendations to researchers using the dot probe, particularly those wishing to investigate individual differences and/or single-patient applications. PMID:25419646

Imaging Voltage in Genetically Defined Neuronal Subpopulations with a Cre Recombinase-Targeted Hybrid Voltage Sensor.

PubMed

Bayguinov, Peter O; Ma, Yihe; Gao, Yu; Zhao, Xinyu; Jackson, Meyer B

2017-09-20

Genetically encoded voltage indicators create an opportunity to monitor electrical activity in defined sets of neurons as they participate in the complex patterns of coordinated electrical activity that underlie nervous system function. Taking full advantage of genetically encoded voltage indicators requires a generalized strategy for targeting the probe to genetically defined populations of cells. To this end, we have generated a mouse line with an optimized hybrid voltage sensor (hVOS) probe within a locus designed for efficient Cre recombinase-dependent expression. Crossing this mouse with Cre drivers generated double transgenics expressing hVOS probe in GABAergic, parvalbumin, and calretinin interneurons, as well as hilar mossy cells, new adult-born neurons, and recently active neurons. In each case, imaging in brain slices from male or female animals revealed electrically evoked optical signals from multiple individual neurons in single trials. These imaging experiments revealed action potentials, dynamic aspects of dendritic integration, and trial-to-trial fluctuations in response latency. The rapid time response of hVOS imaging revealed action potentials with high temporal fidelity, and enabled accurate measurements of spike half-widths characteristic of each cell type. Simultaneous recording of rapid voltage changes in multiple neurons with a common genetic signature offers a powerful approach to the study of neural circuit function and the investigation of how neural networks encode, process, and store information. SIGNIFICANCE STATEMENT Genetically encoded voltage indicators hold great promise in the study of neural circuitry, but realizing their full potential depends on targeting the sensor to distinct cell types. Here we present a new mouse line that expresses a hybrid optical voltage sensor under the control of Cre recombinase. Crossing this line with Cre drivers generated double-transgenic mice, which express this sensor in targeted cell types. In brain slices from these animals, single-trial hybrid optical voltage sensor recordings revealed voltage changes with submillisecond resolution in multiple neurons simultaneously. This imaging tool will allow for the study of the emergent properties of neural circuits and permit experimental tests of the roles of specific types of neurons in complex circuit activity. Copyright © 2017 the authors 0270-6474/17/379305-15$15.00/0.

Prediction of the Aerothermodynamic Environment of the Huygens Probe

NASA Technical Reports Server (NTRS)

Hollis, Brian R.; Striepe, Scott A.; Wright, Michael J.; Bose, Deepak; Sutton, Kenneth; Takashima, Naruhisa

2005-01-01

An investigation of the aerothermodynamic environment of the Huygens entry probe has been conducted. A Monte Carlo simulation of the trajectory of the probe during entry into Titan's atmosphere was performed to identify a worst-case heating rate trajectory. Flowfield and radiation transport computations were performed at points along this trajectory to obtain convective and radiative heat-transfer distributions on the probe's heat shield. This investigation identified important physical and numerical factors, including atmospheric CH4 concentration, transition to turbulence, numerical diffusion modeling, and radiation modeling, which strongly influenced the aerothermodynamic environment.

Modulation of the Foreign Body Reaction for Implants in the Subcutaneous Space: Microdialysis Probes as Localized Drug Delivery/Sampling Devices

PubMed Central

Mou, Xiaodun; Lennartz, Michelle R; Loegering, Daniel J; Stenken, Julie A

2011-01-01

Modulation of the foreign body reaction is considered to be an important step toward creation of implanted sensors with reliable long-term performance. In this work, microdialysis probes were implanted into the subcutaneous space of Sprague-Dawley rats. The probe performance was evaluated by comparing collected endogenous glucose concentrations with internal standard calibration (2-deoxyglucose, antipyrine, and vitamin B12). Probes were tested until failure, which for this work was defined as loss of fluid flow. In order to determine the effect of fibrous capsule formation on probe function, monocyte chemoattractant protein-1/CC chemokine ligand 2 (MCP-1/CCL2) was delivered locally via the probe to increase capsule thickness and dexamethasone 21-phosphate was delivered to reduce capsule thickness. Probes delivering MCP-1 had a capsule that was twice the thickness (500–600 μm) of control probes (200–225 μm) and typically failed 2 days earlier than control probes. Probes delivering dexamethasone 21-phosphate had more fragile capsules and the probes typically failed 2 days later than controls. Unexpectedly, extraction efficiency and collected glucose concentrations exhibited minor differences between groups. This is an interesting result in that the foreign body capsule formation was related to the duration of probe function but did not consistently relate to probe calibration. PMID:21722577

Comparative testing of pulse oximeter probes.

PubMed

van Oostrom, Johannes H; Melker, Richard J

2004-05-01

The testing of pulse oximeter probes is generally limited to the integrity of the electrical circuit and does not include the optical properties of the probes. Few pulse oximeter testers evaluate the accuracy of both the monitor and the probe. We designed a study to compare the accuracy of nonproprietary probes (OSS Medical) designed for use with Nellcor, Datex-Ohmeda, and Criticare pulse oximeter monitors with that of their corresponding proprietary probes by using a commercial off-the-shelf pulse oximeter tester (Index). The Index pulse oximeter tester does include testing of the optical properties of the pulse oximeter probes. The pulse oximeter tester was given a controlled input that simulated acute apnea. Desaturation curves were automatically recorded from the pulse oximeter monitors with a data-collection computer. Comparisons between equivalent proprietary and nonproprietary probes were performed. Data were analyzed by using univariate and multivariate general linear model analysis. Five OSS Medical probe models were statistically better than the equivalent proprietary probes. The remainder of the probes were statistically similar. Comparative and simulation studies can have significant advantages over human studies because they are cost-effective, evaluate equipment in a clinically relevant scenario, and pose no risk to patients, but they are limited by the realism of the simulation. We studied the performance of pulse oximeter probes in a simulated environment. Our results show significant differences between some probes that affect the accuracy of measurement.

A Direct Method for Mapping the Center of Pressure Measured by an Insole Pressure Sensor System to the Shoe's Local Coordinate System.

PubMed

Weaver, Brian T; Braman, Jerrod E; Haut, Roger C

2016-06-01

A direct method to express the center of pressure (CoP) measured by an insole pressure sensor system (IPSS) into a known coordinate system measured by motion tracking equipment is presented. A custom probe was constructed with reflective markers to allow its tip to be precisely tracked with motion tracking equipment. This probe was utilized to activate individual sensors on an IPSS that was placed in a shoe fitted with reflective markers used to establish a local shoe coordinate system. When pressed onto the IPSS the location of the probe's tip was coincident with the CoP measured by the IPSS (IPSS-CoP). Two separate pushes (i.e., data points) were used to develop vectors in each respective coordinate system. Simple vector mathematics determined the rotational and translational components of the transformation matrix needed to express the IPSS-CoP into the local shoe coordinate system. Validation was performed by comparing IPSS-CoP with an embedded force plate measured CoP (FP-CoP) from data gathered during kinematic trials. Six male subjects stood on an embedded FP and performed anterior/posterior (AP) sway, internal rotation, and external rotation of the body relative to a firmly planted foot. The IPSS-CoP was highly correlated with the FP-CoP for all motions, root mean square errors (RMSRRs) were comparable to other research, and there were no statistical differences between the displacement of the IPSS-CoP and FP-CoP for both the AP and medial/lateral (ML) axes, respectively. The results demonstrated that this methodology could be utilized to determine the transformation variables need to express IPSS-CoP into a known coordinate system measured by motion tracking equipment and that these variables can be determined outside the laboratory anywhere motion tracking equipment is available.

Building versatile bipartite probes for quantum metrology

NASA Astrophysics Data System (ADS)

Farace, Alessandro; De Pasquale, Antonella; Adesso, Gerardo; Giovannetti, Vittorio

2016-01-01

We consider bipartite systems as versatile probes for the estimation of transformations acting locally on one of the subsystems. We investigate what resources are required for the probes to offer a guaranteed level of metrological performance, when the latter is averaged over specific sets of local transformations. We quantify such a performance via the average skew information (AvSk), a convex quantity which we compute in closed form for bipartite states of arbitrary dimensions, and which is shown to be strongly dependent on the degree of local purity of the probes. Our analysis contrasts and complements the recent series of studies focused on the minimum, rather than the average, performance of bipartite probes in local estimation tasks, which was instead determined by quantum correlations other than entanglement. We provide explicit prescriptions to characterize the most reliable states maximizing the AvSk, and elucidate the role of state purity, separability and correlations in the classification of optimal probes. Our results can help in the identification of useful resources for sensing, estimation and discrimination applications when complete knowledge of the interaction mechanism realizing the local transformation is unavailable, and access to pure entangled probes is technologically limited.

A Cyber-Astronaut's Final Moves

NASA Technical Reports Server (NTRS)

2005-01-01

This image shows how Deep Impact's impactor targeted comet Tempel 1 as the spacecraft made its final approach in the early morning hours of July 4, Eastern time. The autonomous navigation system on the probe was designed to make as many as three impactor targeting maneuvers, identified as ITMs in this picture, to correct its course to the comet.

The upper left dot indicates where the probe would have passed the comet's nucleus if no maneuvers were performed. The dot below the nucleus shows where the probe would have flown past the comet if only the first maneuver was made. The leftmost dot on the nucleus marks the spot where the probe would have crunched the comet if only the first two maneuvers had been performed. The lower dot on the nucleus indicates the vicinity where, once the third maneuver was performed, the probe met its final reward and collided with the comet.

Design of 240,000 orthogonal 25mer DNA barcode probes.

PubMed

Xu, Qikai; Schlabach, Michael R; Hannon, Gregory J; Elledge, Stephen J

2009-02-17

DNA barcodes linked to genetic features greatly facilitate screening these features in pooled formats using microarray hybridization, and new tools are needed to design large sets of barcodes to allow construction of large barcoded mammalian libraries such as shRNA libraries. Here we report a framework for designing large sets of orthogonal barcode probes. We demonstrate the utility of this framework by designing 240,000 barcode probes and testing their performance by hybridization. From the test hybridizations, we also discovered new probe design rules that significantly reduce cross-hybridization after their introduction into the framework of the algorithm. These rules should improve the performance of DNA microarray probe designs for many applications.

Design of 240,000 orthogonal 25mer DNA barcode probes

PubMed Central

Xu, Qikai; Schlabach, Michael R.; Hannon, Gregory J.; Elledge, Stephen J.

2009-01-01

DNA barcodes linked to genetic features greatly facilitate screening these features in pooled formats using microarray hybridization, and new tools are needed to design large sets of barcodes to allow construction of large barcoded mammalian libraries such as shRNA libraries. Here we report a framework for designing large sets of orthogonal barcode probes. We demonstrate the utility of this framework by designing 240,000 barcode probes and testing their performance by hybridization. From the test hybridizations, we also discovered new probe design rules that significantly reduce cross-hybridization after their introduction into the framework of the algorithm. These rules should improve the performance of DNA microarray probe designs for many applications. PMID:19171886

MTBDRplus and MTBDRsl Assays: Absence of Wild-Type Probe Hybridization and Implications for Detection of Drug-Resistant Tuberculosis

PubMed Central

Georghiou, Sophia B.; Catanzaro, Donald; Rodrigues, Camilla; Crudu, Valeriu; Victor, Thomas C.; Garfein, Richard S.; Catanzaro, Antonino; Rodwell, Timothy C.

2016-01-01

Accurate identification of drug-resistant Mycobacterium tuberculosis is imperative for effective treatment and subsequent reduction in disease transmission. Line probe assays rapidly detect mutations associated with resistance and wild-type sequences associated with susceptibility. Examination of molecular-level performance is necessary for improved assay result interpretation and for continued diagnostic development. Using data collected from a large, multisite diagnostic study, probe hybridization results from line probe assays, MTBDRplus and MTBDRsl, were compared to those of sequencing, and the diagnostic performance of each individual mutation and wild-type probe was assessed. Line probe assay results classified as resistant due to the absence of wild-type probe hybridization were compared to those of sequencing to determine if novel mutations were inhibiting wild-type probe hybridization. The contribution of absent wild-type probe hybridization to the detection of drug resistance was assessed via comparison to a phenotypic reference standard. In our study, mutation probes demonstrated significantly higher specificities than wild-type probes and wild-type probes demonstrated marginally higher sensitivities than mutation probes, an ideal combination for detecting the presence of resistance conferring mutations while yielding the fewest number of false-positive results. The absence of wild-type probe hybridization without mutation probe hybridization was determined to be primarily the result of failure of mutation probe hybridization and not the result of novel or rare mutations. Compared to phenotypic culture-based drug susceptibility testing, the absence of wild-type probe hybridization without mutation probe hybridization significantly contributed to the detection of phenotypic rifampin and fluoroquinolone resistance with negligible increases in false-positive results. PMID:26763971

Effects of Electrical Stimulation in the Inferior Colliculus on Frequency Discrimination by Rhesus Monkeys and Implications for the Auditory Midbrain Implant

PubMed Central

Ross, Deborah A.; Puñal, Vanessa M.; Agashe, Shruti; Dweck, Isaac; Mueller, Jerel; Grill, Warren M.; Wilson, Blake S.

2016-01-01

Understanding the relationship between the auditory selectivity of neurons and their contribution to perception is critical to the design of effective auditory brain prosthetics. These prosthetics seek to mimic natural activity patterns to achieve desired perceptual outcomes. We measured the contribution of inferior colliculus (IC) sites to perception using combined recording and electrical stimulation. Monkeys performed a frequency-based discrimination task, reporting whether a probe sound was higher or lower in frequency than a reference sound. Stimulation pulses were paired with the probe sound on 50% of trials (0.5–80 μA, 100–300 Hz, n = 172 IC locations in 3 rhesus monkeys). Electrical stimulation tended to bias the animals' judgments in a fashion that was coarsely but significantly correlated with the best frequency of the stimulation site compared with the reference frequency used in the task. Although there was considerable variability in the effects of stimulation (including impairments in performance and shifts in performance away from the direction predicted based on the site's response properties), the results indicate that stimulation of the IC can evoke percepts correlated with the frequency-tuning properties of the IC. Consistent with the implications of recent human studies, the main avenue for improvement for the auditory midbrain implant suggested by our findings is to increase the number and spatial extent of electrodes, to increase the size of the region that can be electrically activated, and to provide a greater range of evoked percepts. SIGNIFICANCE STATEMENT Patients with hearing loss stemming from causes that interrupt the auditory pathway after the cochlea need a brain prosthetic to restore hearing. Recently, prosthetic stimulation in the human inferior colliculus (IC) was evaluated in a clinical trial. Thus far, speech understanding was limited for the subjects and this limitation is thought to be partly due to challenges in harnessing the sound frequency representation in the IC. Here, we tested the effects of IC stimulation in monkeys trained to report the sound frequencies they heard. Our results indicate that the IC can be used to introduce a range of frequency percepts and suggest that placement of a greater number of electrode contacts may improve the effectiveness of such implants. PMID:27147659

A Meta-Analysis and Systematic Review of the Literature to Evaluate Potential Threats to Internal Validity in Probe Procedures for Chained Tasks

ERIC Educational Resources Information Center

Alexander, Jennifer L.; Smith, Katie A.; Mataras, Theologia; Shepley, Sally B.; Ayres, Kevin M.

2015-01-01

The two most frequently used methods for assessing performance on chained tasks are single opportunity probes (SOPs) and multiple opportunity probes (MOPs). Of the two, SOPs may be easier and less time-consuming but can suppress actual performance. In comparison, MOPs can provide more information but present the risk of participants acquiring…

Calibration and Use of B Dot Probes for Electromagnetic Measuring

DTIC Science & Technology

1977-08-09

response. E. Time Domain Reflectometry Measurements Pulse impedance measurements for the 1.75-in. diameter double-gap probe design were first performed...Far Field (Radiation) Patterns of a B Dot Probe 1. Anechoic Chamber The facility utilized for the probe patterns was the NASA 120-ft chamber at

From storage to manipulation: How the neural correlates of verbal working memory reflect varying demands on inner speech.

PubMed

Marvel, Cherie L; Desmond, John E

2012-01-01

The ability to store and manipulate online information may be enhanced by an inner speech mechanism that draws upon motor brain regions. Neural correlates of this mechanism were examined using event-related functional magnetic resonance imaging (fMRI). Sixteen participants completed two conditions of a verbal working memory task. In both conditions, participants viewed one or two target letters. In the "storage" condition, these targets were held in mind across a delay. Then a probe letter was presented, and participants indicated by button press whether the probe matched the targets. In the "manipulation" condition, participants identified new targets by thinking two alphabetical letters forward of each original target (e.g., f→h). Participants subsequently indicated whether the probe matched the newly derived targets. Brain activity during the storage and manipulation conditions was examined specifically during the delay phase in order to directly compare manipulation versus storage processes. Activations that were common to both conditions, yet disproportionately greater with manipulation, were observed in the left inferior frontal cortex, premotor cortex, and anterior insula, bilaterally in the parietal lobes and superior cerebellum, and in the right inferior cerebellum. This network shares substrates with overt speech and may represent an inner speech pathway that increases activity with greater working memory demands. Additionally, an inverse correlation was observed between manipulation-related brain activity (on correct trials) and test accuracy in the left premotor cortex, anterior insula, and bilateral superior cerebellum. This inverse relationship may represent intensification of inner speech as one struggles to maintain performance levels. © 2011 Elsevier Inc. All rights reserved.

A Coaxial Dual-element Focused Ultrasound Probe for Guidance of Epidural Catheterization: An Experimental Study.

PubMed

Dong, Guo-Chung; Chiu, Li-Chen; Ting, Chien-Kun; Hsu, Jia-Ruei; Huang, Chih-Chung; Chang, Yin; Chen, Gin-Shin

2017-09-01

Ultrasound guidance for epidural block has improved clinical blind-trial problems but the design of present ultrasonic probes poses operating difficulty of ultrasound-guided catheterization, increasing the failure rate. The purpose of this study was to develop a novel ultrasonic probe to avoid needle contact with vertebral bone during epidural catheterization. The probe has a central circular passage for needle insertion. Two focused annular transducers are deployed around the passage for on-axis guidance. A 17-gauge insulated Tuohy needle containing the self-developed fiber-optic-modified stylet was inserted into the back of the anesthetized pig, in the lumbar region under the guidance of our ultrasonic probe. The inner transducer of the probe detected the shallow echo signals of the peak-peak amplitude of 2.8 V over L3 at the depth of 2.4 cm, and the amplitude was decreased to 0.8 V directly over the L3 to L4 interspace. The outer transducer could detect the echoes from the deeper bone at the depth of 4.5 cm, which did not appear for the inner transducer. The operator tilted the probe slightly in left-right and cranial-caudal directions until the echoes at the depth of 4.5 cm disappeared, and the epidural needle was inserted through the central passage of the probe. The needle was advanced and stopped when the epidural space was identified by optical technique. The needle passed without bone contact. Designs of the hollow probe for needle pass and dual transducers with different focal lengths for detection of shallow and deep vertebrae may benefit operation, bone/nonbone identification, and cost.

Cognitive inflexibility in obsessive-compulsive disorder

PubMed Central

Gruner, Patricia; Pittenger, Christopher

2016-01-01

Obsessive-Compulsive Disorder (OCD) is characterized by maladaptive patterns of repetitive, inflexible cognition and behavior that suggest a lack of cognitive flexibility. Consistent with this clinical observation, many neurocognitive studies suggest behavioral and neurobiological abnormalities in cognitive flexibility in individuals with OCD. Meta-analytic reviews support a pattern of cognitive inflexibility, with effect sizes generally in the medium range. Heterogeneity in assessments and the way underlying constructs have been operationalized point to the need for better standardization across studies, as well as more refined overarching models of cognitive flexibility and executive function. Neuropsychological assessments of cognitive flexibility include measures of attentional set shifting, reversal and alternation, cued task switching paradigms, cognitive control measures such as the Trail-Making and Stroop tasks, and several measures of motor inhibition. Differences in the cognitive constructs and neural substrates associated with these measures suggest that performance within these different domains should be examined separately. Additional factors, such as the number of consistent trials prior to a shift and whether a shift is explicitly signaled or must be inferred from a change in reward contingencies, may influence performance, and thus mask or accentuate deficits. Several studies have described abnormalities in neural activation in the absence of differences in behavioral performance, suggesting that our behavioral probes may not be adequately sensitive, but also offering important insights into potential compensatory processes. The fact that deficits of moderate effect size are seen across a broad range of classic neuropsychological tests in OCD presents a conceptual challenge, as clinical symptomatology suggests greater specificity. Traditional cognitive probes may not be sufficient to delineate specific domains of deficit in this and other neuropsychiatric disorders; a new generation of behavioral tasks that test more specific underlying constructs, supplemented by neuroimaging to provide greater insight into the underlying processes, may be needed. PMID:27491478

A probe for blood-vessel and spinal interiors

NASA Technical Reports Server (NTRS)

Frazer, R. E.

1978-01-01

Probe design allows insertion into lumen of blood vessels to perform oximetry and investigate plaque on interior vessel walls. Probe is more accurate than standard oximetry procedures of determining oxygenation of circulating blood.

Startle modulation and explicit valence evaluations dissociate during backward fear conditioning.

PubMed

Luck, Camilla C; Lipp, Ottmar V

2017-05-01

Blink startle magnitude is linearly modulated by affect such that, relative to neutral stimuli, startle magnitude is inhibited during pleasant stimuli and potentiated during unpleasant stimuli. Andreatta, Mühlberger, Yarali, Gerber, and Pauli (2010), however, report a dissociation between startle modulation and explicit valence evaluations during backward conditioning, a procedure in which the unconditional stimulus precedes the conditional stimulus (CS). Relative to controls, startles elicited during the CS were inhibited, suggesting that the CS had acquired positive valence, but participants still evaluated the CS as unpleasant after the experiment. In Experiment 1, we aimed to replicate this dissociation using a trial-by-trial measure of CS valence to measure startle modulation and CS valence simultaneously during forward and backward differential fear conditioning. In Experiment 2, we examined whether early and late portions of the CS could acquire differential valence by presenting startle probes at early and late probe positions during the CS. In both experiments, the dissociation between startle modulation and explicit valence evaluations in backward conditioning replicated, with CS+ evaluated as less pleasant than CS-, but startles elicited during CS+ inhibited relative to CS-. In Experiment 2, we provide preliminary evidence that this inhibition was present early, but not late, during the CS+. The results replicate the dissociation between implicit and explicit CS valence reported by Andreatta et al. (2010) using a trial-by-trial measure of valence. We also provide preliminary evidence that this dissociation may occur because the implicit and explicit measures are recorded at different times during the CS presentation. © 2017 Society for Psychophysiological Research.

Novel Multisensor Probe for Monitoring Bladder Temperature During Locoregional Chemohyperthermia for Nonmuscle-Invasive Bladder Cancer: Technical Feasibility Study

PubMed Central

Geijsen, Debby E.; Zum Vörde Sive Vörding, Paul J.; Schooneveldt, Gerben; Sijbrands, Jan; Hulshof, Maarten C.; de la Rosette, Jean; de Reijke, Theo M.; Crezee, Hans

2013-01-01

Abstract Background and Purpose: The effectiveness of locoregional hyperthermia combined with intravesical instillation of mitomycin C to reduce the risk of recurrence and progression of intermediate- and high-risk nonmuscle-invasive bladder cancer is currently investigated in clinical trials. Clinically effective locoregional hyperthermia delivery necessitates adequate thermal dosimetry; thus, optimal thermometry methods are needed to monitor accurately the temperature distribution throughout the bladder wall. The aim of the study was to evaluate the technical feasibility of a novel intravesical device (multi-sensor probe) developed to monitor the local bladder wall temperatures during loco-regional C-HT. Materials and Methods: A multisensor thermocouple probe was designed for deployment in the human bladder, using special sensors to cover the bladder wall in different directions. The deployment of the thermocouples against the bladder wall was evaluated with visual, endoscopic, and CT imaging in bladder phantoms, porcine models, and human bladders obtained from obduction for bladder volumes and different deployment sizes of the probe. Finally, porcine bladders were embedded in a phantom and subjected to locoregional heating to compare probe temperatures with additional thermometry inside and outside the bladder wall. Results: The 7.5 cm thermocouple probe yielded optimal bladder wall contact, adapting to different bladder volumes. Temperature monitoring was shown to be accurate and representative for the actual bladder wall temperature. Conclusions: Use of this novel multisensor probe could yield a more accurate monitoring of the bladder wall temperature during locoregional chemohyperthermia. PMID:24112045

Implementation of probe data performance measures.

DOT National Transportation Integrated Search

2017-04-03

This report presents results from a 12-month project where three arterial analysis tools based on probe vehicle segment speed data were developed for District 6. A case study of 5 arterials and two incidents was performed.

Performance Comparison of High-Speed Dual-Pneumatic Vitrectomy Cutters during Simulated Vitrectomy with Balanced Salt Solution.

PubMed

Abulon, Dina Joy K; Buboltz, David C

2015-02-01

To measure flow rate of balanced salt solution and IOP during simulated vitrectomy using two sets of high-speed dual-pneumatic probes. A closed-model eye system measured IOP and flow rate of a balanced salt solution through infusion cannula. The Constellation Vision System was tested with two sets of high-speed dual-pneumatic probes (UltraVit 23-gauge and enhanced 25+-gauge 5000-cpm probes; UltraVit 23-gauge and enhanced 25+-gauge 7500-cpm probes; n = 6 each) under different vacuum levels and cut rates in three duty cycle modes. In both probe sets, flow rates were dependent on cut rate with the biased open and biased closed duty cycles. Flow rates were highest with the biased open duty cycle, lower with the 50/50 duty cycle, and lowest with the biased closed duty cycle. IOP, as expected, was inversely associated with flow rate using both probe sets. The 7500-cpm probes offer greater control and customization compared with 5000-cpm probes under certain experimental conditions. At maximum cut rates, performance of 7500-cpm probes was similar to that of 5000-cpm probes, suggesting that 7500-cpm probes may be used without sacrifice of flow rate and IOP stability. Customization of vitrectomy parameters allows greater surgeon control during vitrectomy and may expand the usefulness of vitrectomy probes.

Comparative performance of CO2 measuring methods: marine aquaculture recirculation system application

USGS Publications Warehouse

Pfeiffer, T.J.; Summerfelt, S.T.; Watten, B.J.

2011-01-01

Many methods are available for the measurement of dissolved carbon dioxide in an aqueous environment. Standard titration is the typical field method for measuring dissolved CO2 in aquaculture systems. However, titrimetric determination of dissolved CO2 in marine water aquaculture systems is unsuitable because of the high dissolved solids, silicates, and other dissolved minerals that interfere with the determination. Other methods used to measure dissolved carbon dioxide in an aquaculture water included use of a wetted CO2 probe analyzer, standard nomographic methods, and calculation by direct measurements of the water's pH, temperature, and alkalinity. The determination of dissolved CO2 in saltwater based on partial pressure measurements and non-dispersive infra-red (NDIR) techniques with a CO2 gas analyzer are widely employed for oceanic surveys of surface ocean CO2 flux and are similar to the techniques employed with the head space unit (HSU) in this study. Dissolved carbon dioxide (DC) determination with the HSU using a infra-red gas analyzer (IRGA) was compared with titrimetric, nomographic, calculated, and probe measurements of CO2 in freshwater and in saltwater with a salinity ranging from 5.0 to 30 ppt, and a CO2 range from 8 to 50 mg/L. Differences in CO2 measurements between duplicate HSUs (0.1–0.2 mg/L) were not statistically significant different. The coefficient of variation for the HSU readings averaged 1.85% which was better than the CO2 probe (4.09%) and that for the titrimetric method (5.84%). In all low, medium and high salinity level trials HSU precision was good, averaging 3.39%. Differences existed between comparison testing of the CO2 probe and HSU measurements with the CO2 probe readings, on average, providing DC estimates that were higher than HSU estimates. Differences between HSU and titration based estimates of DC increased with salinity and reached a maximum at 32.2 ppt. These differences were statistically significant (P < 0.05) at all salinity levels greater than 0.3 ppt. Results indicated reliable replicated results from the head space unit with varying salinity and dissolved carbon dioxide concentrations.

New approach to real-time nucleic acids detection: folding polymerase chain reaction amplicons into a secondary structure to improve cleavage of Förster resonance energy transfer probes in 5′-nuclease assays

PubMed Central

Kutyavin, Igor V.

2010-01-01

The article describes a new technology for real-time polymerase chain reaction (PCR) detection of nucleic acids. Similar to Taqman, this new method, named Snake, utilizes the 5′-nuclease activity of Thermus aquaticus (Taq) DNA polymerase that cleaves dual-labeled Förster resonance energy transfer (FRET) probes and generates a fluorescent signal during PCR. However, the mechanism of the probe cleavage in Snake is different. In this assay, PCR amplicons fold into stem–loop secondary structures. Hybridization of FRET probes to one of these structures leads to the formation of optimal substrates for the 5′-nuclease activity of Taq. The stem–loop structures in the Snake amplicons are introduced by the unique design of one of the PCR primers, which carries a special 5′-flap sequence. It was found that at a certain length of these 5′-flap sequences the folded Snake amplicons have very little, if any, effect on PCR yield but benefit many aspects of the detection process, particularly the signal productivity. Unlike Taqman, the Snake system favors the use of short FRET probes with improved fluorescence background. The head-to-head comparison study of Snake and Taqman revealed that these two technologies have more differences than similarities with respect to their responses to changes in PCR protocol, e.g. the variations in primer concentration, annealing time, PCR asymmetry. The optimal PCR protocol for Snake has been identified. The technology’s real-time performance was compared to a number of conventional assays including Taqman, 3′-MGB-Taqman, Molecular Beacon and Scorpion primers. The test trial showed that Snake supersedes the conventional assays in the signal productivity and detection of sequence variations as small as single nucleotide polymorphisms. Due to the assay’s cost-effectiveness and simplicity of design, the technology is anticipated to quickly replace all known conventional methods currently used for real-time nucleic acid detection. PMID:19969535

Investigation of sarizotan's impact on the pharmacokinetics of probe drugs for major cytochrome P450 isoenzymes: a combined cocktail trial.

PubMed

Krösser, Sonja; Neugebauer, Roland; Dolgos, Hugues; Fluck, Markus; Rost, Karl-Ludwig; Kovar, Andreas

2006-04-01

The 5HT(1A) receptor agonist sarizotan is in clinical development for the treatment of dyskinesia, a potentially disabling complication in Parkinson's disease. We investigated the effect of sarizotan on the clinical pharmacokinetics of probe drugs for cytochrome P450 (CYP) to evaluate the risk of CYP-related drug-drug interactions. This was a double-blind, randomised, two-period cross-over interaction study with repeated administration of 5 mg sarizotan HCl or placebo b.i.d. for 8 days in 18 healthy volunteers. On day 4, a single dose of 100 mg metoprolol (CYP2D6 probe) was administered. On day 8, single doses of 100 mg caffeine (CYP1A2 probe), 50 mg diclofenac (CYP2C9 probe), 100 mg mephenytoin (CYP2C19 probe) and 7.5 mg midazolam (CYP3A4 probe) were simultaneously applied. Pharmacokinetic parameters for probe drugs and their metabolites in plasma and urinary recovery were determined. Concentration-time profiles and pharmacokinetic parameters of all probes and their metabolites remained unchanged after co-administration of sarizotan, compared with placebo. Analysis of variance of the area under the plasma concentration-time curve for probe drugs/metabolites, metabolic ratios and urinary excretion resulted in 90% confidence intervals within the acceptance range (0.8-1.25), indicating the absence of drug-drug interactions. At a dose higher than that intended for clinical use (1 mg b.i.d.), sarizotan had no effect on the metabolism and pharmacokinetics of specific probe drugs for CYP isoenzymes 1A2, 2C19, 2C9, 2D6 and 3A4. Pharmacokinetic interactions with co-administered drugs metabolised by these CYP isoforms are not expected, and dose adjustment of co-administered CYP substrates is not necessary.

Alpha Oscillations Are Causally Linked to Inhibitory Abilities in Ageing.

PubMed

Borghini, Giulia; Candini, Michela; Filannino, Cristina; Hussain, Masud; Walsh, Vincent; Romei, Vincenzo; Zokaei, Nahid; Cappelletti, Marinella

2018-05-02

Aging adults typically show reduced ability to ignore task-irrelevant information, an essential skill for optimal performance in many cognitive operations, including those requiring working memory (WM) resources. In a first experiment, young and elderly human participants of both genders performed an established WM paradigm probing inhibitory abilities by means of valid, invalid, and neutral retro-cues. Elderly participants showed an overall cost, especially in performing invalid trials, whereas younger participants' general performance was comparatively higher, as expected.Inhibitory abilities have been linked to alpha brain oscillations but it is yet unknown whether in aging these oscillations (also typically impoverished) and inhibitory abilities are causally linked. To probe this possible causal link in aging, we compared in a second experiment parietal alpha-transcranial alternating current stimulation (tACS) with either no stimulation (Sham) or with two control stimulation frequencies (theta- and gamma-tACS) in the elderly group while performing the same WM paradigm. Alpha- (but not theta- or gamma-) tACS selectively and significantly improved performance (now comparable to younger adults' performance in the first experiment), particularly for invalid cues where initially elderly showed the highest costs. Alpha oscillations are therefore causally linked to inhibitory abilities and frequency-tuned alpha-tACS interventions can selectively change these abilities in the elderly. SIGNIFICANCE STATEMENT Ignoring task-irrelevant information, an ability associated to rhythmic brain activity in the alpha frequency band, is fundamental for optimal performance. Indeed, impoverished inhibitory abilities contribute to age-related decline in cognitive functions like working memory (WM), the capacity to briefly hold information in mind. Whether in aging adults alpha oscillations and inhibitory abilities are causally linked is yet unknown. We experimentally manipulated frequency-tuned brain activity using transcranial alternating current stimulation (tACS), combined with a retro-cue paradigm assessing WM and inhibition. We found that alpha-tACS induced a significant improvement in target responses and misbinding errors, two indexes of inhibition. We concluded that in aging alpha oscillations are causally linked to inhibitory abilities, and that despite being impoverished, these abilities are still malleable. Copyright © 2018 the authors 0270-6474/18/384419-12$15.00/0.

Parker Solar Probe Light Bar Test

NASA Image and Video Library

2018-06-05

In the Astrotech processing facility in Titusville, Florida, near NASA's Kennedy Space Center, on Tuesday, June 5, 2018, technicians and engineers perform light bar testing on NASA's Parker Solar Probe. The Parker Solar Probe will launch on a United Launch Alliance Delta IV Heavy rocket from Space Launch Complex 37 at Cape Canaveral Air Force Station in Florida no earlier than Aug. 4, 2018. The mission will perform the closest-ever observations of a star when it travels through the Sun's atmosphere, called the corona. The probe will rely on measurements and imaging to revolutionize our understanding of the corona and the Sun-Earth connection.

Sound intensity probe for ultrasonic field in water using light-emitting diodes and piezoelectric elements

NASA Astrophysics Data System (ADS)

Zeng, Xi; Mizuno, Yosuke; Nakamura, Kentaro

2017-12-01

The sound intensity vector provides useful information on the state of an ultrasonic field in water, since sound intensity is a vector quantity expressing the direction and magnitude of the sound field. In the previous studies on sound intensity measurement in water, conventional piezoelectric sensors and metal cables were used, and the transmission distance was limited. A new configuration of a sound intensity probe suitable for ultrasonic measurement in water is proposed and constructed for trial in this study. The probe consists of light-emitting diodes and piezoelectric elements, and the output signals are transmitted through fiber optic cables as intensity-modulated light. Sound intensity measurements of a 26 kHz ultrasonic field in water are demonstrated. The difference in the intensity vector state between the water tank with and without sound-absorbing material on its walls was successfully observed.

Use of microdose phenotyping to individualise dosing of patients.

PubMed

Hohmann, Nicolas; Haefeli, Walter E; Mikus, Gerd

2015-09-01

Administering the right amount of the right drug at the right time is a key mission of clinical medicine. This comprises dose adaptation according to a patient's intrinsic and extrinsic factors influencing drug disposition. Several biomarkers are available for dose adaptation; still, prediction of individual drug disposition may be improved. Phenotyping is the quantification of drug metabolism with probe substrates specific to drug-metabolising enzymes. This allows measurement of baseline metabolism and changes after modulation of drug metabolism. This article explores the concept of phenotyping using pharmacologically ineffective microdoses of probe substrates to obtain information on drug metabolism. Several probe drugs such as midazolam for cytochrome P450 3A have already been used, but validation of other microdosed probe drugs, analytical procedures and drug formulations still face some challenges that have to be overcome. Since microdosed probe drugs have no risk of adverse drug reactions or interference with therapy, more widespread use is possible. This allows drug-drug interaction data to be safely obtained during first-in-man studies, enhancing the clinical safety of human healthy volunteers and patients in clinical trials, and, most importantly, allows determination of the drug-metabolising phenotype in severely ill patients. With harmless probe drugs at hand quantifying drug metabolism and adapting the dose accordingly, a phenotyping-based dosing strategy could become reality, offering the possibility of individualised drug therapy with reduced adverse effects and fewer therapeutic failures.

Electro-optical Probing Of Terahertz Integrated Circuits

NASA Technical Reports Server (NTRS)

Bhasin, K. B.; Romanofsky, R.; Whitaker, J. F.; Valdmanis, J. A.; Mourou, G.; Jackson, T. A.

1990-01-01

Electro-optical probe developed to perform noncontact, nondestructive, and relatively noninvasive measurements of electric fields over broad spectrum at millimeter and shorter wavelengths in integrated circuits. Manipulated with conventional intregrated-circuit-wafer-probing equipment and operated without any special preparation of integrated circuits. Tip of probe small electro-optical crystal serving as proximity electric-field sensor.

Validation of double Langmuir probe in-orbit performance onboard a nano-satellite

NASA Astrophysics Data System (ADS)

Tejumola, Taiwo Raphael; Zarate Segura, Guillermo Wenceslao; Kim, Sangkyun; Khan, Arifur; Cho, Mengu

2018-03-01

Many plasma measurement systems have been proposed and used onboard different satellites to characterize space plasma. Most of these systems employed the technique of Langmuir probes either using the single or double probes methods. Recent growth of lean satellites has positioned it on advantage to be used for space science missions using Langmuir probes because of its simplicity and convenience. However, single Langmuir probes are not appropriate to be used on lean satellites because of their limited conducting area which leads to spacecraft charging and drift of the instrument's electrical ground during measurement. Double Langmuir probes technique can overcome this limitation, as a measurement reference in relation to the spacecraft is not required. A double Langmuir probe measurement system was designed and developed at Kyushu Institute of Technology for HORYU-IV satellite, which is a 10 kg, 30 cm cubic class lean satellite launched into Low Earth Orbit on 17th February 2016. This paper presents the on-orbit performance and validation of the double Langmuir probe measurement using actual on-orbit measured data and computer simulations.

Development of a new mini-invasive tumour hyperthermia probe using high-temperature water vapour.

PubMed

Yu, Tian-Hua; Zhou, Yi-Xin; Liu, Jing

2004-01-01

A new mini-invasive hyperthermia probe using high-temperature water vapour for deep regional tumour treatment was developed in this paper. The vacuum insulation mechanism was incorporated into the probe to avoid heating damage to the normal tissues around the edge of the insertion path. To better understand the heat transfer behaviour in living tissues due to operation of the probe, theoretical models based on the Pennes' equation were established and two closed form analytical solutions under constant flux or temperature heating at the tip of probe were obtained. Parametric studies were performed to investigate the influence of various parameters on the temperature response of tissues heated by the probe. Further, several simulating experiments on the actual heating performance of the probe fabricated in this paper were conducted on the in vitro biological materials (fresh pork) and phantom gel. It was demonstrated that the probe can cause a high enough temperature over the treatment area to thermally destroy the tumour tissue in due time, while the temperature over the surrounding healthy tissues can be kept below a safe threshold value. This mini-invasive heating probe may have significant applications in future clinical tumour hyperthermia.

Design and characterization of planar capacitive imaging probe based on the measurement sensitivity distribution

NASA Astrophysics Data System (ADS)

Yin, X.; Chen, G.; Li, W.; Huthchins, D. A.

2013-01-01

Previous work indicated that the capacitive imaging (CI) technique is a useful NDE tool which can be used on a wide range of materials, including metals, glass/carbon fibre composite materials and concrete. The imaging performance of the CI technique for a given application is determined by design parameters and characteristics of the CI probe. In this paper, a rapid method for calculating the whole probe sensitivity distribution based on the finite element model (FEM) is presented to provide a direct view of the imaging capabilities of the planar CI probe. Sensitivity distributions of CI probes with different geometries were obtained. Influencing factors on sensitivity distribution were studied. Comparisons between CI probes with point-to-point triangular electrode pair and back-to-back triangular electrode pair were made based on the analysis of the corresponding sensitivity distributions. The results indicated that the sensitivity distribution could be useful for optimising the probe design parameters and predicting the imaging performance.

Design complexity in termite-fishing tools of chimpanzees (Pan troglodytes)

PubMed Central

Sanz, Crickette; Call, Josep; Morgan, David

2009-01-01

Adopting the approach taken with New Caledonian crows (Corvus moneduloides), we present evidence of design complexity in one of the termite-fishing tools of chimpanzees (Pan troglodytes) in the Goualougo Triangle, Republic of Congo. Prior to termite fishing, chimpanzees applied a set of deliberate, distinguishable actions to modify herb stems to fashion a brush-tipped probe, which is different from the form of fishing tools used by chimpanzees in East and West Africa. This means that ‘brush-tipped fishing probes’, unlike ‘brush sticks’, are not a by-product of use but a deliberate design feature absent in other chimpanzee populations. The specialized modifications to prepare the tool for termite fishing, measures taken to repair non-functional brushes and appropriate orientation of the modified end suggest that these wild chimpanzees are attentive to tool modifications. We also conducted experimental trials that showed that a brush-tipped probe is more effective in gathering insects than an unmodified fishing probe. Based on these findings, we suggest that chimpanzees in the Congo Basin have developed an improved fishing probe design. PMID:19324641

Improved detection of electrical activity with a voltage probe based on a voltage-sensing phosphatase.

PubMed

Tsutsui, Hidekazu; Jinno, Yuka; Tomita, Akiko; Niino, Yusuke; Yamada, Yoshiyuki; Mikoshiba, Katsuhiko; Miyawaki, Atsushi; Okamura, Yasushi

2013-09-15

  One of the most awaited techniques in modern physiology is the sensitive detection of spatiotemporal electrical activity in a complex network of excitable cells. The use of genetically encoded voltage probes has been expected to enable such analysis. However, in spite of recent progress, existing probes still suffer from low signal amplitude and/or kinetics too slow to detect fast electrical activity. Here, we have developed an improved voltage probe named Mermaid2, which is based on the voltage-sensor domain of the voltage-sensing phosphatase from Ciona intestinalis and Förster energy transfer between a pair of fluorescent proteins. In mammalian cells, Mermaid2 permits ratiometric readouts of fractional changes of more than 50% over a physiologically relevant voltage range with fast kinetics, and it was used to follow a train of action potentials at frequencies of up to 150 Hz. Mermaid2 was also able to detect single action potentials and subthreshold voltage responses in hippocampal neurons in vitro, in addition to cortical electrical activity evoked by sound stimuli in single trials in living mice.

Periosteoplasty for covering gingival recessions: Clinical results

PubMed Central

Virnik, Sascha; Chiari, Friedrich Michael; Gaggl, Alexander

2009-01-01

This is a case series in which a new technique for the surgical treatment of periodontal recessions is presented along with the results of the first clinical trial. A new technique of periodontal flap surgery was performed on 30 patients with severe periodontal recessions of the upper or lower front teeth. Root and soft tissue scaling was carried out with an open approach, then the periosteum was incised and mobilized at the apical part of the mucoperiosteum flap to cover the defect before the mucoperiosteum was reattached and fixed by sutures. Sulcus bleeding, periodontal probing depths, attachment loss and the length of the attached gingiva of the affected teeth were recorded preoperatively and at 3, 6, and 12 months postoperatively. Every clinical parameter was improved by surgery. No sulcus bleeding was observed at any time during the postoperative follow-up. A mean reattachment of 5.5 mm was noticed 12 months postoperatively at a mean probing depth of 0.3 mm. The mean height of the attached gingiva was 0 mm before surgery, 2.3 mm at three and six months postoperatively, and 2.2 mm at 12 months. The periosteum eversion technique is suitable for the treatment of gingival recessions resulting in good gingival function and a clear improvement in aesthetics. PMID:23674900

NK1 receptor antagonism and emotional processing in healthy volunteers.

PubMed

Chandra, P; Hafizi, S; Massey-Chase, R M; Goodwin, G M; Cowen, P J; Harmer, C J

2010-04-01

The neurokinin-1 (NK(1)) receptor antagonist, aprepitant, showed activity in several animal models of depression; however, its efficacy in clinical trials was disappointing. There is little knowledge of the role of NK(1) receptors in human emotional behaviour to help explain this discrepancy. The aim of the current study was to assess the effects of a single oral dose of aprepitant (125 mg) on models of emotional processing sensitive to conventional antidepressant drug administration in 38 healthy volunteers, randomly allocated to receive aprepitant or placebo in a between groups double blind design. Performance on measures of facial expression recognition, emotional categorisation, memory and attentional visual-probe were assessed following the drug absorption. Relative to placebo, aprepitant improved recognition of happy facial expressions and increased vigilance to emotional information in the unmasked condition of the visual probe task. In contrast, aprepitant impaired emotional memory and slowed responses in the facial expression recognition task suggesting possible deleterious effects on cognition. These results suggest that while antagonism of NK(1) receptors does affect emotional processing in humans, its effects are more restricted and less consistent across tasks than those of conventional antidepressants. Human models of emotional processing may provide a useful means of assessing the likely therapeutic potential of new treatments for depression.

Impaired distractor inhibition on a selective attention task in unmedicated, depressed subjects.

PubMed

MacQueen, G M; Tipper, S P; Young, L T; Joffe, R T; Levitt, A J

2000-05-01

Impaired distractor inhibition may contribute to the selective attention deficits observed in depressed patients, but studies to date have not tested the distractor inhibition theory against the possibility that processes such as transient memory review processes may account for the observed deficits. A negative priming paradigm can dissociate inhibition from such a potentially confounding process called object review. The negative priming task also isolates features of the distractor such as colour and location for independent examination. A computerized negative priming task was used in which colour, identification and location features of a stimulus and distractor were systematically manipulated across successive prime and probe trials. Thirty-two unmedicated subjects with DSM-IV diagnoses of non-psychotic unipolar depression were compared with 32 age, sex and IQ matched controls. Depressed subjects had reduced levels of negative priming for conditions where the colour feature of the stimulus was repeated across prime and probe trials but not when identity or location was the repeated feature. When both the colour and location feature were the repeated feature across trials, facilitation in response was apparent. The pattern of results supports studies that found reduced distractor inhibition in depressed subjects, and suggests that object review is intact in these subjects. Greater impairment in negative priming for colour versus location suggests that subjects may have greater impairment in the visual stream associated with processing colour features.

Prime Retrieval of Motor Responses in Negative Priming

ERIC Educational Resources Information Center

Mayr, Susanne; Buchner, Axel; Dentale, Sandra

2009-01-01

Three auditory identification experiments were designed to specify the prime-response retrieval model of negative priming (S. Mayr & A. Buchner, 2006), which assumes that the prime response is retrieved in ignored repetition trials and interferes with probe responding. In Experiment 1, shortly before (in Experiment 1A) or after (in Experiment 1B)…

A single meal containing raw, crushed garlic influences expression of immunity- and cancer-related genes in whole blood of humans

USDA-ARS?s Scientific Manuscript database

Preclinical and epidemiological studies suggest that garlic intake is inversely associated with the progression of cancer and cardiovascular disease. To probe mechanisms of garlic action in humans, we conducted a randomized crossover feeding trial in which 17 volunteers consumed a garlic-containing...

Research on the Sensing Performance of the Tuning Fork-Probe as a Micro Interaction Sensor

PubMed Central

Gao, Fengli; Li, Xide

2015-01-01

The shear force position system has been widely used in scanning near-field optical microscopy (SNOM) and recently extended into the force sensing area. The dynamic properties of a tuning fork (TF), the core component of this system, directly determine the sensing performance of the shear positioning system. Here, we combine experimental results and finite element method (FEM) analysis to investigate the dynamic behavior of the TF probe assembled structure (TF-probe). Results from experiments under varying atmospheric pressures illustrate that the oscillation amplitude of the TF-probe is linearly related to the quality factor, suggesting that decreasing the pressure will dramatically increase the quality factor. The results from FEM analysis reveal the influences of various parameters on the resonant performance of the TF-probe. We compared numerical results of the frequency spectrum with the experimental data collected by our recently developed laser Doppler vibrometer system. Then, we investigated the parameters affecting spatial resolution of the SNOM and the dynamic response of the TF-probe under longitudinal and transverse interactions. It is found that the interactions in transverse direction is much more sensitive than that in the longitudinal direction. Finally, the TF-probe was used to measure the friction coefficient of a silica–silica interface. PMID:26404310

The reliability and stability of visual working memory capacity.

PubMed

Xu, Z; Adam, K C S; Fang, X; Vogel, E K

2018-04-01

Because of the central role of working memory capacity in cognition, many studies have used short measures of working memory capacity to examine its relationship to other domains. Here, we measured the reliability and stability of visual working memory capacity, measured using a single-probe change detection task. In Experiment 1, the participants (N = 135) completed a large number of trials of a change detection task (540 in total, 180 each of set sizes 4, 6, and 8). With large numbers of both trials and participants, reliability estimates were high (α > .9). We then used an iterative down-sampling procedure to create a look-up table for expected reliability in experiments with small sample sizes. In Experiment 2, the participants (N = 79) completed 31 sessions of single-probe change detection. The first 30 sessions took place over 30 consecutive days, and the last session took place 30 days later. This unprecedented number of sessions allowed us to examine the effects of practice on stability and internal reliability. Even after much practice, individual differences were stable over time (average between-session r = .76).

Nonvocal language acquisition in adolescents with severe physical disabilities: Bliss symbol versus iconic stimulus formats.

PubMed Central

Hurlbut, B I; Iwata, B A; Green, J D

1982-01-01

This study compared training in two language systems for three severely handicapped, nonvocal adolescents: the Bliss symbol system and an iconic picture system. Following baseline, training and review trials were implemented using an alternating treatments design. Daily probes were conducted to assess maintenance, stimulus generalization, and response generalization, and data were collected on spontaneous usage of either language system throughout the school day. Results showed that students required approximately four times as many trials to acquire Bliss symbols as iconic pictures, and that students maintained a higher percentage of iconic pictures. Stimulus generalization occurred in both language systems, while the number of correct responses during responses generalization probes was much greater for the iconic system. Finally, students almost always showed more iconic responses than Bliss responses in daily spontaneous usage. These results suggest that an iconic system might be more readily spontaneous usage. These results suggest than an iconic system might be more readily acquired, maintained, and generalized to daily situations. Implications of these findings for the newly verbal person were discussed. PMID:6181049

ProbeZT: Simulation of transport coefficients of molecular electronic junctions under environmental effects using Büttiker's probes

NASA Astrophysics Data System (ADS)

Korol, Roman; Kilgour, Michael; Segal, Dvira

2018-03-01

We present our in-house quantum transport package, ProbeZT. This program provides linear response coefficients: electrical and electronic thermal conductances, as well as the thermopower of molecular junctions in which electrons interact with the surrounding thermal environment. Calculations are performed based on the Büttiker probe method, which introduces decoherence, energy exchange and dissipation effects phenomenologically using virtual electrode terminals called probes. The program can realize different types of probes, each introducing various environmental effects, including elastic and inelastic scattering of electrons. The molecular system is described by an arbitrary tight-binding Hamiltonian, allowing the study of different geometries beyond simple one-dimensional wires. Applications of the program to study the thermoelectric performance of molecular junctions are illustrated. The program also has a built-in functionality to simulate electron transport in double-stranded DNA molecules based on a tight-binding (ladder) description of the junction.

The attentional white bear phenomenon: the mandatory allocation of attention to expected distractor locations.

PubMed

Tsal, Yehoshua; Makovski, Tal

2006-04-01

The authors devised a prestimulus-probe method to assess the allocation of attention as a function of participants' top-down expectancies concerning distractor and target locations. Participants performed the flanker task, and distractor locations remained fixed. On some trials, instead of the flanker display, either 2 simultaneous dots or a horizontal line appeared. The dot in the expected distractor location was perceived to occur before the dot in the expected empty location, and the line appeared to extend from the expected distractor location to the expected empty location, suggesting that attention is allocated to expected distractor locations prior to stimulus onset. The authors propose that a process-all mechanism guides attention to expected locations of all stimuli regardless of task demands and that this constitutes a major cause for failures of selective attention.

Experimental plasma studies

NASA Technical Reports Server (NTRS)

Dunn, M. G.

1972-01-01

The rate coefficients for the reactions C(+) + e(-) + e(-) yields C + e(-) and CO(+) + e(-) yields C + O were measured over the electron temperature range of approximately 1500 deg K to 7000 deg K. The measurements were performed in CO that had expanded from equilibrium reservoir conditions of 7060 deg K at 17.3 atm pressure and from 6260 deg K at 10.0 atm pressure. Two RAM flight probes were used to measure electron density and electron temperature in the expanding flow of a shock tunnel. Experiments were performed in the inviscid flow with both probes and in the nozzle-wall boundary layer with the constant bias-voltage probe. The distributions of electron density and electron temperature were independently measured using voltage-swept thin-wire probes. Thin-wire Langmuir probes were also used to measure the electron-density and electron-temperature distributions in the boundary layer of a sharp flat plate located on the nozzle centerline. Admittance measurements were performed with the RAM C and RAM C-C S-band antennas in the presence of an ionized boundary layer.

The Huygens Atmospheric Structure Instrument (HASI): Expected Results at Titan and Performance Verification in Terrestrial Atmosphere

NASA Technical Reports Server (NTRS)

Ferri, F.; Fulchignoni, M.; Colombatti, G.; Stoppato, P. F. Lion; Zarnecki, J. C.; Harri, A. M.; Schwingenschuh, K.; Hamelin, M.; Flamini, E.; Bianchini, G.;

Single point aerosol sampling: evaluation of mixing and probe performance in a nuclear stack.

PubMed

Rodgers, J C; Fairchild, C I; Wood, G O; Ortiz, C A; Muyshondt, A; McFarland, A R

1996-01-01

Alternative reference methodologies have been developed for sampling of radionuclides from stacks and ducts, which differ from the methods previously required by the United States Environmental Protection Agency. These alternative reference methodologies have recently been approved by the U.S. EPA for use in lieu of the current standard techniques. The standard EPA methods are prescriptive in selection of sampling locations and in design of sampling probes whereas the alternative reference methodologies are performance driven. Tests were conducted in a stack at Los Alamos National Laboratory to demonstrate the efficacy of some aspects of the alternative reference methodologies. Coefficients of variation of velocity, tracer gas, and aerosol particle profiles were determined at three sampling locations. Results showed that numerical criteria placed upon the coefficients of variation by the alternative reference methodologies were met at sampling stations located 9 and 14 stack diameters from the flow entrance, but not at a location that was 1.5 diameters downstream from the inlet. Experiments were conducted to characterize the transmission of 10 microns aerodynamic diameter liquid aerosol particles through three types of sampling probes. The transmission ratio (ratio of aerosol concentration at the probe exit plane to the concentration in the free stream) was 107% for a 113 L min-1 (4-cfm) anisokinetic shrouded probe, but only 20% for an isokinetic probe that follows the existing EPA standard requirements. A specially designed isokinetic probe showed a transmission ratio of 63%. The shrouded probe performance would conform to the alternative reference methodologies criteria; however, the isokinetic probes would not.

Preliminary evaluation of several disinfection/sterilization techniques for use with microdialysis probes.

PubMed

Huff, Jacquelyn K; Bresnahan, James F; Davies, Malonne I

2003-06-06

This study evaluated the suitability of some disinfection and sterilization methods for use with microdialysis probes. Disinfection or sterilization should minimize the tissue inflammatory reaction and improve the long-term health of rats on study and ensure the quality of data obtained by microdialysis sampling. Furthermore, the treatment should not negatively impact probe integrity or sampling performance. The techniques chosen for evaluation included two disinfection methods (70% ethanol and a commercial contact lens solution) and two sterilization methods (hydrogen peroxide plasma, and e-beam radiation). Linear microdialysis probes treated by these processes were compared to untreated probes removed from the manufacturer's packaging as if sterile (the control group). The probes were aseptically implanted in the livers of rats and monitored for 72 hours. The parameters chosen to evaluate probe performance were relative sample mass recovery and the relative in vivo extraction efficiency of the probe for caffeine. Post mortem bacterial counts and histopathology examination of liver tissue were also conducted. The probes remained intact and functional for the entire study period. The methods tested did not acutely alter the probes although hydrogen peroxide plasma and contact lens solution groups showed reduced extraction efficiencies. Minimal tissue damage was observed surrounding the probes and acute inflammatory reaction was mild to moderate. Low numbers of bacterial colonies from the implantation sites indicates that the health of animals in this study was not impaired. This was also true for the control group (untreated probe).

The truth will out: interrogative polygraphy ("lie detection") with event-related brain potentials.

PubMed

Farwell, L A; Donchin, E

1991-09-01

The feasibility of using Event Related Brain Potentials (ERPs) in Interrogative Polygraphy ("Lie Detection") was tested by examining the effectiveness of the Guilty Knowledge Test designed by Farwell and Donchin (1986, 1988). The subject is assigned an arbitrary task requiring discrimination between experimenter-designated targets and other, irrelevant stimuli. A group of diagnostic items ("probes"), which to the unwitting are indistinguishable from the irrelevant items, are embedded among the irrelevant. For subjects who possess "guilty knowledge" these probes are distinct from the irrelevants and are likely to elicit a P300, thus revealing their possessing the special knowledge that allows them to differentiate the probes from the irrelevants. We report two experiments in which this paradigm was tested. In Experiment 1, 20 subjects participated in one of two mock espionage scenarios and were tested for their knowledge of both scenarios. All stimuli consisted of short phrases presented for 300 ms each at an interstimulus interval of 1550 ms. A set of items were designated as "targets" and appeared on 17% of the trials. Probes related to the scenarios also appeared on 17% of the trials. The rest of the items were irrelevants. Subjects responded by pressing one switch following targets, and the other following irrelevants (and, of course, probes). ERPs were recorded from FZ, CZ, and PZ. As predicted, targets elicited large P300s in all subjects. Probes associated with a given scenario elicited a P300 in subjects who participated in that scenario. A bootstrapping method was used to assess the quality of the decision for each subject. The algorithm declared the decision indeterminate in 12.5% of the cases. In all other cases a decision was made. There were no false positives and no false negatives: whenever a determination was made it was accurate. The second experiment was virtually identical to the first, with identical results, except that this time 4 subjects were tested, each of which had a minor brush with the law. Subjects were tested to determine whether they possessed information on their own "crimes." The results were as expected; the Guilty Knowledge Test determined correctly which subject possessed which information. The implications of these data both for the practice of Interrogative Polygraphy and the interpretation of the P300 are discussed.

Evaluation of Simulated Clinical Breast Exam Motion Patterns Using Marker-Less Video Tracking

PubMed Central

Azari, David P.; Pugh, Carla M.; Laufer, Shlomi; Kwan, Calvin; Chen, Chia-Hsiung; Yen, Thomas Y.; Hu, Yu Hen; Radwin, Robert G.

2016-01-01

Objective This study investigates using marker-less video tracking to evaluate hands-on clinical skills during simulated clinical breast examinations (CBEs). Background There are currently no standardized and widely accepted CBE screening techniques. Methods Experienced physicians attending a national conference conducted simulated CBEs presenting different pathologies with distinct tumorous lesions. Single hand exam motion was recorded and analyzed using marker-less video tracking. Four kinematic measures were developed to describe temporal (time pressing and time searching) and spatial (area covered and distance explored) patterns. Results Mean differences between time pressing, area covered, and distance explored varied across the simulated lesions. Exams were objectively categorized as either sporadic, localized, thorough, or efficient for both temporal and spatial categories based on spatiotemporal characteristics. The majority of trials were temporally or spatially thorough (78% and 91%), exhibiting proportionally greater time pressing and time searching (temporally thorough) and greater area probed with greater distance explored (spatially thorough). More efficient exams exhibited proportionally more time pressing with less time searching (temporally efficient) and greater area probed with less distance explored (spatially efficient). Just two (5.9 %) of the trials exhibited both high temporal and spatial efficiency. Conclusions Marker-less video tracking was used to discriminate different examination techniques and measure when an exam changes from general searching to specific probing. The majority of participants exhibited more thorough than efficient patterns. Application Marker-less video kinematic tracking may be useful for quantifying clinical skills for training and assessment. PMID:26546381

NASA Smart Surgical Probe Project

NASA Technical Reports Server (NTRS)

Mah, Robert W.; Andrews, Russell J.; Jeffrey, Stefanie S.; Guerrero, Michael; Papasin, Richard; Koga, Dennis (Technical Monitor)

2002-01-01

Information Technologies being developed by NASA to assist astronaut-physician in responding to medical emergencies during long space flights are being employed for the improvement of women's health in the form of "smart surgical probe". This technology, initially developed for neurosurgery applications, not only has enormous potential for the diagnosis and treatment of breast cancer, but broad applicability to a wide range of medical challenges. For the breast cancer application, the smart surgical probe is being designed to "see" a suspicious lump, determine by its features if it is cancerous, and ultimately predict how the disease may progress. A revolutionary early breast cancer detection tool based on this technology has been developed by a commercial company and is being tested in human clinical trials at the University of California at Davis, School of Medicine. The smart surgical probe technology makes use of adaptive intelligent software (hybrid neural networks/fuzzy logic algorithms) with the most advanced physiologic sensors to provide real-time in vivo tissue characterization for the detection, diagnosis and treatment of tumors, including determination of tumor microenvironment and evaluation of tumor margins. The software solutions and tools from these medical applications will lead to the development of better real-time minimally-invasive smart surgical probes for emergency medical care and treatment of astronauts on long space flights.

The effect of orthodontic bands or tubes upon periodontal status during the initial phase of orthodontic treatment

PubMed Central

Al-Anezi, Saud A.

2015-01-01

Introduction Orthodontic bands cause periodontal inflammation. In theory, the use of a buccal tube (bond) instead of a band should prevent or minimize periodontal changes because the bonds are positioned away from the gingival margins. Objective The primary aim of this study was to investigate the periodontal status of orthodontic bands compared with bonds in the first three months of orthodontic treatment. Materials and methods Twenty-four orthodontic patients (mean age = 12.6 years) were enrolled in this Randomized Controlled Trial (RCT). Using the cross-mouth technique, bands and bonds were used in opposite quadrants. Periodontal parameters including the presence or absence of Bleeding On Probing (BOP) and Probing Depths (PDs) were taken at the start and three months into treatment. Results Bands caused a statistically significant change in the Bleeding On Probing (BOP) (P = 0.001 and 0.021) and bonds displayed a statistically insignificant change in the Bleeding On Probing (BOP) (P = 0.125 and 1.00) for the upper and lower arch. The difference in Probing Depths (PDs) between bands and bonds was also statistically significant (P = 0.001). Conclusion Molar bands are associated with greater periodontal inflammation compared with molar bonds in the first three months of fixed orthodontic treatment. PMID:26236124

Cyclic coding for Brillouin optical time-domain analyzers using probe dithering.

PubMed

Iribas, Haritz; Loayssa, Alayn; Sauser, Florian; Llera, Miguel; Le Floch, Sébastien

2017-04-17

We study the performance limits of mono-color cyclic coding applied to Brillouin optical time-domain analysis (BOTDA) sensors that use probe wave dithering. BOTDA analyzers with dithering of the probe use a dual-probe-sideband setup in which an optical frequency modulation of the probe waves along the fiber is introduced. This avoids non-local effects while keeping the Brillouin threshold at its highest level, thus preventing the spontaneous Brillouin scattering from generating noise in the deployed sensing fiber. In these conditions, it is possible to introduce an unprecedented high probe power into the sensing fiber, which leads to an enhancement of the signal-to-noise ratio (SNR) and consequently to a performance improvement of the analyzer. The addition of cyclic coding in these set-ups can further increase the SNR and accordingly enhance the performance. However, this unprecedented probe power levels that can be employed result in the appearance of detrimental effects in the measurement that had not previously been observed in other BOTDA set-ups. In this work, we analyze the distortion in the decoding process and the errors in the measurement that this distortion causes, due to three factors: the power difference of the successive pulses of a code sequence, the appearance of first-order non-local effects and the non-linear amplification of the probe wave that results when using mono-color cyclic coding of the pump pulses. We apply the results of this study to demonstrate the performance enhancement that can be achieved in a long-range dithered dual-probe BOTDA. A 164-km fiber-loop is measured with 1-m spatial resolution, obtaining 3-MHz Brillouin frequency shift measurement precision at the worst contrast location. To the best of our knowledge, this is the longest sensing distance achieved with a BOTDA sensor using mono-color cyclic coding.

Outer planet atmospheric entry probes - An overview of technology readiness

NASA Technical Reports Server (NTRS)

Vojvodich, N. S.; Reynolds, R. T.; Grant, T. L.; Nachtsheim, P. R.

1975-01-01

Entry probe systems for characterizing, by in situ measurements, the atmospheric properties, chemical composition, and cloud structure of the planets Saturn, Uranus, and Jupiter are examined from the standpoint of unique mission requirements, associated subsystem performance, and degree of commonality of design. Past earth entry vehicles (PAET) and current planetary spacecraft (Pioneer Venus probes and Viking lander) are assessed to identify the extent of potential subsystem inheritance, as well as to establish the significant differences, in both form and function, relative to outer planet requirements. Recent research results are presented and reviewed for the most critical probe technology areas, including: science accommodation, telecommunication, and entry heating and thermal protection. Finally presented is a brief discussion of the use of decision analysis techniques for quantifying various probe heat-shield test alternatives and performance risk.

Minimum-variance Brownian motion control of an optically trapped probe.

PubMed

Huang, Yanan; Zhang, Zhipeng; Menq, Chia-Hsiang

2009-10-20

This paper presents a theoretical and experimental investigation of the Brownian motion control of an optically trapped probe. The Langevin equation is employed to describe the motion of the probe experiencing random thermal force and optical trapping force. Since active feedback control is applied to suppress the probe's Brownian motion, actuator dynamics and measurement delay are included in the equation. The equation of motion is simplified to a first-order linear differential equation and transformed to a discrete model for the purpose of controller design and data analysis. The derived model is experimentally verified by comparing the model prediction to the measured response of a 1.87 microm trapped probe subject to proportional control. It is then employed to design the optimal controller that minimizes the variance of the probe's Brownian motion. Theoretical analysis is derived to evaluate the control performance of a specific optical trap. Both experiment and simulation are used to validate the design as well as theoretical analysis, and to illustrate the performance envelope of the active control. Moreover, adaptive minimum variance control is implemented to maintain the optimal performance in the case in which the system is time varying when operating the actively controlled optical trap in a complex environment.

Performance of Pylons Upstream of a Cavity-Based Flameholder in Non-Reacting Supersonic Flow (POSTPRINT)

DTIC Science & Technology

2006-07-01

inches. Measurements are performed using a pitot , cone-static probe and total temperature probe with similar test meshes. All probes are...transverse direction (y/d = 0.0) is the upstream lip of the cavity. In each figure, the bow shock originates just upstream of the injection port and tends...to be the strongest shock feature. In the baseline configurations, the bow shock initially penetrates perpendicular to the main flow due to the

pH Meter probe assembly

DOEpatents

Hale, C.J.

1983-11-15

An assembly for mounting a pH probe in a flowing solution, such as a sanitary sewer line, which prevents the sensitive glass portion of the probe from becoming coated with grease, oil, and other contaminants, whereby the probe gives reliable pH indication over an extended period of time. The pH probe assembly utilizes a special filter media and a timed back-rinse feature for flushing clear surface contaminants of the filter. The flushing liquid is of a known pH and is utilized to check performance of the probe. 1 fig.

pH Meter probe assembly

DOEpatents

Hale, Charles J.

1983-01-01

An assembly for mounting a pH probe in a flowing solution, such as a sanitary sewer line, which prevents the sensitive glass portion of the probe from becoming coated with grease, oil, and other contaminants, whereby the probe gives reliable pH indication over an extended period of time. The pH probe assembly utilizes a special filter media and a timed back-rinse feature for flushing clear surface contaminants of the filter. The flushing liquid is of a known pH and is utilized to check performance of the probe.

Within-Hemifield Competition in Early Visual Areas Limits the Ability to Track Multiple Objects with Attention

PubMed Central

Alvarez, George A.; Cavanagh, Patrick

2014-01-01

It is much easier to divide attention across the left and right visual hemifields than within the same visual hemifield. Here we investigate whether this benefit of dividing attention across separate visual fields is evident at early cortical processing stages. We measured the steady-state visual evoked potential, an oscillatory response of the visual cortex elicited by flickering stimuli, of moving targets and distractors while human observers performed a tracking task. The amplitude of responses at the target frequencies was larger than that of the distractor frequencies when participants tracked two targets in separate hemifields, indicating that attention can modulate early visual processing when it is divided across hemifields. However, these attentional modulations disappeared when both targets were tracked within the same hemifield. These effects were not due to differences in task performance, because accuracy was matched across the tracking conditions by adjusting target speed (with control conditions ruling out effects due to speed alone). To investigate later processing stages, we examined the P3 component over central-parietal scalp sites that was elicited by the test probe at the end of the trial. The P3 amplitude was larger for probes on targets than on distractors, regardless of whether attention was divided across or within a hemifield, indicating that these higher-level processes were not constrained by visual hemifield. These results suggest that modulating early processing stages enables more efficient target tracking, and that within-hemifield competition limits the ability to modulate multiple target representations within the hemifield maps of the early visual cortex. PMID:25164651

Diagnosis of Acute Cellular Rejection Using Probe-Based Confocal Laser Endomicroscopy in Lung Transplant Recipients: a Prospective, Multicenter Trial.

PubMed

Keller, Cesar A; Khoor, Andras; Arenberg, Douglas A; Smith, Michael A; Islam, Shaheen U

2018-05-29

Acute cellular rejection (ACR) in lung transplant recipients requires demonstration of perivascular lymphocytic infiltration in alveolar tissue samples from transbronchial biopsies (TBBs). Probe-based confocal laser endomicroscopy (pCLE) allows in vivo observation of alveolar, vascular, and cellular microstructures in the lung with potential to identify ACR. The objective of our prospective, blinded, multicenter observational study was to identify pCLE findings in patients with ACR diagnosed histopathologically by TBB. Lung transplant recipients undergoing diagnostic bronchoscopies within 1 year posttransplant for suspected ACR had pCLE video imaging obtained immediately prior to tissue sampling via TBB. Findings of 2 pCLE criteria, abundant alveolar cellularity and perivascular cellularity (PVC), were assessed by 4 investigators familiar with pCLE and compared to histopathologic criteria of ACR to derive sensitivity, specificity, area under the receiver operating characteristic curve, and accuracy. Interobserver agreement was assessed by calculating intraclass coefficient and Fleiss κ. Findings were analyzed before and after a consensus meeting of investigators on interpreting images. Thirty pCLE procedures were performed on 24 patients, 8 showing ACR in TBB. Diagnostic performance and interobserver agreement using pCLE to identify PVC were significantly higher than those of abundant alveolar cellularity (P<.01). The number of blood vessels identified with PVC on pCLE was significantly correlated with histopathologic activity grading of ACR (P<.01). PVC agreement among investigators significantly improved after consensus meeting (P<.01) CONCLUSIONS: When found on pCLE, PVC is a feasible and reproducible criterion for assessment of ACR in vivo, but there is a learning curve for image interpretation.

[Ridge preservation with synthetic nanocrystalline hydroxyapatite reduces the severity of gingival invaginations-a prospective clinical study].

PubMed

Reichert, Christoph; Wenghoefer, Matthias; Kutschera, Eric; Götz, Werner; Jäger, Andreas

2014-01-01

Gingival invaginations develop after tooth extraction and subsequent orthodontic space closure. Aetiological factors and long-term effects of gingival invaginations on oral health are nearly unknown. In addition, preventive or therapeutic strategies are rare. This prospective clinical study employing the split mouth technique was performed to investigate the effect of extraction socket augmentation with a synthetic nanocrystalline hydroxyapatite (NanoBone(®) Artoss, Rostock, Germany) on the incidence and degree of gingival invaginations. A total of 10 orthodontic patients with need for symmetric premolar extractions offering a total of 28 extractions were included in this trial. The study plan provided one extraction site to be augmented with synthetic nanocrystalline hydroxyapatite (NanoBone(®)), the other served as control. After primary wound healing, space closure was performed under defined biomechanical conditions. After space closure was accomplished, occurrence and degree of gingival invaginations as well as probing depths of the adjacent teeth mesial and distal to the extractions were determined and dental radiographs were taken. The degree of gingival invaginations and probing depths mesial and distal of the extraction were significantly reduced on NanoBone(®) augmented extraction sites. In addition, 70% of the radiographs revealed translucent and hyperdense areas on the intervention side after space closure. Apical root resorption was found in 2 patients on both the NanoBone(®) side and the control side. Ridge preservation with NanoBone(®) appeared to reduce the severity of gingival invaginations. Further investigation on long-term effects is mandatory to eliminate the appearance of adverse effects.

Hollow fiber-optic Raman probes for small experimental animals

NASA Astrophysics Data System (ADS)

Katagiri, Takashi; Hattori, Yusuke; Suzuki, Toshiaki; Matsuura, Yuji; Sato, Hidetoshi

2007-02-01

Two types of hollow fiber-optic probes are developed to measure the in vivo Raman spectra of small animals. One is the minimized probe which is end-sealed with the micro-ball lens. The measured spectra reflect the information of the sample's sub-surface. This probe is used for the measurement of the esophagus and the stomach via an endoscope. The other probe is a confocal Raman probe which consists of a single fiber and a lens system. It is integrated into the handheld microscope. A simple and small multimodal probe is realized because the hollow optical fiber requires no optical filters. The performance of each probe is examined and the effectiveness of these probes for in vivo Raman spectroscopy is shown by animal tests.

A rational regulatory approach for positron emission tomography imaging probes: from "first in man" to NDA approval and reimbursement.

PubMed

Barrio, Jorge R; Marcus, Carol S; Hung, Joseph C; Keppler, Jennifer S

2004-01-01

We propose a new regulatory approach for positron emission tomography (PET) molecular imaging probes, essential tools in today's medicine. Even though the focus of this paper is on positron-emitting labeled probes, it is also justified to extend this proposed regulatory approach to other diagnostic nuclear medicine radiopharmaceuticals. Key aspects of this proposal include: (1) PET molecular imaging probes would be placed in a "no significant risk" category, similar to that category for devices in current Food and Drug Administration (FDA) regulations, based on overwhelming scientific evidence that demonstrates their faultless safety profile; (2) the FDA-sanctioned Radioactive Drug Research Committee (RDRC) will oversee all diagnostic research with these probes. The newly defined RDRC should approve "first in man" use; supervise a broader spectrum of diagnostic research protocols, including those looking to demonstrate initial efficacy, as well as multicenter clinical trials and the use of molecular imaging probes as a screening tool in drug discovery. The current investigational new drug (IND) mechanism is thus eliminated for these diagnostic probes; (3) when a molecular imaging probe has demonstrated diagnostic efficacy, FDA approval (i.e., NDA) will be sought. The review will be done by a newly constituted Radioactive Drug Advisory Committee (RDAC) composed of experts chosen by the professional societies, who would provide a binding assessment of the adequacy of the safety and efficacy data. When the RDAC recommends its diagnostic use on scientific and medical grounds, the molecular imaging probe becomes FDA approved. After a molecular imaging probe is approved for a diagnostic indication, the existing mechanism to seek reimbursement will be utilized; and (4) the FDA would retain its direct oversight function for traditional manufacturers engaged in commercial distribution of the approved diagnostic molecular imaging probes (i.e., under NDA) to monitor compliance with existing US Pharmacopeia (USP) requirements. With abbreviated and more appropriate regulations, new PET molecular imaging probes for diagnostic use would be then rapidly incorporated into the mainstream diagnostic medicine. Equally importantly, this approach would facilitate the use of molecular imaging in drug discovery and development, which would substantially reduce the costs and time required to bring new therapeutic drugs to market.

Probing the nature of deficits in the 'Approximate Number System' in children with persistent Developmental Dyscalculia.

PubMed

Bugden, Stephanie; Ansari, Daniel

2016-09-01

In the present study we examined whether children with Developmental Dyscalculia (DD) exhibit a deficit in the so-called 'Approximate Number System' (ANS). To do so, we examined a group of elementary school children who demonstrated persistent low math achievement over 4 years and compared them to typically developing (TD), aged-matched controls. The integrity of the ANS was measured using the Panamath (www.panamath.org) non-symbolic numerical discrimination test. Children with DD demonstrated imprecise ANS acuity indexed by larger Weber fraction (w) compared to TD controls. Given recent findings showing that non-symbolic numerical discrimination is affected by visual parameters, we went further and investigated whether children performed differently on trials on which number of dots and their overall area were either congruent or incongruent with each other. This analysis revealed that differences in w were only found between DD and TD children on the incongruent trials. In addition, visuo-spatial working memory strongly predicts individual differences in ANS acuity (w) during the incongruent trials. Thus the purported ANS deficit in DD can be explained by a difficulty in extracting number from an array of dots when area is anti-correlated with number. These data highlight the role of visuo-spatial working memory during the extraction process, and demonstrate that close attention needs to be paid to perceptual processes invoked by tasks thought to represent measures of the ANS. © 2015 John Wiley & Sons Ltd.

Timing performance of the silicon PET insert probe

PubMed Central

Studen, A.; Burdette, D.; Chesi, E.; Cindro, V.; Clinthorne, N. H.; Cochran, E.; Grošičar, B.; Kagan, H.; Lacasta, C.; Linhart, V.; Mikuž, M.; Stankova, V.; Weilhammer, P.; Žontar, D.

2010-01-01

Simulation indicates that PET image could be improved by upgrading a conventional ring with a probe placed close to the imaged object. In this paper, timing issues related to a PET probe using high-resistivity silicon as a detector material are addressed. The final probe will consist of several (four to eight) 1-mm thick layers of silicon detectors, segmented into 1 × 1 mm2 pads, each pad equivalent to an independent p + nn+ diode. A proper matching of events in silicon with events of the external ring can be achieved with a good timing resolution. To estimate the timing performance, measurements were performed on a simplified model probe, consisting of a single 1-mm thick detector with 256 square pads (1.4 mm side), coupled with two VATAGP7s, application-specific integrated circuits. The detector material and electronics are the same that will be used for the final probe. The model was exposed to 511 keV annihilation photons from an 22Na source, and a scintillator (LYSO)–PMT assembly was used as a timing reference. Results were compared with the simulation, consisting of four parts: (i) GEANT4 implemented realistic tracking of electrons excited by annihilation photon interactions in silicon, (ii) calculation of propagation of secondary ionisation (electron–hole pairs) in the sensor, (iii) estimation of the shape of the current pulse induced on surface electrodes and (iv) simulation of the first electronics stage. A very good agreement between the simulation and the measurements were found. Both indicate reliable performance of the final probe at timing windows down to 20 ns. PMID:20215445

Timing performance of the silicon PET insert probe.

PubMed

Studen, A; Burdette, D; Chesi, E; Cindro, V; Clinthorne, N H; Cochran, E; Grosicar, B; Kagan, H; Lacasta, C; Linhart, V; Mikuz, M; Stankova, V; Weilhammer, P; Zontar, D

2010-01-01

Simulation indicates that PET image could be improved by upgrading a conventional ring with a probe placed close to the imaged object. In this paper, timing issues related to a PET probe using high-resistivity silicon as a detector material are addressed. The final probe will consist of several (four to eight) 1-mm thick layers of silicon detectors, segmented into 1 x 1 mm(2) pads, each pad equivalent to an independent p + nn+ diode. A proper matching of events in silicon with events of the external ring can be achieved with a good timing resolution. To estimate the timing performance, measurements were performed on a simplified model probe, consisting of a single 1-mm thick detector with 256 square pads (1.4 mm side), coupled with two VATAGP7s, application-specific integrated circuits. The detector material and electronics are the same that will be used for the final probe. The model was exposed to 511 keV annihilation photons from an (22)Na source, and a scintillator (LYSO)-PMT assembly was used as a timing reference. Results were compared with the simulation, consisting of four parts: (i) GEANT4 implemented realistic tracking of electrons excited by annihilation photon interactions in silicon, (ii) calculation of propagation of secondary ionisation (electron-hole pairs) in the sensor, (iii) estimation of the shape of the current pulse induced on surface electrodes and (iv) simulation of the first electronics stage. A very good agreement between the simulation and the measurements were found. Both indicate reliable performance of the final probe at timing windows down to 20 ns.

On Trial: the Compatibility of Measurement in the Physical and Social Sciences

NASA Astrophysics Data System (ADS)

Cano, S. J.; Vosk, T.; Pendrill, L. R.; Stenner, A. J.

2016-11-01

In this paper, we put social measurement on trial: providing two perspectives arguing why measurement in the social and in the physical sciences are incompatible and counter with two perspectives supporting compatibility. For the case ‘against’, we first argue that there is a lack of definition in the social sciences. Thus, while measurement in the physical sciences is supported by empirical evidence, calibrated instruments, and predictive theory that work together to test the quantitative nature of properties, measurement in the social sciences, in the main, rests on a vague, discretionary definition of measurement that places hardly any restrictions on empirical data, does not require calibrated instruments, and rarely articulates predictive theories. The second argument for the case ‘against’ introduces the problem associated with psychometrics, including different approaches, methodologies, criteria for success and failure, and considerations as to what counts as measurement. Making the first case ‘for’, we highlight practical principles for improved social measurement including units, laws, theory, and metrology. The second argument ‘for’ introduces the exemplar of the Lexile Framework for reading that exploits metrological principles and parallels the paths taken by, for example, thermometry. We conclude by proposing a way forward potentially applicable to both physical and social measurement, in which inferences are modelled in terms of a measurement system, where specifically the output of the instrument in response to probing the object (‘entity’) is a performance metric, i.e. how well the set-up performs the assessment.

Changes in forearm muscle temperature alter renal vascular responses to isometric handgrip.

PubMed

Kuipers, Nathan T; Sauder, Charity L; Kearney, Matthew L; Ray, Chester A

2007-12-01

The purpose of the present study was to examine the effect of heating and cooling the forearm muscles on renal vascular responses to ischemic isometric handgrip (IHG). It was hypothesized that heating and cooling the forearm would augment and attenuate, respectively, renal vascular responses to IHG. Renal vascular responses to IHG were studied during forearm heating at 39 degrees C (n = 15, 26 +/- 1 yr) and cooling at 26 degrees C (n = 12, 26 +/- 1 yr). For a control trial, subjects performed the experimental protocol while the forearm was normothermic (approximately 34 degrees C). Muscle temperature (measured by intramuscular probe) was controlled by changing the temperature of water cycling through a water-perfused sleeve. The experimental protocol was as follows: 3 min at baseline, 1 min of ischemia, ischemic IHG to fatigue, and 2 min of postexercise muscle ischemia. At rest, renal artery blood velocity (RBV; Doppler ultrasound) and renal vascular conductance (RVC = RBV/mean arterial blood pressure) were not different between normothermia and the two thermal conditions. During ischemic IHG, there were greater decreases in RBV and RVC in the heating trial. However, RBV and RVC were similar during postexercise muscle ischemia during heating and normothermia. RVC decreased less during cooling than in normothermia while the subjects performed the ischemic IHG protocol. During postexercise muscle ischemia, RVC was greater during cooling than in normothermia. These results indicate that heating augments mechanoreceptor-mediated renal vasoconstriction whereas cooling blunts metaboreceptor-mediated renal vasoconstriction.

Determination of plasma density from data on the ion current to cylindrical and planar probes

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

Voloshin, D. G., E-mail: dvoloshin@mics.msu.su; Vasil’eva, A. N.; Kovalev, A. S.

2016-12-15

To improve probe methods of plasma diagnostics, special probe measurements were performed and numerical models describing ion transport to a probe with allowance for collisions were developed. The current–voltage characteristics of cylindrical and planar probes were measured in an RF capacitive discharge in argon at a frequency of 81 MHz and plasma densities of 10{sup 10}–10{sup 11} cm{sup –3}, typical of modern RF reactors. 1D and 2D numerical models based on the particle-in-cell method with Monte Carlo collisions for simulating ion motion and the Boltzmann equilibrium for electrons are developed to describe current collection by a probe. The models weremore » used to find the plasma density from the ion part of the current–voltage characteristic, study the effect of ion collisions, and verify simplified approaches to determining the plasma density. A 1D hydrodynamic model of the ion current to a cylindrical probe with allowance for ion collisions is proposed. For a planar probe, a method to determine the plasma density from the averaged numerical results is developed. A comparative analysis of different approaches to calculating the plasma density from the ion current to a probe is performed.« less

'Incremental thermocouple probe' for testing insulation erosion on a rocket motor

NASA Technical Reports Server (NTRS)

Gould, Reginald J.

1993-01-01

An incremental thermocouple probe was developed to measure insulation erosion during a solid rocket motor firing. The probe's new and unique design is described along with its theory of operation. Data from an actual firing are reported which show that the probe's performance greatly exceeded predictions and present technology as a temperature measurement device and as an event gage.

Small Next-Generation Atmospheric Probe (SNAP) Concept

NASA Technical Reports Server (NTRS)

Sayanagi, K. M.; Dillman, R. A.; Simon, A. A.; Atkinson, D. H.; Wong, M. H.; Spilker, T. R.; Saikia, S.; Li, J.; Hope, D.

2017-01-01

We present the Small Next-Generation Atmospheric Probe (SNAP) as a secondary payload concept for future missions to giant planets. As a case study, we examine the advantages, cost and risk of adding SNAP to the future Uranus Orbiter and Probe flag-ship mission; in combination with the missions main probe, SNAP would perform atmospheric in-situ measurements at a second location.

Characterizing the performance of an affordable, multichannel conductivity probe for density measurements in stratified flows

NASA Astrophysics Data System (ADS)

Subramanian, Balaji; Carminati, Marco; Luzzatto-Fegiz, Paolo

2017-11-01

In stratified flows, conductivity (combined with temperature) is often used to measure density. The conductivity probes typically used can resolve very fine spatial scales, but on the downside they are fragile, expensive, sensitive to environmental noise and have only single channel capability. Recently a low-cost, robust, arduino-based probe called Conduino was developed, which can be valuable in a wide range of applications where resolving extremely small spatial scales is not needed. This probe uses micro-USB connectors as actual conductivity sensors with a custom designed electronic board for simultaneous acquisition from multiple probes, with conductivity resolution comparable to commercially available PME conductivity probe. A detailed assessment of performance of this Conduino probe is described here. To establish time response and sensitivity as a function of electrode geometry, we build a variety of shapes for different kinds of applications, with tip spacing ranging from 0.5-2.5 mm, and with electrode length ranging from 2.3-6 mm. We set up a two-layer density profile and traverse it rapidly, yielding a time response comparable to PME. The Conduino's multi-channel capability is used to operate probe arrays, which helps to construct density fields in stratified flows.

Aircraft Conflict Analysis and Real-Time Conflict Probing Using Probabilistic Trajectory Modeling

NASA Technical Reports Server (NTRS)

Yang, Lee C.; Kuchar, James K.

2000-01-01

Methods for maintaining separation between aircraft in the current airspace system have been built from a foundation of structured routes and evolved procedures. However, as the airspace becomes more congested and the chance of failures or operational error become more problematic, automated conflict alerting systems have been proposed to help provide decision support and to serve as traffic monitoring aids. The problem of conflict detection and resolution has been tackled from a number of different ways, but in this thesis, it is recast as a problem of prediction in the presence of uncertainties. Much of the focus is concentrated on the errors and uncertainties from the working trajectory model used to estimate future aircraft positions. The more accurate the prediction, the more likely an ideal (no false alarms, no missed detections) alerting system can be designed. Additional insights into the problem were brought forth by a review of current operational and developmental approaches found in the literature. An iterative, trial and error approach to threshold design was identified. When examined from a probabilistic perspective, the threshold parameters were found to be a surrogate to probabilistic performance measures. To overcome the limitations in the current iterative design method, a new direct approach is presented where the performance measures are directly computed and used to perform the alerting decisions. The methodology is shown to handle complex encounter situations (3-D, multi-aircraft, multi-intent, with uncertainties) with relative ease. Utilizing a Monte Carlo approach, a method was devised to perform the probabilistic computations in near realtime. Not only does this greatly increase the method's potential as an analytical tool, but it also opens up the possibility for use as a real-time conflict alerting probe. A prototype alerting logic was developed and has been utilized in several NASA Ames Research Center experimental studies.

Benefits of Aldosterone Receptor Antagonism in Chronic Kidney Disease (BARACK D) trial-a multi-centre, prospective, randomised, open, blinded end-point, 36-month study of 2,616 patients within primary care with stage 3b chronic kidney disease to compare the efficacy of spironolactone 25 mg once daily in addition to routine care on mortality and cardiovascular outcomes versus routine care alone: study protocol for a randomized controlled trial.

PubMed

Hill, Nathan R; Lasserson, Daniel; Thompson, Ben; Perera-Salazar, Rafael; Wolstenholme, Jane; Bower, Peter; Blakeman, Thomas; Fitzmaurice, David; Little, Paul; Feder, Gene; Qureshi, Nadeem; Taal, Maarten; Townend, Jonathan; Ferro, Charles; McManus, Richard; Hobbs, Fd Richard

2014-05-08

Chronic kidney disease (CKD) is common and increasing in prevalence. Cardiovascular disease (CVD) is a major cause of morbidity and death in CKD, though of a different phenotype to the general CVD population. Few therapies have proved effective in modifying the increased CVD risk or rate of renal decline in CKD. There are accumulating data that aldosterone receptor antagonists (ARA) may offer cardio-protection and delay renal impairment in patients with the CV phenotype in CKD. The use of ARA in CKD has therefore been increasingly advocated. However, no large study of ARA with renal or CVD outcomes is underway. The study is a prospective randomised open blinded endpoint (PROBE) trial set in primary care where patients will mainly be identified by their GPs or from existing CKD lists. They will be invited if they have been formally diagnosed with CKD stage 3b or there is evidence of stage 3b CKD from blood results (eGFR 30-44 mL/min/1.73 m2) and fulfil the other inclusion/exclusion criteria. Patients will be randomised to either spironolactone 25 mg once daily in addition to routine care or routine care alone and followed-up for 36 months. BARACK D is a PROBE trial to determine the effect of ARA on mortality and cardiovascular outcomes (onset or progression of CVD) in patients with stage 3b CKD. EudraCT: 2012-002672-13ISRTN: ISRCTN44522369.

Impact of the Daily Use of a Microcrystal Hydroxyapatite Dentifrice on De Novo Plaque Formation and Clinical/Microbiological Parameters of Periodontal Health. A Randomized Trial

PubMed Central

Schlagenhauf, Ulrich; May, Theodor W.; Gravemeier, Martina; Prior, Karola; Petersilka, Gregor; Ehmke, Benjamin

2016-01-01

Aim This 12-week prospective, randomized, double-blind, two-center trial evaluated the impact of a microcrystalline zinc hydroxyapatite (mHA) dentifrice on plaque formation rate (PFR) in chronic periodontitis patients. We hypothesized that mHA precipitates cause delayed plaque development when compared to a fluoridated control (AmF/SnF2), and therefore would improve periodontal health. Material & Methods At baseline and after 4 and 12 weeks, PFR and other clinical and microbiological parameters were recorded. Seventy periodontitis patients received a mHA or AmF/SnF2 dentifrice as daily oral care without hygiene instructions. Four weeks after baseline, participants received full mouth debridement and continued using the dentifrices for another 8 weeks. Results Primary outcome PFR did not change statistically significantly from baseline to weeks 4 and 12, neither in mHA (n = 33; 51.7±17.2% vs. 48.5±16.65% vs. 48.4±19.9%) nor in AmF/SnF2-group (n = 34; 52.3±17.5% vs. 52.5±21.3% vs. 46.1±21.8%). Secondary clinical parameters such as plaque control record, gingival index, bleeding on probing, and pocket probing depth improved, but between-group differences were not statistically significant. Microbiological analyses showed similar slight decreases in colony-forming units in both groups. Conclusion In patients with mild-to-moderate periodontitis, periodontal therapy and use of a mHA-or AmF/SnF2 dentifrice without instructions induced comparable improvements in periodontal health but did not significantly reduce the PFR. Trial Registration ClincalTrials.gov NCT02697539 PMID:27467683

Attention bias in earthquake-exposed survivors: an event-related potential study.

PubMed

Zhang, Yan; Kong, Fanchang; Han, Li; Najam Ul Hasan, Abbasi; Chen, Hong

2014-12-01

The Chinese Wenchuan earthquake, which happened on the 28th of May in 2008, may leave deep invisible scars in individuals. China has a large number of children and adolescents, who tend to be most vulnerable because they are in an early stage of human development and possible post-traumatic psychological distress may have a life-long consequence. Trauma survivors without post-traumatic stress disorder (PTSD) have received little attention in previous studies, especially in event-related potential (ERP) studies. We compared the attention bias to threat stimuli between the earthquake-exposed group and the control group in a masked version of the dot probe task. The target probe presented at the same space location consistent with earthquake-related words was the congruent trial, while in the space location of neutral words was the incongruent trial. Thirteen earthquake-exposed middle school students without PTSD and 13 matched controls were included in this investigation. The earthquake-exposed group showed significantly faster RTs to congruent trials than to incongruent trials. The earthquake-exposed group produced significantly shorter C1 and P1 latencies and larger C1, P1 and P2 amplitudes than the control group. In particular, enhanced P1 amplitude to threat stimuli was observed in the earthquake-exposed group. These findings are in agreement with the prediction that earthquake-exposed survivors have an attention bias to threat stimuli. The traumatic event had a much greater effect on earthquake-exposed survivors even if they showed no PTSD symptoms than individuals in the controls. These results will provide neurobiological evidences for effective intervention and prevention to post-traumatic mental problems. Copyright © 2014 Elsevier B.V. All rights reserved.

Effects of radiofrequency probe application on irrigation fluid temperature in the wrist joint.

PubMed

Sotereanos, Dean G; Darlis, Nickolaos A; Kokkalis, Zinon T; Zanaros, George; Altman, Gregory T; Miller, Mark Carl

2009-12-01

Radiofrequency (RF) probes used in wrist arthroscopy may raise joint fluid temperature, increasing the risk of capsular and ligamentous damage. The purposes of the current study were to measure joint fluid temperature during wrist arthroscopy with the use of RF probes, and to determine whether using an outlet portal will reduce the maximum temperature. We performed wrist arthroscopy on 8 cadaveric arms. Ablation and coagulation cycles using RF probe were performed at documented locations within the joint. This was done for 60-second intervals on both the radial and ulnar side of the wrist, to mimic clinical practice. We used 4 fiberoptic phosphorescent probes to measure temperature (radial, ulnar, inflow-tube, and outflow-tube probes) and measured joint fluid temperature with and without outflow. There was a significant difference between wrists with and without outflow when examining maximum ablation temperatures (p < .002). All specimens showed higher maximum and average ablation temperatures without outflow. Maximum joint temperatures, greater than 60 degrees C, were observed in only no-outflow conditions. In performing RF ablation during wrist arthroscopy, the use of an outlet portal reduces the joint fluid temperature. Without an outlet portal, maximum temperatures can exceed desirable levels when using ablation; such temperatures have the potential to damage adjacent tissues. It is useful to maintain adequate outflow when using the radiofrequency probes during wrist arthroscopy.

Performance of a combined three-hole conductivity probe for void fraction and velocity measurement in air-water flows

NASA Astrophysics Data System (ADS)

Borges, João Eduardo; Pereira, Nuno H. C.; Matos, Jorge; Frizell, Kathleen H.

2010-01-01

The development of a three-hole pressure probe with back-flushing combined with a conductivity probe, used for measuring simultaneously the magnitude and direction of the velocity vector in complex air-water flows, is described in this paper. The air-water flows envisaged in the current work are typically those occurring around the rotors of impulse hydraulic turbines (like the Pelton and Cross-Flow turbines), where the flow direction is not known prior to the data acquisition. The calibration of both the conductivity and three-hole pressure components of the combined probe in a rig built for the purpose, where the probe was placed in a position similar to that adopted for the flow measurements, will be reported. After concluding the calibration procedure, the probe was utilized in the outside region of a Cross-Flow turbine rotor. The experimental results obtained in the present study illustrate the satisfactory performance of the combined probe, and are encouraging toward its use for characterizing the velocity field of other complex air-water flows.

Comparative measurements of plasma potential with ball-pen and Langmuir probe in low-temperature magnetized plasma

NASA Astrophysics Data System (ADS)

Zanáška, M.; Adámek, J.; Peterka, M.; Kudrna, P.; Tichý, M.

2015-03-01

The ball-pen probe (BPP) is used for direct plasma potential measurements in magnetized plasma. The probe can adjust the ratio of the electron and ion saturation currents Isat-/Isat+ to be close to one and therefore its I-V characteristic becomes nearly symmetric. If this is achieved, the floating potential of the BPP is close to the plasma potential. Because of its rather simple construction, it offers an attractive probe for measurements in magnetized plasma. Comparative measurements of plasma potential by BPPs of different dimensions as well as one Langmuir probe (LP) in an argon discharge plasma of a cylindrical magnetron were performed at various experimental conditions. An additional comparison by an emissive probe was also performed. All these types of probes provide similar values of plasma potential in a wide range of plasma parameters. Our results for three different BPP dimensions indicate that the BPP can be operated in a cylindrical magnetron DC argon discharge if the value of the ratio of the magnetic field and neutral gas pressure, B/p, is greater than approximately 10 mT/Pa.

Performance measures to characterize directional corridor travel time delay based on probe vehicle data : final report.

DOT National Transportation Integrated Search

2015-10-01

Anonymous probe vehicle data are currently being collected on roadways throughout the United States. These data are being incorporated into local and statewide mobility reports to measure the performance of freeways and arterial systems. Predefined s...

Performance of Pylons Upstream of a Cavity-Based Flameholder in Non-Reacting Supersonic Flow (Postprint)

DTIC Science & Technology

2006-07-01

location of 0.75 inches. Measurements are performed using a pitot , cone-static probe and total temperature probe with similar test meshes. All probes are...the transverse direction (y/d = 0.0) is the upstream lip of the cavity. In each figure, the bow shock originates just upstream of the injection port...and tends to be the strongest shock feature. In the baseline configurations, the bow shock initially penetrates perpendicular to the main flow due to

Surface enhanced Raman gene probe and methods thereof

DOEpatents

Vo-Dinh, T.

1998-09-29

The subject invention disclosed herein is a new gene probe biosensor and methods based on surface enhanced Raman scattering (SERS) label detection. The SER gene probe biosensor comprises a support means, a SER gene probe having at least one oligonucleotide strand labeled with at least one SERS label, and a SERS active substrate disposed on the support means and having at least one of the SER gene probes adsorbed thereon. Biotargets such as bacterial and viral DNA, RNA and PNA are detected using a SER gene probe via hybridization to oligonucleotide strands complementary to the SER gene probe. The support means supporting the SERS active substrate includes a fiberoptic probe, an array of fiberoptic probes for performance of multiple assays and a waveguide microsensor array with charge-coupled devices or photodiode arrays. 18 figs.

Surface enhanced Raman gene probe and methods thereof

DOEpatents

Vo-Dinh, Tuan

1998-01-01

The subject invention disclosed herein is a new gene probe biosensor and methods thereof based on surface enhanced Raman scattering (SERS) label detection. The SER gene probe biosensor comprises a support means, a SER gene probe having at least one oligonucleotide strand labeled with at least one SERS label, and a SERS active substrate disposed on the support means and having at least one of the SER gene probes adsorbed thereon. Biotargets such as bacterial and viral DNA, RNA and PNA are detected using a SER gene probe via hybridization to oligonucleotide strands complementary to the SER gene probe. The support means supporting the SERS active substrate includes a fiberoptic probe, an array of fiberoptic probes for performance of multiple assays and a waveguide microsensor array with charge-coupled devices or photodiode arrays.

Surface enhanced Raman gene probe and methods thereof

DOEpatents

Vo-Dinh, T.

1998-02-24

The subject invention disclosed is a new gene probe biosensor and methods based on surface enhanced Raman scattering (SERS) label detection. The SER gene probe biosensor comprises a support means, a SER gene probe having at least one oligonucleotide strand labeled with at least one SERS label, and a SERS active substrate disposed on the support means and having at least one of the SER gene probes adsorbed thereon. Biotargets such as bacterial and viral DNA, RNA and PNA are detected using a SER gene probe via hybridization to oligonucleotide strands complementary to the SER gene probe. The support means includes a fiberoptic probe, an array of fiberoptic probes for performance of multiple assays and a waveguide microsensor array with charge-coupled devices or photodiode arrays. 18 figs.

Surface enhanced Raman gene probe and methods thereof

DOEpatents

Vo-Dinh, T.

1998-07-21

The subject invention disclosed is a new gene probe biosensor and methods based on surface enhanced Raman scattering (SERS) label detection. The SER gene probe biosensor comprises a support means, a SER gene probe having at least one oligonucleotide strand labeled with at least one SERS label, and a SERS active substrate disposed on the support means and having at least one of the SER gene probes adsorbed. Biotargets such as bacterial and viral DNA, RNA and PNA are detected using a SER gene probe via hybridization to oligonucleotide strands complementary to the SER gene probe. The support means supporting the SERS active substrate includes a fiberoptic probe, an array of fiberoptic probes for performance of multiple assays and a waveguide microsensor array with charge-coupled devices or photodiode arrays. 18 figs.

The Effect of Reading Duration on the Reliability and Validity of Middle School Students' ORF Performance

ERIC Educational Resources Information Center

Barth, Amy E.; Stuebing, Karla K.; Fletcher, Jack M.; Denton, Carolyn A.; Vaughn, Sharon; Francis, David

2014-01-01

We evaluated the technical adequacy of oral reading fluency (ORF) probes in which 1,472 middle school students with and without reading difficulties read fluency probes for 60 s versus reading the full passage. Results suggested that the reliability of 60-s probes (rs = 0.75) was not substantively different than full passage probes (rs = 0.77)…

Does the Effort of Processing Potential Incentives Influence the Adaption of Context Updating in Older Adults?

PubMed Central

Schmitt, Hannah; Kray, Jutta; Ferdinand, Nicola K.

2017-01-01

A number of aging studies suggest that older adults process positive and negative information differently. For instance, the socioemotional selectivity theory postulates that older adults preferably process positive information in service of emotional well-being (Reed and Carstensen, 2012). Moreover, recent research has started to investigate whether incentives like gains or losses can influence cognitive control in an ongoing task. In an earlier study (Schmitt et al., 2015), we examined whether incentive cues, indicating potential monetary gains, losses, or neutral outcomes for good performance in the following trial, would influence older adults’ ability to exert cognitive control. Cognitive control was measured in an AX-Continuous-Performance-Task (AX-CPT) in which participants had to select their responses to probe stimuli depending on a preceding context cue. In this study, we did not find support for a positivity effect in older adults, but both gains and losses led to enhanced context processing. As the trial-wise presentation mode may be too demanding on cognitive resources for such a bias to occur, the main goal of the present study was to examine whether motivational mindsets, induced by block-wise presentation of incentives, would result in a positivity effect. For this reason, we examined 17 older participants (65–76 years) in the AX-CPT using a block-wise presentation of incentive cues and compared them to 18 older adults (69–78 years) with the trial-wise presentation mode from our earlier study (Schmitt et al., 2015). Event-related potentials were recorded to the onset of the motivational cue and during the AX-CPT. Our results show that (a) older adults initially process cues signaling potential losses more strongly, but later during the AX-CPT invest more cognitive resources in preparatory processes like context updating in conditions with potential gains, and (b) block-wise and trial-wise presentation of incentive cues differentially influenced cognitive control. When incentives were presented block-wise, the above described valence effects were consistently found. In contrast, when incentives were presented trial-wise, the effects were mixed and salience as well as valence effects can be obtained. Hence, how positive and negative incentive cues influence cognitive control in older adults is dependent on demands of cue processing. PMID:29170649

Does the Effort of Processing Potential Incentives Influence the Adaption of Context Updating in Older Adults?

PubMed

Schmitt, Hannah; Kray, Jutta; Ferdinand, Nicola K

2017-01-01

A number of aging studies suggest that older adults process positive and negative information differently. For instance, the socioemotional selectivity theory postulates that older adults preferably process positive information in service of emotional well-being (Reed and Carstensen, 2012). Moreover, recent research has started to investigate whether incentives like gains or losses can influence cognitive control in an ongoing task. In an earlier study (Schmitt et al., 2015), we examined whether incentive cues, indicating potential monetary gains, losses, or neutral outcomes for good performance in the following trial, would influence older adults' ability to exert cognitive control. Cognitive control was measured in an AX-Continuous-Performance-Task (AX-CPT) in which participants had to select their responses to probe stimuli depending on a preceding context cue. In this study, we did not find support for a positivity effect in older adults, but both gains and losses led to enhanced context processing. As the trial-wise presentation mode may be too demanding on cognitive resources for such a bias to occur, the main goal of the present study was to examine whether motivational mindsets, induced by block-wise presentation of incentives, would result in a positivity effect. For this reason, we examined 17 older participants (65-76 years) in the AX-CPT using a block-wise presentation of incentive cues and compared them to 18 older adults (69-78 years) with the trial-wise presentation mode from our earlier study (Schmitt et al., 2015). Event-related potentials were recorded to the onset of the motivational cue and during the AX-CPT. Our results show that (a) older adults initially process cues signaling potential losses more strongly, but later during the AX-CPT invest more cognitive resources in preparatory processes like context updating in conditions with potential gains, and (b) block-wise and trial-wise presentation of incentive cues differentially influenced cognitive control. When incentives were presented block-wise, the above described valence effects were consistently found. In contrast, when incentives were presented trial-wise, the effects were mixed and salience as well as valence effects can be obtained. Hence, how positive and negative incentive cues influence cognitive control in older adults is dependent on demands of cue processing.

SONOlysis in prevention of Brain InfaRctions During Internal carotid Endarterectomy (SONOBIRDIE) trial - study protocol for a randomized controlled trial.

PubMed

Hrbáč, Tomáš; Netuka, David; Beneš, Vladimír; Nosáľ, Vladimír; Kešnerová, Petra; Tomek, Aleš; Fadrná, Táňa; Beneš, Vladimír; Fiedler, Jiří; Přibáň, Vladimír; Brozman, Miroslav; Langová, Kateřina; Herzig, Roman; Školoudík, David

2017-01-17

Carotid endarterectomy (CEA) is a beneficial procedure for selected patients with an internal carotid artery (ICA) stenosis. Surgical risk of CEA varies from between 2 and 15%. The aim of the study is to demonstrate the safety and effectiveness of sonolysis (continual transcranial Doppler monitoring, TCD) using a 2-MHz diagnostic probe with maximal diagnostic energy on the reduction of the incidence of stroke, transient ischemic attack (TIA) and brain infarction detected using magnetic resonance imaging (MRI) by the activation of the endogenous fibrinolytic system during CEA. Design: a multicenter, randomized, double-blind, sham-controlled trial. international, multicenter trial for patients with at least 70% symptomatic or asymptomatic ICA stenosis undergoing CEA. patients with symptomatic or asymptomatic ICA stenosis of at least 70% are candidates for CEA; a sufficient temporal bone window for TCD; aged 40-85 years, functionally independent; provision of signed informed consent. Randomization: consecutive patients will be assigned to the sonolysis or control (sham procedure) group by computer-generated 1:1 randomization. Prestudy calculations showed that a minimum of 704 patients in each group is needed to reach a significant difference with an alpha value of 0.05 (two-tailed) and a beta value of 0.8 assuming that 10% would be lost to follow-up or refuse to participate in the study (estimated 39 endpoints). the primary endpoint is the incidence of stroke or TIA during 30 days after CEA and the incidence of new ischemic lesions on brain MRI performed 24 h after CEA in the sonolysis and control groups. Secondary endpoints are occurrence of death, any stroke, or myocardial infarction within 30 days, changes in cognitive functions 1 year post procedure related to pretreatment scores, and number of new lesions and occurrence of new lesions ≥0.5 mL on post-procedural brain MRI. descriptive statistics and linear/logistic multiple regression models will be performed. Clinical relevance will be measured as relative risk reduction, absolute risk reduction and the number needed to treat. Reduction of the periprocedural complications of CEA using sonolysis as a widely available and cheap method may significantly increase the safety of CEA and extend the indication criteria for CEA. ClinicalTrials.gov, NCT02398734 . Registered on 20 March 2015.

Hyperdeactivation of the Default Mode Network in People With Schizophrenia When Focusing Attention in Space.

PubMed

Hahn, Britta; Harvey, Alexander N; Gold, James M; Fischer, Bernard A; Keller, William R; Ross, Thomas J; Stein, Elliot A

2016-09-01

When studying selective attention in people with schizophrenia (PSZ), a counterintuitive but replicated finding has been that PSZ display larger performance benefits than healthy control subjects (HCS) by cues that predicts the location of a target stimulus relative to non-predictive cues. Possible explanations are that PSZ hyperfocus attention in response to predictive cues, or that an inability to maintain a broad attentional window impairs performance when the cue is non-predictive. Over-recruitment of regions involved in top-down focusing of spatial attention in response to predictive cues would support the former possibility, and an inappropriate recruitment of these regions in response to non-predictive cues the latter. We probed regions of the dorsal attention network while PSZ (N = 20) and HCS (N = 20) performed a visuospatial attention task. A central cue either predicted at which of 4 peripheral locations a target signal would appear, or it gave no information about the target location. As observed previously, PSZ displayed a larger reaction time difference between predictive and non-predictive cue trials than HCS. Activity in frontoparietal and occipital regions was greater for predictive than non-predictive cues. This effect was almost identical between PSZ and HCS. There was no sign of over-recruitment when the cue was predictive, or of inappropriate recruitment when the cue was non-predictive. However, PSZ differed from HCS in their cue-dependent deactivation of the default mode network. Unexpectedly, PSZ displayed significantly greater deactivation than HCS in predictive cue trials, which may reflect a tendency to expend more processing resources when focusing attention in space. © The Author 2016. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Differential Acetylcholine Release in the Prefrontal Cortex and Hippocampus During Pavlovian Trace and Delay Conditioning

PubMed Central

Flesher, M. Melissa; Butt, Allen E.; Kinney-Hurd, Brandee L.

2011-01-01

Pavlovian trace conditioning critically depends on the medial prefrontal cortex (mPFC) and hippocampus (HPC), whereas delay conditioning does not depend on these brain structures. Given that the cholinergic basal forebrain system modulates activity in both the mPFC and HPC, it was reasoned that the level of acetylcholine (ACh) release in these regions would show distinct profiles during testing in trace and delay conditioning paradigms. To test this assumption, microdialysis probes were implanted unilaterally into the mPFC and HPC of rats that were pre-trained in appetitive trace and delay conditioning paradigms using different conditional stimuli in the two tasks. On the day of microdialysis testing, dialysate samples were collected during a quiet baseline interval before trials were initiated, and again during performance in separate blocks of trace and delay conditioning trials in each animal. ACh levels were quantified using high performance liquid chromatography and electrochemical detection techniques. Consistent with our hypothesis, results showed that ACh release in the mPFC was greater during trace conditioning than during delay conditioning. The level of ACh released during trace conditioning in the HPC was also greater than the levels observed during delay conditioning. While ACh efflux in both the mPFC and HPC selectively increased during trace conditioning, ACh levels in the mPFC during trace conditioning testing showed the greatest increases observed. These results demonstrate a dissociation in cholinergic activation of the mPFC and HPC during performance in trace but not delay appetitive conditioning, where this cholinergic activity may contribute to attentional mechanisms, adaptive response timing, or memory consolidation necessary for successful trace conditioning. PMID:21514394

Procedures for Behavioral Experiments in Head-Fixed Mice

PubMed Central

Guo, Zengcai V.; Hires, S. Andrew; Li, Nuo; O'Connor, Daniel H.; Komiyama, Takaki; Ophir, Eran; Huber, Daniel; Bonardi, Claudia; Morandell, Karin; Gutnisky, Diego; Peron, Simon; Xu, Ning-long; Cox, James; Svoboda, Karel

2014-01-01

The mouse is an increasingly prominent model for the analysis of mammalian neuronal circuits. Neural circuits ultimately have to be probed during behaviors that engage the circuits. Linking circuit dynamics to behavior requires precise control of sensory stimuli and measurement of body movements. Head-fixation has been used for behavioral research, particularly in non-human primates, to facilitate precise stimulus control, behavioral monitoring and neural recording. However, choice-based, perceptual decision tasks by head-fixed mice have only recently been introduced. Training mice relies on motivating mice using water restriction. Here we describe procedures for head-fixation, water restriction and behavioral training for head-fixed mice, with a focus on active, whisker-based tactile behaviors. In these experiments mice had restricted access to water (typically 1 ml/day). After ten days of water restriction, body weight stabilized at approximately 80% of initial weight. At that point mice were trained to discriminate sensory stimuli using operant conditioning. Head-fixed mice reported stimuli by licking in go/no-go tasks and also using a forced choice paradigm using a dual lickport. In some cases mice learned to discriminate sensory stimuli in a few trials within the first behavioral session. Delay epochs lasting a second or more were used to separate sensation (e.g. tactile exploration) and action (i.e. licking). Mice performed a variety of perceptual decision tasks with high performance for hundreds of trials per behavioral session. Up to four months of continuous water restriction showed no adverse health effects. Behavioral performance correlated with the degree of water restriction, supporting the importance of controlling access to water. These behavioral paradigms can be combined with cellular resolution imaging, random access photostimulation, and whole cell recordings. PMID:24520413

The NASA Performance Assessment Workstation: cognitive performance during head-down bed rest.

PubMed

Shehab, R L; Schlegel, R E; Schiflett, S G; Eddy, D R

1998-01-01

The NASA Performance Assessment Workstation was used to assess cognitive performance changes in eight males subjected to seventeen days of 6 degrees head-down bed rest. PAWS uses six performance tasks to assess directed and divided attention, spatial, mathematical, and memory skills, and tracking ability. Subjective scales assess overall fatigue and mood state. Subjects completed training trials, practice trials, bed rest trials, and recovery trials. The last eight practice trials and all bed rest trials were performed with subjects lying face-down on a gurney. In general, there was no apparent cumulative effect of bed rest. Following a short period of performance stabilization, a slight but steady trend of performance improvement was observed across all trials. For most tasks, this trend of performance improvement was enhanced during recovery. No statistically significant differences in performance were observed when comparing bed rest with the control period. Additionally, fatigue scores showed little change across all periods.

The NASA performance assessment workstation: Cognitive performance during head-down bed rest

NASA Astrophysics Data System (ADS)

Shehab, Randa L.; Schlegel, Robert E.; Schiflett, Samuel G.; Eddy, Douglas R.

The NASA Performance Assessment Workstation was used to assess cognitive performance changes in eight males subjected to seventeen days of 6 ° head-down bed rest. PAWS uses six performance tasks to assess directed and divided attention, spatial, mathematical, and memory skills, and tracking ability. Subjective scales assess overall fatigue and mood state. Subjects completed training trials, practice trials, bed rest trials, and recovery trials. The last eight practice trials and all bed rest trials were performed with subjects lying face-down on a gurney. In general, there was no apparent cumulative effect of bed rest. Following a short period of performance stabilization, a slight but steady trend of performance improvement was observed across all trials. For most tasks, this trend of performance improvement was enhanced during recovery. No statistically significant differences in performance were observed when comparing bed rest with the control period. Additionally, fatigue scores showed little change across all periods.

A revised design for microarray experiments to account for experimental noise and uncertainty of probe response.

PubMed

Pozhitkov, Alex E; Noble, Peter A; Bryk, Jarosław; Tautz, Diethard

2014-01-01

Although microarrays are analysis tools in biomedical research, they are known to yield noisy output that usually requires experimental confirmation. To tackle this problem, many studies have developed rules for optimizing probe design and devised complex statistical tools to analyze the output. However, less emphasis has been placed on systematically identifying the noise component as part of the experimental procedure. One source of noise is the variance in probe binding, which can be assessed by replicating array probes. The second source is poor probe performance, which can be assessed by calibrating the array based on a dilution series of target molecules. Using model experiments for copy number variation and gene expression measurements, we investigate here a revised design for microarray experiments that addresses both of these sources of variance. Two custom arrays were used to evaluate the revised design: one based on 25 mer probes from an Affymetrix design and the other based on 60 mer probes from an Agilent design. To assess experimental variance in probe binding, all probes were replicated ten times. To assess probe performance, the probes were calibrated using a dilution series of target molecules and the signal response was fitted to an adsorption model. We found that significant variance of the signal could be controlled by averaging across probes and removing probes that are nonresponsive or poorly responsive in the calibration experiment. Taking this into account, one can obtain a more reliable signal with the added option of obtaining absolute rather than relative measurements. The assessment of technical variance within the experiments, combined with the calibration of probes allows to remove poorly responding probes and yields more reliable signals for the remaining ones. Once an array is properly calibrated, absolute quantification of signals becomes straight forward, alleviating the need for normalization and reference hybridizations.

Clinical effects of probiotics containing Bacillus species on gingivitis: a pilot randomized controlled trial.

PubMed

Alkaya, B; Laleman, I; Keceli, S; Ozcelik, O; Cenk Haytac, M; Teughels, W

2017-06-01

Lactobacillus spp. and bifidobacteria are the most frequently used probiotics in oral health research. However, although probiotic effects have been suggested for other genera, such as bacilli, no trials are available to describe the effect of bacilli probiotics on gingivitis in humans. The aim of the present study was to evaluate the clinical effects of a bacilli-containing toothpaste, a mouthrinse and a toothbrush cleaner versus a placebo in patients with generalized gingivitis. In this double-blind placebo-controlled randomized clinical trial, nonsmoking, systemically healthy patients with generalized gingivitis were included. They used a placebo or an experimental probiotic Bacillus subtilis-, Bacillus megaterium- and Bacillus pumulus-containing toothpaste, mouthrinse and toothbrush cleaner for 8 wk. Primary outcome measures of interest were plaque and gingivitis index, and the secondary outcome measures were pocket probing depth and bleeding on probing. Twenty male and 20 female patients were randomized over the two groups. All participants could be included in the final analysis. Although plaque and gingivitis indices were significantly reduced after 8 wk, no intergroup differences could be found at any time point. Also, for the secondary outcome measure, intragroup but no intergroup differences could be detected. No harm or unintended effects were reported by the patients after using the study products. This study did not show any statistically significant differences between a placebo and a bacilli-containing toothpaste, mouthrinse and toothbrush cleaner on gingivitis parameters. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Maternal administration of melatonin prevents spatial learning and memory deficits induced by developmental ethanol and lead co-exposure.

PubMed

Soleimani, Elham; Goudarzi, Iran; Abrari, Kataneh; Lashkarbolouki, Taghi

2017-05-01

Melatonin is a radical scavenger with the ability to remove reactive oxidant species. There is report that co-exposure to lead and ethanol during developmental stages induces learning and memory deficits and oxidative stress. Here, we studied the effect of melatonin, with strong antioxidant properties, on memory deficits induced by lead and ethanol co-exposure and oxidative stress in hippocampus. Pregnant rats in lead and ethanol co-exposure group received lead acetate of 0.2% in distilled drinking water and ethanol (4g/kg) by oral gavages once daily from the 5th day of gestation until weaning. Rats received 10mg/kg melatonin by oral gavages. On postnatal days (PD) 30, rats trained with six trials per day for 6 consecutive days in the water maze. On day 37, a probe test was done and oxidative stress markers in the hippocampus were evaluated. Results demonstrated lead and ethanol co-exposed rats exhibited higher escape latency during training trials and reduced time spent in target quadrant, higher escape location latency in probe trial test and had significantly higher malondialdehyde (MDA) levels, significantly lower superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) activities in the hippocampus. Melatonin treatment could improve memory deficits, antioxidants activity and reduced MDA levels in the hippocampus. We conclude, co-exposure to lead and ethanol impair memory and melatonin can prevent from it by oxidative stress modulation. Copyright © 2017 Elsevier Inc. All rights reserved.

Introduction of argon beam coagulation functionality to robotic procedures using the ABC D-Flex probe: equivalency to an existing laparoscopic instrument

NASA Astrophysics Data System (ADS)

Merchel, Renée. A.; Barnes, Kelli S.; Taylor, Kenneth D.

2015-03-01

INTRODUCTION: The ABC® D-Flex Probe utilizes argon beam coagulation (ABC) technology to achieve hemostasis during minimally invasive surgery. A handle on the probe allows for integration with robotic surgical systems and introduces ABC to the robotic toolbox. To better understand the utility of D-Flex, this study compares the performance of the D-Flex probe to an existing ABC laparoscopic probe through ex vivo tissue analysis. METHODS: Comparisons were performed to determine the effect of four parameters: ABC device, tissue type, activation duration, and distance from tissue. Ten ABC D-Flex probes were used to create 30 burn samples for each comparison. Ex vivo bovine liver and porcine muscle were used as tissue models. The area and depth of each burn was measured using a light microscope. The resulting dimensional data was used to correlate tissue effect with each variable. RESULTS: D-Flex created burns which were smaller in surface area than the laparoscopic probe at all power levels. Additionally, D-Flex achieved thermal penetration levels equivalent to the laparoscopic probe. CONCLUSION: D-Flex implements a small 7F geometry which creates a more focused beam. When used with robotic precision, quick localized superficial hemostasis can be achieved with minimal collateral damage. Additionally, D-Flex achieved equivalent thermal penetration levels at lower power and argon flow-rate settings than the laparoscopic probe.

Deep influence of passive low energy consumption multi-storey residential building in cold region

NASA Astrophysics Data System (ADS)

Shuai, Zhang; Lihua, Zhao; Rong, Jin; Dong, Junyan

2018-02-01

The example of passive architecture demonstration building in Jilin Province, China, based on the practical experience of this project, the control index of passive and low energy consumption residential buildings in cold and passive buildings is referenced by reference to the German construction standard and the Chinese residence construction document, “passive ultra-low energy consumption green Building Technology Guide (Trial)”. The requirement of passive low energy residential buildings on the ground heat transfer coefficient limits is determined, and the performance requirements of passive residential buildings are discussed. This paper analyzes the requirement of the passive low energy residential building on the ground heat transfer coefficient limit, and probes into the influence factors of the ground thermal insulation of the passive low energy consumption residential building. The construction method of passive low energy consumption residential building is proposed.

Comparative Performance of Linear Multielectrode Probes and Single-Tip Electrodes for Intracortical Microstimulation and Single-Neuron Recording in Macaque Monkey

PubMed Central

Ferroni, Carolina G.; Maranesi, Monica; Livi, Alessandro; Lanzilotto, Marco; Bonini, Luca

2017-01-01

Intracortical microstimulation (ICMS) is one of the most widely employed techniques for providing causal evidence of the relationship between neuronal activity and specific motor, perceptual, or even cognitive functions. In recent years, several new types of linear multielectrode silicon probes have been developed, allowing researchers to sample neuronal activity at different depths along the same cortical site simultaneously and with high spatial precision. Nevertheless, silicon multielectrode probes have been rarely employed for ICMS studies and, more importantly, it is unknown whether and to what extent they can be used for combined recording and stimulation experiments. Here, we addressed these issues during both acute and chronic conditions. First, we compared the behavioral outcomes of ICMS delivered to the hand region of a monkey's motor cortex with multielectrode silicon probes, commercially available multisite stainless-steel probes and single-tip glass-coated tungsten microelectrodes. The results for all three of the probes were reliable and similar. Furthermore, we tested the impact of long-train ICMS delivered through chronically implanted silicon probes at different time intervals, from 1 to 198 days after ICMS sessions, showing that although the number of recorded neurons decreased over time, in line with previous studies, ICMS did not alter silicon probes' recording capabilities. These findings indicate that in ICMS experiments, the performance of linear multielectrode silicon probes is comparable to that of both single-tip and multielectrode stainless-steel probes, suggesting that the silicon probes can be successfully used for combined recording and stimulation studies in chronic conditions. PMID:29187815

Comparative Performance of Linear Multielectrode Probes and Single-Tip Electrodes for Intracortical Microstimulation and Single-Neuron Recording in Macaque Monkey.

PubMed

Ferroni, Carolina G; Maranesi, Monica; Livi, Alessandro; Lanzilotto, Marco; Bonini, Luca

2017-01-01

Intracortical microstimulation (ICMS) is one of the most widely employed techniques for providing causal evidence of the relationship between neuronal activity and specific motor, perceptual, or even cognitive functions. In recent years, several new types of linear multielectrode silicon probes have been developed, allowing researchers to sample neuronal activity at different depths along the same cortical site simultaneously and with high spatial precision. Nevertheless, silicon multielectrode probes have been rarely employed for ICMS studies and, more importantly, it is unknown whether and to what extent they can be used for combined recording and stimulation experiments. Here, we addressed these issues during both acute and chronic conditions. First, we compared the behavioral outcomes of ICMS delivered to the hand region of a monkey's motor cortex with multielectrode silicon probes, commercially available multisite stainless-steel probes and single-tip glass-coated tungsten microelectrodes. The results for all three of the probes were reliable and similar. Furthermore, we tested the impact of long-train ICMS delivered through chronically implanted silicon probes at different time intervals, from 1 to 198 days after ICMS sessions, showing that although the number of recorded neurons decreased over time, in line with previous studies, ICMS did not alter silicon probes' recording capabilities. These findings indicate that in ICMS experiments, the performance of linear multielectrode silicon probes is comparable to that of both single-tip and multielectrode stainless-steel probes, suggesting that the silicon probes can be successfully used for combined recording and stimulation studies in chronic conditions.

Reproducibility of the cutoff probe for the measurement of electron density

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

Kim, D. W.; Oh, W. Y.; You, S. J., E-mail: sjyou@cnu.ac.kr

2016-06-15

Since a plasma processing control based on plasma diagnostics attracted considerable attention in industry, the reproducibility of the diagnostics using in this application has become a great interest. Because the cutoff probe is one of the potential candidates for this application, knowing the reproducibility of the cutoff probe measurement becomes quit important in the cutoff probe application research. To test the reproducibility of the cutoff probe measurement, in this paper, a comparative study among the different cutoff probe measurements was performed. The comparative study revealed remarkable result: the cutoff probe has a great reproducibility for the electron density measurement, i.e.,more » there are little differences among measurements by different probes made by different experimenters. The discussion including the reason for the result was addressed via this paper by using a basic measurement principle of cutoff probe and a comparative experiment with Langmuir probe.« less

Influence of Donor on the Sensing Performance of a Series of Through-Bond Energy Transfer-Based Two-photon Fluorescent Cu(2+) Probes.

PubMed

Zhang, Yu-Jin; Wang, Xin; Zhou, Yong; Wang, Chuan-Kui

2016-07-01

Optical properties of a series of molecular two-photon fluorescent Cu(2+) probes containing the same acceptor (rhodamine group) are analyzed using time-dependent density functional theory in combination with analytical response theory. Special emphasis is placed on evolution of the probes' optical properties in the presence of Cu(2+) . In this study, the compound with naphthalene as the donor is shown to be excellent ratiometric fluorescent chemosensor, whereas the compound with quinoline derivative as the donor shows off/on-typed colorimetric fluorescent response. For the compound with naphthalimide derivative as the donor, changing the connection between the donor and acceptor can efficiently prevent the fluorescent quenching of the probe both in the absence and presence of Cu(2+) . The donor moiety and the connection between donor and acceptor are thus found to play dominant roles on sensing performance of these probes. Moreover, distributions of molecular orbitals involved in the excitation and emission of the probes are analyzed to explore responsive mechanism of the probes. The through-bond energy transfer process is theoretically demonstrated. Our results are used to elucidate the available experimental measurements. This work is helpful to understand the relationships of structure with optical properties for the studied probes. © 2016 The American Society of Photobiology.

Assembled Cantilever Fiber Touch Trigger Probe for Three-Dimensional Measurement of Microstructures

PubMed Central

Zou, Limin; Ni, He; Zhang, Peng; Ding, Xuemei

2017-01-01

In this paper, an assembled cantilever fiber touch trigger probe was developed for three-dimensional measurements of clear microstructures. The probe consists of a shaft assembled vertically to an optical fiber cantilever and a probing sphere located at the free end of the shaft. The laser is emitted from the free end of the fiber cantilever and converges on the photosensitive surface of the camera through the lens. The position shift of the light spot centroid was used to detect the performance of the optical fiber cantilever, which changed dramatically when the probing sphere touched the objects being measured. Experimental results indicated that the sensing system has sensitivities of 3.32 pixels/μm, 1.35 pixels/μm, and 7.38 pixels/μm in the x, y, and z directions, respectively, and resolutions of 10 nm, 30 nm, and 5 nm were achieved in the x, y, and z, respectively. An experiment on micro slit measurement was performed to verify the high aspect ratio measurement capability of the assembled cantilever fiber (ACF) probe and to calibrate the effective two-point diameter of the probing sphere. The two-point probe sphere diameter was found to be 174.634 μm with a standard uncertainly of 0.045 μm. PMID:29156602

Sharp-Tip Silver Nanowires Mounted on Cantilevers for High-Aspect-Ratio High-Resolution Imaging.

PubMed

Ma, Xuezhi; Zhu, Yangzhi; Kim, Sanggon; Liu, Qiushi; Byrley, Peter; Wei, Yang; Zhang, Jin; Jiang, Kaili; Fan, Shoushan; Yan, Ruoxue; Liu, Ming

2016-11-09

Despite many efforts to fabricate high-aspect-ratio atomic force microscopy (HAR-AFM) probes for high-fidelity, high-resolution topographical imaging of three-dimensional (3D) nanostructured surfaces, current HAR probes still suffer from unsatisfactory performance, low wear-resistivity, and extravagant prices. The primary objective of this work is to demonstrate a novel design of a high-resolution (HR) HAR AFM probe, which is fabricated through a reliable, cost-efficient benchtop process to precisely implant a single ultrasharp metallic nanowire on a standard AFM cantilever probe. The force-displacement curve indicated that the HAR-HR probe is robust against buckling and bending up to 150 nN. The probes were tested on polymer trenches, showing a much better image fidelity when compared with standard silicon tips. The lateral resolution, when scanning a rough metal thin film and single-walled carbon nanotubes (SW-CNTs), was found to be better than 8 nm. Finally, stable imaging quality in tapping mode was demonstrated for at least 15 continuous scans indicating high resistance to wear. These results demonstrate a reliable benchtop fabrication technique toward metallic HAR-HR AFM probes with performance parallel or exceeding that of commercial HAR probes, yet at a fraction of their cost.

Assembled Cantilever Fiber Touch Trigger Probe for Three-Dimensional Measurement of Microstructures.

PubMed

Zou, Limin; Ni, He; Zhang, Peng; Ding, Xuemei

2017-11-20

In this paper, an assembled cantilever fiber touch trigger probe was developed for three-dimensional measurements of clear microstructures. The probe consists of a shaft assembled vertically to an optical fiber cantilever and a probing sphere located at the free end of the shaft. The laser is emitted from the free end of the fiber cantilever and converges on the photosensitive surface of the camera through the lens. The position shift of the light spot centroid was used to detect the performance of the optical fiber cantilever, which changed dramatically when the probing sphere touched the objects being measured. Experimental results indicated that the sensing system has sensitivities of 3.32 pixels/μm, 1.35 pixels/μm, and 7.38 pixels/μm in the x, y, and z directions, respectively, and resolutions of 10 nm, 30 nm, and 5 nm were achieved in the x, y, and z, respectively. An experiment on micro slit measurement was performed to verify the high aspect ratio measurement capability of the assembled cantilever fiber (ACF) probe and to calibrate the effective two-point diameter of the probing sphere. The two-point probe sphere diameter was found to be 174.634 μm with a standard uncertainly of 0.045 μm.

Representing Color Ensembles.

PubMed

Chetverikov, Andrey; Campana, Gianluca; Kristjánsson, Árni

2017-10-01

Colors are rarely uniform, yet little is known about how people represent color distributions. We introduce a new method for studying color ensembles based on intertrial learning in visual search. Participants looked for an oddly colored diamond among diamonds with colors taken from either uniform or Gaussian color distributions. On test trials, the targets had various distances in feature space from the mean of the preceding distractor color distribution. Targets on test trials therefore served as probes into probabilistic representations of distractor colors. Test-trial response times revealed a striking similarity between the physical distribution of colors and their internal representations. The results demonstrate that the visual system represents color ensembles in a more detailed way than previously thought, coding not only mean and variance but, most surprisingly, the actual shape (uniform or Gaussian) of the distribution of colors in the environment.

Design and spacecraft-integration of RTGs for solar probe

NASA Technical Reports Server (NTRS)

Schock, A.; Noravian, H.; Or, T.; Sankarankandath, V.

1990-01-01

The design, analysis, and spacecraft integration of radioisotope thermoelectric generators (RTG) to power the Solar Probe under study at NASA JPL is described. The mission of the Solar Probe is to explore the solar corona by performing in situ measurements at up to four solar radii to the sun. Design constraints for the RTG are discussed. The chief challenge in the design and system integration of the Solar Probe's RTG is a heat rejection problem. Two RTG orientations, horizontal and oblique, are analyzed for effectiveness and results are summarized in chart form. A number of cooling strategies are also investigated, including heat-pipe and reflector-cooled options. A methodology and general computer code are presented for analyzing the performance of arbitrarily obstructed RTGs with both axial and circumferential temperature, voltage, and current variation. This methodology is applied to the specific example of the Solar Probe RTG obstructed by a semicylindrical reflector of 15-inch radius.

[Research progress of probe design software of oligonucleotide microarrays].

PubMed

Chen, Xi; Wu, Zaoquan; Liu, Zhengchun

2014-02-01

DNA microarray has become an essential medical genetic diagnostic tool for its high-throughput, miniaturization and automation. The design and selection of oligonucleotide probes are critical for preparing gene chips with high quality. Several sets of probe design software have been developed and are available to perform this work now. Every set of the software aims to different target sequences and shows different advantages and limitations. In this article, the research and development of these sets of software are reviewed in line with three main criteria, including specificity, sensitivity and melting temperature (Tm). In addition, based on the experimental results from literatures, these sets of software are classified according to their applications. This review will be helpful for users to choose an appropriate probe-design software. It will also reduce the costs of microarrays, improve the application efficiency of microarrays, and promote both the research and development (R&D) and commercialization of high-performance probe design software.

Evaluation of the effectiveness and efficiency of two stimulus prompt strategies with severely handicapped students.

PubMed Central

Steege, M W; Wacker, D P; McMahon, C M

1987-01-01

In this study we compared the effectiveness and efficiency of two treatment packages that used stimulus prompt sequences and task analyses for teaching community living skills to severely handicapped students. Four severely and multiply handicapped students were trained to perform four tasks: (a) making toast, (b) making popcorn, (c) operating a clothes dryer, and (d) operating a washing machine. Following baseline, each student was exposed to two types of training procedures, each involving a task analysis of the target behavior. Training Procedure 1 (Traditional) utilized a least-to-most restrictive prompt sequence. Training Procedure 2 (Prescriptive) utilized ongoing behavioral assessment data to identify discriminative stimuli. The assessment data were used to prescribe instructional prompts across successive training trials. Performance on the tasks was evaluated within a combination multiple baseline (across subjects) and probe (across tasks) design. Training conditions were counterbalanced across subjects and tasks. Results indicated that both training procedures were equally effective in increasing independent task acquisition for subjects on all tasks; however, the prescriptive procedure was the more efficient procedure. PMID:3667479

Effects of spatial training on transitive inference performance in humans and rhesus monkeys

PubMed Central

Gazes, Regina Paxton; Lazareva, Olga F.; Bergene, Clara N.; Hampton, Robert R.

2015-01-01

It is often suggested that transitive inference (TI; if A>B and B>C then A>C) involves mentally representing overlapping pairs of stimuli in a spatial series. However, there is little direct evidence to unequivocally determine the role of spatial representation in TI. We tested whether humans and rhesus monkeys use spatial representations in TI by training them to organize seven images in a vertical spatial array. Then, we presented subjects with a TI task using these same images. The implied TI order was either congruent or incongruent with the order of the trained spatial array. Humans in the congruent condition learned premise pairs more quickly, and were faster and more accurate in critical probe tests, suggesting that the spatial arrangement of images learned during spatial training influenced subsequent TI performance. Monkeys first trained in the congruent condition also showed higher test trial accuracy when the spatial and inferred orders were congruent. These results directly support the hypothesis that humans solve TI problems by spatial organization, and suggest that this cognitive mechanism for inference may have ancient evolutionary roots. PMID:25546105

[Evaluation of the efficacy of powered and manual toothbrushes in preventing oral diseases (Systematic review with meta-analysis)].

PubMed

Nagy, Pál; Kövér, Krisztián; Gera, István; Horváth, Attila

2016-03-01

The removal of dental plaque plays an essential role in the maintenance of oral health. Numerous powered and manual toothbrushes were manufactured to achieve this goal, but even up to this day different opinions and research results have been revealed to assess the priority of the mentioned devices. Comparison of powered and manual toothbrushes on the basis of periodontal parameters and safety. Electronic search of the databases of MEDLINE and EMBASE (until May 2014) was carried out with the help of keywords in order to find relevant trials. The inclusion criteria were as follows: randomised controlled clinical trials, adult population, the presence of at least 15 permanent teeth. Split-mouth trials and interventions carried out by dental professionals, were excluded. Primary outcomes were the changes of plaque and gingival indices, while secondary outcomes were probing pocket depth (PPD), safety and quality assessment. The effect-size of the interventions was expressed by the standardised mean difference (SMD) with 95% confidence interval (CI). Random-effects models were performed. Electronic search resulted in 173 hits. 21 trials with the total number of 1500 subjects were then eligible for the meta-analysis. Both toothbrushes were safe, without considerable side effects on soft or hard tissues. Powered toothbrushes seemed to be generally more effective in removing plaque (-9%), reducing gingivitis (-6%) and preventing calculus formation. The SMDs for plaque and gingival indices were -0,40 (95% Cl: -0,95 to -0,16) and -0,29 (95% Cl: -0,56 to -0,03) respectively, in favour of the powered devices. There was no significant difference in changes of PPD. By further dividing the powered toothbrushes according to their mode of action, the plaque removal effect of the rotation oscillation (plus three dimensional), side to side sonic and ultrasonic toothbrushes seemed to be significantly better, than their manual ones, while the counter oscillation and the ionic toothbrushes did not perform better. Quality assessment and sensitivity analysis revealed various types of bias up to a certain extent. Consequently, no trial was found to be eligible for the highest quality criteria. The investigated rotation oscillation and vibrating toothbrushes appeared to be statistically more effective than their manual counterparts, although there is little known about its clinical relevance. The advantage of the electric toothbrushes disappears in case of adequately instructed and motivated patients that highlights the importance of individualised oral hygiene education. The design of the trials shows high heterogeneity, therefore their clinical implications should be handled carefully.

How I do it: feasibility of a new ultrasound probe fixator to facilitate high quality stress echocardiography.

PubMed

Salden, O A E; van Everdingen, W M; Spee, R; Doevendans, P A; Cramer, M J

2018-03-27

Stress echocardiography (SE) has recently regained momentum as an important diagnostic tool for the assessment of both ischemic and non-ischemic heart disease. Performing SE during physical exercise is challenging due to a suboptimal patient position and vigorous movements of the patient's chest. This hampers a stable ultrasound position and reduces the diagnostic performance of SE. A stable ultrasound probe position would facilitate producing high quality images during continuous measurements. With Probefix (Usono, Eindhoven, The Netherlands), a newly developed tool to fixate the ultrasound probe to the patient's chest, stabilization of the probe during physical exercise is possible. The technique of SE with the Probefix and its' feasibility are evaluated in a small pilot study. Probefix fixates the ultrasound probe to the patient's chest, using two chest straps and a fixation device. The ultrasound probe position and angle may be altered with a relative high degree of freedom. We tested the Probefix for continuous echocardiographic imaging in 12 study subjects during supine and upright ergometer stress tests. One patient was unable to perform exercise and in two study subjects good quality images were not achieved. In the other patients (82%) a stable probe position was obtained, with subsequent good quality echocardiographic images during SE. We have demonstrated the feasibility of the Probefix support during ergometer tests in supine and upright positions and conclude that this external fixator may facilitate continuous monitoring of cardiac function in a group of patients.

Evaluation of a dual-probe real time PCR system for detection of mandarin in commercial orange juice.

PubMed

Pardo, Miguel Angel

2015-04-01

A dual-probe real time PCR assay, based on the simultaneous detection of two TaqMan® probes, was evaluated for the detection of mandarin in orange juice. A single conserved polymorphism, located at the 314 position of intron belongs to chloroplast trnL gene, was confirmed by sequencing in 30 mandarin, 28 orange cultivars and 13 hybrids. The assay was also successfully evaluated in a blind trial against analysing 60 samples from different industrial processes in different countries around the world. The detection limit of the assay was established in 1% presence of mandarin detectable in processed orange juice and with a 100% precision. The quantitative application of the assay on citrus mixtures was also investigated, pointing out that the number of chloroplast DNA copies is too variable for its possible use as quantitative analysis. This assay can be employed as a routine methodology to control the accidental mixing during industrial processes and to deter intentional fraud. Copyright © 2014 Elsevier Ltd. All rights reserved.

Measurement of dentin hypersensitivity with the Jay Sensitivity Sensor Probe and the Yeaple probe to compare relief from dentin hypersensitivity by dentifrices.

PubMed

Kakar, Ashish; Kakar, Kanupriya

2013-05-01

To compare relief from dentin hypersensitivity (DH) after use of dentifrices formulated with potassium nitrate or fluoride. For the study, DH evaluations were conducted with the Jay Sensitivity Sensor Probe (Jay Probe), a novel tactile hypersensitivity instrument, in conjunction with three other DH methods, i.e. Yeaple probe (tactile), air blast, and the Visual Analog Scale (VAS). Adults (n = 100) who presented two teeth with DH and met study criteria were enrolled for this double-blind, randomized, parallel, controlled clinical trial conducted in an outpatient setting. DH evaluations at baseline were conducted by the tactile, air blast, and VAS methods. Subjects were randomly assigned a dentifrice formulated with 5% potassium nitrate and 1,000 ppm fluoride (as sodium monofluorophosphate) (Colgate Sensitive toothpaste; Test) or a commercially available fluoride dentifrice with 1,000 ppm fluoride as sodium monofluorophosphate (Colgate Cibaca toothpaste; Negative control). Subjects were recalled for DH evaluations after 4 and 8 weeks of product use. 85 subjects completed the entire study with evaluable results. Both treatments resulted in significant reductions in DH from baseline to all recall visits. In comparison to the Negative control, subjects in the Test group demonstrated significantly greater reductions for all DH evaluations at both 4 and 8 weeks (P < 0.05). Average tactile DH scores at week 8 for the Test and Negative control groups were 36.25 and 15.24 with the Yeaple probe and 35 and 12.43 with the Jay probe. Correspondingly, subjects in the Test group demonstrated significantly greater reductions in air blast and VAS responses for DH than those in the Negative control group (P < 0.05).

Control of Working Memory in Rhesus Monkeys (Macaca mulatta)

PubMed Central

Tu, Hsiao-Wei; Hampton, Robert R.

2014-01-01

Cognitive control is critical for efficiently using the limited resources in working memory. It is well established that humans use rehearsal to increase the probability of remembering needed information, but little is known in nonhumans, with some studies reporting the absence of active control and others subject to alternative explanations. We trained monkeys in a visual matching-to-sample paradigm with a post-sample memory cue. Monkeys either saw a remember cue that predicted the occurrence of a matching test that required memory for the sample, or a forget cue that predicted a discrimination test that did not require memory of the sample. Infrequent probe trials on which monkeys were given tests of the type not cued on that trial were used to assess whether memory was under cognitive control. Our procedures controlled for reward expectation and for the surprising nature of the probes. Monkeys matched less accurately after forget cues, while discrimination accuracy was equivalent in the two cue conditions. We also tested monkeys with lists of two consecutive sample images that shared the same cue. Again, memory for expected memory tests was superior to that on unexpected tests. Together these results show that monkeys cognitively control their working memory. PMID:25436219

The recolonization hypothesis in a full-mouth or multiple-session treatment protocol: a blinded, randomized clinical trial.

PubMed

Zijnge, Vincent; Meijer, Henriette F; Lie, Mady-Ann; Tromp, Jan A H; Degener, John E; Harmsen, Hermie J M; Abbas, Frank

2010-06-01

To test recolonization of periodontal lesions after full-mouth scaling and root planing (FM-SRP) or multiple session-SRP (MS-SRP) in a randomized clinical trial and whether FM-SRP and MS-SRP result in different clinical outcomes. Thirty-nine subjects were randomly assigned to FM-SRP or MS-SRP groups. At baseline and after 3 months, probing pocket depth (PPD), plaque index (PlI) and bleeding on probing (BoP) were recorded. At baseline, immediately after treatment, after 1, 2, 7, 14 and 90 days, paper point samples from a single site from the maxillary right quadrant were collected for microbiological analysis of five putative pathogens by polymerase chain reaction. FM-SRP and MS-SRP resulted in significant reductions in PPD, BoP and PlI and the overall detection frequencies of the five species after 3 months without significant differences between treatments. Compared with MS-SRP, FM-SRP resulted in less recolonization of the five species, significantly for Treponema denticola, in the tested sites. FM-SRP and MS-SRP result in overall clinically and microbiologically comparable outcomes where recolonization of periodontal lesions may be better prevented by FM-SRP.

Monkeys show recognition without priming in a classification task

PubMed Central

Basile, Benjamin M.; Hampton, Robert R.

2012-01-01

Humans show visual perceptual priming by identifying degraded images faster and more accurately if they have seen the original images, while simultaneously failing to recognize the same images. Such priming is commonly thought, with little evidence, to be widely distributed phylogenetically. Following Brodbeck (1997), we trained rhesus monkeys (Macaca mulatta) to categorize photographs according to content (e.g., birds, fish, flowers, people). In probe trials, we tested whether monkeys were faster or more accurate at categorizing degraded versions of previously seen images (primed) than degraded versions of novel images (unprimed). Monkeys categorized reliably, but showed no benefit from having previously seen the images. This finding was robust across manipulations of image quality (color, grayscale, line drawings), type of image degradation (occlusion, blurring), levels of processing, and number of repetitions of the prime. By contrast, in probe matching-to-sample trials, monkeys recognized the primes, demonstrating that they remembered the primes and could discriminate them from other images in the same category under the conditions used to test for priming. Two experiments that replicated Brodbeck’s (1997) procedures also produced no evidence of priming. This inability to find priming in monkeys under perceptual conditions sufficient for recognition presents a puzzle. PMID:22975587

Online attention modification for social anxiety disorder: replication of a randomized controlled trial.

PubMed

Carleton, R Nicholas; Teale Sapach, Michelle J N; Oriet, Chris; LeBouthillier, Daniel M

2017-01-01

Social anxiety disorder (SAD) models posit vigilance for external social threat cues and exacerbated self-focused attention as key in disorder development and maintenance. Evidence indicates a modified dot-probe protocol may reduce symptoms of SAD; however, the efficacy when compared to a standard protocol and long-term maintenance of treatment gains remains unclear. Furthermore, the efficacy of such protocols on SAD-related constructs remains relatively unknown. The current investigation clarified these associations using a randomized control trial replicating and extending previous research. Participants with SAD (n = 113; 71% women) were randomized to complete a standard (i.e. control) or modified (i.e. active) dot-probe protocol consisting of 15-min sessions twice weekly for four weeks. Self-reported symptoms were measured at baseline, post-treatment, and 4-month and 8-month follow-ups. Hierarchical linear modeling indicated significant self-reported reductions in symptoms of social anxiety, fear of negative evaluation, trait anxiety, and depression, but no such reductions in fear of positive evaluation. Symptom changes did not differ based on condition and were maintained at 8-month follow-up. Attentional biases during the dot-probe task were not related to symptom change. Overall, our results replicate support for the efficacy of both protocols in reducing symptoms of SAD and specific related constructs, and suggest a role of exposure, expectancy, or practice effects, rather than attention modification, in effecting such reductions. The current results also support distinct relationships between fears of negative and positive evaluation and social anxiety. Further research focused on identifying the mechanisms of change in attention modification protocols appears warranted.

Validated surrogate endpoints needed for peri-implantitis.

PubMed

Lee, Dong Won

2011-01-01

Pubmed, Cochrane and Lilac databases, Google, Google Scholar, hand searching of websites of major dental journals. The reference list of five recently published systematic reviews on peri-implantitis treatment were also screened for potential studies. Randomised controlled trials and non-randomised studies in English, German, French, Spanish and Italian on peri-implantitis treatment in humans were included. Case series, case reports and cross sectional or non-therapy studies were excluded from the assessment of endpoints. No minimum follow up time was set for studies that were included. Data were extracted in duplicate by two reviewers and disagreements were resolved by consensus. True endpoints for peri-implantitis treatment were considered only if they provided evidence of tangible benefit to the patient. The outcome variables regarded as true endpoints were implant failure, aesthetic assessment and variables related to quality of life, but these were only considered if they were clearly identified as an objective of the research, not as an outcome of treatment. Surrogate endpoints were considered as those measurements of clinical outcomes such as probing pocket depth and clinical attachment level. Fourteen studies were included in this review with data on implant failure presented solely as consequence of peri-implantitis therapy. No true endpoint was described for any study on peri-implantitis. Mean pocket probing depth, clinical attachment level and bleeding on probing were the three surrogate endpoints cited most often in the literature. All endpoints used in the trials reviewed are surrogates of clinical events, such as implant failure. Clinical surrogate endpoints should be validated to assess the real effect of these measures on true endpoints.

Common and differential electrophysiological mechanisms underlying semantic object memory retrieval probed by features presented in different stimulus types.

PubMed

Chiang, Hsueh-Sheng; Eroh, Justin; Spence, Jeffrey S; Motes, Michael A; Maguire, Mandy J; Krawczyk, Daniel C; Brier, Matthew R; Hart, John; Kraut, Michael A

2016-08-01

How the brain combines the neural representations of features that comprise an object in order to activate a coherent object memory is poorly understood, especially when the features are presented in different modalities (visual vs. auditory) and domains (verbal vs. nonverbal). We examined this question using three versions of a modified Semantic Object Retrieval Test, where object memory was probed by a feature presented as a written word, a spoken word, or a picture, followed by a second feature always presented as a visual word. Participants indicated whether each feature pair elicited retrieval of the memory of a particular object. Sixteen subjects completed one of the three versions (N=48 in total) while their EEG were recorded simultaneously. We analyzed EEG data in four separate frequency bands (delta: 1-4Hz, theta: 4-7Hz; alpha: 8-12Hz; beta: 13-19Hz) using a multivariate data-driven approach. We found that alpha power time-locked to response was modulated by both cross-modality (visual vs. auditory) and cross-domain (verbal vs. nonverbal) probing of semantic object memory. In addition, retrieval trials showed greater changes in all frequency bands compared to non-retrieval trials across all stimulus types in both response-locked and stimulus-locked analyses, suggesting dissociable neural subcomponents involved in binding object features to retrieve a memory. We conclude that these findings support both modality/domain-dependent and modality/domain-independent mechanisms during semantic object memory retrieval. Copyright © 2016 Elsevier B.V. All rights reserved.

Detection of knockdown resistance (kdr) mutations in Anopheles gambiae: a comparison of two new high-throughput assays with existing methods

PubMed Central

Bass, Chris; Nikou, Dimitra; Donnelly, Martin J; Williamson, Martin S; Ranson, Hilary; Ball, Amanda; Vontas, John; Field, Linda M

2007-01-01

Background Knockdown resistance (kdr) is a well-characterized mechanism of resistance to pyrethroid insecticides in many insect species and is caused by point mutations of the pyrethroid target site the para-type sodium channel. The presence of kdr mutations in Anopheles gambiae, the most important malaria vector in Africa, has been monitored using a variety of molecular techniques. However, there are few reports comparing the performance of these different assays. In this study, two new high-throughput assays were developed and compared with four established techniques. Methods Fluorescence-based assays based on 1) TaqMan probes and 2) high resolution melt (HRM) analysis were developed to detect kdr alleles in An. gambiae. Four previously reported techniques for kdr detection, Allele Specific Polymerase Chain Reaction (AS-PCR), Heated Oligonucleotide Ligation Assay (HOLA), Sequence Specific Oligonucleotide Probe – Enzyme-Linked ImmunoSorbent Assay (SSOP-ELISA) and PCR-Dot Blot were also optimized. The sensitivity and specificity of all six assays was then compared in a blind genotyping trial of 96 single insect samples that included a variety of kdr genotypes and African Anopheline species. The relative merits of each assay was assessed based on the performance in the genotyping trial, the length/difficulty of each protocol, cost (both capital outlay and consumable cost), and safety (requirement for hazardous chemicals). Results The real-time TaqMan assay was both the most sensitive (with the lowest number of failed reactions) and the most specific (with the lowest number of incorrect scores). Adapting the TaqMan assay to use a PCR machine and endpoint measurement with a fluorimeter showed a slight reduction in sensitivity and specificity. HRM initially gave promising results but was more sensitive to both DNA quality and quantity and consequently showed a higher rate of failure and incorrect scores. The sensitivity and specificity of AS-PCR, SSOP-ELISA, PCR Dot Blot and HOLA was fairly similar with a small number of failures and incorrect scores. Conclusion The results of blind genotyping trials of each assay indicate that where maximum sensitivity and specificity are required the TaqMan real-time assay is the preferred method. However, the cost of this assay, particularly in terms of initial capital outlay, is higher than that of some of the other methods. TaqMan assays using a PCR machine and fluorimeter are nearly as sensitive as real-time assays and provide a cost saving in capital expenditure. If price is a primary factor in assay choice then the AS-PCR, SSOP-ELISA, and HOLA are all reasonable alternatives with the SSOP-ELISA approach having the highest throughput. PMID:17697325

Cognitive control of familiarity: directed forgetting reduces proactive interference in working memory.

PubMed

Festini, Sara B; Reuter-Lorenz, Patricia A

2014-03-01

Proactive interference (PI) occurs when previously learned information interferes with new learning. In a working memory task, PI induces longer response times and more errors to recent negative probes than to new probes, presumably because the recent probe's familiarity invites a "yes" response. Warnings, longer intertrial intervals, and the increased contextual salience of the probes can reduce but not eliminate PI, suggesting that cognitive control over PI is limited. Here we tested whether control exerted in the form of intentional forgetting performed during working memory can reduce the magnitude of PI. In two experiments, participants performed a working memory task with directed-forgetting instructions and the occasional presentation of recent probes. Surprise long-term memory testing indicated better memory for to-be-remembered than for to-be-forgotten items, documenting the classic directed-forgetting effect. Critically, in working memory, PI was virtually eliminated for recent probes from prior to-be-forgotten lists, as compared to recent probes from prior to-be-remembered lists. Thus cognitive control, when executed via directed forgetting, can reduce the adverse and otherwise persistent interference from familiarity, an effect that we attribute to attenuated memory representations of the to-be-forgotten items.

Energy Donor Effect on the Sensing Performance for a Series of FRET-Based Two-Photon Fluorescent Hg2+ Probes.

PubMed

Zhang, Yujin; Hu, Wei

2017-01-25

Nonlinear optical properties of a series of newly-synthesized molecular fluorescent probes for Hg 2+ containing the same acceptor (rhodamine group) are analyzed by using time-dependent density functional theory in combination with analytical response theory. Special emphasis is placed on evolution of the probes' optical properties in the absence and presence of Hg 2+ . These compounds show drastic changes in their photoabsorption and photoemission properties when they react with Hg 2+ , indicating that they are excellent candidates for ratiometric and colorimetric fluorescent chemosensors. Most importantly, the energy donor moiety is found to play a dominant role in sensing performance of these probes. Two-photon absorption cross sections of the compounds are increased with the presence of Hg 2+ , which theoretically suggests the possibility of the probes to be two-photon fluorescent Hg 2+ sensors. Moreover, analysis of molecular orbitals is presented to explore responsive mechanism of the probes, where the fluorescence resonant energy transfer process is theoretically demonstrated. Our results elucidate the available experimental measurements. This work provides guidance for designing efficient two-photon fluorescent probes that are geared towards biological and chemical applications.

A new OTDR based on probe frequency multiplexing

NASA Astrophysics Data System (ADS)

Lu, Lidong; Liang, Yun; Li, Binglin; Guo, Jinghong; Zhang, Xuping

2013-12-01

Two signal multiplexing methods are proposed and experimentally demonstrated in optical time domain reflectometry (OTDR) for fault location of optical fiber transmission line to obtain high measurement efficiency. Probe signal multiplexing is individually obtained by phase modulation for generation of multi-frequency and time sequential frequency probe pulses. The backscattered Rayleigh light of the multiplexing probe signals is transferred to corresponding heterodyne intermediate frequency (IF) through heterodyning with the single frequency local oscillator (LO). Then the IFs are simultaneously acquired by use of a data acquisition card (DAQ) with sampling rate of 100Msps, and the obtained data are processed by digital band pass filtering (BPF), digital down conversion (DDC) and digital low pass filtering (BPF) procedure. For each probe frequency of the detected signals, the extraction of the time domain reflecting signal power is performed by parallel computing method. For a comprehensive performance comparison with conventional coherent OTDR on the probe frequency multiplexing methods, the potential for enhancement of dynamic range, spatial resolution and measurement time are analyzed and discussed. Experimental results show that by use of the probe frequency multiplexing method, the measurement efficiency of coherent OTDR can be enhanced by nearly 40 times.

Comparative measurements of plasma potential with ball-pen and Langmuir probe in low-temperature magnetized plasma

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

Zanáška, M.; Kudrna, P.; Tichý, M.

The ball-pen probe (BPP) is used for direct plasma potential measurements in magnetized plasma. The probe can adjust the ratio of the electron and ion saturation currents I{sub sat}{sup −}/I{sub sat}{sup +} to be close to one and therefore its I-V characteristic becomes nearly symmetric. If this is achieved, the floating potential of the BPP is close to the plasma potential. Because of its rather simple construction, it offers an attractive probe for measurements in magnetized plasma. Comparative measurements of plasma potential by BPPs of different dimensions as well as one Langmuir probe (LP) in an argon discharge plasma ofmore » a cylindrical magnetron were performed at various experimental conditions. An additional comparison by an emissive probe was also performed. All these types of probes provide similar values of plasma potential in a wide range of plasma parameters. Our results for three different BPP dimensions indicate that the BPP can be operated in a cylindrical magnetron DC argon discharge if the value of the ratio of the magnetic field and neutral gas pressure, B/p, is greater than approximately 10 mT/Pa.« less

Possible concepts for an in situ Saturn probe mission

NASA Astrophysics Data System (ADS)

Coustenis, Athena; Lebreton, Jean-Pierre; Mousis, Olivier; Atkinson, David H.; Lunine, Jonathan I.; Reh, Kim R.; Fletcher, Leigh N.; Simon-Miller, Amy A.; Atreya, Sushil; Brinckerhoff, William B.; Cavalie, Thibault; Colaprete, Anthony; Gautier, Daniel; Guillot, Tristan; Mahaffy, Paul R.; Marty, Bernard; Morse, Andy; Sims, Jon; Spilker, Tom; Spilker, Linda

2014-05-01

In situ exploration of Saturn's atmosphere would bring insights in two broad themes: the formation history of our solar system and the processes at play in planetary atmospheres. The science case for in situ measurements at Saturn are developed in [1] and two companion abstracts (see Mousis et al., and Atkinson et al.). They are summarized here. Measurements of Saturn's bulk chemical and isotopic composition would place important constraints on the volatile reservoirs in the protosolar nebula and hence on the formation mechanisms. An in situ probe, penetrating from the upper atmosphere (μbar level) into the convective weather layer to a minimum depth of 10 bar, would also contribute to our knowledge of Saturn's atmospheric structure, dynamics, composition, chemistry and cloud-forming processes. Different mission architectures are envisaged, all based on an entry probe that would descend through Saturn's stratosphere and troposphere under parachute down to a minimum of 10 bars [1]. Future studies will focus on the trade-offs between science return and the added design complexity of a probe that could operate at pressures larger than 10 bars. Accelerometry measurements may also be performed during the entry phase in the higher part of the stratosphere prior to starting measurements under parachute. A carrier system would be required to deliver the probe along its interplanetary trajectory to the desired atmospheric entry point at Saturn. The entry site would be carefully selected. Three possible mission configurations are currently under study (with different risk/cost trades): • Configuration 1: Probe + Carrier. After probe delivery, the carrier would follow its path and be destroyed during atmospheric entry, but could perform pre-entry science. The carrier would not be used as a radio relay, but the probe would transmit its data to the ground system via a direct-to-Earth (DTE) RF link; • Configuration 2: Probe + Carrier/Relay. The probe would detach from the carrier several months prior to probe entry. The carrier trajectory would be designed to enable probe data relay during over-flight as well as performing approach and flyby science; • Configuration 3: Probe + Orbiter (similar to the Galileo Orbiter/Probe). As for Configuration 2, but after probe relay during over-flight, the orbiter would transition to a Saturn orbit and continue to perform orbital science. In all three configurations, the carrier/orbiter would be equipped with a combination of solar panels, secondary batteries and possibly a set of primary batteries for phases that require a high power demand, for example during the probe entry phase. Nuclear power would be considered for the carrier or the orbiter only if available solar power technology would be found to be infeasible. To match the measurement requirements, a model payload could include a mass spectrometer, a tunable laser system, a helium abundance detector, an atmospheric structure instrument, accelerometers, temperature sensors, pressure profile, Doppler wind and nephelometer instruments, etc. Such a mission would greatly benefit from strong international collaborations. References [1] Mousis et al. 2014, "Scientific Rationale of Saturn's in situ exploration", submitted to PSS (and references therein).

Atmospheric Probe Model: Construction and Wind Tunnel Tests

NASA Technical Reports Server (NTRS)

Vogel, Jerald M.

1998-01-01

The material contained in this document represents a summary of the results of a low speed wind tunnel test program to determine the performance of an atmospheric probe at low speed. The probe configuration tested consists of a 2/3 scale model constructed from a combination of hard maple wood and aluminum stock. The model design includes approximately 130 surface static pressure taps. Additional hardware incorporated in the baseline model provides a mechanism for simulating external and internal trailing edge split flaps for probe flow control. Test matrix parameters include probe side slip angle, external/internal split flap deflection angle, and trip strip applications. Test output database includes surface pressure distributions on both inner and outer annular wings and probe center line velocity distributions from forward probe to aft probe locations.

Single-Cell Resolution Imaging of Retinal Ganglion Cell Apoptosis In Vivo Using a Cell-Penetrating Caspase-Activatable Peptide Probe

PubMed Central

Qiu, Xudong; Johnson, James R.; Wilson, Bradley S.; Gammon, Seth T.; Piwnica-Worms, David; Barnett, Edward M.

2014-01-01

Peptide probes for imaging retinal ganglion cell (RGC) apoptosis consist of a cell-penetrating peptide targeting moiety and a fluorophore-quencher pair flanking an effector caspase consensus sequence. Using ex vivo fluorescence imaging, we previously validated the capacity of these probes to identify apoptotic RGCs in cell culture and in an in vivo rat model of N-methyl- D-aspartate (NMDA)-induced neurotoxicity. Herein, using TcapQ488, a new probe designed and synthesized for compatibility with clinically-relevant imaging instruments, and real time imaging of a live rat RGC degeneration model, we fully characterized time- and dose-dependent probe activation, signal-to-noise ratios, and probe safety profiles in vivo. Adult rats received intravitreal injections of four NMDA concentrations followed by varying TcapQ488 doses. Fluorescence fundus imaging was performed sequentially in vivo using a confocal scanning laser ophthalmoscope and individual RGCs displaying activated probe were counted and analyzed. Rats also underwent electroretinography following intravitreal injection of probe. In vivo fluorescence fundus imaging revealed distinct single-cell probe activation as an indicator of RGC apoptosis induced by intravitreal NMDA injection that corresponded to the identical cells observed in retinal flat mounts of the same eye. Peak activation of probe in vivo was detected 12 hours post probe injection. Detectable fluorescent RGCs increased with increasing NMDA concentration; sensitivity of detection generally increased with increasing TcapQ488 dose until saturating at 0.387 nmol. Electroretinography following intravitreal injections of TcapQ488 showed no significant difference compared with control injections. We optimized the signal-to-noise ratio of a caspase-activatable cell penetrating peptide probe for quantitative non-invasive detection of RGC apoptosis in vivo. Full characterization of probe performance in this setting creates an important in vivo imaging standard for functional evaluation of future probe analogues and provides a basis for extending this strategy into glaucoma-specific animal models. PMID:24586415

Impairments in multisensory processing are not universal to the autism spectrum: no evidence for crossmodal priming deficits in Asperger syndrome.

PubMed

David, Nicole; R Schneider, Till; Vogeley, Kai; Engel, Andreas K

2011-10-01

Individuals suffering from autism spectrum disorders (ASD) often show a tendency for detail- or feature-based perception (also referred to as "local processing bias") instead of more holistic stimulus processing typical for unaffected people. This local processing bias has been demonstrated for the visual and auditory domains and there is evidence that multisensory processing may also be affected in ASD. Most multisensory processing paradigms used social-communicative stimuli, such as human speech or faces, probing the processing of simultaneously occuring sensory signals. Multisensory processing, however, is not limited to simultaneous stimulation. In this study, we investigated whether multisensory processing deficits in ASD persist when semantically complex but nonsocial stimuli are presented in succession. Fifteen adult individuals with Asperger syndrome and 15 control persons participated in a visual-audio priming task, which required the classification of sounds that were either primed by semantically congruent or incongruent preceding pictures of objects. As expected, performance on congruent trials was faster and more accurate compared with incongruent trials (crossmodal priming effect). The Asperger group, however, did not differ significantly from the control group. Our results do not support a general multisensory processing deficit, which is universal to the entire autism spectrum. Copyright © 2011, International Society for Autism Research, Wiley-Liss, Inc.

Dose-response effect of black maca (Lepidium meyenii) in mice with memory impairment induced by ethanol.

PubMed

Rubio, Julio; Yucra, Sandra; Gasco, Manuel; Gonzales, Gustavo F

2011-10-01

Previous studies have shown that black variety of maca has beneficial effects on learning and memory in experimental animal models. The present study aimed to determine whether the hydroalcoholic extract of black maca (BM) showed a dose-response effect in mice treated with ethanol 20% (EtOH) as a model of memory impairment. Mice were divided in the following groups: control, EtOH, ascorbic acid (AA) and 0.125, 0.25, 0.50 and 1.00 g/kg of BM plus EtOH. All treatments were orally administered for 28 days. Open field test was performed to determine locomotor activity and water Morris maze was done to determine spatial memory. Also, total polyphenol content in the hydroalcoholic extract of BM was determined (0.65 g pyrogallol/100 g). Mice treated with EtOH took more time to find the hidden platform than control during escape acquisition trials; meanwhile, AA and BM reversed the effect of EtOH. In addition, AA and BM ameliorated the deleterious effect of EtOH during the probe trial. Correlation analyses showed that the effect of BM a dose-dependent behavior. Finally, BM improved experimental memory impairment induced by ethanol in a dose-response manner due, in part, to its content of polyphenolic compounds.

Early handling effect on female rat spatial and non-spatial learning and memory.

PubMed

Plescia, Fulvio; Marino, Rosa A M; Navarra, Michele; Gambino, Giuditta; Brancato, Anna; Sardo, Pierangelo; Cannizzaro, Carla

2014-03-01

This study aims at providing an insight into early handling procedures on learning and memory performance in adult female rats. Early handling procedures were started on post-natal day 2 until 21, and consisted in 15 min, daily separations of the dams from their litters. Assessment of declarative memory was carried out in the novel-object recognition task; spatial learning, reference- and working memory were evaluated in the Morris water maze (MWM). Our results indicate that early handling induced an enhancement in: (1) declarative memory, in the object recognition task, both at 1h and 24h intervals; (2) reference memory in the probe test and working memory and behavioral flexibility in the "single-trial and four-trial place learning paradigm" of the MWM. Short-term separation by increasing maternal care causes a dampening in HPA axis response in the pups. A modulated activation of the stress response may help to protect brain structures, involved in cognitive function. In conclusion, this study shows the long-term effects of a brief maternal separation in enhancing object recognition-, spatial reference- and working memory in female rats, remarking the impact of early environmental experiences and the consequent maternal care on the behavioral adaptive mechanisms in adulthood. Copyright © 2013 Elsevier B.V. All rights reserved.

Using mental visual imagery to improve autobiographical memory and episodic future thinking in relapsing-remitting multiple sclerosis patients: A randomised-controlled trial study.

PubMed

Ernst, Alexandra; Blanc, Frédéric; De Seze, Jérôme; Manning, Liliann

2015-01-01

The co-occurrence of autobiographical memory (AM) and episodic future thinking (EFT) impairment has been documented in relapsing-remitting multiple sclerosis (RR-MS) patients. On these bases, we aimed at probing the efficacy of a mental visual imagery (MVI)-based facilitation programme on AM and EFT functioning in the context of a randomised-controlled trial study in RR-MS patients. Using the Autobiographical Interview (AI), 40 patients presenting with an AM/EFT impairment were randomly assigned in three groups: (i) the experimental (n = 17), who followed the MVI programme, (ii) the verbal control (n = 10), who followed a sham verbal programme, and (iii) the stability groups (n = 13), who underwent the AM/EFT test twice, with no intervention in between. AI's second assessment scores showed a significant improvement of AM and EFT performance only for the experimental group, with a long-term robustness of treatment benefits. The control and stability groups' results ruled out nursing and test learning effects as explanations of AM/EFT improvement. These benefits were corroborated by the patients' comments, which indicated an effective MVI strategy transfer to daily life. Our results suggest that the MVI programme tackles a common cognitive process of scene construction present in AM and EFT.

Transitioning to future air traffic management: effects of imperfect automation on controller attention and performance.

PubMed

Rovira, Ericka; Parasuraman, Raja

2010-06-01

This study examined whether benefits of conflict probe automation would occur in a future air traffic scenario in which air traffic service providers (ATSPs) are not directly responsible for freely maneuvering aircraft but are controlling other nonequipped aircraft (mixed-equipage environment). The objective was to examine how the type of automation imperfection (miss vs. false alarm) affects ATSP performance and attention allocation. Research has shown that the type of automation imperfection leads to differential human performance costs. Participating in four 30-min scenarios were 12 full-performance-level ATSPs. Dependent variables included conflict detection and resolution performance, eye movements, and subjective ratings of trust and self confidence. ATSPs detected conflicts faster and more accurately with reliable automation, as compared with manual performance. When the conflict probe automation was unreliable, conflict detection performance declined with both miss (25% conflicts detected) and false alarm automation (50% conflicts detected). When the primary task of conflict detection was automated, even highly reliable yet imperfect automation (miss or false alarm) resulted in serious negative effects on operator performance. The further in advance that conflict probe automation predicts a conflict, the greater the uncertainty of prediction; thus, designers should provide users with feedback on the state of the automation or other tools that allow for inspection and analysis of the data underlying the conflict probe algorithm.

0.4 Microns Spatial Resolution with 1 GHz (lambda = 30 cm) Evanescent Microwave Probe

NASA Technical Reports Server (NTRS)

Tabib-Azar, M.; Su, D.-P.; Pohar, A.; LeClair, S. R.; Ponchak, George E.

1999-01-01

In this article we describe evanescent field imaging of material nonuniformities with a record resolution of 0.4 microns at 1 GHz (lambda(sub g)/750000), using a resonant stripline scanning microwave probe. A chemically etched tip is used as a point-like evanescent field emitter and a probe-sample distance modulation is employed to improve the signal-to-noise ratio. Images obtained by evanescent microwave probe, by optical microscope, and by scanning tunneling microscope are presented for comparison. Probe was calibrated to perform quantitative conductivity measurements. The principal factors affecting the ultimate resolution of evanescent microwave probe are also discussed.

The resonant radio-frequency magnetic probe tuned by coaxial cable.

PubMed

Sun, B; Huo, W G; Ding, Z F

2012-08-01

In this paper, the resonant rf magnetic probe is upgraded by replacing the rotary capacitor in the old version with the series-connected coaxial cable. The numerical calculation and the measurement with the prototype probe show that the rf magnetic probe can achieve resonance at a middle length of the series-connected coaxial cable. The good electrical symmetry of the new rf magnetic probe is ensured by both the identity of series-connected coaxial cables and the new structure of the primary winding. Practical measurements conduced on an rf inductively coupled plasma source demonstrate that performances of the new rf magnetic probe are good.

Multi-hole pressure probes to air data system for subsonic small-scale air vehicles

NASA Astrophysics Data System (ADS)

Shevchenko, A. M.; Berezin, D. R.; Puzirev, L. N.; Tarasov, A. Z.; Kharitonov, A. M.; Shmakov, A. S.

2016-10-01

A brief review of research performed to develop multi-hole probes to measure of aerodynamic angles, dynamic head, and static pressure of a flying vehicle. The basis of these works is the application a well-known classical multi-hole pressure probe technique of measuring of a 3D flow to use in the air data system. Two multi-hole pressure probes with spherical and hemispherical head to air-data system for subsonic small-scale vehicles have been developed. A simple analytical probe model with separation of variables is proposed. The probes were calibrated in the wind tunnel, one of them is in-flight tested.

Connective tissue graft vs. emdogain: A new approach to compare the outcomes.

PubMed

Sayar, Ferena; Akhundi, Nasrin; Gholami, Sanaz

2013-01-01

The aim of this clinical trial study was to clinically evaluate the use of enamel matrix protein derivative combined with the coronally positioned flap to treat gingival recession compared to the subepithelial connective tissue graft by a new method to obtain denuded root surface area. Thirteen patients, each with two or more similar bilateral Miller class I or II gingival recession (40 recessions) were randomly assigned to the test (enamel matrix protein derivative + coronally positioned flap) or control group (subepithelial connective tissue graft). Recession depth, width, probing depth, keratinized gingival, and plaque index were recorded at baseline and at one, three, and six months after treatment. A stent was used to measure the denuded root surface area at each examination session. Results were analyzed using Kolmogorov-Smirnov, Wilcoxon, Friedman, paired-sample t test. The average percentages of root coverage for control and test groups were 63.3% and 55%, respectively. Both groups showed significant keratinized gingival increase (P < 0.05). Recession depth decreased significantly in both groups. Root surface area was improved significantly from baseline with no significant difference between the two study groups (P > 0.05). The results of Friedman test were significant for clinical indices (P < 0.05), except for probing depth in control group (P = 0.166). Enamel matrix protein derivative showed the same results as subepithelial connective tissue graft with relatively easy procedure to perform and low patient morbidity.

Elemental-sensitive Detection of the Chemistry in Batteries through Soft X-ray Absorption Spectroscopy and Resonant Inelastic X-ray Scattering.

PubMed

Wu, Jinpeng; Sallis, Shawn; Qiao, Ruimin; Li, Qinghao; Zhuo, Zengqing; Dai, Kehua; Guo, Zixuan; Yang, Wanli

2018-04-17

Energy storage has become more and more a limiting factor of today's sustainable energy applications, including electric vehicles and green electric grid based on volatile solar and wind sources. The pressing demand of developing high-performance electrochemical energy storage solutions, i.e., batteries, relies on both fundamental understanding and practical developments from both the academy and industry. The formidable challenge of developing successful battery technology stems from the different requirements for different energy-storage applications. Energy density, power, stability, safety, and cost parameters all have to be balanced in batteries to meet the requirements of different applications. Therefore, multiple battery technologies based on different materials and mechanisms need to be developed and optimized. Incisive tools that could directly probe the chemical reactions in various battery materials are becoming critical to advance the field beyond its conventional trial-and-error approach. Here, we present detailed protocols for soft X-ray absorption spectroscopy (sXAS), soft X-ray emission spectroscopy (sXES), and resonant inelastic X-ray scattering (RIXS) experiments, which are inherently elemental-sensitive probes of the transition-metal 3d and anion 2p states in battery compounds. We provide the details on the experimental techniques and demonstrations revealing the key chemical states in battery materials through these soft X-ray spectroscopy techniques.

Optogenetic Approaches to Drug Discovery in Neuroscience and Beyond.

PubMed

Zhang, Hongkang; Cohen, Adam E

2017-07-01

Recent advances in optogenetics have opened new routes to drug discovery, particularly in neuroscience. Physiological cellular assays probe functional phenotypes that connect genomic data to patient health. Optogenetic tools, in particular tools for all-optical electrophysiology, now provide a means to probe cellular disease models with unprecedented throughput and information content. These techniques promise to identify functional phenotypes associated with disease states and to identify compounds that improve cellular function regardless of whether the compound acts directly on a target or through a bypass mechanism. This review discusses opportunities and unresolved challenges in applying optogenetic techniques throughout the discovery pipeline - from target identification and validation, to target-based and phenotypic screens, to clinical trials. Copyright © 2017 Elsevier Ltd. All rights reserved.

Far-Field Plume Measurements of a Nested-Channel Hall-Effect Thruster (PREPRINT)

DTIC Science & Technology

2010-12-13

nude Faraday probe, retarding potential analyzer, and ExB probe. Data from these probes were used to calculate utilization efficiencies from existing...USA Far-field plume measurements were performed on the X2 nested-channel Hall-effect thruster using an ar- ray of diagnostics, including a nude Faraday...mode to nested-channel mode by utilizing a traditional array of far-field diagnostics, which include a nude Faraday probe, retarding potential analyzer

Commercial NiMH Cells in LEO Cycling: Thermal Vacuum Life Test Performed for the Floating Potential Probe (FPP)

NASA Technical Reports Server (NTRS)

Darcy, Eric; Strangways, Brad

2003-01-01

Contents include the following: 1. Introduction: What is the (Floating Potential Probe) FPP? Why was NiMH battery selected? Haw well would crimped seal cell performed in long term vacuum exposure? 2. Verification tests: Battery description. Test methods. Results. Main findings. FPP status.

Performance Evaluation Gravity Probe B Design

NASA Technical Reports Server (NTRS)

Francis, Ronnie; Wells, Eugene M.

1996-01-01

This final report documents the work done to develop a 6 degree-of-freedom simulation of the Lockheed Martin Gravity Probe B (GPB) Spacecraft. This simulation includes the effects of vehicle flexibility and propellant slosh. The simulation was used to investigate the control performance of the spacecraft when subjected to realistic on orbit disturbances.

O1.3. A COMPUTATIONAL TRIAL-BY-TRIAL EEG ANALYSIS OF HIERARCHICAL PRECISION-WEIGHTED PREDICTION ERRORS

PubMed Central

Tomiello, Sara; Schöbi, Dario; Weber, Lilian; Haker, Helene; Sandra, Iglesias; Stephan, Klaas Enno

2018-01-01

Abstract Background Action optimisation relies on learning about past decisions and on accumulated knowledge about the stability of the environment. In Bayesian models of learning, belief updating is informed by multiple, hierarchically related, precision-weighted prediction errors (pwPEs). Recent work suggests that hierarchically different pwPEs may be encoded by specific neurotransmitters such as dopamine (DA) and acetylcholine (ACh). Abnormal dopaminergic and cholinergic modulation of N-methyl-D-aspartate (NMDA) receptors plays a central role in the dysconnection hypothesis, which considers impaired synaptic plasticity a central mechanisms in the pathophysiology of schizophrenia. Methods To probe the dichotomy between DA and ACh and to investigate timing parameters of pwPEs, we tested 74 healthy male volunteers performing a probabilistic reward associative learning task in which the contingency between cues and rewards changed over 160 trials between 0.8 and 0.2. Furthermore, the current study employed pharmacological interventions (amisulpride / biperiden / placebo) and genetic analyses (COMT and ChAT) to probe DA and ACh modulation of these computational quantities. The study was double-blind and between-subject. We inferred, from subject-specific behavioural data, a low-level choice PE about the reward outcome, a high-level PE about the probability of the outcome as well as the respective precision-weights (uncertainties) and used them, in a trial-by-trial analysis, to explain electroencephalogram (EEG) signals (64 channels). Behavioural data was modelled implementing three versions of the Hierarchical Gaussian Filter (HGF), a Rescorla-Wagner model, and a Sutton model with a dynamic learning rate. The computational trajectories of the winning model were used as regressors in single-subject trial-by-trial GLM analyses at the sensor level. The resulting parameter estimates were entered into 2nd-level ANOVAs. The reported results were family-wise error corrected at the peak-level (p<0.05) across the whole brain and time window (outcome phase: 0 - 500ms). Results A three-level HGF best explained the data and was used to compute the computational regressors for EEG analyses. We found a significant interaction between pharmacology and COMT for the high-level precision-weight (uncertainty). Specifically: - At 276 ms after outcome presentation the difference between Met/Met and Val/Met was more positive for amisulpride than for biperiden over occipital electrodes. - At 274ms and 278 ms after outcome presentation the difference between Met/Met and Val/Met was more negative over fronto-temporal electrodes for amisulpride than for placebo, and for amisulpride than for biperiden, respectively. No significant results were detected for the other computational quantities or for the ChAT gene. Discussion The differential effects of pharmacology on the processing of high-level precision-weight (uncertainty) were modulated by the DA-related gene COMT. Previous results linked high-level PEs to the cholinergic basal forebrain. One possible explanation for the current results is that high-level computational quantities are represented in cholinergic regions, which in turn are influenced by dopaminergic projections. In order to disentangle dopaminergic and cholinergic effects on synaptic plasticity further analyses will concentrate on biophysical models (e.g. DCM). This may prove useful in detecting pathophysiological subgroups and might therefore be of high relevance in a clinical setting.

Radiation dosimetry of the fibrin-binding probe 64Cu-FBP8 and its feasibility for positron emission tomography imaging of deep vein thrombosis and pulmonary embolism in rats

PubMed Central

Blasi, Francesco; Oliveira, Bruno L; Rietz, Tyson A; Rotile, Nicholas J; Day, Helen; Naha, Pratap C; Cormode, David P; Izquierdo-Garcia, David; Catana, Ciprian; Caravan, Peter

2016-01-01

The diagnosis of deep venous thromboembolic disease is still challenging despite the progress of current thrombus imaging modalities and new diagnostic algorithms. We recently reported the high target uptake and thrombus imaging efficacy of the novel fibrin-specific positron emission tomography probe 64Cu-FBP8. Here, we tested the feasibility of 64Cu-FBP8-PET to detect source thrombi and culprit emboli after deep vein thrombosis and pulmonary embolism (DVT-PE). To support clinical translation of 64Cu-FBP8, we performed a human dosimetry estimation using time-dependent biodistribution in rats. Methods Sprague-Dawley rats (n=7) underwent ferric chloride application on the femoral vein to trigger thrombosis. Pulmonary embolism was induced 30 min or 2 days after deep vein thrombosis by intrajugular injection of a preformed blood clot labeled with 125I-Fibrinogen. PET imaging was performed to detect the clots, and single-photon emission tomography (SPECT) was used to confirm in vivo the location of the pulmonary emboli. Ex vivo gamma-counting and histopathology were used to validate the imaging findings. Detailed biodistribution was performed in healthy rats (n=30) at different time-points after 64Cu-FBP8 administration to estimate human radiation dosimetry. Longitudinal whole-body PET/MR imaging (n=2) was performed after 64Cu-FBP8 administration to further assess radioactivity clearance. Results 64Cu-FBP8-PET imaging detected the location of lung emboli and venous thrombi after DVT-PE, revealing significant differences in uptake between target and background tissues (P<0.001). In vivo SPECT imaging and ex vivo gamma-counting confirmed the location of the lung emboli. PET quantification of the venous thrombi revealed that probe uptake was greater in younger clots than in older ones, a result confirmed by ex vivo analyses (P<0.001). Histopathology revealed an age-dependent reduction of thrombus fibrin content (P=0.006), further supporting the imaging findings. Biodistribution and whole-body PET/MR imaging showed rapid, primarily renal, body clearance of 64Cu-FBP8. The effective dose was estimated to be 0.021 mSv/MBq for male and 0.027 mSv/MBq for female, supporting the feasibility of using 64Cu-FBP8 in human trials. Conclusions We showed that 64Cu-FBP8-PET is a feasible approach to image DVT-PE, and that radiogenic adverse health effects should not limit the clinical translation of 64Cu-FBP8. PMID:25977464

Resistivity Measurement by Dual-Configuration Four-Probe Method

NASA Astrophysics Data System (ADS)

Yamashita, Masato; Nishii, Toshifumi; Mizutani, Hiroya

2003-02-01

The American Society for Testing and Materials (ASTM) Committee has published a new technique for the measurement of resistivity which is termed the dual-configuration four-probe method. The resistivity correction factor is the function of only the data which are obtained from two different electrical configurations of the four probes. The measurement of resistivity and sheet resistance are performed for graphite rectangular plates and indium tin oxide (ITO) films by the conventional four-probe method and the dual-configuration four-probe method. It is demonstrated that the dual-configuration four-probe method which includes a probe array with equal separations of 10 mm can be applied to specimens having thicknesses up to 3.7 mm if a relative resistivity difference up to 5% is allowed.

Salience Is Only Briefly Represented: Evidence from Probe-Detection Performance

ERIC Educational Resources Information Center

Donk, Mieke; Soesman, Leroy

2010-01-01

Salient objects in the visual field tend to capture attention. The present study aimed to examine the time-course of salience effects using a probe-detection task. Eight experiments investigated how the salience of different orientation singletons affected probe reaction time as a function of stimulus onset asynchrony (SOA) between the…

40 CFR 85.2232 - Calibrations, adjustments-EPA 81.

Code of Federal Regulations, 2012 CFR

2012-07-01

... readings using the span gas through the probe and through the calibration port shall be made and compared... through the probe. This paragraph does not prevent those who wish to always adjust the analyzer to the... without a calibration port, perform a simple leak check (e.g., cap the probe). Repair any leaks before...

40 CFR 85.2232 - Calibrations, adjustments-EPA 81.

Code of Federal Regulations, 2011 CFR

2011-07-01

... readings using the span gas through the probe and through the calibration port shall be made and compared... through the probe. This paragraph does not prevent those who wish to always adjust the analyzer to the... without a calibration port, perform a simple leak check (e.g., cap the probe). Repair any leaks before...

40 CFR 85.2232 - Calibrations, adjustments-EPA 81.

Code of Federal Regulations, 2013 CFR

2013-07-01

... readings using the span gas through the probe and through the calibration port shall be made and compared... through the probe. This paragraph does not prevent those who wish to always adjust the analyzer to the... without a calibration port, perform a simple leak check (e.g., cap the probe). Repair any leaks before...

A computer-controlled apparatus for Seebeck inhomogeneity testing of sheathed thermocouples

NASA Technical Reports Server (NTRS)

Burkett, Cecil G., Jr.; Bauserman, Willard A., Jr.

1993-01-01

Mineral-insulated metal-sheathed (MIMS) thermocouple assemblies are used throughout industry and research facilities as a method of temperature measurement where requirements for either harsh environmental conditions exist, or where rigidity of the measurement probe is required. Seebeck inhomogeneity is the abnormal variation of the Seebeck coefficient from point to point in a material. It is not disclosed in conventional calibration. A standardized method of measuring thermoelectric inhomogeneity along the thermocouple probe length is not available. Therefore, calibration for sheathed probes normally does not include testing of probe inhomogeneity. The measurement accuracy would be severely impacted if significant inhomogeneity and a temperature gradient were present in the same region of the probe. A computer-controlled system for determining inhomogeneities was designed, fabricated, and tested. This system provides an accurate method for the identification of the location of inhomogeneity along the length of a sheathed thermocouple and for the quantification of the inhomogeneity. This paper will discuss the apparatus and procedure used to perform these tests and will present data showing tests performed on sheathed thermocouple probes.

A study of the high-precision displacement laser probe

NASA Astrophysics Data System (ADS)

Fan, Yuming; Zhang, Guoxiong

2006-06-01

On the basis of the measuring principle of the dynamic active optical confocal probe based on time difference measurement that has a reference path, a dynamic active optical confocal probe based on time difference measurement but has no reference path is developed. In this paper, the working principle of this optical confocal probe is dissertated. A large-scale integrated measuring system is designed to simplify the structure of the probe and to enhance the stability of the probe. Single-chip microcomputer system with a high-speed ADC is selected in the measurement and control system of the probe. At the end of the paper, experiments on the performance of the optical confocal probe based on time difference measurement with no reference path are carried out. Experiment results show that the probe has a measuring resolution of 0.05μm, a measuring range of 0.2mm and a linearity of 0.4μm.

(99m)Tc-Annexin A5 quantification of apoptotic tumor response: a systematic review and meta-analysis of clinical imaging trials.

PubMed

Belhocine, Tarik Z; Blankenberg, Francis G; Kartachova, Marina S; Stitt, Larry W; Vanderheyden, Jean-Luc; Hoebers, Frank J P; Van de Wiele, Christophe

2015-12-01

(99m)Tc-Annexin A5 has been used as a molecular imaging probe for the visualization, characterization and measurement of apoptosis. In an effort to define the quantitative (99m)Tc-annexin A5 uptake criteria that best predict tumor response to treatment, we performed a systematic review and meta-analysis of the results of all clinical imaging trials found in the literature or publicly available databases. Included in this review were 17 clinical trials investigating quantitative (99m)Tc-annexin A5 (qAnx5) imaging using different parameters in cancer patients before and after the first course of chemotherapy and/or radiation therapy. Qualitative assessment of the clinical studies for diagnostic accuracy was performed using the QUADAS-2 criteria. Of these studies, five prospective single-center clinical trials (92 patients in total) were included in the meta-analysis after exclusion of one multicenter clinical trial due to heterogeneity. Pooled positive predictive values (PPV) and pooled negative predictive values (NPV) (with 95% CI) were calculated using Meta-Disc software version 1.4. Absolute quantification and/or relative quantification of (99m)Tc-annexin A5 uptake were performed at baseline and after the start of treatment. Various quantitative parameters have been used for the calculation of (99m)Tc-annexin A5 tumor uptake and delta (Δ) tumor changes post-treatment compared to baseline including: tumor-to-background ratio (TBR), ΔTBR, tumor-to-noise ratio, relative tumor ratio (TR), ΔTR, standardized tumor uptake ratio (STU), ΔSTU, maximum count per pixel within the tumor volume (Cmax), Cmax%, absolute ΔU and percentage (ΔU%), maximum ΔU counts, semiquantitative visual scoring, percent injected dose (%ID) and %ID/cm(3). Clinical trials investigating qAnx5 imaging have included patients with lung cancer, lymphoma, breast cancer, head and neck cancer and other less common tumor types. In two phase I/II single-center clinical trials, an increase of ≥25% in uptake following treatment was considered a significant threshold for an apoptotic tumor response (partial response, complete response). In three other phase I/II clinical trials, increases of ≥28%, ≥42% and ≥47% in uptake following treatment were found to be the mean cut-off levels in responders. In a phase II/III multicenter clinical trial, an increase of ≥23% in uptake following treatment was found to be the minimum cut-off level for a tumor response. In one clinical trial, no significant difference in (99m)Tc-annexin A5 uptake in terms of %ID was found in healthy tissues after chemotherapy compared to baseline. In two other clinical trials, intraobserver and interobserver measurements of (99m)Tc-annexin A5 tumor uptake were found to be reproducible (mean difference <5%, kappa =  0.90 and 0.82, respectively) and to be highly correlated with treatment outcome (Spearman r = 0.99, p < 0.0001). The meta-analysis demonstrated a pooled positive PPV of 100% (95% CI 92 - 100%) and a pooled NPV of 70% (95% CI 55 - 82%) for prediction of a tumor response after the first course of chemotherapy and/or radiotherapy in terms of ΔU%. In a symmetric sROC analysis, the AUC was 0.919 and the Q* index was 85.21 %. Quantitative (99m)Tc-annexin A5 imaging has been investigated in clinical trials for the assessment of apoptotic tumor responses. This meta-analysis showed a high pooled PPV and a moderate pooled NPV with ΔU cut-off values ranging between 20% and 30%. Standardization of quantification and harmonization of results are required for high-quality clinical research. A standardized uptake value score (SUV, ΔSUV) using quantitative SPECT/CT imaging may be a promising approach to the simple, reproducible and semiquantitative assessment of apoptotic tumor changes.

IL-6 deficiency alters spatial memory in 4- and 24-month-old mice.

PubMed

Bialuk, Izabela; Taranta, Andrzej; Winnicka, Maria Małgorzata

2018-06-19

Significance of interleukin 6 (IL-6) deficiency in cognitive processes was evaluated in 4- and 24-month-old C57BL/6J IL-6-deficient (IL-6 KO) and control (WT) mice in Morris water maze (MWM), holeboard test (HB) and elevated plus maze (EPM). During 3-day learning escape latency time (ELT) was longer in IL-6 KO than in WT mice, however their swimming was slower, floating longer, and path length did not differ. The comparison of ELT and the distance traveled between the first and the third learning day within each group revealed significant decrease of ELT in all groups with the highest difference in 4-month-old WT mice, and significant decrease of distance traveled only in both groups of WT mice. In a single probe trial, performed 24 h after the last learning session, there were no major differences in the absolute values of ELT, but ELT turned out to be significantly shorter in both IL-6 KO groups, when it was compared to the ELT on the last learning day, indicating on better memory retrieval. In HB test only significant increase in number of rearings in aged WT mice, and in EPM significant prolongation of open arm time and higher number of open arm entries in 4-month-old IL-6 KO mice were observed. Results of HB and EPM tests showed that alterations of learning and reference memory observed in MWM were specific to cognition. Attenuation of learning ability in young adult IL-6-deficient mice assessed in MWM suggests that physiological level of IL-6 is involved in mechanisms engaged in proper memory formation, and it may also indicate on the importance of IL-6 signaling in brain development. Maintained on similar level in both 4- and 24-month-old IL-6 KO mice learning ability and its attenuation in 24-month-old vs 4-month-old WT mice indicates on slower age-related memory decline in mice not expressing IL-6. Better performance of IL-6 KO mice in the probe trial points to their reference memory improvement and may also indicate that IL-6 plays a role in mechanism responsible for cognitive flexibility. Copyright © 2018 Elsevier Inc. All rights reserved.

Combination of hand-held probe and microscopy for fluorescence guided surgery in the brain tumor marginal zone.

PubMed

Richter, Johan C O; Haj-Hosseini, Neda; Hallbeck, Martin; Wårdell, Karin

2017-06-01

Visualization of the tumor is crucial for differentiating malignant tissue from healthy brain during surgery, especially in the tumor marginal zone. The aim of the study was to introduce a fluorescence spectroscopy-based hand-held probe (HHF-probe) for tumor identification in combination with the fluorescence guided resection surgical microscope (FGR-microscope), and evaluate them in terms of diagnostic performance and practical aspects of fluorescence detection. Eighteen operations were performed on 16 patients with suspected high-grade glioma. The HHF-probe and the FGR-microscope were used for detection of protoporphyrin (PpIX) fluorescence induced by 5-aminolevulinic acid (5-ALA) and evaluated against histopathological analysis and visual grading done through the FGR-microscope by the surgeon. A ratio of PpIX fluorescence intensity to the autofluorescence intensity (fluorescence ratio) was used to quantify the spectra detected by the probe. Fluorescence ratio medians (range 0 - 40) measured by the probe were related to the intensity of the fluorescence in the FGR-microscope, categorized as "none" (0.3, n=131), "weak" (1.6, n=34) and "strong" (5.4, n=28). Of 131 "none" points in the FGR-microscope, 88 (67%) exhibited fluorescence with the HHF-probe. For the tumor marginal zone, the area under the receiver operator characteristics (ROC) curve was 0.49 for the FGR-microscope and 0.65 for the HHF-probe. The probe was integrated in the established routine of tumor resection using the FGR-microscope. The HHF-probe was superior to the FGR-microscope in sensitivity; it detected tumor remnants after debulking under the FGR-microscope. The combination of the HHF-probe and the FGR-microscope was beneficial especially in the tumor marginal zone. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Astigmatism corrected common path probe for optical coherence tomography.

PubMed

Singh, Kanwarpal; Yamada, Daisuke; Tearney, Guillermo

2017-03-01

Optical coherence tomography (OCT) catheters for intraluminal imaging are subject to various artifacts due to reference-sample arm dispersion imbalances and sample arm beam astigmatism. The goal of this work was to develop a probe that minimizes such artifacts. Our probe was fabricated using a single mode fiber at the tip of which a glass spacer and graded index objective lens were spliced to achieve the desired focal distance. The signal was reflected using a curved reflector to correct for astigmatism caused by the thin, protective, transparent sheath that surrounds the optics. The probe design was optimized using Zemax, a commercially available optical design software. Common path interferometric operation was achieved using Fresnel reflection from the tip of the focusing graded index objective lens. The performance of the probe was tested using a custom designed spectrometer-based OCT system. The probe achieved an axial resolution of 15.6 μm in air, a lateral resolution 33 μm, and a sensitivity of 103 dB. A scattering tissue phantom was imaged to test the performance of the probe for astigmatism correction. Images of the phantom confirmed that this common-path, astigmatism-corrected OCT imaging probe had minimal artifacts in the axial, and lateral dimensions. In this work, we developed an astigmatism-corrected, common path probe that minimizes artifacts associated with standard OCT probes. This design may be useful for OCT applications that require high axial and lateral resolutions. Lasers Surg. Med. 49:312-318, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Efficient design of multituned transmission line NMR probes: the electrical engineering approach.

PubMed

Frydel, J A; Krzystyniak, M; Pienkowski, D; Pietrzak, M; de Sousa Amadeu, N; Ratajczyk, T; Idzik, K; Gutmann, T; Tietze, D; Voigt, S; Fenn, A; Limbach, H H; Buntkowsky, G

2011-01-01

Transmission line-based multi-channel solid state NMR probes have many advantages regarding the cost of construction, number of RF-channels, and achievable RF-power levels. Nevertheless, these probes are only rarely employed in solid state-NMR-labs, mainly owing to the difficult experimental determination of the necessary RF-parameters. Here, the efficient design of multi-channel solid state MAS-NMR probes employing transmission line theory and modern techniques of electrical engineering is presented. As technical realization a five-channel ((1)H, (31)P, (13)C, (2)H and (15)N) probe for operation at 7 Tesla is described. This very cost efficient design goal is a multi port single coil transmission line probe based on the design developed by Schaefer and McKay. The electrical performance of the probe is determined by measuring of Scattering matrix parameters (S-parameters) in particular input/output ports. These parameters are compared to the calculated parameters of the design employing the S-matrix formalism. It is shown that the S-matrix formalism provides an excellent tool for examination of transmission line probes and thus the tool for a rational design of these probes. On the other hand, the resulting design provides excellent electrical performance. From a point of view of Nuclear Magnetic Resonance (NMR), calibration spectra of particular ports (channels) are of great importance. The estimation of the π/2 pulses length for all five NMR channels is presented. Copyright © 2011 Elsevier Inc. All rights reserved.

Construction, in vitro and in vivo evaluation of an in-house conductance meter for measurement of skin hydration.

PubMed

Hamed, Saja H; Altrabsheh, Bilal; Assa'd, Tareq; Jaradat, Said; Alshra'ah, Mohammad; Aljamal, Abdulfattah; Alkhatib, Hatim S; Almalty, Abdul-Majeed

2012-12-01

Different probes are used in dermato-cosmetic research to measure the electrical properties of the skin. The principle governing the choice of the geometry and material of the measuring probe is not well defined in the literature and some device's measuring principles are not accessible for the scientific community. The purpose of this work was to develop a simple inexpensive conductance meter for the objective in vivo evaluation of skin hydration. The conductance meter probe was designed using the basic equation governing wave propagation along Transverse Electromagnetic transmission lines. It consisted of two concentric copper circular electrodes printed on FR4 dielectric material. The performance of the probe was validated by evaluating its measurement depth, its ability to monitor in vitro water sorption-desorption and in vivo skin hydration effect in comparison to that of the Corneometer CM 825. The measurement depth of the probe, 15 μm, was comparable to that of CM 825. The in vitro readings of the probe correlated strongly with the amount of water adsorbed on filter paper. Skin hydration after application of a moisturizer was monitored effectively by the new probe with good correlation to the results of CM 825. In conclusion, a simple probe for evaluating skin hydration was made from off-the-shelf materials and its performance was validated in comparison to a commercially available probe. Copyright © 2012 IPEM. Published by Elsevier Ltd. All rights reserved.

Cyclic Voltammetry Probe Approach Curves with Alkali Amalgams at Mercury Sphere-Cap Scanning Electrochemical Microscopy Probes.

PubMed

Barton, Zachary J; Rodríguez-López, Joaquín

2017-03-07

We report a method of precisely positioning a Hg-based ultramicroelectrode (UME) for scanning electrochemical microscopy (SECM) investigations of any substrate. Hg-based probes are capable of performing amalgamation reactions with metal cations, which avoid unwanted side reactions and positive feedback mechanisms that can prove problematic for traditional probe positioning methods. However, prolonged collection of ions eventually leads to saturation of the amalgam accompanied by irreversible loss of Hg. In order to obtain negative feedback positioning control without risking damage to the SECM probe, we implement cyclic voltammetry probe approach surfaces (CV-PASs), consisting of CVs performed between incremental motor movements. The amalgamation current, peak stripping current, and integrated stripping charge extracted from a shared CV-PAS give three distinct probe approach curves (CV-PACs), which can be used to determine the tip-substrate gap to within 1% of the probe radius. Using finite element simulations, we establish a new protocol for fitting any CV-PAC and demonstrate its validity with experimental results for sodium and potassium ions in propylene carbonate by obtaining over 3 orders of magnitude greater accuracy and more than 20-fold greater precision than existing methods. Considering the timescales of diffusion and amalgam saturation, we also present limiting conditions for obtaining and fitting CV-PAC data. The ion-specific signals isolated in CV-PACs allow precise and accurate positioning of Hg-based SECM probes over any sample and enable the deployment of CV-PAS SECM as an analytical tool for traditionally challenging conditions.

Real-time PCR probe optimization using design of experiments approach.

PubMed

Wadle, S; Lehnert, M; Rubenwolf, S; Zengerle, R; von Stetten, F

2016-03-01

Primer and probe sequence designs are among the most critical input factors in real-time polymerase chain reaction (PCR) assay optimization. In this study, we present the use of statistical design of experiments (DOE) approach as a general guideline for probe optimization and more specifically focus on design optimization of label-free hydrolysis probes that are designated as mediator probes (MPs), which are used in reverse transcription MP PCR (RT-MP PCR). The effect of three input factors on assay performance was investigated: distance between primer and mediator probe cleavage site; dimer stability of MP and target sequence (influenza B virus); and dimer stability of the mediator and universal reporter (UR). The results indicated that the latter dimer stability had the greatest influence on assay performance, with RT-MP PCR efficiency increased by up to 10% with changes to this input factor. With an optimal design configuration, a detection limit of 3-14 target copies/10 μl reaction could be achieved. This improved detection limit was confirmed for another UR design and for a second target sequence, human metapneumovirus, with 7-11 copies/10 μl reaction detected in an optimum case. The DOE approach for improving oligonucleotide designs for real-time PCR not only produces excellent results but may also reduce the number of experiments that need to be performed, thus reducing costs and experimental times.

Design of planar microcoil-based NMR probe ensuring high SNR

NASA Astrophysics Data System (ADS)

Ali, Zishan; Poenar, D. P.; Aditya, Sheel

2017-09-01

A microNMR probe for ex vivo applications may consist of at least one microcoil, which can be used as the oscillating magnetic field (MF) generator as well as receiver coil, and a sample holder, with a volume in the range of nanoliters to micro-liters, placed near the microcoil. The Signal-to-Noise ratio (SNR) of such a probe is, however, dependent not only on its design but also on the measurement setup, and the measured sample. This paper introduces a performance factor P independent of both the proton spin density in the sample and the external DC magnetic field, and which can thus assess the performance of the probe alone. First, two of the components of the P factor (inhomogeneity factor K and filling factor η ) are defined and an approach to calculate their values for different probe variants from electromagnetic simulations is devised. A criterion based on dominant component of the magnetic field is then formulated to help designers optimize the sample volume which also affects the performance of the probe, in order to obtain the best SNR for a given planar microcoil. Finally, the P factor values are compared between different planar microcoils with different number of turns and conductor aspect ratios, and planar microcoils are also compared with conventional solenoids. These comparisons highlight which microcoil geometry-sample volume combination will ensure a high SNR under any external setup.

Functional evaluation of the endotics system, a new disposable self-propelled robotic colonoscope: in vitro tests and clinical trial.

PubMed

Cosentino, Felice; Tumino, Emanuele; Passoni, Giovanni Rubis; Morandi, Elisabetta; Capria, Alfonso

2009-08-01

Currently, the best method for CRC screening is colonoscopy, which ideally (where possible) is performed under partial or deep sedation. This study aims to evaluate the efficacy of the Endotics System, a new robotic device composed of a workstation and a disposable probe, in performing accurate and well-tolerated colonoscopies. This new system could also be considered a precursor of other innovating vectors for atraumatic locomotion through natural orifices such as the bowel. The flexible probe adapts its shape to the complex contours of the colon, thereby exerting low strenuous forces during its movement. These novel characteristics allow for a painless and safe colonoscopy, thus eliminating all major associated risks such as infection, cardiopulmonary complications and colon perforation. An experimental study was devised to investigate stress pattern differences between traditional and robotic colonoscopy, in which 40 enrolled patients underwent both robotic and standard colonoscopy within the same day. The stress pattern related to robotic colonoscopy was 90% lower than that of standard colonoscopy. Additionally, the robotic colonoscopy demonstrated a higher diagnostic accuracy, since, due to the lower insufflation rate, it was able to visualize small polyps and angiodysplasias not seen during the standard colonoscopy. All patients rated the robotic colonoscopy as virtually painless compared to the standard colonoscopy, ranking pain and discomfort as 0.9 and 1.1 respectively, on a scale of O to 10, versus 6.9 and 6.8 respectively for the standard device. The new Endotics System demonstrates efficacy in the diagnosis of colonic pathologies using a procedure nearly completely devoid of pain. Therefore, this system can also be looked upon as the first step toward developing and implementing colonoscopy with atraumatic locomotion through the bowel while maintaining a high level of diagnostic accuracy;

The effects of an Ayurvedic medicinal toothpaste on clinical, microbiological and oral hygiene parameters in patients with chronic gingivitis: a double-blind, randomised, placebo-controlled, parallel allocation clinical trial.

PubMed

Howshigan, J; Perera, K; Samita, S; Rajapakse, P S

2015-12-01

Plant derived preparations have been essential components for maintenance of oral hygiene and the treatment of oral diseases globally since ancient times. Acacia chundra Willd, Adhatoda vasica Nees., Mimusops elengi L., Piper nigrum L., Pongamia pinnate L. Pirerre, Quercus infectoria Olivier., Syzygium aromaticum L., Terminalia chebula Retz., Zingiber offici-nale Roscoe., individually or in combination, have been used for this purpose because of their beneficial effects. To study the efficacy of an Ayurvedic toothpaste containing these herbs in patients with chronic gingivitis. Otherwise healthy males and non-pregnant females (n=80) aged 18-35 years with ≥20 teeth were randomly assigned to Group 1 (herbal toothpaste) and Group 2 (placebo toothpaste). Quigley Hein plaque index (PS), bleeding on probing (BOP) and probing pocket depth (PPD), were recorded for all teeth at six sites, and one ml of resting saliva was collected to ascertain anaerobic and aerobic bacterial counts at baseline, and at 4, 8, 12 and 24 weeks. Full-mouth prophylaxis was performed and instructions for brushing with the allocated toothpaste for 6 months were given at baseline. Sixty-six participants, 34 in Group 1 and 32 in Group 2 completed the study. Clinical examinations were performed by the same examiner blinded to group allocation. Linear mixed model analysis revealed significant reductions of PS, BOP, PPD (p<0.0001) and total salivary anaerobic counts (p<0.05) in Group 1 at all prescribed visits compared to Group 2. Moreover the reduction increased overtime. No unpleasant effects of toothpaste use were reported. This study provides robust evidence of the beneficial antiplaque and antigingivitis effects of the test herbal toothpaste Sudantha® on patients with chronic gingivitis.

In situ medical simulation investigation of emergency department procedural sedation with randomized trial of experimental bedside clinical process guidance intervention.

PubMed

Siegel, Nathan A; Kobayashi, Leo; Dunbar-Viveiros, Jennifer A; Devine, Jeffrey; Al-Rasheed, Rakan S; Gardiner, Fenwick G; Olsson, Krister; Lai, Stella; Jones, Mark S; Dannecker, Max; Overly, Frank L; Gosbee, John W; Portelli, David C; Jay, Gregory D

2015-06-01

Patient safety during emergency department procedural sedation (EDPS) can be difficult to study. Investigators sought to delineate and experimentally assess EDPS performance and safety practices of senior-level emergency medicine residents through in situ simulation. Study sessions used 2 pilot-tested EDPS scenarios with critical action checklists, institutional forms, embedded probes, and situational awareness questionnaires. An experimental informatics system was separately developed for bedside EDPS process guidance. Postgraduate year 3 and 4 subjects completed both scenarios in randomized order; only experimental subjects were provided with the experimental system during second scenarios. Twenty-four residents were recruited into a control group (n = 12; 6.2 ± 7.4 live EDPS experience) and experimental group (n = 12; 11.3 ± 8.2 live EDPS experience [P = 0.10]). Critical actions for EDPS medication selection, induction, and adverse event recognition with resuscitation were correctly performed by most subjects. Presedation evaluations, sedation rescue preparation, equipment checks, time-outs, and documentation were frequently missed. Time-outs and postsedation assessments increased during second scenarios in the experimental group. Emergency department procedural sedation safety probe detection did not change across scenarios in either group. Situational awareness scores were 51% ± 7% for control group and 58% ± 12% for experimental group. Subjects using the experimental system completed more time-outs and scored higher Simulation EDPS Safety Composite Scores, although without comprehensive improvements in EDPS practice or safety. Study simulations delineated EDPS and assessed safety behaviors in senior emergency medicine residents, who exhibited the requisite medical knowledge base and procedural skill set but lacked some nontechnical skills that pertain to emergency department microsystem functions and patient safety. The experimental system exhibited limited impact only on in-simulation time-out compliance.

Within-hemifield competition in early visual areas limits the ability to track multiple objects with attention.

PubMed

Störmer, Viola S; Alvarez, George A; Cavanagh, Patrick

2014-08-27

It is much easier to divide attention across the left and right visual hemifields than within the same visual hemifield. Here we investigate whether this benefit of dividing attention across separate visual fields is evident at early cortical processing stages. We measured the steady-state visual evoked potential, an oscillatory response of the visual cortex elicited by flickering stimuli, of moving targets and distractors while human observers performed a tracking task. The amplitude of responses at the target frequencies was larger than that of the distractor frequencies when participants tracked two targets in separate hemifields, indicating that attention can modulate early visual processing when it is divided across hemifields. However, these attentional modulations disappeared when both targets were tracked within the same hemifield. These effects were not due to differences in task performance, because accuracy was matched across the tracking conditions by adjusting target speed (with control conditions ruling out effects due to speed alone). To investigate later processing stages, we examined the P3 component over central-parietal scalp sites that was elicited by the test probe at the end of the trial. The P3 amplitude was larger for probes on targets than on distractors, regardless of whether attention was divided across or within a hemifield, indicating that these higher-level processes were not constrained by visual hemifield. These results suggest that modulating early processing stages enables more efficient target tracking, and that within-hemifield competition limits the ability to modulate multiple target representations within the hemifield maps of the early visual cortex. Copyright © 2014 the authors 0270-6474/14/3311526-08$15.00/0.

The effect of nonsurgical periodontal therapy on hemoglobin A1c levels in persons with type 2 diabetes and chronic periodontitis: a randomized clinical trial.

PubMed

Engebretson, Steven P; Hyman, Leslie G; Michalowicz, Bryan S; Schoenfeld, Elinor R; Gelato, Marie C; Hou, Wei; Seaquist, Elizabeth R; Reddy, Michael S; Lewis, Cora E; Oates, Thomas W; Tripathy, Devjit; Katancik, James A; Orlander, Philip R; Paquette, David W; Hanson, Naomi Q; Tsai, Michael Y

2013-12-18

Chronic periodontitis, a destructive inflammatory disorder of the supporting structures of the teeth, is prevalent in patients with diabetes. Limited evidence suggests that periodontal therapy may improve glycemic control. To determine if nonsurgical periodontal treatment reduces levels of glycated hemoglobin (HbA1c) in persons with type 2 diabetes and moderate to advanced chronic periodontitis. The Diabetes and Periodontal Therapy Trial (DPTT), a 6-month, single-masked, multicenter, randomized clinical trial. Participants had type 2 diabetes, were taking stable doses of medications, had HbA1c levels between 7% and less than 9%, and untreated chronic periodontitis. Five hundred fourteen participants were enrolled between November 2009 and March 2012 from diabetes and dental clinics and communities affiliated with 5 academic medical centers. The treatment group (n = 257) received scaling and root planing plus chlorhexidine oral rinse at baseline and supportive periodontal therapy at 3 and 6 months. The control group (n = 257) received no treatment for 6 months. Difference in change in HbA1c level from baseline between groups at 6 months. Secondary outcomes included changes in probing pocket depths, clinical attachment loss, bleeding on probing, gingival index, fasting glucose level, and Homeostasis Model Assessment (HOMA2) score. Enrollment was stopped early because of futility. At 6 months, mean HbA1c levels in the periodontal therapy group increased 0.17% (SD, 1.0), compared with 0.11% (SD, 1.0) in the control group, with no significant difference between groups based on a linear regression model adjusting for clinical site (mean difference, -0.05% [95% CI, -0.23% to 0.12%]; P = .55). Periodontal measures improved in the treatment group compared with the control group at 6 months, with adjusted between-group differences of 0.28 mm (95% CI, 0.18 to 0.37) for probing depth, 0.25 mm (95% CI, 0.14 to 0.36) for clinical attachment loss, 13.1% (95% CI, 8.1% to 18.1%) for bleeding on probing, and 0.27 (95% CI, 0.17 to 0.37) for gingival index (P < .001 for all). Nonsurgical periodontal therapy did not improve glycemic control in patients with type 2 diabetes and moderate to advanced chronic periodontitis. These findings do not support the use of nonsurgical periodontal treatment in patients with diabetes for the purpose of lowering levels of HbA1c. clinicaltrials.gov Identifier: NCT00997178.

Dose-dependent social-cognitive effects of intranasal oxytocin delivered with novel Breath Powered device in adults with autism spectrum disorder: a randomized placebo-controlled double-blind crossover trial

PubMed Central

Quintana, D S; Westlye, L T; Hope, S; Nærland, T; Elvsåshagen, T; Dørum, E; Rustan, Ø; Valstad, M; Rezvaya, L; Lishaugen, H; Stensønes, E; Yaqub, S; Smerud, K T; Mahmoud, R A; Djupesland, P G; Andreassen, O A

2017-01-01

The neuropeptide oxytocin has shown promise as a treatment for symptoms of autism spectrum disorders (ASD). However, clinical research progress has been hampered by a poor understanding of oxytocin’s dose–response and sub-optimal intranasal delivery methods. We examined two doses of oxytocin delivered using a novel Breath Powered intranasal delivery device designed to improve direct nose-to-brain activity in a double-blind, crossover, randomized, placebo-controlled trial. In a randomized sequence of single-dose sessions, 17 male adults with ASD received 8 international units (IU) oxytocin, 24IU oxytocin or placebo followed by four social-cognitive tasks. We observed an omnibus main effect of treatment on the primary outcome measure of overt emotion salience as measured by emotional ratings of faces (η2=0.18). Compared to placebo, 8IU treatment increased overt emotion salience (P=0.02, d=0.63). There was no statistically significant increase after 24IU treatment (P=0.12, d=0.4). The effects after 8IU oxytocin were observed despite no significant increase in peripheral blood plasma oxytocin concentrations. We found no significant effects for reading the mind in the eyes task performance or secondary outcome social-cognitive tasks (emotional dot probe and face-morphing). To our knowledge, this is the first trial to assess the dose-dependent effects of a single oxytocin administration in autism, with results indicating that a low dose of oxytocin can significantly modulate overt emotion salience despite minimal systemic exposure. PMID:28534875

Dose-dependent social-cognitive effects of intranasal oxytocin delivered with novel Breath Powered device in adults with autism spectrum disorder: a randomized placebo-controlled double-blind crossover trial.

PubMed

Quintana, D S; Westlye, L T; Hope, S; Nærland, T; Elvsåshagen, T; Dørum, E; Rustan, Ø; Valstad, M; Rezvaya, L; Lishaugen, H; Stensønes, E; Yaqub, S; Smerud, K T; Mahmoud, R A; Djupesland, P G; Andreassen, O A

2017-05-23

The neuropeptide oxytocin has shown promise as a treatment for symptoms of autism spectrum disorders (ASD). However, clinical research progress has been hampered by a poor understanding of oxytocin's dose-response and sub-optimal intranasal delivery methods. We examined two doses of oxytocin delivered using a novel Breath Powered intranasal delivery device designed to improve direct nose-to-brain activity in a double-blind, crossover, randomized, placebo-controlled trial. In a randomized sequence of single-dose sessions, 17 male adults with ASD received 8 international units (IU) oxytocin, 24IU oxytocin or placebo followed by four social-cognitive tasks. We observed an omnibus main effect of treatment on the primary outcome measure of overt emotion salience as measured by emotional ratings of faces (η 2 =0.18). Compared to placebo, 8IU treatment increased overt emotion salience (P=0.02, d=0.63). There was no statistically significant increase after 24IU treatment (P=0.12, d=0.4). The effects after 8IU oxytocin were observed despite no significant increase in peripheral blood plasma oxytocin concentrations. We found no significant effects for reading the mind in the eyes task performance or secondary outcome social-cognitive tasks (emotional dot probe and face-morphing). To our knowledge, this is the first trial to assess the dose-dependent effects of a single oxytocin administration in autism, with results indicating that a low dose of oxytocin can significantly modulate overt emotion salience despite minimal systemic exposure.

[Analysis on microdialysis probe recovery of baicalin in vitro and in vivo based on LC-MS/MS].

PubMed

Chen, Teng-Fei; Liu, Jian-Xun; Zhang, Ying; Lin, Li; Song, Wen-Ting; Yao, Ming-Jiang

2017-06-01

To further study the brain behavior and the pharmacokinetics of baicalin in intercellular fluid of brain, and study the recovery rate and stability of brain and blood microdialysis probe of baicalin in vitro and in vivo. The concentration of baicalin in brain and blood microdialysates was determined by LC-MS/MS and the probe recovery for baicalin was calculated. The effects of different flow rates (0.50, 1.0, 1.5, 2.0，3.0 μL•min⁻¹) on recovery in vitro were determined by incremental method and decrement method. The effects of different drug concentrations (50.00, 200.0, 500.0, 1 000 μg•L⁻¹) and using times (0, 1, 2) on recovery in vitro were determined by incremental method. The probe recovery stability and effect of flow rate on recovery in vivo were determined by decrement method, and its results were compared with those in in vitro trial. The in vitro recovery of brain and blood probe of baicalin was decreased with the increase of flow rate under the same concentration; and at the same flow rate, different concentrations of baicalin had little influence on the recovery. The probe which had been used for 2 times showed no obvious change in probe recovery by syringe with 2% heparin sodium and ultrapure water successively. In vitro recovery rates obtained by incremental method and decrement method were approximately equal under the same condition, and the in vivo recovery determined by decrement method was similar with the in vitro results and they were showed a good stability within 10 h. The results showed that decrement method can be used for pharmacokinetic study of baicalin, and can be used to study probe recovery in vivo at the same time. Copyright© by the Chinese Pharmaceutical Association.

Measurements of Optical Turbulence Parameters Aboard the Aircraft Carrier USS LEXINGTON.

DTIC Science & Technology

1982-09-30

EFFECTS ON SHIP-TO-SHIP TRACKER PERFORMANCE ...... 10 E. FREQUENCY SPECTRA OF MICROTHERMAL FLUCTUATIONS ............. 13 9. CONCLUSIONS...in Fig. 2. It consisted of a Contel model MT-2 microthermal unit with modified probe system as discussed below, a RMS log amplifier, a HP 59313A 2 oI...probe system provided with the Contel system(4 ) was replaced with the probe assembly built for use in the Harris microthermal probe system(5 ). The

Fully Integrated, Miniature, High-Frequency Flow Probe Utilizing MEMS Leadless SOI Technology

NASA Technical Reports Server (NTRS)

Ned, Alex; Kurtz, Anthony; Shang, Tonghuo; Goodman, Scott; Giemette. Gera (d)

2013-01-01

This work focused on developing, fabricating, and fully calibrating a flowangle probe for aeronautics research by utilizing the latest microelectromechanical systems (MEMS), leadless silicon on insulator (SOI) sensor technology. While the concept of angle probes is not new, traditional devices had been relatively large due to fabrication constraints; often too large to resolve flow structures necessary for modern aeropropulsion measurements such as inlet flow distortions and vortices, secondary flows, etc. Mea surements of this kind demanded a new approach to probe design to achieve sizes on the order of 0.1 in. (.3 mm) diameter or smaller, and capable of meeting demanding requirements for accuracy and ruggedness. This approach invoked the use of stateof- the-art processing techniques to install SOI sensor chips directly onto the probe body, thus eliminating redundancy in sensor packaging and probe installation that have historically forced larger probe size. This also facilitated a better thermal match between the chip and its mount, improving stability and accuracy. Further, the leadless sensor technology with which the SOI sensing element is fabricated allows direct mounting and electrical interconnecting of the sensor to the probe body. This leadless technology allowed a rugged wire-out approach that is performed at the sensor length scale, thus achieving substantial sensor size reductions. The technology is inherently capable of high-frequency and high-accuracy performance in high temperatures and harsh environments.

Comparing student performance on paper- and computer-based math curriculum-based measures.

PubMed

Hensley, Kiersten; Rankin, Angelica; Hosp, John

2017-01-01

As the number of computerized curriculum-based measurement (CBM) tools increases, it is necessary to examine whether or not student performance can generalize across a variety of test administration modes (i.e., paper or computer). The purpose of this study is to compare math fact fluency on paper versus computer for 197 upper elementary students. Students completed identical sets of probes on paper and on the computer, which were then scored for digits correct, problems correct, and accuracy. Results showed a significant difference in performance between the two sets of probes, with higher fluency rates on the paper probes. Because decisions about levels of student support and interventions often rely on measures such as these, more research in this area is needed to examine the potential differences in student performance between paper-based and computer-based CBMs.

Temporal prediction abilities are mediated by motor effector and rhythmic expertise.

PubMed

Manning, Fiona C; Harris, Jennifer; Schutz, Michael

2017-03-01

Motor synchronization is a critical part of musical performance and listening. Recently, motor control research has described how movements that contain more available degrees of freedom are more accurately timed. Previously, we demonstrated that stick tapping improves perception in a timing detection task, where percussionists greatly outperformed non-percussionists only when tapping along. Since most synchronization studies implement finger tapping to examine simple motor synchronization, here we completed a similar task where percussionists and non-percussionists synchronized using finger tapping; movement with fewer degrees of freedom than stick tapping. Percussionists and non-percussionists listened to an isochronous beat sequence and identified the timing of a probe tone. On half of the trials, they tapped along with their index finger, and on the other half of the trials, they listened without moving prior to making timing judgments. We found that both groups benefited from tapping overall. Interestingly, percussionists performed only marginally better than did non-percussionists when finger tapping and no different when listening alone, differing from past studies reporting highly superior timing abilities in percussionists. Additionally, we found that percussionist finger tapping was less variable and less asynchronous than was non-percussionist tapping. Moreover, in both groups finger tapping was more variable and more asynchronous than stick tapping in our previous study. This study demonstrates that the motor effector implemented in tapping studies affects not only synchronization abilities, but also subsequent prediction abilities. We discuss these findings in light of effector-specific training and degrees of freedom in motor timing, both of which impact timing abilities to different extents.

Emotional instability but intact spatial cognition in adenosine receptor 1 knock out mice.

PubMed

Lang, Undine E; Lang, Florian; Richter, Kerstin; Vallon, Volker; Lipp, Hans-Peter; Schnermann, Jürgen; Wolfer, David P

2003-10-17

Several lines of evidence point to the involvement of adenosine in the regulation of important central mechanisms such as cognition, arousal, aggression and anxiety. In order to elucidate the involvement of the adenosine A1 receptor (A1AR) in spatial learning and the control of exploratory behaviour, we assessed A1AR knockout mice (A1AR-/-) and their wild-type littermates (A1AR+/+) in a place navigation task in the water maze and in a battery of forced and free exploration tests. In the water maze, A1AR-/- mice showed normal escape latencies and were indistinguishable from controls with respect to measures of spatial performance during both training and probe trial. But despite normal performance they showed increased wall hugging, most prominently after the relocation of the goal platform for reversal training. Quantitative analysis of strategy choices indicated that wall hugging was increased mainly at the expense of chaining and passive floating, whereas the frequency of trials characterised as direct swims or focal searching was normal in A1AR-/- mice. These results indicate intact spatial cognition, but mildly altered emotional reactions to the water maze environment. In line with this interpretation, A1AR-/- mice showed normal levels and patterns of activity, but a mild increase of some measures of anxiety in our battery of forced and free exploration paradigms. These results are in line with findings published using a genetically similar line, but demonstrate that the magnitude of the changes and the range of affected behavioural measures may vary considerably depending on the environmental conditions during testing.

Laboratory plasma probe studies

NASA Technical Reports Server (NTRS)

Heikkila, W. J.

1975-01-01

Diagnostic experiments performed in a collisionless plasma using CO2 as the working gas are described. In particular, simultaneous measurements that have been performed by means of Langmuir- and RF-probes are presented. A resonance occurring above the parallel resonance in the frequency characteristic of a two electrode system is interpreted as being due to the resonant excitation of electroacoustic waves.

A new second-puncture probe for CO2 laser laparoscopy.

PubMed

Daniell, J F; Herbert, C M

1985-02-01

A new second-puncture probe system was designed for aiming and firing the CO2 laser under laparoscopic control. The probe allows simultaneous suction of the smoke from vaporization and insufflation of fresh CO2 for maintenance of an adequate pneumoperitoneum during use. A 200-mm focusing lens attaches the probe to any surgical CO2 laser with an articulated arm. The new probe is 10 cm shorter than standard probes, allowing the application of a wider range of power densities during laser laparoscopy and making surgery easier to perform. Our initial experiences with this new instrument have involved both laboratory animals and patients with endometriosis, adnexal adhesions and distal tubal obstruction.

Preliminary Evidence for an Association Between Social Anxiety Symptoms and Avoidance of Negative Faces in School-Age Children

ERIC Educational Resources Information Center

Stirling, Lucy J.; Eley, Thalia C.; Clark, David M.

2006-01-01

Attentional biases with regard to emotional facial expressions are associated with social anxiety in adults. We investigated whether similar relations exist in children. Seventy-nine 8- to 11-year-olds completed a probe detection task. On a given trial, 1 of 3 pairs of faces was presented: negative-neutral, negative-positive, and positive-neutral.…

Evidence for Decay in Verbal Short-Term Memory: A Commentary on Berman, Jonides, and Lewis (2009)

ERIC Educational Resources Information Center

Campoy, Guillermo

2012-01-01

M. G. Berman, J. Jonides, and R. L. Lewis (2009) adapted the recent-probes task to investigate the causes of forgetting in short-term memory. In 7 experiments, they studied the persistence of memory traces by assessing the level of proactive interference generated by previous-trial items over a range of intertrial intervals. None of the…

The Preignition and Autoignition Oxidation of Alternatives to Petroleum Derived JP-8 and their Surrogate Components in a Pressurized Flow Reactor and Single Cylinder Research Engine

DTIC Science & Technology

2009-09-01

sample probe consisted of TIG welding the 3/8” sample probe shaft to the sample probe tip (Koert, 1990 and Lenhert, 2004b). Silver solder was...was performed in the Drexel University Machine Shop. Conventional TIG welding was sufficient for welding the 3/8” O.D. tube to the sample probe tip...However, to TIG weld the thermocouple and the glass lined tube to the sample probe tip, extreme care had to be taken so as not to damage the

High Performance Nuclear Magnetic Resonance Imaging Using Magnetic Resonance Force Microscopy

DTIC Science & Technology

2013-12-12

Micron- Size Ferromagnet . Physical Review Letters, 92(3) 037205 (2004) [22] A. Z. Genack and A. G. Redeld. Theory of nuclear spin diusion in a...perform spatially resolved scanned probe studies of spin dynamics in nanoscale ensembles of few electron spins of varying size . Our research culminated...perform spatially resolved scanned probe studies of spin dynamics in nanoscale ensembles of few electron spins of varying size . Our research culminated

Cognitive inflexibility in Obsessive-Compulsive Disorder.

PubMed

Gruner, Patricia; Pittenger, Christopher

2017-03-14

Obsessive-Compulsive Disorder (OCD) is characterized by maladaptive patterns of repetitive, inflexible cognition and behavior that suggest a lack of cognitive flexibility. Consistent with this clinical observation, many neurocognitive studies suggest behavioral and neurobiological abnormalities in cognitive flexibility in individuals with OCD. Meta-analytic reviews support a pattern of cognitive inflexibility, with effect sizes generally in the medium range. Heterogeneity in assessments and the way underlying constructs have been operationalized point to the need for better standardization across studies, as well as more refined overarching models of cognitive flexibility and executive function (EF). Neuropsychological assessments of cognitive flexibility include measures of attentional set shifting, reversal and alternation, cued task-switching paradigms, cognitive control measures such as the Trail-Making and Stroop tasks, and several measures of motor inhibition. Differences in the cognitive constructs and neural substrates associated with these measures suggest that performance within these different domains should be examined separately. Additional factors, such as the number of consistent trials prior to a shift and whether a shift is explicitly signaled or must be inferred from a change in reward contingencies, may influence performance, and thus mask or accentuate deficits. Several studies have described abnormalities in neural activation in the absence of differences in behavioral performance, suggesting that our behavioral probes may not be adequately sensitive, but also offering important insights into potential compensatory processes. The fact that deficits of moderate effect size are seen across a broad range of classic neuropsychological tests in OCD presents a conceptual challenge, as clinical symptomatology suggests greater specificity. Traditional cognitive probes may not be sufficient to delineate specific domains of deficit in this and other neuropsychiatric disorders; a new generation of behavioral tasks that test more specific underlying constructs, supplemented by neuroimaging to provide insight into the underlying processes, may be needed. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

Mass Spectrometry for Planetary Probes: Past, Present and Future

NASA Technical Reports Server (NTRS)

Niemann, Hasso B.; Harpold, Dan N.; Jamieson, Brian G.; Mahaffy, Paul R.

2005-01-01

Atmospheric entry probes present a unique opportunity for performing quantitative analysis of extra-terrestrial atmospheres in cases where remote sensing alone may not be sufficient and measurements with balloons or aircraft is not practical. An entry probe can provide a complete vertical profile of atmospheric parameters including chemical composition, which cannot be obtained with most other techniques. There are, however, unique challenges associated with building instruments for an entry probe, as compared to orbiters, landers, or rovers. Conditions during atmospheric entry are extreme, there are inherent time constraints due to the short duration of the experiment, and the instrument experiences rapid environmental changes in temperature and pressure as it descends. In addition, there are resource limitations, i.e. mass, power, size and bandwidth. Finally, the demands on the instrument design are determined in large part by conditions (pressure, temperature, composition) unique to the particular body under study, and as a result there is no one-size-fits-all instrument for an atmospheric probe. Many of these requirements can be more easily met by miniaturizing the probe instrument. Our experience building mass spectrometers for atmospheric entry probes leads us to believe that the time is right for a fundamental change in the way spaceflight mass spectrometers are built. The emergence over the past twenty years of Micro-electro- mechanical Systems (MEMS), utilizing lithographic semiconductor fabrication techniques to produce instrument systems in miniature, holds great promise for application to spaceflight mass spectrometry. A highly miniaturized, high performance and low-power mass spectrometer would be an enormous benefit to future entry probe missions, allowing, for example, parallel measurements (e.g., multiple simultaneous gas chromatographic analyses and direct atmospheric leaks.) Such an instrument would also enable mass spectrometry on board small multiple entry probes. In the development of a MEMS Mass Spectrometer, the challenge facing us is to move beyond the proof-of-concept, where research dollars tend to focus, and carry out the detailed work of developing a high performance mass spectrometer system on a chip which meets the unique technical requirements for an atmospheric entry probe described above.

A 2.5-mm diameter probe for photoacoustic and ultrasonic endoscopy.

PubMed

Yang, Joon-Mo; Chen, Ruimin; Favazza, Christopher; Yao, Junjie; Li, Chiye; Hu, Zhilin; Zhou, Qifa; Shung, K Kirk; Wang, Lihong V

2012-10-08

We have created a 2.5-mm outer diameter integrated photo-acoustic and ultrasonic mini-probe which can be inserted into a standard video endoscope's instrument channel. A small-diameter focused ultrasonic transducer made of PMN-PT provides adequate signal sensitivity, and enables miniaturization of the probe. Additionally, this new endoscopic probe utilizes the same scanning mirror and micromotor-based built-in actuator described in our previous reports; however, the length of the rigid distal section of the new probe has been further reduced to ~35 mm. This paper describes the technical details of the mini-probe and presents experimental results that both quantify the imaging performance and demonstrate its in vivo imaging capability, which suggests that it could work as a mini-probe for certain clinical applications.

A 2.5-mm diameter probe for photoacoustic and ultrasonic endoscopy

PubMed Central

Yang, Joon-Mo; Chen, Ruimin; Favazza, Christopher; Yao, Junjie; Li, Chiye; Hu, Zhilin; Zhou, Qifa; Shung, K. Kirk; Wang, Lihong V.

2012-01-01

We have created a 2.5-mm outer diameter integrated photo-acoustic and ultrasonic mini-probe which can be inserted into a standard video endoscope’s instrument channel. A small-diameter focused ultrasonic transducer made of PMN-PT provides adequate signal sensitivity, and enables miniaturization of the probe. Additionally, this new endoscopic probe utilizes the same scanning mirror and micromotor-based built-in actuator described in our previous reports; however, the length of the rigid distal section of the new probe has been further reduced to ~35 mm. This paper describes the technical details of the mini-probe and presents experimental results that both quantify the imaging performance and demonstrate its in vivo imaging capability, which suggests that it could work as a mini-probe for certain clinical applications. PMID:23188360

Characterization of Akiyama probe applied to dual-probes atomic force microscope

NASA Astrophysics Data System (ADS)

Wang, Hequn; Gao, Sitian; Li, Wei; Shi, Yushu; Li, Qi; Li, Shi; Zhu, Zhendong

2016-10-01

The measurement of nano-scale line-width has always been important and difficult in the field of nanometer measurements, while the rapid development of integrated circuit greatly raises the demand again. As one kind of scanning probe microscope (SPM), atomic force microscope (AFM) can realize quasi three-dimensional measurement, which is widely used in nanometer scale line-width measurement. Our team researched a dual-probes atomic force microscope, which can eliminate the prevalent effect of probe width on measurement results. In dual-probes AFM system, a novel head are newly designed. A kind of self-sensing and self-exciting probes which is Nanosensors cooperation's patented probe—Akiyama probe, is used in this novel head. The Akiyama probe applied to dual-probe atomic force microscope is one of the most important issues. The characterization of Akiyama probe would affect performance and accuracy of the whole system. The fundamental features of the Akiyama probe are electrically and optically characterized in "approach-withdraw" experiments. Further investigations include the frequency response of an Akiyama probe to small mechanical vibrations externally applied to the tip and the effective loading force yielding between the tip and the sample during the periodic contact. We hope that the characterization of the Akiyama probe described in this paper will guide application for dual-probe atomic force microscope.

Intracellular O2 sensing probe based on cell-penetrating phosphorescent nanoparticles.

PubMed

Fercher, Andreas; Borisov, Sergey M; Zhdanov, Alexander V; Klimant, Ingo; Papkovsky, Dmitri B

2011-07-26

A new intracellular O(2) (icO(2)) sensing probe is presented, which comprises a nanoparticle (NP) formulation of a cationic polymer Eudragit RL-100 and a hydrophobic phosphorescent dye Pt(II)-tetrakis(pentafluorophenyl)porphyrin (PtPFPP). Using the time-resolved fluorescence (TR-F) plate reader set-up, cell loading was investigated in detail, particularly the effects of probe concentration, loading time, serum content in the medium, cell type, density, etc. The use of a fluorescent analogue of the probe in conjunction with confocal microscopy and flow cytometry analysis, revealed that cellular uptake of the NPs is driven by nonspecific energy-dependent endocytosis and that the probe localizes inside the cell close to the nucleus. Probe calibration in biological environment was performed, which allowed conversion of measured phosphorescence lifetime signals into icO(2) concentration (μM). Its analytical performance in icO(2) sensing experiments was demonstrated by monitoring metabolic responses of mouse embryonic fibroblast cells under ambient and hypoxic macroenvironment. The NP probe was seen to generate stable and reproducible signals in different types of mammalian cells and robust responses to their metabolic stimulation, thus allowing accurate quantitative analysis. High brightness and photostability allow its use in screening experiments with cell populations on a commercial TR-F reader, and for single cell analysis on a fluorescent microscope.

A nested array of rRNA targeted probes for the detection and identification of enterococci by reverse hybridization.

PubMed

Behr, T; Koob, C; Schedl, M; Mehlen, A; Meier, H; Knopp, D; Frahm, E; Obst, U; Schleifer, K; Niessner, R; Ludwig, W

2000-12-01

Complete 23S and almost complete 16S rRNA gene sequences were determined for the type strains of the validly described Enterococcus species, Melissococcus pluton and Tetragenococcus halophilus. A comprehensive set of rRNA targeted specific oligonucleotide hybridization probes was designed according to the multiple probe concept. In silico probe design and evaluation was performed using the respective tools of the ARB program package in combination with the ARB databases comprising the currently available 16S as well as 23S rRNA primary structures. The probes were optimized with respect to their application for reverse hybridization in microplate format. The target comprising 16S and 23S rDNA was amplified and labeled by PCR (polymerase chain reaction) using general primers targeting a wide spectrum of bacteria. Alternatively, amplification of two adjacent rDNA fragments of enterococci was performed by using specific primers. In vitro evaluation of the probe set was done including all Enterococcus type strains, and a selection of other representatives of the gram-positive bacteria with a low genomic DNA G+C content. The optimized probe set was used to analyze enriched drinking water samples as well as original samples from waste water treatment plants.

Timing Calibration in PET Using a Time Alignment Probe

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

Moses, William W.; Thompson, Christopher J.

2006-05-05

We evaluate the Scanwell Time Alignment Probe for performing the timing calibration for the LBNL Prostate-Specific PET Camera. We calibrate the time delay correction factors for each detector module in the camera using two methods--using the Time Alignment Probe (which measures the time difference between the probe and each detector module) and using the conventional method (which measures the timing difference between all module-module combinations in the camera). These correction factors, which are quantized in 2 ns steps, are compared on a module-by-module basis. The values are in excellent agreement--of the 80 correction factors, 62 agree exactly, 17 differ bymore » 1 step, and 1 differs by 2 steps. We also measure on-time and off-time counting rates when the two sets of calibration factors are loaded into the camera and find that they agree within statistical error. We conclude that the performance using the Time Alignment Probe and conventional methods are equivalent.« less

Enhancement of low-temperature thermometry by strong coupling

NASA Astrophysics Data System (ADS)

Correa, Luis A.; Perarnau-Llobet, Martí; Hovhannisyan, Karen V.; Hernández-Santana, Senaida; Mehboudi, Mohammad; Sanpera, Anna

2017-12-01

We consider the problem of estimating the temperature T of a very cold equilibrium sample. The temperature estimates are drawn from measurements performed on a quantum Brownian probe strongly coupled to it. We model this scenario by resorting to the canonical Caldeira-Leggett Hamiltonian and find analytically the exact stationary state of the probe for arbitrary coupling strength. In general, the probe does not reach thermal equilibrium with the sample, due to their nonperturbative interaction. We argue that this is advantageous for low-temperature thermometry, as we show in our model that (i) the thermometric precision at low T can be significantly enhanced by strengthening the probe-sampling coupling, (ii) the variance of a suitable quadrature of our Brownian thermometer can yield temperature estimates with nearly minimal statistical uncertainty, and (iii) the spectral density of the probe-sample coupling may be engineered to further improve thermometric performance. These observations may find applications in practical nanoscale thermometry at low temperatures—a regime which is particularly relevant to quantum technologies.

Comparison of Ventilatory Measures and 20 km Time Trial Performance.

PubMed

Peveler, Willard W; Shew, Brandy; Johnson, Samantha; Sanders, Gabe; Kollock, Roger

2017-01-01

Performance threshold measures are used to predict cycling performance. Previous research has focused on long time trials (≥ 40 km) using power at ventilatory threshold and respiratory threshold to estimate time trial performance. As intensity greatly differs during shorter time trails applying findings from longer time trials may not be appropriate. The use of heart rate measures to determine 20 km time trial performance has yet to be examined. The purpose of this study was to determine the effectiveness of heart rate measures at ventilatory threshold (VE/VO 2 Plotted and VT determined by software) and respiratory threshold (RER of 0.95, 1.00, and 1.05) to predict 20 km time trial performance. Eighteen cyclists completed a VO 2max protocol and two 20 km time trials. Average heart rates from 20 km time trials were compared with heart rates from performance threshold measures (VT plotted, VT software, and an RER at 0.95, 1.00, and 1.05) using repeated measures ANOVA. Significance was set a priori at P ≤ 0.05. The only measure not found to be significantly different in relation to time trial performance was HR at an RER of 1.00 (166.61±12.70 bpm vs. 165.89 ± 9.56 bpm, p = .671). VT plotting and VT determined by software were found to underestimate time trial performance by 3% and 8% respectively. From these findings it is recommended to use heart rate at a RER of 1.00 in order to determine 20 km time trial intensity.

Reproducibility of gastrocnemius medialis muscle architecture during treadmill running.

PubMed

Giannakou, Erasmia; Aggeloussis, Nickos; Arampatzis, Adamantios

2011-12-01

The purpose of this study was to assess the reproducibility of fascicle length (FL) and pennation angle (PA) of gastrocnemius medialis (GM) muscle during running in vivo. Twelve male recreational long distance runners (mean±SD; age: 24±3 years, mass: 76±7kg) ran on a treadmill at a speed of 3.0m/s, wearing their own running shoes, for two different 10min sessions that were at least 2 days apart. For each test day 10 acceptable trials were recorded. Ankle and knee joint angle data were recorded by a Vicon 624 system with three cameras operating at 120Hz. B-mode ultrasonography was used to examine fascicle length and pennation angle of gastrocnemius medialis muscle. The ultrasound probe was firmly secured on the muscle belly using a lightweight foam fixation. The results indicated that fascicle length and pennation angle demonstrated high reproducibility values during treadmill running both for within and between test days. The root mean square scores between the repeated waveforms of pennation angle and fascicle length were small (∼2° and ∼3.5mm, respectively). However, ∼14 trials for pennation angle and ∼9 trials for fascicle length may be required in order to record accurate data from muscle architecture parameters. In conclusion, ultrasound measurements may be highly reproducible during dynamic movements such as treadmill running, provided that a proper fixation is used in order to assure the constant location and orientation of the ultrasound probe throughout the movement. Copyright © 2011 Elsevier Ltd. All rights reserved.

A normalization model suggests that attention changes the weighting of inputs between visual areas

PubMed Central

Cohen, Marlene R.

2017-01-01

Models of divisive normalization can explain the trial-averaged responses of neurons in sensory, association, and motor areas under a wide range of conditions, including how visual attention changes the gains of neurons in visual cortex. Attention, like other modulatory processes, is also associated with changes in the extent to which pairs of neurons share trial-to-trial variability. We showed recently that in addition to decreasing correlations between similarly tuned neurons within the same visual area, attention increases correlations between neurons in primary visual cortex (V1) and the middle temporal area (MT) and that an extension of a classic normalization model can account for this correlation increase. One of the benefits of having a descriptive model that can account for many physiological observations is that it can be used to probe the mechanisms underlying processes such as attention. Here, we use electrical microstimulation in V1 paired with recording in MT to provide causal evidence that the relationship between V1 and MT activity is nonlinear and is well described by divisive normalization. We then use the normalization model and recording and microstimulation experiments to show that the attention dependence of V1–MT correlations is better explained by a mechanism in which attention changes the weights of connections between V1 and MT than by a mechanism that modulates responses in either area. Our study shows that normalization can explain interactions between neurons in different areas and provides a framework for using multiarea recording and stimulation to probe the neural mechanisms underlying neuronal computations. PMID:28461501

A normalization model suggests that attention changes the weighting of inputs between visual areas.

PubMed

Ruff, Douglas A; Cohen, Marlene R

2017-05-16

Models of divisive normalization can explain the trial-averaged responses of neurons in sensory, association, and motor areas under a wide range of conditions, including how visual attention changes the gains of neurons in visual cortex. Attention, like other modulatory processes, is also associated with changes in the extent to which pairs of neurons share trial-to-trial variability. We showed recently that in addition to decreasing correlations between similarly tuned neurons within the same visual area, attention increases correlations between neurons in primary visual cortex (V1) and the middle temporal area (MT) and that an extension of a classic normalization model can account for this correlation increase. One of the benefits of having a descriptive model that can account for many physiological observations is that it can be used to probe the mechanisms underlying processes such as attention. Here, we use electrical microstimulation in V1 paired with recording in MT to provide causal evidence that the relationship between V1 and MT activity is nonlinear and is well described by divisive normalization. We then use the normalization model and recording and microstimulation experiments to show that the attention dependence of V1-MT correlations is better explained by a mechanism in which attention changes the weights of connections between V1 and MT than by a mechanism that modulates responses in either area. Our study shows that normalization can explain interactions between neurons in different areas and provides a framework for using multiarea recording and stimulation to probe the neural mechanisms underlying neuronal computations.

SU-E-T-610: Phosphor-Based Fiber Optic Probes for Proton Beam Characterization

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

Darafsheh, A; Soldner, A; Liu, H

2015-06-15

Purpose: To investigate feasibility of using fiber optics probes with rare-earth-based phosphor tips for proton beam radiation dosimetry. We designed and fabricated a fiber probe with submillimeter resolution (<0.5 mm3) based on TbF3 phosphors and evaluated its performance for measurement of proton beam including profiles and range. Methods: The fiber optic probe with TbF3 phosphor tip, embedded in tissue-mimicking phantoms was irradiated with double scattering proton beam with energy of 180 MeV. Luminescence spectroscopy was performed by a CCD-coupled spectrograph to analyze the emission spectra of the fiber tip. In order to measure the spatial beam profile and percentage depthmore » dose, we used singular value decomposition method to spectrally separate the phosphors ionoluminescence signal from the background Cerenkov radiation signal. Results: The spectra of the TbF3 fiber probe showed characteristic ionoluminescence emission peaks at 489, 542, 586, and 620 nm. By using singular value decomposition we found the contribution of the ionoluminescence signal to measure the percentage depth dose in phantoms and compared that with measurements performed with ion chamber. We observed quenching effect at the spread out Bragg peak region, manifested as under-responding of the signal, due to the high LET of the beam. However, the beam profiles were not dramatically affected by the quenching effect. Conclusion: We have evaluated the performance of a fiber optic probe with submillimeter resolution for proton beam dosimetry. We demonstrated feasibility of spectral separation of the Cerenkov radiation from the collected signal. Such fiber probes can be used for measurements of proton beams profile and range. The experimental apparatus and spectroscopy method developed in this work provide a robust platform for characterization of proton-irradiated nanophosphor particles for ultralow fluence photodynamic therapy or molecular imaging applications.« less

Development and investigation of flexible polymer neural probe for chronic neural recording

NASA Astrophysics Data System (ADS)

Smith, Courtney; Song, Kyo D.; Yoon, Hargsoon; Kim, Woong-Ki; Zeng, Tao; Sanford, Larry D.

2012-04-01

Neural recording through microelectrodes requires biocompatibility and long term chronic usage. With a potential for various applications and effort to improve the performance of neural recording probes, consideration is taken to the tissue and cellular effects in these device designs. The degeneration of neurons due to brain tissue motion is an issue along with brain tissue inflammation in the insertion of the probes. To account for motion and irritation the material structure of the probes must be improved upon. This research presents the fabrication of neural probes on the microscale utilizing flexible polymers. Polyimide neural probes have been considered possibly to reduce degradation in their variability caused by brain motion. The microfabrication of the polyimide neural probe has an increased flexibility while accounting for biocompatibility and the needs for chronic use. Through microfabrication processes a needle probe is produced and tested for neural recording.

Radiolabeled inorganic nanoparticles for positron emission tomography imaging of cancer: an overview

PubMed Central

CHAKRAVARTY, Rubel; GOEL, Shreya; DASH, Ashutosh; CAI, Weibo

2017-01-01

Over the last few years, a plethora of radiolabeled inorganic nanoparticles have been developed and evaluated for their potential use as probes in positron emission tomography (PET) imaging of a wide variety of cancers. Inorganic nanoparticles represent an emerging paradigm in molecular imaging probe design, allowing the incorporation of various imaging modalities, targeting ligands, and therapeutic payloads into a single vector. A major challenge in this endeavor is to develop disease-specific nanoparticles with facile and robust radiolabeling strategies. Also, the radiolabeled nanoparticles should demonstrate adequate in vitro and in vivo stability, enhanced sensitivity for detection of disease at an early stage, optimized in vivo pharmacokinetics for reduced non-specific organ uptake, and improved targeting for achieving high efficacy. Owing to these challenges and other technological and regulatory issues, only a single radiolabeled nanoparticle formulation, namely “C-dots” (Cornell dots), has found its way into clinical trials thus far. This review describes the available options for radiolabeling of nanoparticles and summarizes the recent developments in PET imaging of cancer in preclinical and clinical settings using radiolabeled nanoparticles as probes. The key considerations toward clinical translation of these novel PET imaging probes are discussed, which will be beneficial for advancement of the field. PMID:28124549

Task probability and report of feature information: what you know about what you 'see' depends on what you expect to need.

PubMed

Pilling, Michael; Gellatly, Angus

2013-07-01

We investigated the influence of dimensional set on report of object feature information using an immediate memory probe task. Participants viewed displays containing up to 36 coloured geometric shapes which were presented for several hundred milliseconds before one item was abruptly occluded by a probe. A cue presented simultaneously with the probe instructed participants to report either about the colour or shape of the probe item. A dimensional set towards the colour or shape of the presented items was induced by manipulating task probability - the relative probability with which the two feature dimensions required report. This was done across two participant groups: One group was given trials where there was a higher report probability of colour, the other a higher report probability of shape. Two experiments showed that features were reported most accurately when they were of high task probability, though in both cases the effect was largely driven by the colour dimension. Importantly the task probability effect did not interact with display set size. This is interpreted as tentative evidence that this manipulation influences feature processing in a global manner and at a stage prior to visual short term memory. Copyright © 2013 Elsevier B.V. All rights reserved.

HERA: an atmospheric probe to unveil the depths of Saturn

NASA Astrophysics Data System (ADS)

Mousis, Olivier; Atkinson, David H.; Amato, Michael; Aslam, Shahid; Atreya, Sushil K.; Blanc, Michel; Bolton, Scott J.; Brugger, Bastien; Calcutt, Simon; Cavalié, Thibault; Charnoz, Sébastien; Coustenis, Athena; DELEUIL, Magali; Ferri, Francesca; Fletcher, Leigh N.; Guillot, Tristan; Hartogh, Paul; Holland, Andrew; Hueso, Ricardo; Keller, Christoph; Kessler, Ernst; Lebreton, Jean-Pierre; leese, Mark; Lellouch, Emmanuel; Levacher, Patrick; Marty, Bernard; Morse, Andrew; Nixon, Conor; Reh, Kim R.; Renard, Jean-Baptiste; Sanchez-Lavega, Agustin; Schmider, François-Xavier; Sheridan, Simon; Simon, Amy A.; Snik, Frans; Spilker, Thomas R.; Stam, Daphne M.; Venkatapathy, Ethiraj; Vernazza, Pierre; Waite, J. Hunter; Wurz, Peter

2016-10-01

The Hera Saturn entry probe mission is proposed as an M-class mission led by ESA with a significant collaboration with NASA. It consists of a Saturn atmospheric probe and a Carrier-Relay spacecraft. Hera will perform in situ measurements of the chemical and isotopic compositions as well as the dynamics of Saturn's atmosphere, with the goal of improving our understanding of the origin, formation, and evolution of Saturn, the giant planets and their satellite systems, with extrapolation to extrasolar planets.The primary science objectives will be addressed by an atmospheric entry probe that would descend under parachute and carry out in situ measurements beginning in the stratosphere to help characterize the location and properties of the tropopause, and continue into the troposphere to pressures of at least 10 bars. All of the science objectives, except for the abundance of oxygen, which may be only addressed indirectly via observations of species whose abundances are tied to the abundance of water, can be achieved by reaching 10 bars. As in previous highly successful collaborative efforts between ESA and NASA, the proposed mission has a baseline concept based on a NASA-provided carrier/data relay spacecraft that would deliver the ESA-provided atmospheric probe to the desired atmospheric entry point at Saturn. ESA's proposed contribution should fit well into the M5 Cosmic Vision ESA call cost envelope.A nominal mission configuration would consist of a probe that detaches from the carrier one to several months prior to probe entry. Subsequent to probe release, the carrier trajectory would be deflected to optimize the over-flight phasing of the probe descent location for both probe data relay as well as performing carrier approach and flyby science, and would allow multiple retransmissions of the probe data for redundancy. The Saturn atmospheric entry probe would in many respects resemble the Jupiter Galileo probe. It is anticipated that the probe architecture for this mission would be battery-powered and accommodate a data relay to the carrier for data collection, storage on board the carrier/data relay, for later retransmission to Earth.

Evidence for proactive interference in the focus of attention of working memory.

PubMed

Carroll, Lauren M; Jalbert, Annie; Penney, Alexander M; Neath, Ian; Surprenant, Aimée M; Tehan, Gerald

2010-09-01

Proactive interference (PI) occurs when an earlier item interferes with memory for a newer item. Whereas some researchers (e.g., Surprenant & Neath, 2009a) argue that PI can be observed in all memory systems, some multiple systems theorists (e.g., Cowan, 1999) propose that items in the focus of attention of working memory are immune to PI. Two experiments tested whether PI occurs when the to-be-remembered items are assumed, by multiple-systems theorists, to be held in the focus of attention. In each experiment, subjects saw four trials in a row with the same type of to-be-remembered items, followed by four trials in a row with a different type of material. On each trial, only 3 stimuli were shown, which is below the capacity limit of the focus of attention, and subjects were asked if a probe item was one of those 3 items seen. In both experiments, response time increased from Trial 1 to Trial 4, suggesting that items from the earlier trials interfered with memory on the later trials. In addition, release from PI was shown in that response times decreased with a change of materials. The results replicate those first reported by Hanley and Scheirer (1975), and pose a problem for theorists who argue that parts of short-term memory are immune to PI. Copyright 2010 APA, all rights reserved.

A randomized controlled trial of pre-conception treatment for periodontal disease to improve periodontal status during pregnancy and birth outcomes.

PubMed

Jiang, Hong; Xiong, Xu; Su, Yi; Zhang, Yiming; Wu, Hongqiao; Jiang, Zhijun; Qian, Xu

2013-12-09

Evidence has suggested that periodontal disease is associated with an increased risk of various adverse pregnancy and birth outcomes. However, several large clinical randomized controlled trials failed to demonstrate periodontal therapy during pregnancy reduced the incidence of adverse pregnancy and birth outcomes. It has been suggested that the pre-conception period may be an optimal period for periodontal disease treatment rather than during pregnancy. To date, no randomized controlled trial (RCT) has examined if treating periodontal disease before pregnancy reduces adverse birth outcomes. This study aims to examine if the pre-conception treatment of periodontal disease will lead to improved periodontal status during late pregnancy and subsequent birth outcomes. A sample of 470 (235 in each arm of the study) pre-conception women who plan to conceive within one year and with periodontal disease will be recruited for the study. All participants will be randomly allocated to the intervention or control group. The intervention group will receive free therapy including dental scaling and root planning (the standard therapy), supragingival prophylaxis, and oral hygiene education. The control group will only receive supragingival prophylaxis and oral hygiene education. Women will be followed throughout their pregnancy and then to childbirth. The main outcomes include periodontal disease status in late pregnancy and birth outcomes measured such as mean birth weight (grams), and mean gestational age (weeks). Periodontal disease will be diagnosed through a dental examination by measuring probing depth, clinical attachment loss and percentage of bleeding on probing (BOP) between gestational age of 32 and 36 weeks. Local and systemic inflammatory mediators are also included as main outcomes. This will be the first RCT to test whether treating periodontal disease among pre-conception women reduces periodontal disease during pregnancy and prevents adverse birth outcomes. If the effect of pre-pregnancy periodontal treatment is confirmed, this intervention could be recommended for application in low- or middle-income countries to improve both oral health and maternal and child health. This trial is registered with Chinese Clinical Trial Registry (ChiCTR): ChiCTR-TRC-12001913.

Effectiveness of adjunctive subgingival administration of amino acids and sodium hyaluronate gel on clinical and immunological parameters in the treatment of chronic periodontitis

PubMed Central

Bevilacqua, Lorenzo; Eriani, Jessica; Serroni, Ilde; Liani, Giuliana; Borelli, Violetta; Castronovo, Gaetano; Di Lenarda, Roberto

2012-01-01

Summary Aims The aim of this clinical trial was to compare clinical and biochemical healing outcomes following ultrasonic mechanical instrumentation versus ultrasonic mechanical instrumentation associated with topical subgingival application of amino acids and sodium hyaluronate gel. Methods Eleven systemically healthy subjects with moderate-severe chronic periodontitis, who had four sites with pocket probing depth and clinical attachment level greater than or equal to 5 mm were randomly assigned to two different types of treatment: two pockets were treated with ultrasonic debridement (Control Group) and two pockets with ultrasonic mechanical instrumentation associated with 0,5 ml of amino acids and sodium hyaluronate gel (Test Group). Probing depth, clinical attachment level, plaque index and bleeding on probing were recorded at baseline, 45 and 90 days. Levels of calprotectin and myeloperoxidase activity in gingival crevicular fluid were assessed at baseline and on day 7 and 45. Results Statistical significance was found between baseline and day 45 in relation to probing depth reduction and bleeding on probing between groups for both of the tested treatments. Significant reductions in μg/sample of calprotectin and myeloperoxidase were found after 1-week and an increase at 45 days in both groups. There were no statistically significant differences between other variables evaluated in this study. Conclusions These data suggest that subgingival application of hyaluronic acid following ultrasonic mechanical instrumentation is beneficial for improving periodontal parameters. PMID:23087790

Massive Memory Revisited: Limitations on Storage Capacity for Object Details in Visual Long-Term Memory

ERIC Educational Resources Information Center

Cunningham, Corbin A.; Yassa, Michael A.; Egeth, Howard E.

2015-01-01

Previous work suggests that visual long-term memory (VLTM) is highly detailed and has a massive capacity. However, memory performance is subject to the effects of the type of testing procedure used. The current study examines detail memory performance by probing the same memories within the same subjects, but using divergent probing methods. The…

Rationale and design of a prospective study: Cervical Dystonia Patient Registry for Observation of OnaBotulinumtoxinA Efficacy (CD PROBE)

PubMed Central

2011-01-01

Background A registry of patients with cervical dystonia (Cervical Dystonia Patient Registry for Observation of onaBotulinumtoxinA Efficacy [CD PROBE]) was initiated to capture data regarding physician practices and patient outcomes with onabotulinumtoxinA (BOTOX®, Allergan, Inc., Irvine, CA, USA). Methods and baseline demographics from an interim analysis are provided. Methods/Design This is a prospective, multicenter, clinical registry in the United States enrolling subjects with cervical dystonia (CD) who are toxin naïve and/or new to the physicians' practices, or who had been in a clinical trial but received their last injection ≥ 16 weeks prior to enrollment. Subjects are followed over 3 injection cycles of onabotulinumtoxinA, with assessments at time of injection and 4-6 weeks later. Information on physician's practice, patient demographics, CD disease history, duration of treatment intervals and neurotoxin dose, dilution, use of electromyography, and muscles injected are collected. Outcomes are assessed by physicians and subjects using various questionnaires. Discussion This ongoing registry includes 609 subjects with the following baseline data: 75.9% female, 93.6% Caucasian, mean age 57.6 ± 14.3, age at symptom onset 48.3 ± 16.2, and time to diagnosis 5.4 ± 8.6 years, with an additional 1.0 ± 3.5 years before treatment. Of those employed at the time of diagnosis, 36.6% stopped working as a result of CD. CD PROBE, the largest clinical registry of CD treatment, will provide useful data on current treatment practices with onabotulinumtoxinA, potentially leading to refinements for optimization of outcomes. Trial registration NCT00836017 PMID:22054223

Diclofenac Suppository as a Preemptive Analgesia in Ultrasound-guided Biopsy of Prostate: Randomized Controlled Trial.

PubMed

Haroon, Naveed; Ather, M Hammad; Khan, Salma; Kumar, Pirkash; Salam, Basit

2015-10-01

To compare preprocedure Diclofenac suppository and Xylocaine gel with Xylocaine gel only in patients undergoing transrectal ultrasound (TRUS)-guided biopsy of prostate for pain. It is a randomized controlled trial conducted on patients undergoing TRUS-guided biopsy for clinical or biochemical suspicion of prostate cancer following a written informed consent and Ethics Review Committee approval. Patients were randomized into 2 groups. Group A included those patients who received Diclofenac suppository 2 hours before in combination with 10 mL of 2% Xylocaine gel 5 minutes before biopsy. Group B received Xylocaine gel only. A visual analog scale was used to measure the pain scores at the time of TRUS probe insertion, just after taking biopsy cores and 2 hours after biopsy. A total of 100 patients were recruited in the study with 50 patients each in group A and B. Mean age of group A was 69.1 ± 10 years and 67.3 ± 8.1 years for group B. The mean pain score for group A and B at the time of probe insertion was 0.08 ± 0.27 and 0.34 ± 0.63 (P = .032), immediately after taking biopsy cores was 1.46 ± 1.15 and 4.68 ± 0.77 (P = .000), and 2 hours after biopsy was 0.14 ± 0.45 vs 2.40 ± 0.81 (P = .000), respectively. The mean pain score at the time of TRUS probe insertion, immediately after taking biopsy cores, and 2 hours after biopsy is statistically significantly higher in group B. Copyright © 2015 Elsevier Inc. All rights reserved.

Contingency-based emotional resilience: effort-based reward training and flexible coping lead to adaptive responses to uncertainty in male rats

PubMed Central

Lambert, Kelly G.; Hyer, Molly M.; Rzucidlo, Amanda A.; Bergeron, Timothy; Landis, Timothy; Bardi, Massimo

2014-01-01

Emotional resilience enhances an animal's ability to maintain physiological allostasis and adaptive responses in the midst of challenges ranging from cognitive uncertainty to chronic stress. In the current study, neurobiological factors related to strategic responses to uncertainty produced by prediction errors were investigated by initially profiling male rats as passive, active or flexible copers (n = 12 each group) and assigning to either a contingency-trained or non-contingency trained group. Animals were subsequently trained in a spatial learning task so that problem solving strategies in the final probe task, as well-various biomarkers of brain activation and plasticity in brain areas associated with cognition and emotional regulation, could be assessed. Additionally, fecal samples were collected to further determine markers of stress responsivity and emotional resilience. Results indicated that contingency-trained rats exhibited more adaptive responses in the probe trial (e.g., fewer interrupted grooming sequences and more targeted search strategies) than the noncontingent-trained rats; additionally, increased DHEA/CORT ratios were observed in the contingent-trained animals. Diminished activation of the habenula (i.e., fos-immunoreactivity) was correlated with resilience factors such as increased levels of DHEA metabolites during cognitive training. Of the three coping profiles, flexible copers exhibited enhanced neuroplasticity (i.e., increased dentate gyrus doublecortin-immunoreactivity) compared to the more consistently responding active and passive copers. Thus, in the current study, contingency training via effort-based reward (EBR) training, enhanced by a flexible coping style, provided neurobiological resilience and adaptive responses to prediction errors in the final probe trial. These findings have implications for psychiatric illnesses that are influenced by altered stress responses and decision-making abilities (e.g., depression). PMID:24808837

Adjunctive Systemic Antimicrobial Therapy vs Asepsis in Conjunction with Guided Tissue Regeneration: A Randomized, Controlled Clinical Trial.

PubMed

Abu-Ta'a, Mahmoud

2016-01-01

This randomized clinical trial compares the usefulness of adjunctive antibiotics, while strict asepsis was followed during periodontal surgery involving guided tissue regeneration. Two groups of 20 consecutive patients each with advanced periodontal disease were randomly assigned to treatment. They displayed one angular defect each with an intrabony component ≥3 mm, probing pocket depth and probing attachment level (PAL) ≥7 mm. Test group included 13 males, mean age 60 years, treated with enamel matrix derivative (EMD) and demineralized freeze-dried bone allograft with modified papilla preservation technique, received oral amoxicillin 1 gm, 1 hour preoperatively and 2 gm for 2 days postoperatively. Control group included 10 males, mean age 57 years, treated with EMD and demineralized freeze-dried bone allograft with modified papilla preservation technique, received no antibiotics. Outcome measures were clinical attachment level (CAL) gain, residual periodontal pocket depth (res. PD), gingival recession (GR), bleeding on probing (BOP), adverse events and postoperative complications. Patients were followed up to 12 months after periodontal surgery involving guided tissue regeneration. There were no significant differences between both groups for CAL gain, res. PD, GR, BOP nor other clinical parameters, though patients' subjective perception of postoperative discomfort was significantly smaller in the group receiving antibiotics. Antibiotics do not provide significant advantages concerning clinical periodontal parameters nor concerning postoperative infections in case of proper asepsis. It does, on the contrary, reduce postoperative discomfort. Regarding the results of this study, adjunc-tive systemic antibiotics in combination with guided tissue regeneration may be useful in reducing postoperative discomfort but may not be helpful for improving periodontal regeneration outcomes.

Contingency-based emotional resilience: effort-based reward training and flexible coping lead to adaptive responses to uncertainty in male rats.

PubMed

Lambert, Kelly G; Hyer, Molly M; Rzucidlo, Amanda A; Bergeron, Timothy; Landis, Timothy; Bardi, Massimo

2014-01-01

Emotional resilience enhances an animal's ability to maintain physiological allostasis and adaptive responses in the midst of challenges ranging from cognitive uncertainty to chronic stress. In the current study, neurobiological factors related to strategic responses to uncertainty produced by prediction errors were investigated by initially profiling male rats as passive, active or flexible copers (n = 12 each group) and assigning to either a contingency-trained or non-contingency trained group. Animals were subsequently trained in a spatial learning task so that problem solving strategies in the final probe task, as well-various biomarkers of brain activation and plasticity in brain areas associated with cognition and emotional regulation, could be assessed. Additionally, fecal samples were collected to further determine markers of stress responsivity and emotional resilience. Results indicated that contingency-trained rats exhibited more adaptive responses in the probe trial (e.g., fewer interrupted grooming sequences and more targeted search strategies) than the noncontingent-trained rats; additionally, increased DHEA/CORT ratios were observed in the contingent-trained animals. Diminished activation of the habenula (i.e., fos-immunoreactivity) was correlated with resilience factors such as increased levels of DHEA metabolites during cognitive training. Of the three coping profiles, flexible copers exhibited enhanced neuroplasticity (i.e., increased dentate gyrus doublecortin-immunoreactivity) compared to the more consistently responding active and passive copers. Thus, in the current study, contingency training via effort-based reward (EBR) training, enhanced by a flexible coping style, provided neurobiological resilience and adaptive responses to prediction errors in the final probe trial. These findings have implications for psychiatric illnesses that are influenced by altered stress responses and decision-making abilities (e.g., depression).

Direction of attention bias to threat relates to differences in fear acquisition and extinction in anxious children.

PubMed

Waters, Allison M; Kershaw, Rachel

2015-01-01

Anxious children show attention biases towards and away from threat stimuli. Moreover, threat avoidance compared to vigilance predicts a poorer outcome from exposure-based treatments, such as cognitive-behavioural therapy (CBT), yet the mechanisms underlying this differential response are unclear. Pavlovian fear conditioning is a widely accepted theory to explain the acquisition and extinction of fear, including exposure-based treatments, such as CBT. In typical fear conditioning experiments, anxious children have shown larger physiological responses to an aversive unconditional stimulus (i.e., US on CS+ trials) and to non-reinforced stimuli (CS-) during fear acquisition and to both CSs during fear extinction compared to non-anxious peers. This study examined whether threat avoidance compared to threat vigilance was related to differences in fear acquisition and extinction in anxious children. Thirty-four clinically-anxious children completed a visual probe task including angry-neutral face pairs to determine the direction of threat attention bias as well as a discriminant conditioning and extinction task in which a geometric shape CS+ was paired with an aversive tone US, while the CS- geometric shape was always presented alone during acquisition trials. Both CSs were presented alone during extinction trials. Fear acquisition and extinction were indexed by skin conductance responses (SCR) and subjective measures. Children were classified as threat vigilant (N = 18) and threat avoidant (n = 16) based on the direction of threat attention bias on the visual probe task. During acquisition, threat avoidant relative to threat vigilant anxious children displayed larger orienting SCRs to both CSs during the first block of trials and larger third interval SCRs to the US on CS+ trials as well as on CS- trials. During extinction, threat avoidant anxious children showed delayed extinction of SCRs to both the CS+ and CS- and reported higher subjective anxiety ratings after extinction compared to threat vigilant anxious children. Threat avoidant anxious children may be more reactive physiologically to novel cues and to stimuli that become associated with threat and this may interfere with extinction learning. These findings could help explain previous evidence that threat avoidant anxious children do not respond as well as threat vigilant anxious children to exposure-based CBT. Copyright © 2014 Elsevier Ltd. All rights reserved.

Measurement of Turbulent Pressure and Temperature Fluctuations in a Gas Turbine Combustor

NASA Technical Reports Server (NTRS)

Passaro, Andrea; LaGraff, John E.; Oldfield, Martin L. G.; Biagioni, Leonardo; Moss, Roger W.; Battelle, Ryan T.; Povinelli, Louis A. (Technical Monitor)

2003-01-01

The present research concerns the development of high-frequency pressure and temperature probes and related instrumentation capable of performing spectral characterization of unsteady pressure and temperature fluctuations over the 0.05 20 kHz range, at the exit of a gas turbine combustor operating at conditions close to nominal ones for large power generation turbomachinery. The probes used a transient technique pioneered at Oxford University; in order to withstand exposure to the harsh environment the probes were fitted on a rapid injection and cooling system jointly developed by Centrospazio CPR and Syracuse University. The experimental runs were performed on a large industrial test rig being operated by ENEL Produzione. The achieved results clearly show the satisfactory performance provided by this diagnostic tool, even though the poor location of the injection port prevented the tests from yielding more insight of the core flow turbulence characteristics. The pressure and temperature probes survived several dozen injections in the combustor hot jet, while consistently providing the intended high frequency performance. The apparatus was kept connected to the combustor during long duration firings, operating as an unobtrusive, self contained, piggy-back experiment: high frequency flow samplings were remotely recorded at selected moments corresponding to different combustor operating conditions.

Challenges and advances in quantum dot fluorescent probes to detect reactive oxygen and nitrogen species: a review.

PubMed

Adegoke, Oluwasesan; Forbes, Patricia B C

2015-03-03

The pathological and physiological effects of reactive oxygen and nitrogen species (ROS/RNS) have instigated increasing awareness in the scientific field with respect to the development of suitable probes for their detection. Among the various probes developed to date, semiconductor quantum dots (QDs) fluorescent probes have attracted significant attention. The unfavourable properties of ROS/RNS with respect to their detection, such as their short lifetimes and the competitive presence of various endogenous reactive species, capable of interfering with the probe in biological matrices, have hindered the effective performance of most probes as well as complicating the design of suitable probes. The development of novel QD fluorescent probes capable of circumventing these problems is thus, of scientific interest. In this review, we highlight the challenges faced, pros and cons and published developments to date, with respect to QD fluorescent probes for ROS/RNS such as H2O2, O2(·-), ·OH, HOCl, NO and ONOO(-). Copyright © 2014 Elsevier B.V. All rights reserved.

A Direct, Quantitative Connection between Molecular Dynamics Simulations and Vibrational Probe Line Shapes.

PubMed

Xu, Rosalind J; Blasiak, Bartosz; Cho, Minhaeng; Layfield, Joshua P; Londergan, Casey H

2018-05-17

A quantitative connection between molecular dynamics simulations and vibrational spectroscopy of probe-labeled systems would enable direct translation of experimental data into structural and dynamical information. To constitute this connection, all-atom molecular dynamics (MD) simulations were performed for two SCN probe sites (solvent-exposed and buried) in a calmodulin-target peptide complex. Two frequency calculation approaches with substantial nonelectrostatic components, a quantum mechanics/molecular mechanics (QM/MM)-based technique and a solvatochromic fragment potential (SolEFP) approach, were used to simulate the infrared probe line shapes. While QM/MM results disagreed with experiment, SolEFP results matched experimental frequencies and line shapes and revealed the physical and dynamic bases for the observed spectroscopic behavior. The main determinant of the CN probe frequency is the exchange repulsion between the probe and its local structural neighbors, and there is a clear dynamic explanation for the relatively broad probe line shape observed at the "buried" probe site. This methodology should be widely applicable to vibrational probes in many environments.

Overestimation of Mach number due to probe shadow

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

Gosselin, J. J.; Thakur, S. C.; Tynan, G. R.

2016-07-15

Comparisons of the plasma ion flow speed measurements from Mach probes and laser induced fluorescence were performed in the Controlled Shear Decorrelation Experiment. We show the presence of the probe causes a low density geometric shadow downstream of the probe that affects the current density collected by the probe in collisional plasmas if the ion-neutral mean free path is shorter than the probe shadow length, L{sub g} = w{sup 2} V{sub drift}/D{sub ⊥}, resulting in erroneous Mach numbers. We then present a simple correction term that provides the corrected Mach number from probe data when the sound speed, ion-neutral mean free path,more » and perpendicular diffusion coefficient of the plasma are known. The probe shadow effect must be taken into account whenever the ion-neutral mean free path is on the order of the probe shadow length in linear devices and the open-field line region of fusion devices.« less

EFFECTS OF A MODIFIED VITRECTOMY PROBE IN SMALL-GAUGE VITRECTOMY: An Experimental Study on the Flow and on the Traction Exerted on the Retina.

PubMed

Rizzo, Stanislao; Fantoni, Gualtiero; de Santis, Giovanni; Lue, Jaw-Chyng Lormen; Ciampi, Jonathan; Palla, Michele; Genovesi Ebert, Federica; Savastano, Alfonso; De Maria, Carmelo; Vozzi, Giovanni; Brant Fernandes, Rodrigo A; Faraldi, Francesco; Criscenti, Giuseppe

2017-09-01

Thorough this experimental study, the physic features of a modified 23-gauge vitrectomy probe were evaluated in vitro. A modified vitrectomy probe to increase vitreous outflow rate with a small-diameter probe, that also minimized tractional forces on the retina, was created and tested. The "new" probe was created by drilling an opening into the inner duct of a traditional 23-gauge probe with electrochemical or electrodischarge micromachining. Both vitreous outflow and tractional forces on the retina were examined using experimental models of vitreous surgery. The additional opening allowed the modified probe to have a cutting rate of 5,000 cuts per minute, while sustaining an outflow approximately 45% higher than in conventional 23-gauge probes. The modified probe performed two cutting actions per cycle, not one, as in standard probes. Because tractional force is influenced by cutting rate, retinal forces were 2.2 times lower than those observed with traditional cutters. The modified probe could be useful in vitreoretinal surgery. It allows for faster vitreous removal while minimizing tractional forces on the retina. Moreover, any available probe can be modified by creating a hole in the inner duct.

Solar Probe Cup: Laboratory Performance

NASA Astrophysics Data System (ADS)

Case, A. W.; Kasper, J. C.; Korreck, K. E.; Stevens, M. L.; Larson, D. E.; Wright, K. H., Jr.; Gallagher, D. L.; Whittlesey, P. L.

2017-12-01

The Solar Probe Cup (SPC) is a Faraday Cup instrument that will fly on the Paker Solar Probe (PSP) spacecraft, orbiting the Sun at as close as 9.86 solar radii. The SPC instrument is designed to measure the thermal solar wind plasma (protons, alphas, and electrons) that will be encountered throughout its close encounter with the Sun. Due to the solar wind flow being primarily radial, the SPC instrument is pointed directly at the Sun, resulting in an extreme thermal environment that must be tolerated throughout the primary data collection phase. Laboratory testing has been performed over the past 6 months to demonstrate the instrument's performance relative to its requirements, and to characterize the measurements over the expected thermal range. This presentation will demonstrate the performance of the instrument as measured in the lab, describe the operational configurations planned for flight, and discuss the data products that will be created.

Sealed magic angle spinning nuclear magnetic resonance probe and process for spectroscopy of hazardous samples

DOEpatents

Cho, Herman M.; Washton, Nancy M.; Mueller, Karl T.; Sears, Jr., Jesse A.; Townsend, Mark R.; Ewing, James R.

2016-06-14

A magic-angle-spinning (MAS) nuclear magnetic resonance (NMR) probe is described that includes double containment enclosures configured to seal and contain hazardous samples for analysis. The probe is of a modular design that ensures containment of hazardous samples during sample analysis while preserving spin speeds for superior NMR performance and convenience of operation.

Achievement Levels of Middle School Students in the Standardized Science and Technology Exam and Formative Assessment Probes: A Comparative Study

ERIC Educational Resources Information Center

Bulunuz, Nermin; Bulunuz, Mizrap; Karagoz, Funda; Tavsanli, Omer Faruk

2016-01-01

The present study has two aims. Firstly, it aims to determine eighth grade students' conceptual understanding of floating and sinking through formative assessment probes. Secondly, it aims to determine whether or not there is a significant difference between students' performance in formative assessment probes and their achievement in the…

An Exemplar-Familiarity Model Predicts Short-Term and Long-Term Probe Recognition across Diverse Forms of Memory Search

ERIC Educational Resources Information Center

Nosofsky, Robert M.; Cox, Gregory E.; Cao, Rui; Shiffrin, Richard M.

2014-01-01

Experiments were conducted to test a modern exemplar-familiarity model on its ability to account for both short-term and long-term probe recognition within the same memory-search paradigm. Also, making connections to the literature on attention and visual search, the model was used to interpret differences in probe-recognition performance across…

Energy Donor Effect on the Sensing Performance for a Series of FRET-Based Two-Photon Fluorescent Hg2+ Probes

PubMed Central

Zhang, Yujin; Hu, Wei

2017-01-01

Nonlinear optical properties of a series of newly-synthesized molecular fluorescent probes for Hg2+ containing the same acceptor (rhodamine group) are analyzed by using time-dependent density functional theory in combination with analytical response theory. Special emphasis is placed on evolution of the probes’ optical properties in the absence and presence of Hg2+. These compounds show drastic changes in their photoabsorption and photoemission properties when they react with Hg2+, indicating that they are excellent candidates for ratiometric and colorimetric fluorescent chemosensors. Most importantly, the energy donor moiety is found to play a dominant role in sensing performance of these probes. Two-photon absorption cross sections of the compounds are increased with the presence of Hg2+, which theoretically suggests the possibility of the probes to be two-photon fluorescent Hg2+ sensors. Moreover, analysis of molecular orbitals is presented to explore responsive mechanism of the probes, where the fluorescence resonant energy transfer process is theoretically demonstrated. Our results elucidate the available experimental measurements. This work provides guidance for designing efficient two-photon fluorescent probes that are geared towards biological and chemical applications. PMID:28772466

Handheld magnetic probe with permanent magnet and Hall sensor for identifying sentinel lymph nodes in breast cancer patients.

PubMed

Sekino, Masaki; Kuwahata, Akihiro; Ookubo, Tetsu; Shiozawa, Mikio; Ohashi, Kaichi; Kaneko, Miki; Saito, Itsuro; Inoue, Yusuke; Ohsaki, Hiroyuki; Takei, Hiroyuki; Kusakabe, Moriaki

2018-01-19

The newly developed radioisotope-free technique based on magnetic nanoparticle detection using a magnetic probe is a promising method for sentinel lymph node biopsy. In this study, a novel handheld magnetic probe with a permanent magnet and magnetic sensor is developed to detect the sentinel lymph nodes in breast cancer patients. An outstanding feature of the probe is the precise positioning of the sensor at the magnetic null point of the magnet, leading to highly sensitive measurements unaffected by the strong ambient magnetic fields of the magnet. Numerical and experimental results show that the longitudinal detection length is approximately 10 mm, for 140 μg of iron. Clinical tests were performed, for the first time, using magnetic and blue dye tracers-without radioisotopes-in breast cancer patients to demonstrate the performance of the probe. The nodes were identified through transcutaneous and ex-vivo measurements, and the iron accumulation in the nodes was quantitatively revealed. These results show that the handheld magnetic probe is useful in sentinel lymph node biopsy and that magnetic techniques are widely being accepted as future standard methods in medical institutions lacking nuclear medicine facilities.

7 CFR 800.117 - Who shall perform original services.

Code of Federal Regulations, 2011 CFR

2011-01-01

... by another official agency upon approval from the Service. (3) Barge probe service. Any official agency may provide probe sampling and inspection service for barge-lots of grain with no restrictions due...

7 CFR 800.117 - Who shall perform original services.

Code of Federal Regulations, 2012 CFR

2012-01-01

... by another official agency upon approval from the Service. (3) Barge probe service. Any official agency may provide probe sampling and inspection service for barge-lots of grain with no restrictions due...

7 CFR 800.117 - Who shall perform original services.

Code of Federal Regulations, 2013 CFR

2013-01-01

... by another official agency upon approval from the Service. (3) Barge probe service. Any official agency may provide probe sampling and inspection service for barge-lots of grain with no restrictions due...

7 CFR 800.117 - Who shall perform original services.

Code of Federal Regulations, 2014 CFR

2014-01-01

... by another official agency upon approval from the Service. (3) Barge probe service. Any official agency may provide probe sampling and inspection service for barge-lots of grain with no restrictions due...

Preparation of near-infrared-labeled targeted contrast agents for clinical translation

NASA Astrophysics Data System (ADS)

Olive, D. Michael

2011-03-01

Targeted fluorophore-labeled contrast agents are moving toward translation to human surgical use. To prepare for future clinical use, we examined the performance of potential ligands targeting the epidermal growth factor receptor, α5β3 integrins, and GLUT transporters for their suitability as directed contrast agents. Each agent was labeled with IRDye 800CW, and near-infrared dye with excitation/emission wavelengths of 789/805 nm, which we determined had favorable toxicity characteristics. The probe molecules examined consisted of Affibodies, nanobodies, peptides, and the sugar 2-deoxy-D-glucose. Each probe was tested for specific and non-specific binding in cell based assays. All probe types showed good performance in mouse models for detecting either spontaneous tumors or tumor xenografts in vivo. Each of the probes tested show promise for future human clinical studies.

Cryogenic probe station for use in automated microwave and noise figure measurements

NASA Technical Reports Server (NTRS)

Taub, Susan R.; Alterovitz, Samuel A.; Young, Paul G.; Ebihara, Ben T.; Romanofsky, Robert R.

1994-01-01

A cryogenic measurement system capable of performing on-wafer RF testing of semiconductor devices and circuits has been developed. This 'CryoProbe Station' can wafer-probe devices and circuits at cryogenic temperatures, thus eliminating the need for wire bonds. The system operates under vacuum created by a sorption pump. It uses an open cycle cooling system that can be cooled with either liquid nitrogen or liquid helium. Presently, it can reach temperatures, as low as 80 K and 37 K for each of the coolants, respectively. The temperature can be raised using a heater and it is stabilized to within 0.2 K by use of a temperature controller. The CryoProbe Station features a 1 by 2 inch stage that can hold large circuits and calibration standards simultaneously. The system is used with a Hewlett Packard 8510C Automatic Network Analyzer (ANA) to obtain S-parameter data over the frequency range 0.045-26.5 GHz. S-parameter data on HEMT (high electron mobility transistors) devices has been obtained with this station. With the use of DEEMBED software from NIST, detailed transmission line studies have been performed. Although the CryoProbe Station is designed for frequencies up to 26.5 GHz, useful transmission line data has been obtained for frequencies as high as 40 GHz. The CryoProbe station has also been used with the ATN noise figure measurement system to perform automatic, temperature dependent noise figure measurements.

Effect of structure on sensing performance of a target induced signaling probe shifting DNA-based (TISPS-DNA) sensor.

PubMed

Yu, Xiang; Yu, Zhigang; Li, Fengqin; Xu, Yanmei; He, Xunjun; Xu, Lan; Shi, Wenbing; Zhang, Guiling; Yan, Hong

2017-05-15

A type of "signal on" displacement-based sensors named target induced signaling probe shifting DNA-based (TISPS-DNA) sensor were developed for a designated DNA detection. The signaling mechanism of the signaling probe (SP) shifting different from the classical conformation/flexibility change mode endows the sensor with high sensitivity. Through using thiolated or no thiolated capturing probe (CP), two 3-probe sensing structures, sensor-1 and sensor-2, were designed and constructed. The systematical comparing research results show that both sensors exhibit some similarities or big differences in sensing performance. On the one hand, the similarity in structures determines the similarity in some aspects of signaling mechanism, background signal, signal changing form, anti-fouling ability and versatility; on the other hand, the slight difference in structures also results in two opposite hybridization modes of gradual increasing resistance and gradual decreasing resistance which can affect the hybridization efficiency between the assistant probe (AP) and the SP, further producing some big differences in sensing performance, for example, apparently different signal enhancement (SE) change, point mutation discrimination ability and response speed. Under the optimized fabrication and detection conditions, both sensors feature high sensitivity for target DNAs with the detection limits of ∼10 fM for sensor-1 and ∼7 fM for sensor-2, respectively. Among many acquired sensing virtues, the sensor-1 shows a peculiar specificity adjustability which is also a highlight in this work. Copyright © 2017 Elsevier B.V. All rights reserved.

Optimal arrangements of fiber optic probes to enhance the spatial resolution in depth for 3D reflectance diffuse optical tomography with time-resolved measurements performed with fast-gated single-photon avalanche diodes

NASA Astrophysics Data System (ADS)

Puszka, Agathe; Di Sieno, Laura; Dalla Mora, Alberto; Pifferi, Antonio; Contini, Davide; Boso, Gianluca; Tosi, Alberto; Hervé, Lionel; Planat-Chrétien, Anne; Koenig, Anne; Dinten, Jean-Marc

2014-02-01

Fiber optic probes with a width limited to a few centimeters can enable diffuse optical tomography (DOT) in intern organs like the prostate or facilitate the measurements on extern organs like the breast or the brain. We have recently shown on 2D tomographic images that time-resolved measurements with a large dynamic range obtained with fast-gated single-photon avalanche diodes (SPADs) could push forward the imaged depth range in a diffusive medium at short source-detector separation compared with conventional non-gated approaches. In this work, we confirm these performances with the first 3D tomographic images reconstructed with such a setup and processed with the Mellin- Laplace transform. More precisely, we investigate the performance of hand-held probes with short interfiber distances in terms of spatial resolution and specifically demonstrate the interest of having a compact probe design featuring small source-detector separations. We compare the spatial resolution obtained with two probes having the same design but different scale factors, the first one featuring only interfiber distances of 15 mm and the second one, 10 mm. We evaluate experimentally the spatial resolution obtained with each probe on the setup with fast-gated SPADs for optical phantoms featuring two absorbing inclusions positioned at different depths and conclude on the potential of short source-detector separations for DOT.

Nonlinear microrheology of dense colloidal suspensions: A mode-coupling theory

NASA Astrophysics Data System (ADS)

Gazuz, I.; Fuchs, M.

2013-03-01

A mode-coupling theory for the motion of a strongly forced probe particle in a dense colloidal suspension is presented. Starting point is the Smoluchowski equation for N bath and a single probe particle. The probe performs Brownian motion under the influence of a strong constant and uniform external force Fex. It is immersed in a dense homogeneous bath of (different) particles also performing Brownian motion. Fluid and glass states are considered; solvent flow effects are neglected. Based on a formally exact generalized Green-Kubo relation, mode coupling approximations are performed and an integration through transients approach applied. A microscopic theory for the nonlinear velocity-force relations of the probe particle in a dense fluid and for the (de-) localized probe in a glass is obtained. It extends the mode coupling theory of the glass transition to strongly forced tracer motion and describes active microrheology experiments. A force threshold is identified which needs to be overcome to pull the probe particle free in a glass. For the model of hard sphere particles, the microscopic equations for the threshold force and the probability density of the localized probe are solved numerically. Neglecting the spatial structure of the theory, a schematic model is derived which contains two types of bifurcation, the glass transition and the force-induced delocalization, and which allows for analytical and numerical solutions. We discuss its phase diagram, forcing effects on the time-dependent correlation functions, and the friction increment. The model was successfully applied to simulations and experiments on colloidal hard sphere systems [Gazuz , Phys. Rev. Lett.PRLTAO0031-900710.1103/PhysRevLett.102.248302 102, 248302 (2009)], while we provide detailed information on its derivation and general properties.

Trial-to-Trial Fluctuations in Attentional State and Their Relation to Intelligence

ERIC Educational Resources Information Center

Unsworth, Nash; McMillan, Brittany D.

2014-01-01

Trial-to-trial fluctuations in attentional state while performing measures of intelligence were examined in the current study. Participants performed various measures of fluid and crystallized intelligence while also providing attentional state ratings prior to each trial. It was found that pre-trial attentional state ratings strongly predicted…

Method of monitoring CO concentrations in hydrogen feed to a PEM fuel cell

DOEpatents

Grot, Stephen Andreas; Meltser, Mark Alexander; Gutowski, Stanley; Neutzler, Jay Kevin; Borup, Rodney Lynn; Weisbrod, Kirk

2000-01-01

The CO concentration in the H.sub.2 feed stream to a PEM fuel cell stack is monitored by measuring current and/or voltage behavior patterns from a PEM-probe communicating with the reformate feed stream. Pattern recognition software may be used to compare the current and voltage patterns from the PEM-probe to current and voltage telltale outputs determined from a reference cell similar to the PEM-probe and operated under controlled conditions over a wide range of CO concentrations in the H.sub.2 fuel stream. The PEM-probe is intermittently purged of any CO build-up on the anode catalyst (e.g., by (1) flushing the anode with air, (2) short circuiting the PEM-probe, or (3) reverse biasing the PEM-probe) to keep the PEM-probe at peak performance levels.

Fast probe of local electronic states in nanostructures utilizing a single-lead quantum dot

PubMed Central

Otsuka, Tomohiro; Amaha, Shinichi; Nakajima, Takashi; Delbecq, Matthieu R.; Yoneda, Jun; Takeda, Kenta; Sugawara, Retsu; Allison, Giles; Ludwig, Arne; Wieck, Andreas D.; Tarucha, Seigo

2015-01-01

Transport measurements are powerful tools to probe electronic properties of solid-state materials. To access properties of local electronic states in nanostructures, such as local density of states, electronic distribution and so on, micro-probes utilizing artificial nanostructures have been invented to perform measurements in addition to those with conventional macroscopic electronic reservoirs. Here we demonstrate a new kind of micro-probe: a fast single-lead quantum dot probe, which utilizes a quantum dot coupled only to the target structure through a tunneling barrier and fast charge readout by RF reflectometry. The probe can directly access the local electronic states with wide bandwidth. The probe can also access more electronic states, not just those around the Fermi level, and the operations are robust against bias voltages and temperatures. PMID:26416582

Multimodal fiber-probe spectroscopy as a clinical tool for diagnosing and classifying biological tissues

NASA Astrophysics Data System (ADS)

Cicchi, Riccardo; Anand, Suresh; Fantechi, Riccardo; Giordano, Flavio; Gacci, Mauro; Conti, Valerio; Nesi, Gabriella; Buccoliero, Anna Maria; Carini, Marco; Guerrini, Renzo; Pavone, Francesco Saverio

2017-07-01

An optical fiber probe for multimodal spectroscopy was designed, developed and used for tissue diagnostics. The probe, based on a fiber bundle with optical fibers of various size and properties, allows performing spectroscopic measurements with different techniques, including fluorescence, Raman, and diffuse reflectance, using the same probe. Two visible laser diodes were used for fluorescence spectroscopy, a laser diode emitting in the NIR was used for Raman spectroscopy, and a fiber-coupled halogen lamp for diffuse reflectance. The developed probe was successfully employed for diagnostic purposes on various tissues, including brain and bladder. In particular, the device allowed discriminating healthy tissue from both tumor and dysplastic tissue as well as to perform tumor grading. The diagnostic capabilities of the method, determined using a cross-validation method with a leave-one-out approach, demonstrated high sensitivity and specificity for all the examined samples, as well as a good agreement with histopathological examination performed on the same samples. The obtained results demonstrated that the multimodal approach is crucial for improving diagnostic capabilities with respect to what can be obtained from individual techniques. The experimental setup presented here can improve diagnostic capabilities on a broad range of tissues and has the potential of being used clinically for guiding surgical resection in the near future.

Ultrasonic immersion probes characterization for use in nondestructive testing according to EN 12668-2:2001

NASA Astrophysics Data System (ADS)

Silva, C. E. R.; Alvarenga, A. V.; Costa-Felix, R. P. B.

2011-02-01

Ultrasound is often used as a Non-Destructive Testing (NDT) technique to analyze components and structures to detect internal and surface flaws. To guarantee reliable measurements, it is necessary to calibrate instruments and properly assess related uncertainties. An important device of an ultrasonic instrument system is its probe, which characterization should be performed according to EN 12668-2. Concerning immersion probes beam profile, the parameters to be assessed are beam divergence, focal distance, width, and zone length. Such parameters are determined by scanning a reflector or a hydrophone throughout the transducer beam. Within the present work, a methodology developed at Inmetro's Laboratory of Ultrasound to evaluate relevant beam parameters is presented, based on hydrophone scan. Water bath and positioning system to move the hydrophone were used to perform the scan. Studied probes were excited by a signal generator, and the waterborne signals were detected by the hydrophone and acquired using an oscilloscope. A user-friendly virtual instrument was developed in LabVIEW to automate the system. The initial tests were performed using 1 and 2.25 MHz-ultrasonic unfocused probes (Ø 1.27 cm), and results were consistent with the manufacturer's specifications. Moreover, expanded uncertainties were lower than 6% for all parameters under consideration.