Highly scalable multichannel mesh electronics for stable chronic brain electrophysiology

PubMed Central

Fu, Tian-Ming; Hong, Guosong; Viveros, Robert D.; Zhou, Tao

2017-01-01

Implantable electrical probes have led to advances in neuroscience, brain−machine interfaces, and treatment of neurological diseases, yet they remain limited in several key aspects. Ideally, an electrical probe should be capable of recording from large numbers of neurons across multiple local circuits and, importantly, allow stable tracking of the evolution of these neurons over the entire course of study. Silicon probes based on microfabrication can yield large-scale, high-density recording but face challenges of chronic gliosis and instability due to mechanical and structural mismatch with the brain. Ultraflexible mesh electronics, on the other hand, have demonstrated negligible chronic immune response and stable long-term brain monitoring at single-neuron level, although, to date, it has been limited to 16 channels. Here, we present a scalable scheme for highly multiplexed mesh electronics probes to bridge the gap between scalability and flexibility, where 32 to 128 channels per probe were implemented while the crucial brain-like structure and mechanics were maintained. Combining this mesh design with multisite injection, we demonstrate stable 128-channel local field potential and single-unit recordings from multiple brain regions in awake restrained mice over 4 mo. In addition, the newly integrated mesh is used to validate stable chronic recordings in freely behaving mice. This scalable scheme for mesh electronics together with demonstrated long-term stability represent important progress toward the realization of ideal implantable electrical probes allowing for mapping and tracking single-neuron level circuit changes associated with learning, aging, and neurodegenerative diseases. PMID:29109247

Reassessment of Non-Monosynaptic Excitation from the Motor Cortex to Motoneurons in Single Motor Units of the Human Biceps Brachii

PubMed Central

Nakajima, Tsuyoshi; Tazoe, Toshiki; Sakamoto, Masanori; Endoh, Takashi; Shibuya, Satoshi; Elias, Leonardo A.; Mezzarane, Rinaldo A.; Komiyama, Tomoyoshi; Ohki, Yukari

2017-01-01

Corticospinal excitation is mediated by polysynaptic pathways in several vertebrates, including dexterous monkeys. However, indirect non-monosynaptic excitation has not been clearly observed following transcranial electrical stimulation (TES) or cervicomedullary stimulation (CMS) in humans. The present study evaluated indirect motor pathways in normal human subjects by recording the activities of single motor units (MUs) in the biceps brachii (BB) muscle. The pyramidal tract was stimulated with weak TES, CMS, and transcranial magnetic stimulation (TMS) contralateral to the recording side. During tasks involving weak co-contraction of the BB and hand muscles, all stimulation methods activated MUs with short latencies. Peristimulus time histograms (PSTHs) showed that responses with similar durations were induced by TES (1.9 ± 1.4 ms) and CMS (2.0 ± 1.4 ms), and these responses often showed multiple peaks with the PSTH peak having a long duration (65.3% and 44.9%, respectively). Such long-duration excitatory responses with multiple peaks were rarely observed in the finger muscles following TES or in the BB following stimulation of the Ia fibers. The responses obtained with TES were compared in the same 14 BB MUs during the co-contraction and isolated BB contraction tasks. Eleven and three units, respectively, exhibited activation with multiple peaks during the two tasks. In order to determine the dispersion effects on the axon conduction velocities (CVs) and synaptic noise, a simulation study that was comparable to the TES experiments was performed with a biologically plausible neuromuscular model. When the model included the monosynaptic-pyramidal tract, multiple peaks were obtained in about 34.5% of the motoneurons (MNs). The experimental and simulation results indicated the existence of task-dependent disparate inputs from the pyramidal tract to the MNs of the upper limb. These results suggested that intercalated interneurons are present in the spinal cord and that these interneurons might be equivalent to those identified in animal experiments. PMID:28194103

Large-scale recording of thalamocortical circuits: in vivo electrophysiology with the two-dimensional electronic depth control silicon probe.

PubMed

Fiáth, Richárd; Beregszászi, Patrícia; Horváth, Domonkos; Wittner, Lucia; Aarts, Arno A A; Ruther, Patrick; Neves, Hercules P; Bokor, Hajnalka; Acsády, László; Ulbert, István

2016-11-01

Recording simultaneous activity of a large number of neurons in distributed neuronal networks is crucial to understand higher order brain functions. We demonstrate the in vivo performance of a recently developed electrophysiological recording system comprising a two-dimensional, multi-shank, high-density silicon probe with integrated complementary metal-oxide semiconductor electronics. The system implements the concept of electronic depth control (EDC), which enables the electronic selection of a limited number of recording sites on each of the probe shafts. This innovative feature of the system permits simultaneous recording of local field potentials (LFP) and single- and multiple-unit activity (SUA and MUA, respectively) from multiple brain sites with high quality and without the actual physical movement of the probe. To evaluate the in vivo recording capabilities of the EDC probe, we recorded LFP, MUA, and SUA in acute experiments from cortical and thalamic brain areas of anesthetized rats and mice. The advantages of large-scale recording with the EDC probe are illustrated by investigating the spatiotemporal dynamics of pharmacologically induced thalamocortical slow-wave activity in rats and by the two-dimensional tonotopic mapping of the auditory thalamus. In mice, spatial distribution of thalamic responses to optogenetic stimulation of the neocortex was examined. Utilizing the benefits of the EDC system may result in a higher yield of useful data from a single experiment compared with traditional passive multielectrode arrays, and thus in the reduction of animals needed for a research study. Copyright © 2016 the American Physiological Society.

Intracortical microstimulation induced changes in spectral and temporal response properties in cat auditory cortex.

PubMed

Valentine, Pamela A; Eggermont, Jos J

2003-09-01

Intracortical microstimulation (ICMS), consisting of a 40 ms burst (rate 300 Hz) of 10 microA pulses, repetitively administered once per second, for a total duration of 1 h, induced cortical reorganization in the primary auditory cortical field of the anesthetized cat. Multiple single-unit activity was simultaneously recorded from three to nine microelectrodes. Spiking activity was recorded from the same units prior to and following the application of ICMS in conjunction with tone pips at the characteristic frequency (CF) of the stimulus electrode. ICMS produced a significant increase in the mean firing rate, and in the occurrence of burst activity. There was an increase in the cross-correlation coefficient (R) for unit pairs recorded from sites distant from the ICMS site, and a decrease in R for unit pairs that were recorded at the stimulation site. ICMS induced a shift in the CF, dependent on the difference between the baseline CF and the ICMS-paired tone pip frequency. ICMS also resulted in broader tuning curves, increased driven peak firing rate and reduced response latency. This suggests a lasting reduction in inhibition in a small region surrounding the ICMS site that allows expansion of the frequency range normally represented in the vicinity of the stimulation electrode.

Development of a brain monitoring system for multimodality investigation in awake rats.

PubMed

Limnuson, Kanokwan; Narayan, Raj K; Chiluwal, Amrit; Bouton, Chad; Ping Wang; Chunyan Li

2016-08-01

Multimodal brain monitoring is an important approach to gain insight into brain function, modulation, and pathology. We have developed a unique micromachined neural probe capable of real-time continuous monitoring of multiple physiological, biochemical and electrophysiological variables. However, to date, it has only been used in anesthetized animals due to a lack of an appropriate interface for awake animals. We have developed a versatile headstage for recording the small neural signal and bridging the sensors to the remote sensing units for multimodal brain monitoring in awake rats. The developed system has been successfully validated in awake rats by simultaneously measuring four cerebral variables: electrocorticography, oxygen tension, temperature and cerebral blood flow. Reliable signal recordings were obtained with minimal artifacts from movement and environmental noise. For the first time, multiple variables of cerebral function and metabolism were simultaneously recorded from awake rats using a single neural probe. The system is envisioned for studying the effects of pharmacologic treatments, mapping the development of central nervous system diseases, and better understanding normal cerebral physiology.

Highly scalable multichannel mesh electronics for stable chronic brain electrophysiology.

PubMed

Fu, Tian-Ming; Hong, Guosong; Viveros, Robert D; Zhou, Tao; Lieber, Charles M

2017-11-21

Implantable electrical probes have led to advances in neuroscience, brain-machine interfaces, and treatment of neurological diseases, yet they remain limited in several key aspects. Ideally, an electrical probe should be capable of recording from large numbers of neurons across multiple local circuits and, importantly, allow stable tracking of the evolution of these neurons over the entire course of study. Silicon probes based on microfabrication can yield large-scale, high-density recording but face challenges of chronic gliosis and instability due to mechanical and structural mismatch with the brain. Ultraflexible mesh electronics, on the other hand, have demonstrated negligible chronic immune response and stable long-term brain monitoring at single-neuron level, although, to date, it has been limited to 16 channels. Here, we present a scalable scheme for highly multiplexed mesh electronics probes to bridge the gap between scalability and flexibility, where 32 to 128 channels per probe were implemented while the crucial brain-like structure and mechanics were maintained. Combining this mesh design with multisite injection, we demonstrate stable 128-channel local field potential and single-unit recordings from multiple brain regions in awake restrained mice over 4 mo. In addition, the newly integrated mesh is used to validate stable chronic recordings in freely behaving mice. This scalable scheme for mesh electronics together with demonstrated long-term stability represent important progress toward the realization of ideal implantable electrical probes allowing for mapping and tracking single-neuron level circuit changes associated with learning, aging, and neurodegenerative diseases. Copyright © 2017 the Author(s). Published by PNAS.

Electromyographic cross-talk within a compartmentalized muscle of the cat.

PubMed Central

English, A W; Weeks, O I

1989-01-01

1. Experiments were conducted to test the extent to which the electromyographic (EMG) activity generated by the activation of single motor units is conducted from one neuromuscular compartment of the cat lateral gastrocnemius (LG) muscle into adjacent compartments. 2. Potentials produced by stimulation of forty-five single motor units were monitored from bipolar fine-wire EMG electrodes which had been implanted either into the centres of each of the four neuromuscular compartments of LG or into regions of the muscle known to lie on the border of contiguous compartments. 3. In all cases single unit potentials could be recorded from the electrodes in the centre of the compartments which clearly identified the compartment of residence of the muscle unit. Regardless of unit type, the amplitude of the potential recorded from electrodes in one compartment was always greater than that recorded from any other compartment. 4. Smaller potentials could be recorded from electrodes in the centre of compartments adjacent to the compartment of residence of the muscle unit. For those motor units where the amplitude of the EMG potentials recorded from the compartment of residence was large, the amplitude of such 'cross-talk' could be greater than the amplitude of potentials recorded from the compartment of residence of smaller motor units. 5. In the case of electrodes placed at compartment boundaries, no clear compartment selectivity of recording of motor unit potentials was evident. 6. These results indicate that great care must be taken in choosing sites of EMG electrode placement when performing kinesiological studies, especially when the amplitude of the EMG activity recorded is of consideration. PMID:2558175

Single unit action potentials in humans and the effect of seizure activity

PubMed Central

Merricks, Edward M.; Smith, Elliot H.; McKhann, Guy M.; Goodman, Robert R.; Bateman, Lisa M.; Emerson, Ronald G.

2015-01-01

Spike-sorting algorithms have been used to identify the firing patterns of isolated neurons (‘single units’) from implanted electrode recordings in patients undergoing assessment for epilepsy surgery, but we do not know their potential for providing helpful clinical information. It is important therefore to characterize both the stability of these recordings and also their context. A critical consideration is where the units are located with respect to the focus of the pathology. Recent analyses of neuronal spiking activity, recorded over extended spatial areas using microelectrode arrays, have demonstrated the importance of considering seizure activity in terms of two distinct spatial territories: the ictal core and penumbral territories. The pathological information in these two areas, however, is likely to be very different. We investigated, therefore, whether units could be followed reliably over prolonged periods of times in these two areas, including during seizure epochs. We isolated unit recordings from several hundred neurons from four patients undergoing video-telemetry monitoring for surgical evaluation of focal neocortical epilepsies. Unit stability could last in excess of 40 h, and across multiple seizures. A key finding was that in the penumbra, spike stereotypy was maintained even during the seizure. There was a net tendency towards increased penumbral firing during the seizure, although only a minority of units (10–20%) showed significant changes over the baseline period, and notably, these also included neurons showing significant reductions in firing. In contrast, within the ictal core territories, regions characterized by intense hypersynchronous multi-unit firing, our spike sorting algorithms failed as the units were incorporated into the seizure activity. No spike sorting was possible from that moment until the end of the seizure, but recovery of the spike shape was rapid following seizure termination: some units reappeared within tens of seconds of the end of the seizure, and over 80% reappeared within 3 min (τrecov = 104 ± 22 s). The recovery of the mean firing rate was close to pre-ictal levels also within this time frame, suggesting that the more protracted post-ictal state cannot be explained by persistent cellular neurophysiological dysfunction in either the penumbral or the core territories. These studies lay the foundation for future investigations of how these recordings may inform clinical practice. See Kimchi and Cash (doi:10.1093/awv264) for a scientific commentary on this article. PMID:26187332

Prevention of triplets and higher order multiples: trends in reproductive medicine.

PubMed

Armour, Kim L; Callister, Lynn Clark

2005-01-01

In the United States and throughout the world, today's healthcare providers are challenged by the risks of multiple gestation pregnancy. Assisted reproductive technologies (ARTs) often used to treat infertility raise ethical issues including informed consent, veracity, and nonmalificence. In the United States, there is the need to improve maternal and fetal/neonatal mortality and morbidity by proposing legislation regulating ART and supporting single embryo transfers with no more than 2 such transfers. Beginning with the diagnosis of infertility, providers have a responsibility to educate, inform, and treat infertile couples. From the moment pregnancy with multiples is confirmed, these families are faced with incredible stressors including decision making on multifetal or selective reduction. Full disclosure of risks involved throughout the course of care should be discussed and documented in the record and plan of care. Currently in the United States, legislation does not regulate ART, including ovulation induction/enhancement and in vitro fertilization. Although the United States does have self-regulation via limited reporting through their professional organization and the Centers for Disease Control and Prevention, an unlimited number of embryos may be transferred. Unfortunately, many healthcare providers have not recognized the responsibility and burden placed on families and society as a whole. Lack of regulation means women may become pregnant with high order multiples, which raises serious moral and ethical issues.

Predictors of seizure occurrence in children undergoing pre-surgical monitoring.

PubMed

Harini, Chellamani; Singh, Kanwaljit; Takeoka, Masanori; Parulkar, Isha; Bergin, Ann Marie; Loddenkemper, Tobias; Kothare, Sanjeev V

2013-10-01

Long-Term-Monitoring (LTM) is a valuable tool for seizure localization/lateralization among children with refractory-epilepsy undergoing pre-surgical-monitoring. The aim of this study was to examine the factors predicting occurrence of single/multiple seizures in children undergoing pre-surgical monitoring in the LTM unit. Chart review was done on 95 consecutive admissions on 92 children (40 females) admitted to the LTM-unit for pre-surgical workup. Relationship between occurrence of multiple (≥ 3) seizures and factors such as home seizure-frequency, demographics, MRI-lesions/seizure-type and localization/AED usage/neurological-exam/epilepsy-duration was evaluated by logistic-regression and survival-analysis. Home seizure-frequency was further categorized into low (up-to 1/month), medium (up-to 1/week) and high (>1/week) and relationship of these categories to the occurrence of multiple seizures was evaluated. Mean length of stay was 5.24 days in all 3 groups. Home seizure frequency was the only factor predicting the occurrence of single/multiple seizures in children undergoing presurgical workup. Other factors (age/sex/MRI-lesions/seizure-type and localization/AED-usage/neurological-exam/epilepsy-duration) did not affect occurrence of single/multiple seizures or time-to-occurrence of first/second seizure. Analysis of the home-seizure frequency categories revealed that 98% admissions in high-frequency, 94% in the medium, and 77% in low-frequency group had at-least 1 seizure recorded during the monitoring. Odds of first-seizure increased in high vs. low-frequency group (p=0.01). Eighty-nine percent admissions in high-frequency, 78% in medium frequency, versus 50% in low-frequency group had ≥ 3 seizures. The odds of having ≥ 3 seizures increased in high-frequency (p=0.0005) and in medium-frequency (p=0.007), compared to low-frequency group. Mean time-to-first-seizure was 2.7 days in low-frequency, 2.1 days in medium, and 2 days in high-frequency group. Time-to-first-seizure in high and medium-frequency was less than in low-frequency group (p<0.0014 and p=0.038). Majority of the admissions (92%) admitted to the LTM-unit for pre-surgical workup had at-least one seizure during a mean length of stay of 5.24 days. Home seizure-frequency was the only predictor influencing occurrence of single/multiple seizures in the LTM unit. Patients with low seizure-frequency are at risk for completing the monitoring with less than the optimum number (<3) of seizures captured. Copyright © 2013 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.

Method and apparatus for fiber optic multiple scattering suppression

NASA Technical Reports Server (NTRS)

Ackerson, Bruce J. (Inventor)

2000-01-01

The instant invention provides a method and apparatus for use in laser induced dynamic light scattering which attenuates the multiple scattering component in favor of the single scattering component. The preferred apparatus utilizes two light detectors that are spatially and/or angularly separated and which simultaneously record the speckle pattern from a single sample. The recorded patterns from the two detectors are then cross correlated in time to produce one point on a composite single/multiple scattering function curve. By collecting and analyzing cross correlation measurements that have been taken at a plurality of different spatial/angular positions, the signal representative of single scattering may be differentiated from the signal representative of multiple scattering, and a near optimum detector separation angle for use in taking future measurements may be determined.

Distributed Representation of Visual Objects by Single Neurons in the Human Brain

PubMed Central

Valdez, André B.; Papesh, Megan H.; Treiman, David M.; Smith, Kris A.; Goldinger, Stephen D.

2015-01-01

It remains unclear how single neurons in the human brain represent whole-object visual stimuli. While recordings in both human and nonhuman primates have shown distributed representations of objects (many neurons encoding multiple objects), recordings of single neurons in the human medial temporal lobe, taken as subjects' discriminated objects during multiple presentations, have shown gnostic representations (single neurons encoding one object). Because some studies suggest that repeated viewing may enhance neural selectivity for objects, we had human subjects discriminate objects in a single, more naturalistic viewing session. We found that, across 432 well isolated neurons recorded in the hippocampus and amygdala, the average fraction of objects encoded was 26%. We also found that more neurons encoded several objects versus only one object in the hippocampus (28 vs 18%, p < 0.001) and in the amygdala (30 vs 19%, p < 0.001). Thus, during realistic viewing experiences, typical neurons in the human medial temporal lobe code for a considerable range of objects, across multiple semantic categories. PMID:25834044

A Systematic Analysis of 2 Monoisocentric Techniques for the Treatment of Multiple Brain Metastases.

PubMed

Narayanasamy, Ganesh; Stathakis, Sotirios; Gutierrez, Alonso N; Pappas, Evangelos; Crownover, Richard; Floyd, John R; Papanikolaou, Niko

2017-10-01

In this treatment planning study, we compare the plan quality and delivery parameters for the treatment of multiple brain metastases using 2 monoisocentric techniques: the Multiple Metastases Element from Brainlab and the RapidArc volumetric-modulated arc therapy from Varian Medical Systems. Eight patients who were treated in our institution for multiple metastases (3-7 lesions) were replanned with Multiple Metastases Element using noncoplanar dynamic conformal arcs. The same patients were replanned with the RapidArc technique in Eclipse using 4 noncoplanar arcs. Both techniques were designed using a single isocenter. Plan quality metrics (conformity index, homogeneity index, gradient index, and R 50% ), monitor unit, and the planning time were recorded. Comparison of the Multiple Metastases Element and RapidArc plans was performed using Shapiro-Wilk test, paired Student t test, and Wilcoxon signed rank test. A paired Wilcoxon signed rank test between Multiple Metastases Element and RapidArc showed comparable plan quality metrics and dose to brain. Mean ± standard deviation values of conformity index were 1.8 ± 0.7 and 1.7 ± 0.6, homogeneity index were 1.3 ± 0.1 and 1.3 ± 0.1, gradient index were 5.0 ± 1.8 and 5.1 ± 1.9, and R 50% were 4.9 ± 1.8 and 5.0 ± 1.9 for Multiple Metastases Element and RapidArc plans, respectively. Mean brain dose was 2.3 and 2.7 Gy for Multiple Metastases Element and RapidArc plans, respectively. The mean value of monitor units in Multiple Metastases Element plan was 7286 ± 1065, which is significantly lower than the RapidArc monitor units of 9966 ± 1533 ( P < .05). For the planning of multiple brain lesions to be treated with stereotactic radiosurgery, Multiple Metastases Element planning software produced equivalent conformity, homogeneity, dose falloff, and brain V 12 Gy but required significantly lower monitor units, when compared to RapidArc plans.

A Systematic Analysis of 2 Monoisocentric Techniques for the Treatment of Multiple Brain Metastases

PubMed Central

Stathakis, Sotirios; Gutierrez, Alonso N.; Pappas, Evangelos; Crownover, Richard; Floyd, John R.; Papanikolaou, Niko

2016-01-01

Background: In this treatment planning study, we compare the plan quality and delivery parameters for the treatment of multiple brain metastases using 2 monoisocentric techniques: the Multiple Metastases Element from Brainlab and the RapidArc volumetric-modulated arc therapy from Varian Medical Systems. Methods: Eight patients who were treated in our institution for multiple metastases (3-7 lesions) were replanned with Multiple Metastases Element using noncoplanar dynamic conformal arcs. The same patients were replanned with the RapidArc technique in Eclipse using 4 noncoplanar arcs. Both techniques were designed using a single isocenter. Plan quality metrics (conformity index, homogeneity index, gradient index, and R50%), monitor unit, and the planning time were recorded. Comparison of the Multiple Metastases Element and RapidArc plans was performed using Shapiro-Wilk test, paired Student t test, and Wilcoxon signed rank test. Results: A paired Wilcoxon signed rank test between Multiple Metastases Element and RapidArc showed comparable plan quality metrics and dose to brain. Mean ± standard deviation values of conformity index were 1.8 ± 0.7 and 1.7 ± 0.6, homogeneity index were 1.3 ± 0.1 and 1.3 ± 0.1, gradient index were 5.0 ± 1.8 and 5.1 ± 1.9, and R50% were 4.9 ± 1.8 and 5.0 ± 1.9 for Multiple Metastases Element and RapidArc plans, respectively. Mean brain dose was 2.3 and 2.7 Gy for Multiple Metastases Element and RapidArc plans, respectively. The mean value of monitor units in Multiple Metastases Element plan was 7286 ± 1065, which is significantly lower than the RapidArc monitor units of 9966 ± 1533 (P < .05). Conclusion: For the planning of multiple brain lesions to be treated with stereotactic radiosurgery, Multiple Metastases Element planning software produced equivalent conformity, homogeneity, dose falloff, and brain V12 Gy but required significantly lower monitor units, when compared to RapidArc plans. PMID:27612917

Distributed representation of visual objects by single neurons in the human brain.

PubMed

Valdez, André B; Papesh, Megan H; Treiman, David M; Smith, Kris A; Goldinger, Stephen D; Steinmetz, Peter N

2015-04-01

It remains unclear how single neurons in the human brain represent whole-object visual stimuli. While recordings in both human and nonhuman primates have shown distributed representations of objects (many neurons encoding multiple objects), recordings of single neurons in the human medial temporal lobe, taken as subjects' discriminated objects during multiple presentations, have shown gnostic representations (single neurons encoding one object). Because some studies suggest that repeated viewing may enhance neural selectivity for objects, we had human subjects discriminate objects in a single, more naturalistic viewing session. We found that, across 432 well isolated neurons recorded in the hippocampus and amygdala, the average fraction of objects encoded was 26%. We also found that more neurons encoded several objects versus only one object in the hippocampus (28 vs 18%, p < 0.001) and in the amygdala (30 vs 19%, p < 0.001). Thus, during realistic viewing experiences, typical neurons in the human medial temporal lobe code for a considerable range of objects, across multiple semantic categories. Copyright © 2015 the authors 0270-6474/15/355180-07$15.00/0.

Successful choice behavior is associated with distinct and coherent network states in anterior cingulate cortex

PubMed Central

Lapish, Christopher C.; Durstewitz, Daniel; Chandler, L. Judson; Seamans, Jeremy K.

2008-01-01

Successful decision making requires an ability to monitor contexts, actions, and outcomes. The anterior cingulate cortex (ACC) is thought to be critical for these functions, monitoring and guiding decisions especially in challenging situations involving conflict and errors. A number of different single-unit correlates have been observed in the ACC that reflect the diverse cognitive components involved. Yet how ACC neurons function as an integrated network is poorly understood. Here we show, using advanced population analysis of multiple single-unit recordings from the rat ACC during performance of an ecologically valid decision-making task, that ensembles of neurons move through different coherent and dissociable states as the cognitive requirements of the task change. This organization into distinct network patterns with respect to both firing-rate changes and correlations among units broke down during trials with numerous behavioral errors, especially at choice points of the task. These results point to an underlying functional organization into cell assemblies in the ACC that may monitor choices, outcomes, and task contexts, thus tracking the animal's progression through “task space.” PMID:18708525

Contextual effects of noise on vocalization encoding in primary auditory cortex

PubMed Central

Ni, Ruiye; Bender, David A.; Shanechi, Amirali M.; Gamble, Jeffrey R.

2016-01-01

Robust auditory perception plays a pivotal function for processing behaviorally relevant sounds, particularly with distractions from the environment. The neuronal coding enabling this ability, however, is still not well understood. In this study, we recorded single-unit activity from the primary auditory cortex (A1) of awake marmoset monkeys (Callithrix jacchus) while delivering conspecific vocalizations degraded by two different background noises: broadband white noise and vocalization babble. Noise effects on neural representation of target vocalizations were quantified by measuring the responses' similarity to those elicited by natural vocalizations as a function of signal-to-noise ratio. A clustering approach was used to describe the range of response profiles by reducing the population responses to a summary of four response classes (robust, balanced, insensitive, and brittle) under both noise conditions. This clustering approach revealed that, on average, approximately two-thirds of the neurons change their response class when encountering different noises. Therefore, the distortion induced by one particular masking background in single-unit responses is not necessarily predictable from that induced by another, suggesting the low likelihood of a unique group of noise-invariant neurons across different background conditions in A1. Regarding noise influence on neural activities, the brittle response group showed addition of spiking activity both within and between phrases of vocalizations relative to clean vocalizations, whereas the other groups generally showed spiking activity suppression within phrases, and the alteration between phrases was noise dependent. Overall, the variable single-unit responses, yet consistent response types, imply that primate A1 performs scene analysis through the collective activity of multiple neurons. NEW & NOTEWORTHY The understanding of where and how auditory scene analysis is accomplished is of broad interest to neuroscientists. In this paper, we systematically investigated neuronal coding of multiple vocalizations degraded by two distinct noises at various signal-to-noise ratios in nonhuman primates. In the process, we uncovered heterogeneity of single-unit representations for different auditory scenes yet homogeneity of responses across the population. PMID:27881720

Contextual effects of noise on vocalization encoding in primary auditory cortex.

PubMed

Ni, Ruiye; Bender, David A; Shanechi, Amirali M; Gamble, Jeffrey R; Barbour, Dennis L

2017-02-01

Robust auditory perception plays a pivotal function for processing behaviorally relevant sounds, particularly with distractions from the environment. The neuronal coding enabling this ability, however, is still not well understood. In this study, we recorded single-unit activity from the primary auditory cortex (A1) of awake marmoset monkeys (Callithrix jacchus) while delivering conspecific vocalizations degraded by two different background noises: broadband white noise and vocalization babble. Noise effects on neural representation of target vocalizations were quantified by measuring the responses' similarity to those elicited by natural vocalizations as a function of signal-to-noise ratio. A clustering approach was used to describe the range of response profiles by reducing the population responses to a summary of four response classes (robust, balanced, insensitive, and brittle) under both noise conditions. This clustering approach revealed that, on average, approximately two-thirds of the neurons change their response class when encountering different noises. Therefore, the distortion induced by one particular masking background in single-unit responses is not necessarily predictable from that induced by another, suggesting the low likelihood of a unique group of noise-invariant neurons across different background conditions in A1. Regarding noise influence on neural activities, the brittle response group showed addition of spiking activity both within and between phrases of vocalizations relative to clean vocalizations, whereas the other groups generally showed spiking activity suppression within phrases, and the alteration between phrases was noise dependent. Overall, the variable single-unit responses, yet consistent response types, imply that primate A1 performs scene analysis through the collective activity of multiple neurons. The understanding of where and how auditory scene analysis is accomplished is of broad interest to neuroscientists. In this paper, we systematically investigated neuronal coding of multiple vocalizations degraded by two distinct noises at various signal-to-noise ratios in nonhuman primates. In the process, we uncovered heterogeneity of single-unit representations for different auditory scenes yet homogeneity of responses across the population. Copyright © 2017 the American Physiological Society.

Existence of multiple receptors in single neurons: responses of single bullfrog olfactory neurons to many cAMP-dependent and independent odorants.

PubMed

Kashiwayanagi, M; Shimano, K; Kurihara, K

1996-11-04

The responses of single bullfrog olfactory neurons to various odorants were measured with the whole-cell patch clamp which offers direct information on cellular events and with the ciliary recording technique to obtain stable quantitative data from many neurons. A large portion of single olfactory neurons (about 64% and 79% in the whole-cell recording and in the ciliary recording, respectively) responded to many odorants with quite diverse molecular structures, including both odorants previously indicated to be cAMP-dependent (increasing) and independent odorants. One odorant elicited a response in many cells; e.g. hedione and citralva elicited the response in 100% and 92% of total neurons examined with the ciliary recording technique. To confirm that a single neuron carries different receptors or transduction pathways, the cross-adaptation technique was applied to single neurons. Application of hedione to a single neuron after desensitization of the current in response to lyral or citralva induced an inward current with a similar magnitude to that applied alone. It was suggested that most single olfactory neurons carry multiple receptors and at least dual transduction pathways.

Fractionated analysis of paired-electrode nerve recordings.

PubMed

Fiore, Lorenzo; Lorenzetti, Walter; Ratti, Giovannino; Geppetti, Laura

2003-12-30

Multi-unit activity recorded from two electrodes positioned at a distance on a nerve may be analysed by cross-correlation, but units similar in direction and velocity of propagation cannot be distinguished and separately evaluated by this method. To overcome this limit, we added two features, represented by the impulse amplitudes of the paired recordings, to the dimension given by the impulse delay. The analysis was fractionated according to the new dimensions. In experimental recordings from the locomotor appendage of the lobster Homarus americanus, the fractionated analysis proved capable of identifying the contributions of single active units, even if these were superimposed and indiscernible in the global cross-correlation histogram. Up to 5 motor and 10 sensory units could be identified. The shape of the paired impulses was evaluated by an averaging procedure. Analogous evaluations on simulated recordings made it possible to estimate the influences exerted on performance by variations in noise level and in the number and firing rate of active units. The global signal could be resolved into single units even under the worst conditions. Accuracy in evaluating the amount of unit activity varied, exceeding 90% in about half of the cases tested; a similar performance was attained by evaluation of the impulse shapes.

Spike detection, characterization, and discrimination using feature analysis software written in LabVIEW.

PubMed

Stewart, C M; Newlands, S D; Perachio, A A

2004-12-01

Rapid and accurate discrimination of single units from extracellular recordings is a fundamental process for the analysis and interpretation of electrophysiological recordings. We present an algorithm that performs detection, characterization, discrimination, and analysis of action potentials from extracellular recording sessions. The program was entirely written in LabVIEW (National Instruments), and requires no external hardware devices or a priori information about action potential shapes. Waveform events are detected by scanning the digital record for voltages that exceed a user-adjustable trigger. Detected events are characterized to determine nine different time and voltage levels for each event. Various algebraic combinations of these waveform features are used as axis choices for 2-D Cartesian plots of events. The user selects axis choices that generate distinct clusters. Multiple clusters may be defined as action potentials by manually generating boundaries of arbitrary shape. Events defined as action potentials are validated by visual inspection of overlain waveforms. Stimulus-response relationships may be identified by selecting any recorded channel for comparison to continuous and average cycle histograms of binned unit data. The algorithm includes novel aspects of feature analysis and acquisition, including higher acquisition rates for electrophysiological data compared to other channels. The program confirms that electrophysiological data may be discriminated with high-speed and efficiency using algebraic combinations of waveform features derived from high-speed digital records.

Object-based benefits without object-based representations.

PubMed

Fougnie, Daryl; Cormiea, Sarah M; Alvarez, George A

2013-08-01

Influential theories of visual working memory have proposed that the basic units of memory are integrated object representations. Key support for this proposal is provided by the same object benefit: It is easier to remember multiple features of a single object than the same set of features distributed across multiple objects. Here, we replicate the object benefit but demonstrate that features are not stored as single, integrated representations. Specifically, participants could remember 10 features better when arranged in 5 objects compared to 10 objects, yet memory for one object feature was largely independent of memory for the other object feature. These results rule out the possibility that integrated representations drive the object benefit and require a revision of the concept of object-based memory representations. We propose that working memory is object-based in regard to the factors that enhance performance but feature based in regard to the level of representational failure. PsycINFO Database Record (c) 2013 APA, all rights reserved.

Robust and accurate decoding of motoneuron behavior and prediction of the resulting force output.

PubMed

Thompson, Christopher K; Negro, Francesco; Johnson, Michael D; Holmes, Matthew R; McPherson, Laura Miller; Powers, Randall K; Farina, Dario; Heckman, Charles J

2018-05-03

The spinal alpha motoneuron is the only cell in the human CNS whose discharge can be routinely recorded in humans. We have reengineered motor unit collection and decomposition approaches, originally developed in humans, to measure the neural drive to muscle and estimate muscle force generation in the decerebrate cat model. Experimental, computational, and predictive approaches are used to demonstrate the validity of this approach across a wide range of modes to activate the motor pool. The utility of this approach is shown through the ability to track individual motor units across trials, allowing for better predictions of muscle force than the electromyography signal, and providing insights in to the stereotypical discharge characteristics in response to synaptic activation of the motor pool. This approach now allows for a direct link between the intracellular data of single motoneurons, the discharge properties of motoneuron populations, and muscle force generation in the same preparation. The discharge of a spinal alpha motoneuron and the resulting contraction of its muscle fibers represents the functional quantum of the motor system. Recent advances in the recording and decomposition of the electromyographic signal allows for the identification of several tens of concurrently active motor units. These detailed population data provide the potential to achieve deep insights into the synaptic organization of motor commands. Yet most of our understanding of the synaptic input to motoneurons is derived from intracellular recordings in animal preparations. Thus, it is necessary to extend the new electrode and decomposition methods to recording of motor unit populations in these same preparations. To achieve this goal, we use high-density electrode arrays and decomposition techniques, analogous to those developed for humans, to record and decompose the activity of tens of concurrently active motor units in a hindlimb muscle in the decerebrate cat. Our results showed that the decomposition method in this animal preparation was highly accurate, with conventional two-source validation providing rates of agreement equal to or superior to those found in humans. Multidimensional reconstruction of the motor unit action potential provides the ability to accurately track the same motor unit across multiple contractions. Additionally, correlational analyses demonstrate that the composite spike train provides better estimates of whole muscle force than conventional estimates obtained from the electromyographic signal. Lastly, stark differences are observed between the modes of activation, in particular tendon vibration produced quantal interspike intervals at integer multiples of the vibration period. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Floating point only SIMD instruction set architecture including compare, select, Boolean, and alignment operations

DOEpatents

Gschwind, Michael K [Chappaqua, NY

2011-03-01

Mechanisms for implementing a floating point only single instruction multiple data instruction set architecture are provided. A processor is provided that comprises an issue unit, an execution unit coupled to the issue unit, and a vector register file coupled to the execution unit. The execution unit has logic that implements a floating point (FP) only single instruction multiple data (SIMD) instruction set architecture (ISA). The floating point vector registers of the vector register file store both scalar and floating point values as vectors having a plurality of vector elements. The processor may be part of a data processing system.

Digital processing of array seismic recordings

USGS Publications Warehouse

Ryall, Alan; Birtill, John

1962-01-01

This technical letter contains a brief review of the operations which are involved in digital processing of array seismic recordings by the methods of velocity filtering, summation, cross-multiplication and integration, and by combinations of these operations (the "UK Method" and multiple correlation). Examples are presented of analyses by the several techniques on array recordings which were obtained by the U.S. Geological Survey during chemical and nuclear explosions in the western United States. Seismograms are synthesized using actual noise and Pn-signal recordings, such that the signal-to-noise ratio, onset time and velocity of the signal are predetermined for the synthetic record. These records are then analyzed by summation, cross-multiplication, multiple correlation and the UK technique, and the results are compared. For all of the examples presented, analysis by the non-linear techniques of multiple correlation and cross-multiplication of the traces on an array recording are preferred to analyses by the linear operations involved in summation and the UK Method.

Flexible microelectrode array for interfacing with the surface of neural ganglia

NASA Astrophysics Data System (ADS)

Sperry, Zachariah J.; Na, Kyounghwan; Parizi, Saman S.; Chiel, Hillel J.; Seymour, John; Yoon, Euisik; Bruns, Tim M.

2018-06-01

Objective. The dorsal root ganglia (DRG) are promising nerve structures for sensory neural interfaces because they provide centralized access to primary afferent cell bodies and spinal reflex circuitry. In order to harness this potential, new electrode technologies are needed which take advantage of the unique properties of DRG, specifically the high density of neural cell bodies at the dorsal surface. Here we report initial in vivo results from the development of a flexible non-penetrating polyimide electrode array interfacing with the surface of ganglia. Approach. Multiple layouts of a 64-channel iridium electrode (420 µm2) array were tested, with pitch as small as 25 µm. The buccal ganglia of invertebrate sea slug Aplysia californica were used to develop handling and recording techniques with ganglionic surface electrode arrays (GSEAs). We also demonstrated the GSEA’s capability to record single- and multi-unit activity from feline lumbosacral DRG related to a variety of sensory inputs, including cutaneous brushing, joint flexion, and bladder pressure. Main results. We recorded action potentials from a variety of Aplysia neurons activated by nerve stimulation, and units were observed firing simultaneously on closely spaced electrode sites. We also recorded single- and multi-unit activity associated with sensory inputs from feline DRG. We utilized spatial oversampling of action potentials on closely-spaced electrode sites to estimate the location of neural sources at between 25 µm and 107 µm below the DRG surface. We also used the high spatial sampling to demonstrate a possible spatial sensory map of one feline’s DRG. We obtained activation of sensory fibers with low-amplitude stimulation through individual or groups of GSEA electrode sites. Significance. Overall, the GSEA has been shown to provide a variety of information types from ganglia neurons and to have significant potential as a tool for neural mapping and interfacing.

Method for Visually Integrating Multiple Data Acquisition Technologies for Real Time and Retrospective Analysis

NASA Technical Reports Server (NTRS)

Bogart, Edward H. (Inventor); Pope, Alan T. (Inventor)

2000-01-01

A system for display on a single video display terminal of multiple physiological measurements is provided. A subject is monitored by a plurality of instruments which feed data to a computer programmed to receive data, calculate data products such as index of engagement and heart rate, and display the data in a graphical format simultaneously on a single video display terminal. In addition live video representing the view of the subject and the experimental setup may also be integrated into the single data display. The display may be recorded on a standard video tape recorder for retrospective analysis.

Recording large-scale neuronal ensembles with silicon probes in the anesthetized rat.

PubMed

Schjetnan, Andrea Gomez Palacio; Luczak, Artur

2011-10-19

Large scale electrophysiological recordings from neuronal ensembles offer the opportunity to investigate how the brain orchestrates the wide variety of behaviors from the spiking activity of its neurons. One of the most effective methods to monitor spiking activity from a large number of neurons in multiple local neuronal circuits simultaneously is by using silicon electrode arrays. Action potentials produce large transmembrane voltage changes in the vicinity of cell somata. These output signals can be measured by placing a conductor in close proximity of a neuron. If there are many active (spiking) neurons in the vicinity of the tip, the electrode records combined signal from all of them, where contribution of a single neuron is weighted by its 'electrical distance'. Silicon probes are ideal recording electrodes to monitor multiple neurons because of a large number of recording sites (+64) and a small volume. Furthermore, multiple sites can be arranged over a distance of millimeters, thus allowing for the simultaneous recordings of neuronal activity in the various cortical layers or in multiple cortical columns (Fig. 1). Importantly, the geometrically precise distribution of the recording sites also allows for the determination of the spatial relationship of the isolated single neurons. Here, we describe an acute, large-scale neuronal recording from the left and right forelimb somatosensory cortex simultaneously in an anesthetized rat with silicon probes (Fig. 2).

Recording Large-scale Neuronal Ensembles with Silicon Probes in the Anesthetized Rat

PubMed Central

Schjetnan, Andrea Gomez Palacio; Luczak, Artur

2011-01-01

Large scale electrophysiological recordings from neuronal ensembles offer the opportunity to investigate how the brain orchestrates the wide variety of behaviors from the spiking activity of its neurons. One of the most effective methods to monitor spiking activity from a large number of neurons in multiple local neuronal circuits simultaneously is by using silicon electrode arrays1-3. Action potentials produce large transmembrane voltage changes in the vicinity of cell somata. These output signals can be measured by placing a conductor in close proximity of a neuron. If there are many active (spiking) neurons in the vicinity of the tip, the electrode records combined signal from all of them, where contribution of a single neuron is weighted by its 'electrical distance'. Silicon probes are ideal recording electrodes to monitor multiple neurons because of a large number of recording sites (+64) and a small volume. Furthermore, multiple sites can be arranged over a distance of millimeters, thus allowing for the simultaneous recordings of neuronal activity in the various cortical layers or in multiple cortical columns (Fig. 1). Importantly, the geometrically precise distribution of the recording sites also allows for the determination of the spatial relationship of the isolated single neurons4. Here, we describe an acute, large-scale neuronal recording from the left and right forelimb somatosensory cortex simultaneously in an anesthetized rat with silicon probes (Fig. 2). PMID:22042361

Meeting the Challenge: The National Cancer Institute's Central Institutional Review Board for Multi-Site Research.

PubMed

Massett, Holly A; Hampp, Sharon L; Goldberg, Jacquelyn L; Mooney, Margaret; Parreco, Linda K; Minasian, Lori; Montello, Mike; Mishkin, Grace E; Davis, Catasha; Abrams, Jeffrey S

2018-03-10

The National Institutes of Health (NIH) issued a new policy that requires a single institutional review board (IRB) of record be used for all protocols funded by the NIH that are carried out at more than one site in the United States, effective January 2018. This policy affects several hundred clinical trials opened annually across the NIH. Limited data exist to compare the use of a single IRB to that of multiple local IRBs, so some institutions are resistant to or distrustful of single IRBs. Since 2001, the National Cancer Institute (NCI) has funded a central IRB (CIRB) that provides human patient reviews for its extensive national cancer clinical trials program. This paper presents data to show the adoption, efficiencies gained, and satisfaction of the CIRB among NCI trial networks and reviews key lessons gleaned from 16 years of experience that may be informative for others charged with implementation of the new NIH single-IRB policy.

Wireless multi-channel single unit recording in freely moving and vocalizing primates

PubMed Central

Roy, Sabyasachi; Wang, Xiaoqin

2011-01-01

The ability to record well-isolated action potentials from individual neurons in naturally behaving animals is crucial for understanding neural mechanisms underlying natural behaviors. Traditional neurophysiology techniques, however, require the animal to be restrained which often restricts natural behavior. An example is the common marmoset (Callithrix jacchus), a highly vocal New World primate species, used in our laboratory to study the neural correlates of vocal production and sensory feedback. When restrained by traditional neurophysiological techniques marmoset vocal behavior is severely inhibited. Tethered recording systems, while proven effective in rodents pose limitations in arboreal animals such as the marmoset that typically roam in a three-dimensional environment. To overcome these obstacles, we have developed a wireless neural recording technique that is capable of collecting single-unit data from chronically implanted multi-electrodes in freely moving marmosets. A lightweight, low power and low noise wireless transmitter (headstage) is attached to a multi-electrode array placed in the premotor cortex of the marmoset. The wireless headstage is capable of transmitting 15 channels of neural data with signal-to-noise ratio (SNR) comparable to a tethered system. To minimize radio-frequency (RF) and electro-magnetic interference (EMI), the experiments were conducted within a custom designed RF/EMI and acoustically shielded chamber. The individual electrodes of the multi-electrode array were periodically advanced to densely sample the cortical layers. We recorded single-unit data over a period of several months from the frontal cortex of two marmosets. These recordings demonstrate the feasibility of using our wireless recording method to study single neuron activity in freely roaming primates. PMID:21933683

Lower layers in the motor cortex are more effective targets for penetrating microelectrodes in cortical prostheses

NASA Astrophysics Data System (ADS)

Parikh, Hirak; Marzullo, Timothy C.; Kipke, Daryl R.

2009-04-01

Improving cortical prostheses requires the development of recording neural interfaces that are efficient in terms of providing maximal control information with minimal interface complexity. While the typical approaches have targeted neurons in the motor cortex with multiple penetrating shanks, an alternative approach is to determine an efficient distribution of electrode sites within the layers of the cortex with fewer penetrating shanks. The objective of this study was to compare unit activity in the upper and lower layers of the cortex with respect to movement and direction in order to inform the design of penetrating microelectrodes. Four rats were implanted bilaterally with multi-site single-shank silicon microelectrode arrays in the neck/shoulder region of the motor cortex. We simultaneously recorded unit activity across all layers of the motor cortex while the animal was engaged in a movement direction task. Localization of the electrode array within the different layers of the cortex was determined by histology. We denoted units from layers 2 and 3 and units as upper layer units, and units from layers 5 and 6 as lower layer units. Analysis of unit spiking activity demonstrated that both the upper and lower layers encode movement and direction information. Unit responses in either cortical layer of the cortex were not preferentially associated with contralateral or ipsilateral movement. Aggregate analysis (633 neurons) and best session analysis (75 neurons) indicated that units in the lower layers (layers 5, 6) are more likely to encode direction information when compared to units in the upper layers (layers 2, 3) (p< 0.05). These results suggest that electrode sites clustered in the lower layers provide access to more salient control information for cortical neuroprostheses.

In Vivo Recording of Single-Unit Activity during Singing in Zebra Finches

PubMed Central

Okubo, Tatsuo S.; Mackevicius, Emily L.; Fee, Michale S.

2015-01-01

The zebra finch is an important model for investigating the neural mechanisms that underlie vocal production and learning. Previous anatomical and gene expression studies have identified an interconnected set of brain areas in this organism that are important for singing. To advance our understanding of how these various brain areas act together to learn and produce a highly stereotyped song, it is necessary to record the activity of individual neurons during singing. Here, we present a protocol for recording single-unit activity in freely moving zebra finches during singing using a miniature, motorized microdrive. It includes procedures for both the microdrive implant surgery and the electrophysiological recordings. There are several advantages of this technique: (1) high-impedance electrodes can be used in the microdrive to obtain well-isolated single units; (2) a motorized microdrive is used to remotely control the electrode position, allowing neurons to be isolated without handling the bird, and (3) a lateral positioner is used to move electrodes into fresh tissue before each penetration, allowing recordings from well-isolated neurons over the course of several weeks. We also describe the application of the antidromic stimulation and the spike collision test to identify neurons based on the axonal projection patterns. PMID:25342072

A combined long-term recording system for single-unit activity and neurotransmitter efflux of a brain slice

NASA Astrophysics Data System (ADS)

Sheu, Y. H.; Young, M. S.

1998-04-01

A combined long-term measurement and recording system for neurotransmission research of brain slices is presented in this study. This system, based on the IBM PC or compatible computer, is capable of simultaneously measuring and recording both single-unit neural electropotential signals and the electrochemical signals of neurotransmitter efflux from the same neuron in a brain slice for long periods of time (time limited largely by hard disk capacity, 100 h or more not being unreasonable with contemporary hardware) using a single carbon microelectrode for both measurements. The combined long-term recording system uses a simple switching circuit to switch periodically the single microelectrode between two data acquisition subsystems, one for electrochemical data and one for electrophysiological data. The simple switching circuit separates the electrophysiological signals and electrochemical signals, overcoming the traditional interference problem caused by the two different measuring techniques. Software designed for the proposed system allows easy reconstruction of the full time course of the compressed measured data and easy, simultaneous display of both types of signals on the same time scale. On-line and recorded displays are available. Test results of a practical implementation of the proposed system verify that the combined long-term recording system meets actual requirements for electrophysiological and neurochemical research.

Incorporating 3D-printing technology in the design of head-caps and electrode drives for recording neurons in multiple brain regions.

PubMed

Headley, Drew B; DeLucca, Michael V; Haufler, Darrell; Paré, Denis

2015-04-01

Recent advances in recording and computing hardware have enabled laboratories to record the electrical activity of multiple brain regions simultaneously. Lagging behind these technical advances, however, are the methods needed to rapidly produce microdrives and head-caps that can flexibly accommodate different recording configurations. Indeed, most available designs target single or adjacent brain regions, and, if multiple sites are targeted, specially constructed head-caps are used. Here, we present a novel design style, for both microdrives and head-caps, which takes advantage of three-dimensional printing technology. This design facilitates targeting of multiple brain regions in various configurations. Moreover, the parts are easily fabricated in large quantities, with only minor hand-tooling and finishing required. Copyright © 2015 the American Physiological Society.

Incorporating 3D-printing technology in the design of head-caps and electrode drives for recording neurons in multiple brain regions

PubMed Central

DeLucca, Michael V.; Haufler, Darrell; Paré, Denis

2015-01-01

Recent advances in recording and computing hardware have enabled laboratories to record the electrical activity of multiple brain regions simultaneously. Lagging behind these technical advances, however, are the methods needed to rapidly produce microdrives and head-caps that can flexibly accommodate different recording configurations. Indeed, most available designs target single or adjacent brain regions, and, if multiple sites are targeted, specially constructed head-caps are used. Here, we present a novel design style, for both microdrives and head-caps, which takes advantage of three-dimensional printing technology. This design facilitates targeting of multiple brain regions in various configurations. Moreover, the parts are easily fabricated in large quantities, with only minor hand-tooling and finishing required. PMID:25652930

Endodontic flare-ups: comparison of incidence between single and multiple visit procedures in patients attending a Nigerian teaching hospital.

PubMed

Oginni, Adeleke O; Udoye, Christopher I

2004-11-26

BACKGROUND: Until recently the most accepted technique of doing root canal treatment stresses multiple visit procedure. Most schools also concentrated upon teaching the multi-visit concept. However, it has now been reported that the procedure of single visit treatment is advocated by at least 70% of schools in all geographical areas. It was therefore the aims of the present study to find the incidence of post-obturation flare-ups following single and multiple visit endodontic treatment procedures, and to establish the relationship between pre-operative and post-obturation pain in patients referred for endodontic therapy in a Nigerian teaching Hospital. METHODS: Data collected included pulp vitality status, the presence or absence of pre-operative, inter-appointment and post-obturation pain. Pain was recorded as none, slight, or moderate/severe. Flare-ups were defined as either patient's report of pain not controlled with over the counter medication or as increasing swelling. The patients were recalled at three specific post-obturation periods, 1st, 7th and 30th day. The presence or absence of pain, or the appropriate degree of pain was recorded for each recall visits and the interval between visits. The compiled data were analysed using chi-square where applicable. P level

Incidence of Exposure of Patients in the United States to Multiple Drugs for Which Pharmacogenomic Guidelines Are Available.

PubMed

Samwald, Matthias; Xu, Hong; Blagec, Kathrin; Empey, Philip E; Malone, Daniel C; Ahmed, Seid Mussa; Ryan, Patrick; Hofer, Sebastian; Boyce, Richard D

2016-01-01

Pre-emptive pharmacogenomic (PGx) testing of a panel of genes may be easier to implement and more cost-effective than reactive pharmacogenomic testing if a sufficient number of medications are covered by a single test and future medication exposure can be anticipated. We analysed the incidence of exposure of individual patients in the United States to multiple drugs for which pharmacogenomic guidelines are available (PGx drugs) within a selected four-year period (2009-2012) in order to identify and quantify the incidence of pharmacotherapy in a nation-wide patient population that could be impacted by pre-emptive PGx testing based on currently available clinical guidelines. In total, 73 024 095 patient records from private insurance, Medicare Supplemental and Medicaid were included. Patients enrolled in Medicare Supplemental age > = 65 or Medicaid age 40-64 had the highest incidence of PGx drug use, with approximately half of the patients receiving at least one PGx drug during the 4 year period and one fourth to one third of patients receiving two or more PGx drugs. These data suggest that exposure to multiple PGx drugs is common and that it may be beneficial to implement wide-scale pre-emptive genomic testing. Future work should therefore concentrate on investigating the cost-effectiveness of multiplexed pre-emptive testing strategies.

Insertion of linear 8.4 μm diameter 16 channel carbon fiber electrode arrays for single unit recordings

PubMed Central

Patel, Paras R.; Na, Kyounghwan; Zhang, Huanan; Kozai, Takashi D. Y.; Kotov, Nicholas A.; Yoon, Euisik; Chestek, Cynthia A.

2016-01-01

Objective Single carbon fiber electrodes (d=8.4 μm) insulated with parylene-c and functionalized with PEDOT:pTS have been shown to record single unit activity but manual implantation of these devices with forceps can be difficult. Without an improvement in the insertion method any increase in the channel count by fabricating carbon fiber arrays would be impractical. In this study, we utilize a water soluble coating and structural backbones that allow us to create, implant, and record from fully functionalized arrays of carbon fibers with ~150 μm pitch. Approach Two approaches were tested for the insertion of carbon fiber arrays. The first method used a PEG coating that temporarily stiffened the fibers while leaving a small portion at the tip exposed. The small exposed portion (500 μm – 1 mm) readily penetrated the brain allowing for an insertion that did not require the handling of each fiber by forceps. The second method involved the fabrication of silicon support structures with individual shanks spaced 150 μm apart. Each shank consisted of a small groove that held an individual carbon fiber. Main results Our results showed that the PEG coating allowed for the chronic implantation of carbon fiber arrays in 5 rats with unit activity detected at 31 days post-implant. The silicon support structures recorded single unit activity in 3 acute rat surgeries. In one of those surgeries a stacked device with 3 layers of silicon support structures and carbon fibers was built and shown to readily insert into the brain with unit activity on select sites. Significance From these studies we have found that carbon fibers spaced at ~150 μm readily insert into the brain. This greatly increases the recording density of chronic neural probes and paves the way for even higher density devices that have a minimal scarring response. PMID:26035638

A microprobe for parallel optical and electrical recordings from single neurons in vivo.

PubMed

LeChasseur, Yoan; Dufour, Suzie; Lavertu, Guillaume; Bories, Cyril; Deschênes, Martin; Vallée, Réal; De Koninck, Yves

2011-04-01

Recording electrical activity from identified neurons in intact tissue is key to understanding their role in information processing. Recent fluorescence labeling techniques have opened new possibilities to combine electrophysiological recording with optical detection of individual neurons deep in brain tissue. For this purpose we developed dual-core fiberoptics-based microprobes, with an optical core to locally excite and collect fluorescence, and an electrolyte-filled hollow core for extracellular single unit electrophysiology. This design provides microprobes with tips < 10 μm, enabling analyses with single-cell optical resolution. We demonstrate combined electrical and optical detection of single fluorescent neurons in rats and mice. We combined electrical recordings and optical Ca²(+) measurements from single thalamic relay neurons in rats, and achieved detection and activation of single channelrhodopsin-expressing neurons in Thy1::ChR2-YFP transgenic mice. The microprobe expands possibilities for in vivo electrophysiological recording, providing parallel access to single-cell optical monitoring and control.

A wireless multi-channel recording system for freely behaving mice and rats.

PubMed

Fan, David; Rich, Dylan; Holtzman, Tahl; Ruther, Patrick; Dalley, Jeffrey W; Lopez, Alberto; Rossi, Mark A; Barter, Joseph W; Salas-Meza, Daniel; Herwik, Stanislav; Holzhammer, Tobias; Morizio, James; Yin, Henry H

2011-01-01

To understand the neural basis of behavior, it is necessary to record brain activity in freely moving animals. Advances in implantable multi-electrode array technology have enabled researchers to record the activity of neuronal ensembles from multiple brain regions. The full potential of this approach is currently limited by reliance on cable tethers, with bundles of wires connecting the implanted electrodes to the data acquisition system while impeding the natural behavior of the animal. To overcome these limitations, here we introduce a multi-channel wireless headstage system designed for small animals such as rats and mice. A variety of single unit and local field potential signals were recorded from the dorsal striatum and substantia nigra in mice and the ventral striatum and prefrontal cortex simultaneously in rats. This wireless system could be interfaced with commercially available data acquisition systems, and the signals obtained were comparable in quality to those acquired using cable tethers. On account of its small size, light weight, and rechargeable battery, this wireless headstage system is suitable for studying the neural basis of natural behavior, eliminating the need for wires, commutators, and other limitations associated with traditional tethered recording systems.

A Wireless Multi-Channel Recording System for Freely Behaving Mice and Rats

PubMed Central

Holtzman, Tahl; Ruther, Patrick; Dalley, Jeffrey W.; Lopez, Alberto; Rossi, Mark A.; Barter, Joseph W.; Salas-Meza, Daniel; Herwik, Stanislav; Holzhammer, Tobias; Morizio, James; Yin, Henry H.

2011-01-01

To understand the neural basis of behavior, it is necessary to record brain activity in freely moving animals. Advances in implantable multi-electrode array technology have enabled researchers to record the activity of neuronal ensembles from multiple brain regions. The full potential of this approach is currently limited by reliance on cable tethers, with bundles of wires connecting the implanted electrodes to the data acquisition system while impeding the natural behavior of the animal. To overcome these limitations, here we introduce a multi-channel wireless headstage system designed for small animals such as rats and mice. A variety of single unit and local field potential signals were recorded from the dorsal striatum and substantia nigra in mice and the ventral striatum and prefrontal cortex simultaneously in rats. This wireless system could be interfaced with commercially available data acquisition systems, and the signals obtained were comparable in quality to those acquired using cable tethers. On account of its small size, light weight, and rechargeable battery, this wireless headstage system is suitable for studying the neural basis of natural behavior, eliminating the need for wires, commutators, and other limitations associated with traditional tethered recording systems. PMID:21765934

Robust tactile sensory responses in finger area of primate motor cortex relevant to prosthetic control

NASA Astrophysics Data System (ADS)

Schroeder, Karen E.; Irwin, Zachary T.; Bullard, Autumn J.; Thompson, David E.; Bentley, J. Nicole; Stacey, William C.; Patil, Parag G.; Chestek, Cynthia A.

2017-08-01

Objective. Challenges in improving the performance of dexterous upper-limb brain-machine interfaces (BMIs) have prompted renewed interest in quantifying the amount and type of sensory information naturally encoded in the primary motor cortex (M1). Previous single unit studies in monkeys showed M1 is responsive to tactile stimulation, as well as passive and active movement of the limbs. However, recent work in this area has focused primarily on proprioception. Here we examined instead how tactile somatosensation of the hand and fingers is represented in M1. Approach. We recorded multi- and single units and thresholded neural activity from macaque M1 while gently brushing individual finger pads at 2 Hz. We also recorded broadband neural activity from electrocorticogram (ECoG) grids placed on human motor cortex, while applying the same tactile stimulus. Main results. Units displaying significant differences in firing rates between individual fingers (p  <  0.05) represented up to 76.7% of sorted multiunits across four monkeys. After normalizing by the number of channels with significant motor finger responses, the percentage of electrodes with significant tactile responses was 74.9%  ±  24.7%. No somatotopic organization of finger preference was obvious across cortex, but many units exhibited cosine-like tuning across multiple digits. Sufficient sensory information was present in M1 to correctly decode stimulus position from multiunit activity above chance levels in all monkeys, and also from ECoG gamma power in two human subjects. Significance. These results provide some explanation for difficulties experienced by motor decoders in clinical trials of cortically controlled prosthetic hands, as well as the general problem of disentangling motor and sensory signals in primate motor cortex during dextrous tasks. Additionally, examination of unit tuning during tactile and proprioceptive inputs indicates cells are often tuned differently in different contexts, reinforcing the need for continued refinement of BMI training and decoding approaches to closed-loop BMI systems for dexterous grasping.

Encoding of Spatial Attention by Primate Prefrontal Cortex Neuronal Ensembles

PubMed Central

Treue, Stefan

2018-01-01

Abstract Single neurons in the primate lateral prefrontal cortex (LPFC) encode information about the allocation of visual attention and the features of visual stimuli. However, how this compares to the performance of neuronal ensembles at encoding the same information is poorly understood. Here, we recorded the responses of neuronal ensembles in the LPFC of two macaque monkeys while they performed a task that required attending to one of two moving random dot patterns positioned in different hemifields and ignoring the other pattern. We found single units selective for the location of the attended stimulus as well as for its motion direction. To determine the coding of both variables in the population of recorded units, we used a linear classifier and progressively built neuronal ensembles by iteratively adding units according to their individual performance (best single units), or by iteratively adding units based on their contribution to the ensemble performance (best ensemble). For both methods, ensembles of relatively small sizes (n < 60) yielded substantially higher decoding performance relative to individual single units. However, the decoder reached similar performance using fewer neurons with the best ensemble building method compared with the best single units method. Our results indicate that neuronal ensembles within the LPFC encode more information about the attended spatial and nonspatial features of visual stimuli than individual neurons. They further suggest that efficient coding of attention can be achieved by relatively small neuronal ensembles characterized by a certain relationship between signal and noise correlation structures. PMID:29568798

Calving distributions of individual bulls in multiple-sire pastures

USDA-ARS?s Scientific Manuscript database

The objective of this project was to quantify patterns in the calving rate of sires in multiple-sire pastures over seven years at a large-scale cow-calf operation. Data consisted of reproductive and genomic records from multiple-sire breeding pastures (n=33) at the United States Meat Animal Research...

Bayesian Estimation of Random Coefficient Dynamic Factor Models

ERIC Educational Resources Information Center

Song, Hairong; Ferrer, Emilio

2012-01-01

Dynamic factor models (DFMs) have typically been applied to multivariate time series data collected from a single unit of study, such as a single individual or dyad. The goal of DFMs application is to capture dynamics of multivariate systems. When multiple units are available, however, DFMs are not suited to capture variations in dynamics across…

Rapid learning in visual cortical networks.

PubMed

Wang, Ye; Dragoi, Valentin

2015-08-26

Although changes in brain activity during learning have been extensively examined at the single neuron level, the coding strategies employed by cell populations remain mysterious. We examined cell populations in macaque area V4 during a rapid form of perceptual learning that emerges within tens of minutes. Multiple single units and LFP responses were recorded as monkeys improved their performance in an image discrimination task. We show that the increase in behavioral performance during learning is predicted by a tight coordination of spike timing with local population activity. More spike-LFP theta synchronization is correlated with higher learning performance, while high-frequency synchronization is unrelated with changes in performance, but these changes were absent once learning had stabilized and stimuli became familiar, or in the absence of learning. These findings reveal a novel mechanism of plasticity in visual cortex by which elevated low-frequency synchronization between individual neurons and local population activity accompanies the improvement in performance during learning.

Tectonostratigraphic reconstruction Cretaceous volcano-sedimentary in the northwestern Andes: from extensional tectonics to arc accretion.

NASA Astrophysics Data System (ADS)

Zapata, S.; Patino, A. M.; Cardona, A.; Mejia, D.; Leon, S.; Jaramillo, J. S.; Valencia, V.; Parra, M.; Hincapie, S.

2014-12-01

Active continental margins characterized by continuous convergence experienced overimposed tectonic configurations that allowed the formation of volcanic arcs, back arc basins, transtensional divergent tectonics or the accretion of exotic volcanic terranes. Such record, particularly the extensional phases, can be partially destroyed and obscure by multiple deformational events, the accretion of exotic terranes and strike slip fragmentation along the margin. The tectonic evolution of the northern Andes during the Mesozoic is the result of post Pangea extension followed by the installation of a long-lived Jurassic volcanic arc (209 - 136 ma) that apparently stops between 136 Ma and 110 Ma. The Quebradagrande Complex has been define as a single Lower Cretaceous volcano-sedimentary unit exposed in the western flank of the Central Cordillera of the Colombian Andes that growth after the Late Jurassic to Early Cretaceous magmatic hiatus. The origin of this unit have been related either to an oceanic volcanic arc or a marginal basin environment. The existence of such contrasting models reflect the regional perspective followed in published studies and the paucity of detail analysis of the volcano-sedimentary sequences.We integrate multiple approaches including structural mapping, stratigraphy, geochemistry, U-Pb provenance and geochronology to improve the understanding of this unit and track the earlier phases of accumulation that are mask on the overimposed tectonic history. Our preliminary results suggest the existence of different volcano-sedimentary units that accumulated between 100 Ma and 82 Ma.The older Lower Cretaceous sequences was deposited over Triassic metamorphic continental crust and include a upward basin deepening record characterized by thick fan delta conglomerates, followed by distal turbidites and a syn-sedimentary volcanic record at 100 ma. The other sequence include a 85 - 82 Ma fringing arc that was also formed close to the continental margin or associated with a continental terrane.This two volcano-sedimentary domains were finally juxtaposed due to the collision with an allochthonous oceanic arc that collide with the Continental margin in the Late Cretaceous marking the initiation of the Andean Orogeny.

Valley-fill sequences and onlap geometries, Lower Cretaceous Muddy Sandstone, Kitty Field, Powder River basin, Wyoming

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

Gardner, M.H.; Gustason, E.R.

1987-05-01

The Muddy Sandstone at Kitty field is a valley-fill sequence that records a late Albian sea level rise and accompanying transgression. The valley was cut during a preceding sea level lowstand. Stratal geometries and facies successions within the valley fill demonstrate the history of transgression was not gradual and progressive. Rather, the valley fill comprises a series of discrete, time-bounded, depositional units which onlap the erosional surface. Five time-bounded depositional units were defined by facies successions and were used to define onlap geometries. Facies successions within individual units record progressive shoaling. Capping each succession, there may be a planar disconformity,more » a thin bioturbated interval, or the deepest water facies of the next depositional event. Thus, the termination of each depositional event is marked by an episode of rapid deepening. At a single geographic location, stratal successions within older depositional units represent more landward facies than those within younger units. Therefore, the onlap geometry of the valley-fill sequence consists of a landward-stepping arrangement of depositional units. The primary reservoirs within the valley-fill sequence, at Kitty field, are laterally coalesced, channel-belt sandstones at the base and barrier island sandstones at the top. Reservoir sandstones of lesser quality occur within the intermediate estuarine facies. The stacking pattern, developed by onlap of the units, results in multiple pay zones within mid-valley reaches. The boundaries of each depositional unit define a high-resolution, chronostratigraphic correlation of valley-fill strata, a correlation corroborated by bentonites. This correlation method gives an accurate description of the internal geometry of valley-fill strata and, therefore, provides a basis for understanding the process of transgressive onlap.« less

Concordance of motor vehicle crash, emergency department, and inpatient hospitalization data sets in the identification of drugs in injured drivers.

PubMed

Bunn, T; Singleton, M; Nicholson, V; Slavova, S

2013-01-01

Prescription drug overdoses, abuse, and sales have increased dramatically in the United States in the last decade. The purpose of the present study was to link crash data with emergency department (ED) and inpatient hospitalization data to assess the concordance between the data sets in the identification of the presence of drugs among injured motor vehicle drivers (passenger cars, passenger trucks, light trucks, and semi-trucks) in Kentucky. Kentucky CRASH data were probabilistically linked to ED data sets for years 2008-2010 and to inpatient hospitalization data sets for years 2000-2010. Statistical analyses were performed. Of the 72,529 linked crash/ED visits, there were 473 drivers with an associated nondependent abuse of drugs diagnosis in the ED, and 930 drivers had drug involvement recorded in the CRASH data (only 163 cases overlapped with drug involvement both recorded in CRASH data and coded as nondependent abuse of drugs in the ED); 64 drivers had multiple drug types present in their system. Of the 20,860 total linked crash/inpatient hospitalization cases, there were 973 drivers diagnosed with nondependent abuse of drugs in the inpatient hospitalization record and 499 drivers had drug involvement recorded in the CRASH data (only 207 overlapped); 250 drivers were diagnosed with multiple drugs in their system. Surveillance data from multiple public health data sets is necessary to identify the presence of drugs in injured drivers involved in motor vehicle crashes. The use of a single surveillance data set alone may significantly underreport the number of drugged drivers who were injured in a motor vehicle collision.

Multiple Generations on Video Tape Recorders.

ERIC Educational Resources Information Center

Wiens, Jacob H.

Helical scan video tape recorders were tested for their dubbing characteristics in order to make selection data available to media personnel. The equipment, two recorders of each type tested, was submitted by the manufacturers. The test was designed to produce quality evaluations for three generations of a single tape, thereby encompassing all…

Complicated jejunal diverticula as surgical emergency: experience at a tertiary care hospital in Peshawar, Pakistan.

PubMed

Ahmed, Ijaz; Naeem, Mohammad; Samad, Ambreen; Nasir, Amir; Aman, Zahid; Ahmed, Siddique; Manan, Fazal

2010-01-01

Diverticula of small intestine are rare. Jejunal diverticula can be single or multiple. Diverticula in the jejunum tend to be large and multiple. Clinically they may be asymptomatic or may give rise to symptoms like pain, flatulence and borborygmi, may produce malabsorption syndrome or may present in emergency with different acute pathologies like perforation, haemorrhage, obstruction, enterolith formation and inflammation. The Objective was to see the pattern of complications in jejunal diverticula presenting as a surgical emergency. This descriptive study was conducted at Surgical Units of the 3 tertiary care Hospitals of Peshawar, for 7 years from January 1, 2002 to December 31, 2008. Study included all patients presenting to and admitted in Surgical Unit, Hayatabad Medical Complex, Peshawar with complicated jejunal diverticula during the above mentioned period. Name, age, sex, other relevant data, history and examination findings and results of investigation were recorded. Uncomplicated jejuna diverticula were excluded from study. The operative findings and the type of complication were recorded. Ten patients were admitted during 7 years of study. Out of all patients 9 were male and 1 was female. Eight out of 10 patients presented with perforation of diverticula while 1 patient had severe inflammation of diverticulum causing pain, ileus and acute abdomen. One patient had acute pain due to adhesion formation. It is seen that complicated jejunal diverticulae are quite rare and the most common complication is perforation. Inflammation and adhesion are other complications with which jejunal diverticula presented during this study.

A spatial database of wildfires in the United States, 1992-2011

NASA Astrophysics Data System (ADS)

Short, K. C.

2013-07-01

The statistical analysis of wildfire activity is a critical component of national wildfire planning, operations, and research in the United States (US). However, there are multiple federal, state, and local entities with wildfire protection and reporting responsibilities in the US, and no single, unified system of wildfire record-keeping exists. To conduct even the most rudimentary interagency analyses of wildfire numbers and area burned from the authoritative systems of record, one must harvest records from dozens of disparate databases with inconsistent information content. The onus is then on the user to check for and purge redundant records of the same fire (i.e. multijurisdictional incidents with responses reported by several agencies or departments) after pooling data from different sources. Here we describe our efforts to acquire, standardize, error-check, compile, scrub, and evaluate the completeness of US federal, state, and local wildfire records from 1992-2011 for the national, interagency Fire Program Analysis (FPA) application. The resulting FPA Fire-occurrence Database (FPA FOD) includes nearly 1.6 million records from the 20 yr period, with values for at least the following core data elements: location at least as precise as a Public Land Survey System section (2.6 km2 grid), discovery date, and final fire size. The FPA FOD is publicly available from the Research Data Archive of the US Department of Agriculture, Forest Service (doi:10.2737/RDS-2013-0009). While necessarily incomplete in some aspects, the database is intended to facilitate fairly high-resolution geospatial analysis of US wildfire activity over the past two decades, based on available information from the authoritative systems of record.

A spatial database of wildfires in the United States, 1992-2011

NASA Astrophysics Data System (ADS)

Short, K. C.

2014-01-01

The statistical analysis of wildfire activity is a critical component of national wildfire planning, operations, and research in the United States (US). However, there are multiple federal, state, and local entities with wildfire protection and reporting responsibilities in the US, and no single, unified system of wildfire record keeping exists. To conduct even the most rudimentary interagency analyses of wildfire numbers and area burned from the authoritative systems of record, one must harvest records from dozens of disparate databases with inconsistent information content. The onus is then on the user to check for and purge redundant records of the same fire (i.e., multijurisdictional incidents with responses reported by several agencies or departments) after pooling data from different sources. Here we describe our efforts to acquire, standardize, error-check, compile, scrub, and evaluate the completeness of US federal, state, and local wildfire records from 1992-2011 for the national, interagency Fire Program Analysis (FPA) application. The resulting FPA Fire-Occurrence Database (FPA FOD) includes nearly 1.6 million records from the 20 yr period, with values for at least the following core data elements: location, at least as precise as a Public Land Survey System section (2.6 km2 grid), discovery date, and final fire size. The FPA FOD is publicly available from the Research Data Archive of the US Department of Agriculture, Forest Service (doi:10.2737/RDS-2013-0009). While necessarily incomplete in some aspects, the database is intended to facilitate fairly high-resolution geospatial analysis of US wildfire activity over the past two decades, based on available information from the authoritative systems of record.

Automated acoustic localization and call association for vocalizing humpback whales on the Navy's Pacific Missile Range Facility.

PubMed

Helble, Tyler A; Ierley, Glenn R; D'Spain, Gerald L; Martin, Stephen W

2015-01-01

Time difference of arrival (TDOA) methods for acoustically localizing multiple marine mammals have been applied to recorded data from the Navy's Pacific Missile Range Facility in order to localize and track humpback whales. Modifications to established methods were necessary in order to simultaneously track multiple animals on the range faster than real-time and in a fully automated way, while minimizing the number of incorrect localizations. The resulting algorithms were run with no human intervention at computational speeds faster than the data recording speed on over forty days of acoustic recordings from the range, spanning multiple years. Spatial localizations based on correlating sequences of units originating from within the range produce estimates having a standard deviation typically 10 m or less (due primarily to TDOA measurement errors), and a bias of 20 m or less (due primarily to sound speed mismatch). An automated method for associating units to individual whales is presented, enabling automated humpback song analyses to be performed.

Ia Afferent input alters the recruitment thresholds and firing rates of single human motor units.

PubMed

Grande, G; Cafarelli, E

2003-06-01

Vibration of the patellar tendon recruits motor units in the knee extensors via excitation of muscle spindles and subsequent Ia afferent input to the alpha-motoneuron pool. Our first purpose was to determine if the recruitment threshold and firing rate of the same motor unit differed when recruited involuntarily via reflex or voluntarily via descending spinal pathways. Although Ia input is excitatory to the alpha-motoneuron pool, it has also been shown paradoxically to inhibit itself. Our second purpose was to determine if vibration of the patellar tendon during a voluntary knee extension causes a change in the firing rate of already recruited motor units. In the first protocol, 10 subjects voluntarily reproduced the same isometric force profile of the knee extensors that was elicited by vibration of the patellar tendon. Single motor unit recordings from the vastus lateralis (VL) were obtained with tungsten microelectrodes and unitary behaviour was examined during both reflex and voluntary knee extensions. Recordings from 135 single motor units showed that both recruitment thresholds and firing rates were lower during reflex contractions. In the second protocol, 7 subjects maintained a voluntary knee extension at 30 N for approximately 40-45 s. Three bursts of patellar tendon vibration were superimposed at regular intervals throughout the contraction and changes in the firing rate of already recruited motor units were examined. A total of 35 motor units were recorded and each burst of superimposed vibration caused a momentary reduction in the firing rates and recruitment of additional units. Our data provide evidence that Ia input modulates the recruitment thresholds and firing rates of motor units providing more flexibility within the neuromuscular system to grade force at low levels of force production.

Postoperative Pain and Flare-Ups: Comparison of Incidence Between Single and Multiple Visit Pulpectomy in Primary Molars

PubMed Central

Gowda, Subhadra Halemane Nagaraj

2017-01-01

Introduction Endodontic treatment performed in either single- or multiple visit can be followed by numerous short- and long term complications. One of the short term complications include postoperative pain and flare–ups. The ability to predict its prevalence and forewarn the patient may go some way towards enabling coping strategies and help dentist in pain management treatment decisions Aim To compare the incidence and intensity of postoperative pain and flare-ups between single- and multiple visit pulpectomy in primary molars. Also, to correlate the preoperative status of the pulp to postoperative pain and flare-ups. Materials and Methods Eighty primary molars indicated for pulpectomy were included in the study and divided into two groups. Tooth treated and preoperative status of the pulp vitality was recorded. All the conventional steps in pulpectomy were followed. Teeth in Group 1 (single visit pulpectomy) were obturated on the same visit. Teeth in Group 2 (multiple visit pulpectomy) were obturated in the subsequent appointment. The recording of postoperative pain, flare-ups, use of medication were done after 24 hours, seven days and one month. Results Four cases in both the groups reported postoperative pain (10%) at 24 hour recall, p=0.74. One flare-up (2.5%) was recorded in each group p=0.67. None of the patients reported pain at seventh day and one month recall. Postoperative pain was recorded in five non-vital teeth (13.5%) and three vital teeth (6.9%). However, it was statistically not significant p=0.53. Conclusion From the perspective of our study there was a low incidence of postoperative pain. The majority of patients in both groups reported no pain or only minimal pain within 24 hours of treatment. There were no differences between single- and multi visit treatment protocols with respect to the incidence of postoperative pain. No significant correlation could be found between pulp vitality and the incidence of postoperative pain. PMID:28511499

The Impact of Multiple Master Patient Index Records on the Business Performance of Health Care Organizations: A Qualitative Grounded Theory Study

ERIC Educational Resources Information Center

Banton, Cynthia L.

2014-01-01

The purpose of this qualitative grounded theory study was to explore and examine the factors that led to the creation of multiple record entries, and present a theory on the impact the problem has on the business performance of health care organizations. A sample of 59 health care professionals across the United States participated in an online…

Chronic monitoring of lower urinary tract activity via a sacral dorsal root ganglia interface

NASA Astrophysics Data System (ADS)

Khurram, Abeer; Ross, Shani E.; Sperry, Zachariah J.; Ouyang, Aileen; Stephan, Christopher; Jiman, Ahmad A.; Bruns, Tim M.

2017-06-01

Objective. Our goal is to develop an interface that integrates chronic monitoring of lower urinary tract (LUT) activity with stimulation of peripheral pathways. Approach. Penetrating microelectrodes were implanted in sacral dorsal root ganglia (DRG) of adult male felines. Peripheral electrodes were placed on or in the pudendal nerve, bladder neck and near the external urethral sphincter. Supra-pubic bladder catheters were implanted for saline infusion and pressure monitoring. Electrode and catheter leads were enclosed in an external housing on the back. Neural signals from microelectrodes and bladder pressure of sedated or awake-behaving felines were recorded under various test conditions in weekly sessions. Electrodes were also stimulated to drive activity. Main results. LUT single- and multi-unit activity was recorded for 4-11 weeks in four felines. As many as 18 unique bladder pressure single-units were identified in each experiment. Some channels consistently recorded bladder afferent activity for up to 41 d, and we tracked individual single-units for up to 23 d continuously. Distension-evoked and stimulation-driven (DRG and pudendal) bladder emptying was observed, during which LUT sensory activity was recorded. Significance. This chronic implant animal model allows for behavioral studies of LUT neurophysiology and will allow for continued development of a closed-loop neuroprosthesis for bladder control.

Multiple vaccinations, health, and recall bias within UK armed forces deployed to Iraq: cohort study.

PubMed

Murphy, Dominic; Hotopf, Matthew; Wessely, Simon

2008-06-30

To assess the relation between self reported number of vaccinations received and health, and between numbers of vaccinations recorded from individuals' medical records and health. First phase of a cohort study. UK armed forces personnel. 4882 randomly selected military personnel deployed to Iraq since 2003 and a subset of 378 whose vaccination records were accessed. Psychological distress, fatigue, symptoms of post-traumatic stress disorder, health perception, and multiple physical symptoms. Personnel who reported receiving two or more vaccinations on a single day were more likely to report symptoms of fatigue (adjusted risk ratio 1.17, 95% confidence interval 1.05 to 1.30), show caseness according to the general health questionnaire (1.31, 1.13 to 1.53), and have multiple physical symptoms (1.32, 1.08 to 1.60). These associations were no longer significant when number of vaccinations recorded in individuals' medical records was used as the independent variable. Multiple vaccinations given to personnel in the UK armed forces in preparation for deployment to Iraq are not associated with adverse health consequences when vaccinations are recorded objectively from medical records. Adverse health consequences associated with self reported multiple vaccinations could be explained by recall bias.

Using Single Sensillum Recording to Detect Olfactory Neuron Responses of Bed Bugs to Semiochemicals.

PubMed

Liu, Feng; Liu, Nannan

2016-01-18

The insect olfactory system plays an important role in detecting semiochemicals in the environment. In particular, the antennal sensilla which house single or multiple neurons inside, are considered to make the major contribution in responding to the chemical stimuli. By directly recording action potential in the olfactory sensillum after exposure to stimuli, single sensillum recording (SSR) technique provides a powerful approach for investigating the neural responses of insects to chemical stimuli. For the bed bug, which is a notorious human parasite, multiple types of olfactory sensillum have been characterized. In this study, we demonstrated neural responses of bed bug olfactory sensilla to two chemical stimuli and the dose-dependent responses to one of them using the SSR method. This approach enables researchers to conduct early screening for individual chemical stimuli on the bed bug olfactory sensilla, which would provide valuable information for the development of new bed bug attractants or repellents and benefits the bed bug control efforts.

Using Single Sensillum Recording to Detect Olfactory Neuron Responses of Bed Bugs to Semiochemicals

PubMed Central

Liu, Feng; Liu, Nannan

2016-01-01

The insect olfactory system plays an important role in detecting semiochemicals in the environment. In particular, the antennal sensilla which house single or multiple neurons inside, are considered to make the major contribution in responding to the chemical stimuli. By directly recording action potential in the olfactory sensillum after exposure to stimuli, single sensillum recording (SSR) technique provides a powerful approach for investigating the neural responses of insects to chemical stimuli. For the bed bug, which is a notorious human parasite, multiple types of olfactory sensillum have been characterized. In this study, we demonstrated neural responses of bed bug olfactory sensilla to two chemical stimuli and the dose-dependent responses to one of them using the SSR method. This approach enables researchers to conduct early screening for individual chemical stimuli on the bed bug olfactory sensilla, which would provide valuable information for the development of new bed bug attractants or repellents and benefits the bed bug control efforts. PMID:26862929

Selective recruitment of single motor units in human flexor digitorum superficialis muscle during flexion of individual fingers.

PubMed

Butler, T J; Kilbreath, S L; Gorman, R B; Gandevia, S C

2005-08-15

Flexor digitorum superficialis (FDS) is an extrinsic multi-tendoned muscle which flexes the proximal interphalangeal joints of the four fingers. It comprises four digital components, each with a tendon that inserts onto its corresponding finger. To determine the degree to which these digital components can be selectively recruited by volition, we recorded the activity of a single motor unit in one component via an intramuscular electrode while the subject isometrically flexed each of the remaining fingers, one at a time. The finger on which the unit principally acted was defined as the 'test finger' and that which flexed isometrically was the 'active' finger. Activity in 79 units was recorded. Isometric finger flexion forces of 50% maximum voluntary contraction (MVC) activated less than 50% of single units in components of FDS acting on fingers that were not voluntarily flexed. With two exceptions, the median recruitment threshold for all active-test finger combinations involving the index, middle, ring and little finger test units was between 49 and 60% MVC (60% MVC being the value assigned to those not recruited). The exceptions were flexion of the little finger while recording from ring finger units (median: 40% MVC), and vice versa (median: 2% MVC). For all active-test finger combinations, only 35/181 units were activated when the active finger flexed at less than 20% MVC, and the fingers were adjacent for 28 of these. Functionally, to recruit FDS units during grasping and lifting, relatively heavy objects were required, although systematic variation occurred with the width of the object. In conclusion, FDS components can be selectively activated by volition and this may be especially important for grasping at high forces with one or more fingers.

Minimally-Invasive Neural Interface for Distributed Wireless Electrocorticogram Recording Systems

PubMed Central

Chang, Sun-Il

2018-01-01

This paper presents a minimally-invasive neural interface for distributed wireless electrocorticogram (ECoG) recording systems. The proposed interface equips all necessary components for ECoG recording, such as the high performance front-end integrated circuits, a fabricated flexible microelectrode array, and wireless communication inside a miniaturized custom-made platform. The multiple units of the interface systems can be deployed to cover a broad range of the target brain region and transmit signals via a built-in intra-skin communication (ISCOM) module. The core integrated circuit (IC) consists of 16-channel, low-power push-pull double-gated preamplifiers, in-channel successive approximation register analog-to-digital converters (SAR ADC) with a single-clocked bootstrapping switch and a time-delayed control unit, an ISCOM module for wireless data transfer through the skin instead of a power-hungry RF wireless transmitter, and a monolithic voltage/current reference generator to support the aforementioned analog and mixed-signal circuit blocks. The IC was fabricated using 250 nm CMOS processes in an area of 3.2 × 0.9 mm2 and achieved the low-power operation of 2.5 µW per channel. Input-referred noise was measured as 5.62 µVrms for 10 Hz to 10 kHz and ENOB of 7.21 at 31.25 kS/s. The implemented system successfully recorded multi-channel neural activities in vivo from a primate and demonstrated modular expandability using the ISCOM with power consumption of 160 µW. PMID:29342103

Minimally-Invasive Neural Interface for Distributed Wireless Electrocorticogram Recording Systems.

PubMed

Chang, Sun-Il; Park, Sung-Yun; Yoon, Euisik

2018-01-17

This paper presents a minimally-invasive neural interface for distributed wireless electrocorticogram (ECoG) recording systems. The proposed interface equips all necessary components for ECoG recording, such as the high performance front-end integrated circuits, a fabricated flexible microelectrode array, and wireless communication inside a miniaturized custom-made platform. The multiple units of the interface systems can be deployed to cover a broad range of the target brain region and transmit signals via a built-in intra-skin communication (ISCOM) module. The core integrated circuit (IC) consists of 16-channel, low-power push-pull double-gated preamplifiers, in-channel successive approximation register analog-to-digital converters (SAR ADC) with a single-clocked bootstrapping switch and a time-delayed control unit, an ISCOM module for wireless data transfer through the skin instead of a power-hungry RF wireless transmitter, and a monolithic voltage/current reference generator to support the aforementioned analog and mixed-signal circuit blocks. The IC was fabricated using 250 nm CMOS processes in an area of 3.2 × 0.9 mm² and achieved the low-power operation of 2.5 µW per channel. Input-referred noise was measured as 5.62 µV rms for 10 Hz to 10 kHz and ENOB of 7.21 at 31.25 kS/s. The implemented system successfully recorded multi-channel neural activities in vivo from a primate and demonstrated modular expandability using the ISCOM with power consumption of 160 µW.

Discharge patterns of human genioglossus motor units during arousal from sleep.

PubMed

Wilkinson, Vanessa; Malhotra, Atul; Nicholas, Christian L; Worsnop, Christopher; Jordan, Amy S; Butler, Jane E; Saboisky, Julian P; Gandevia, Simon C; White, David P; Trinder, John

2010-03-01

Single motor unit recordings of the human genioglossus muscle reveal motor units with a variety of discharge patterns. Integrated multiunit electromyographic recordings of genioglossus have demonstrated an abrupt increase in the muscle's activity at arousal from sleep. The aim of the present study was to determine the effect of arousal from sleep on the activity of individual motor units as a function of their particular discharge pattern. Genioglossus activity was measured using intramuscular fine-wire electrodes inserted via a percutaneous approach. Arousals from sleep were identified using the ASDA criterion and the genioglossus electromyogram recordings analyzed for single motor unit activity. Sleep research laboratory. Sleep and respiratory data were collected in 8 healthy subjects (6 men). 138 motor units were identified during prearousalarousal sleep: 25% inspiratory phasic, 33% inspiratory tonic, 4% expiratory phasic, 3% expiratory tonic, and 35% tonic. At arousal from sleep inspiratory phasic units significantly increased the proportion of a breath over which they were active, but did not appreciably increase their rate of firing. 80 new units were identified at arousals, 75% were inspiratory, many of which were active for only 1 or 2 breaths. 22% of units active before arousal, particularly expiratory and tonic units, stopped at the arousal. Increased genioglossus muscle activity at arousal from sleep is primarily due to recruitment of inspiratory phasic motor units. Further, activity within the genioglossus motoneuron pool is reorganized at arousal as, in addition to recruitment, approximately 20% of units active before arousals stopped firing.

Acceleration of discrete stochastic biochemical simulation using GPGPU.

PubMed

Sumiyoshi, Kei; Hirata, Kazuki; Hiroi, Noriko; Funahashi, Akira

2015-01-01

For systems made up of a small number of molecules, such as a biochemical network in a single cell, a simulation requires a stochastic approach, instead of a deterministic approach. The stochastic simulation algorithm (SSA) simulates the stochastic behavior of a spatially homogeneous system. Since stochastic approaches produce different results each time they are used, multiple runs are required in order to obtain statistical results; this results in a large computational cost. We have implemented a parallel method for using SSA to simulate a stochastic model; the method uses a graphics processing unit (GPU), which enables multiple realizations at the same time, and thus reduces the computational time and cost. During the simulation, for the purpose of analysis, each time course is recorded at each time step. A straightforward implementation of this method on a GPU is about 16 times faster than a sequential simulation on a CPU with hybrid parallelization; each of the multiple simulations is run simultaneously, and the computational tasks within each simulation are parallelized. We also implemented an improvement to the memory access and reduced the memory footprint, in order to optimize the computations on the GPU. We also implemented an asynchronous data transfer scheme to accelerate the time course recording function. To analyze the acceleration of our implementation on various sizes of model, we performed SSA simulations on different model sizes and compared these computation times to those for sequential simulations with a CPU. When used with the improved time course recording function, our method was shown to accelerate the SSA simulation by a factor of up to 130.

Acceleration of discrete stochastic biochemical simulation using GPGPU

PubMed Central

Sumiyoshi, Kei; Hirata, Kazuki; Hiroi, Noriko; Funahashi, Akira

2015-01-01

For systems made up of a small number of molecules, such as a biochemical network in a single cell, a simulation requires a stochastic approach, instead of a deterministic approach. The stochastic simulation algorithm (SSA) simulates the stochastic behavior of a spatially homogeneous system. Since stochastic approaches produce different results each time they are used, multiple runs are required in order to obtain statistical results; this results in a large computational cost. We have implemented a parallel method for using SSA to simulate a stochastic model; the method uses a graphics processing unit (GPU), which enables multiple realizations at the same time, and thus reduces the computational time and cost. During the simulation, for the purpose of analysis, each time course is recorded at each time step. A straightforward implementation of this method on a GPU is about 16 times faster than a sequential simulation on a CPU with hybrid parallelization; each of the multiple simulations is run simultaneously, and the computational tasks within each simulation are parallelized. We also implemented an improvement to the memory access and reduced the memory footprint, in order to optimize the computations on the GPU. We also implemented an asynchronous data transfer scheme to accelerate the time course recording function. To analyze the acceleration of our implementation on various sizes of model, we performed SSA simulations on different model sizes and compared these computation times to those for sequential simulations with a CPU. When used with the improved time course recording function, our method was shown to accelerate the SSA simulation by a factor of up to 130. PMID:25762936

A state space approach for piecewise-linear recurrent neural networks for identifying computational dynamics from neural measurements.

PubMed

Durstewitz, Daniel

2017-06-01

The computational and cognitive properties of neural systems are often thought to be implemented in terms of their (stochastic) network dynamics. Hence, recovering the system dynamics from experimentally observed neuronal time series, like multiple single-unit recordings or neuroimaging data, is an important step toward understanding its computations. Ideally, one would not only seek a (lower-dimensional) state space representation of the dynamics, but would wish to have access to its statistical properties and their generative equations for in-depth analysis. Recurrent neural networks (RNNs) are a computationally powerful and dynamically universal formal framework which has been extensively studied from both the computational and the dynamical systems perspective. Here we develop a semi-analytical maximum-likelihood estimation scheme for piecewise-linear RNNs (PLRNNs) within the statistical framework of state space models, which accounts for noise in both the underlying latent dynamics and the observation process. The Expectation-Maximization algorithm is used to infer the latent state distribution, through a global Laplace approximation, and the PLRNN parameters iteratively. After validating the procedure on toy examples, and using inference through particle filters for comparison, the approach is applied to multiple single-unit recordings from the rodent anterior cingulate cortex (ACC) obtained during performance of a classical working memory task, delayed alternation. Models estimated from kernel-smoothed spike time data were able to capture the essential computational dynamics underlying task performance, including stimulus-selective delay activity. The estimated models were rarely multi-stable, however, but rather were tuned to exhibit slow dynamics in the vicinity of a bifurcation point. In summary, the present work advances a semi-analytical (thus reasonably fast) maximum-likelihood estimation framework for PLRNNs that may enable to recover relevant aspects of the nonlinear dynamics underlying observed neuronal time series, and directly link these to computational properties.

Investment in different sized SMRs: Economic evaluation of stochastic scenarios by INCAS code

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

Barenghi, S.; Boarin, S.; Ricotti, M. E.

2012-07-01

Small Modular LWR concepts are being developed and proposed to investors worldwide. They capitalize on operating track record of GEN II LWR, while introducing innovative design enhancements allowed by smaller size and additional benefits from the higher degree of modularization and from deployment of multiple units on the same site. (i.e. 'Economy of Multiple' paradigm) Nevertheless Small Modular Reactors pay for a dis-economy of scale that represents a relevant penalty on a capital intensive investment. Investors in the nuclear power generation industry face a very high financial risk, due to high capital commitment and exceptionally long pay-back time. Investment riskmore » arise from uncertainty that affects scenario conditions over such a long time horizon. Risk aversion is increased by current adverse conditions of financial markets and general economic downturn, as is the case nowadays. This work investigates both the investment profitability and risk of alternative investments in a single Large Reactor or in multiple SMR of different sizes drawing information from project's Internal Rate of Return stochastic distribution. multiple SMR deployment on a single site with total power installed, equivalent to a single LR. Uncertain scenario conditions and stochastic input assumptions are included in the analysis, representing investment uncertainty and risk. Results show that, despite the combination of much larger number of stochastic variables in SMR fleets, uncertainty of project profitability is not increased, as compared to LR: SMR have features able to smooth IRR variance and control investment risk. Despite dis-economy of scale, SMR represent a limited capital commitment and a scalable investment option that meet investors' interest, even in developed and mature markets, that are traditional marketplace for LR. (authors)« less

Output Properties of the Cortical Hindlimb Motor Area in Spinal Cord-Injured Rats.

PubMed

Frost, Shawn B; Dunham, Caleb L; Barbay, Scott; Krizsan-Agbas, Dora; Winter, Michelle K; Guggenmos, David J; Nudo, Randolph J

2015-11-01

The purpose of this study was to examine neuronal activity levels in the hindlimb area of motor cortex following spinal cord injury (SCI) in rats and compare the results with measurements in normal rats. Fifteen male Fischer-344 rats received a 200 Kdyn contusion injury in the thoracic cord at level T9-T10. After a minimum of 4 weeks following SCI, intracortical microstimulation (ICMS) and single-unit recording techniques were used in both the forelimb and hindlimb motor areas (FLA, HLA) under ketamine anesthesia. Although movements could be evoked using ICMS in the forelimb area with relatively low current levels, no movements or electromyographical responses could be evoked from ICMS in the HLA in any of the injured rats. During the same procedure, electrophysiological recordings were obtained with a single-shank, 16-channel Michigan probe (Neuronexus) to monitor activity. Neural spikes were discriminated using principle component analysis. Neural activity (action potentials) was collected and digitized for a duration of 5 min. Despite the inability to evoke movement from stimulation of cortex, robust single-unit activity could be recorded reliably from hindlimb motor cortex in SCI rats. Activity in the motor cortex of SCI rats was significantly higher compared with uninjured rats, and increased in hindlimb and forelimb motor cortex by similar amounts. These results demonstrate that in a rat model of thoracic SCI, an increase in single-unit cortical activity can be reliably recorded for several weeks post-injury.

Output Properties of the Cortical Hindlimb Motor Area in Spinal Cord-Injured Rats

PubMed Central

Dunham, Caleb L.; Barbay, Scott; Krizsan-Agbas, Dora; Winter, Michelle K.; Guggenmos, David J.; Nudo, Randolph J.

2015-01-01

Abstract The purpose of this study was to examine neuronal activity levels in the hindlimb area of motor cortex following spinal cord injury (SCI) in rats and compare the results with measurements in normal rats. Fifteen male Fischer-344 rats received a 200 Kdyn contusion injury in the thoracic cord at level T9–T10. After a minimum of 4 weeks following SCI, intracortical microstimulation (ICMS) and single-unit recording techniques were used in both the forelimb and hindlimb motor areas (FLA, HLA) under ketamine anesthesia. Although movements could be evoked using ICMS in the forelimb area with relatively low current levels, no movements or electromyographical responses could be evoked from ICMS in the HLA in any of the injured rats. During the same procedure, electrophysiological recordings were obtained with a single-shank, 16-channel Michigan probe (Neuronexus) to monitor activity. Neural spikes were discriminated using principle component analysis. Neural activity (action potentials) was collected and digitized for a duration of 5 min. Despite the inability to evoke movement from stimulation of cortex, robust single-unit activity could be recorded reliably from hindlimb motor cortex in SCI rats. Activity in the motor cortex of SCI rats was significantly higher compared with uninjured rats, and increased in hindlimb and forelimb motor cortex by similar amounts. These results demonstrate that in a rat model of thoracic SCI, an increase in single-unit cortical activity can be reliably recorded for several weeks post-injury. PMID:26406381

Adaptive video-based vehicle classification technique for monitoring traffic : [executive summary].

DOT National Transportation Integrated Search

2015-08-01

Federal Highway Administration (FHWA) recommends axle-based classification standards to map : passenger vehicles, single unit trucks, and multi-unit trucks, at Automatic Traffic Recorder (ATR) stations : statewide. Many state Departments of Transport...

14 CFR 27.1457 - Cockpit voice recorders.

Code of Federal Regulations, 2014 CFR

2014-01-01

... service to essential or emergency loads. (ii) It remains powered for as long as possible without... combination unit, no single electrical failure external to the recorder may disable both the cockpit voice... or by any other loss of power to the electrical power bus. (e) The record container must be located...

14 CFR 29.1457 - Cockpit voice recorders.

Code of Federal Regulations, 2014 CFR

2014-01-01

... without jeopardizing service to essential or emergency loads. (ii) It remains powered for as long as... boxes or in a combination unit, no single electrical failure external to the recorder may disable both... shutdown or by any other loss of power to the electrical power bus. (e) The record container must be...

True 3D digital holographic tomography for virtual reality applications

NASA Astrophysics Data System (ADS)

Downham, A.; Abeywickrema, U.; Banerjee, P. P.

2017-09-01

Previously, a single CCD camera has been used to record holograms of an object while the object is rotated about a single axis to reconstruct a pseudo-3D image, which does not show detailed depth information from all perspectives. To generate a true 3D image, the object has to be rotated through multiple angles and along multiple axes. In this work, to reconstruct a true 3D image including depth information, a die is rotated along two orthogonal axes, and holograms are recorded using a Mach-Zehnder setup, which are subsequently numerically reconstructed. This allows for the generation of multiple images containing phase (i.e., depth) information. These images, when combined, create a true 3D image with depth information which can be exported to a Microsoft® HoloLens for true 3D virtual reality.

Motor impulsivity differentiates between psychiatric inpatients with multiple versus single lifetime suicide attempts.

PubMed

Colborn, Victoria A; LaCroix, Jessica M; Neely, Laura L; Tucker, Jennifer; Perera, Kanchana; Daruwala, Samantha E; Grammer, Geoffrey; Weaver, Jennifer; Ghahramanlou-Holloway, Marjan

2017-07-01

A history of multiple suicide attempts conveys greater risk for suicide than a single attempt. Impulsivity may partially explain the association between multiple attempts and increased risk. We examined trait impulsivity, ability to engage in goal-directed behaviors, and impulse control among psychiatrically hospitalized United States military personnel and their dependents. Individuals with a history of multiple versus single attempts had significantly higher motor impulsivity, indicating spur of the moment action. Providers are encouraged to directly assess and treat motor impulsivity among suicidal individuals. Further research should explore whether motor impulsivity is a mechanism of change in psychosocial suicide prevention interventions. Copyright © 2017. Published by Elsevier B.V.

System Synchronizes Recordings from Separated Video Cameras

NASA Technical Reports Server (NTRS)

Nail, William; Nail, William L.; Nail, Jasper M.; Le, Doung T.

2009-01-01

A system of electronic hardware and software for synchronizing recordings from multiple, physically separated video cameras is being developed, primarily for use in multiple-look-angle video production. The system, the time code used in the system, and the underlying method of synchronization upon which the design of the system is based are denoted generally by the term "Geo-TimeCode(TradeMark)." The system is embodied mostly in compact, lightweight, portable units (see figure) denoted video time-code units (VTUs) - one VTU for each video camera. The system is scalable in that any number of camera recordings can be synchronized. The estimated retail price per unit would be about $350 (in 2006 dollars). The need for this or another synchronization system external to video cameras arises because most video cameras do not include internal means for maintaining synchronization with other video cameras. Unlike prior video-camera-synchronization systems, this system does not depend on continuous cable or radio links between cameras (however, it does depend on occasional cable links lasting a few seconds). Also, whereas the time codes used in prior video-camera-synchronization systems typically repeat after 24 hours, the time code used in this system does not repeat for slightly more than 136 years; hence, this system is much better suited for long-term deployment of multiple cameras.

Evaluating the Use of Existing Data Sources, Probabilistic Linkage, and Multiple Imputation to Build Population-based Injury Databases Across Phases of Trauma Care

PubMed Central

Newgard, Craig; Malveau, Susan; Staudenmayer, Kristan; Wang, N. Ewen; Hsia, Renee Y.; Mann, N. Clay; Holmes, James F.; Kuppermann, Nathan; Haukoos, Jason S.; Bulger, Eileen M.; Dai, Mengtao; Cook, Lawrence J.

2012-01-01

Objectives The objective was to evaluate the process of using existing data sources, probabilistic linkage, and multiple imputation to create large population-based injury databases matched to outcomes. Methods This was a retrospective cohort study of injured children and adults transported by 94 emergency medical systems (EMS) agencies to 122 hospitals in seven regions of the western United States over a 36-month period (2006 to 2008). All injured patients evaluated by EMS personnel within specific geographic catchment areas were included, regardless of field disposition or outcome. The authors performed probabilistic linkage of EMS records to four hospital and postdischarge data sources (emergency department [ED] data, patient discharge data, trauma registries, and vital statistics files) and then handled missing values using multiple imputation. The authors compare and evaluate matched records, match rates (proportion of matches among eligible patients), and injury outcomes within and across sites. Results There were 381,719 injured patients evaluated by EMS personnel in the seven regions. Among transported patients, match rates ranged from 14.9% to 87.5% and were directly affected by the availability of hospital data sources and proportion of missing values for key linkage variables. For vital statistics records (1-year mortality), estimated match rates ranged from 88.0% to 98.7%. Use of multiple imputation (compared to complete case analysis) reduced bias for injury outcomes, although sample size, percentage missing, type of variable, and combined-site versus single-site imputation models all affected the resulting estimates and variance. Conclusions This project demonstrates the feasibility and describes the process of constructing population-based injury databases across multiple phases of care using existing data sources and commonly available analytic methods. Attention to key linkage variables and decisions for handling missing values can be used to increase match rates between data sources, minimize bias, and preserve sampling design. PMID:22506952

Improving medical records filing in a municipal hospital in Ghana.

PubMed

Teviu, E A A; Aikins, M; Abdulai, T I; Sackey, S; Boni, P; Afari, E; Wurapa, F

2012-09-01

Medical records are kept in the interest of both the patient and clinician. Proper filing of patient's medical records ensures easy retrieval and contributes to decreased patient waiting time at the hospital and continuity of care. This paper reports on an intervention study to address the issue of misfiling and multiple patient folders in a health facility. Intervention study. Municipal Hospital, Goaso, Asunafo North District, Brong Ahafo Region, Ghana. Methods employed for data collection were records review, direct observation and tracking of folders. Interventions instituted were staff durbars, advocacy and communication, consultations, in-service trainings, procurement and monitoring. Factors contributing to issuance of multiple folders and misfiling were determined. Proportion of multiple folders was estimated. Results revealed direct and indirect factors contributing to issuance of multiple patient folders and misfiling. Interventions and monitoring reduce acquisition of numerous medical folders per patient and misfiling. After the intervention, there was significant reduction in the use of multiple folders (i.e., overall 97% reduction) and a high usage of single patient medical folders (i.e., 99%). In conclusion, a defined medical records filing system with adequate training, logistics and regular monitoring and supervision minimises issuance of multiple folders and misfiling.

Motor unit number estimation and quantitative needle electromyography in stroke patients.

PubMed

Kouzi, Ioanna; Trachani, Eftichia; Anagnostou, Evangelos; Rapidi, Christina-Anastasia; Ellul, John; Sakellaropoulos, George C; Chroni, Elisabeth

2014-12-01

To evaluate the effect of upper motor neuron damage upon motor units' function by means of two separate and supplementary electrophysiological methods. The abductor digiti minimi muscle of the non-paretic and the paretic side was studied in forty-six stroke patients with (a) motor unit number estimation (MUNE) - adapted multiple point stimulation method and (b) computerized quantitative needle electromyography (EMG) assessing the configuration of voluntary recruited motor unit potentials. Main outcome comparisons were focused on differences between non-paretic and paretic side. On the affected hands mean MUNE value was significantly lower and mean area of the surface recorded single motor unit potentials was significantly larger than the corresponding ones on the non-paretic hands. EMG findings did not reveal remarkable differences between the two sides. Neither severity nor chronicity of stroke was related to MUNE or EMG parameters. MUNE results, which suggested reduced motor unit numbers in stroke patients, in conjunction with the normal EMG features in these same muscles has given rise to different interpretations. In a clinical setting, reinnervation type changes in the EMG similar to that occurring in neuronopathies or axonal neuropathies should not be expected in muscles with central neurogenic lesion. Copyright © 2014 Elsevier Ltd. All rights reserved.

Truck Traffic Iowa : 2010

DOT National Transportation Integrated Search

2011-01-01

Truck volumes represented on this map are Annual Average Daily Traffic Volumes between major traffic generators: i.e., Highway Junctions and Cities. : Truck volumes include 6-Tire and 3 Axle single unit trucks, buses and all multiple unit trucks.

Integration trumps selection in object recognition.

PubMed

Saarela, Toni P; Landy, Michael S

2015-03-30

Finding and recognizing objects is a fundamental task of vision. Objects can be defined by several "cues" (color, luminance, texture, etc.), and humans can integrate sensory cues to improve detection and recognition [1-3]. Cortical mechanisms fuse information from multiple cues [4], and shape-selective neural mechanisms can display cue invariance by responding to a given shape independent of the visual cue defining it [5-8]. Selective attention, in contrast, improves recognition by isolating a subset of the visual information [9]. Humans can select single features (red or vertical) within a perceptual dimension (color or orientation), giving faster and more accurate responses to items having the attended feature [10, 11]. Attention elevates neural responses and sharpens neural tuning to the attended feature, as shown by studies in psychophysics and modeling [11, 12], imaging [13-16], and single-cell and neural population recordings [17, 18]. Besides single features, attention can select whole objects [19-21]. Objects are among the suggested "units" of attention because attention to a single feature of an object causes the selection of all of its features [19-21]. Here, we pit integration against attentional selection in object recognition. We find, first, that humans can integrate information near optimally from several perceptual dimensions (color, texture, luminance) to improve recognition. They cannot, however, isolate a single dimension even when the other dimensions provide task-irrelevant, potentially conflicting information. For object recognition, it appears that there is mandatory integration of information from multiple dimensions of visual experience. The advantage afforded by this integration, however, comes at the expense of attentional selection. Copyright © 2015 Elsevier Ltd. All rights reserved.

Three-Dimensional Medical Image Analysis Using Local Dynamic Algorithm Selection on a Multiple-Instruction, Multiple-Data Architecture

DTIC Science & Technology

1989-01-01

is represented by a number, called a Hounsfield Unit (HU), which represents the attenuation within the volume relative to the attenuation of the same...volume of water. Hounsfield Unit values range from -1000 to +3000, with a value of zero assigned to the attenuation of water. A HU value of -1000...represented by a 3D array. Each array element represents a single voxel, and the value of the array entry is the corresponding scaled Hounsfield Unit value

Emergency recompression: clinical audit of service delivery at a national level.

PubMed

Ross, John As; Sayer, Martin Dj

2009-03-01

Clinical audit is an essential element to the maintenance or improvement of delivery of any medical service. During the development phase of a National Recompression Registration Service for Scotland, clinical audit was initiated to provide a standardised tool to monitor the quality of outcome with respect to the severity of presentation. A functional audit process was an essential consideration for planned future measurement of treatment efficacy at local (single hyperbaric unit) and national (multiple hyperbaric units) scales. The audit process was designed to be undemanding, robust and informative, irrespective of the experience of treatment centre and of the clinician in charge of treatment. The clinical records from 104 cases of divers with decompression illness were used to derive and evaluate measures of severity and clinical outcome that could be used for audit and quality assurance. The various measures of disease severity were examined against clinical outcome and days spent in care after admission to a hyperbaric unit. An initial version of the clinical audit format that was developed from this process is presented.

Quantifying short-lived events in multistate ionic current measurements.

PubMed

Balijepalli, Arvind; Ettedgui, Jessica; Cornio, Andrew T; Robertson, Joseph W F; Cheung, Kin P; Kasianowicz, John J; Vaz, Canute

2014-02-25

We developed a generalized technique to characterize polymer-nanopore interactions via single channel ionic current measurements. Physical interactions between analytes, such as DNA, proteins, or synthetic polymers, and a nanopore cause multiple discrete states in the current. We modeled the transitions of the current to individual states with an equivalent electrical circuit, which allowed us to describe the system response. This enabled the estimation of short-lived states that are presently not characterized by existing analysis techniques. Our approach considerably improves the range and resolution of single-molecule characterization with nanopores. For example, we characterized the residence times of synthetic polymers that are three times shorter than those estimated with existing algorithms. Because the molecule's residence time follows an exponential distribution, we recover nearly 20-fold more events per unit time that can be used for analysis. Furthermore, the measurement range was extended from 11 monomers to as few as 8. Finally, we applied this technique to recover a known sequence of single-stranded DNA from previously published ion channel recordings, identifying discrete current states with subpicoampere resolution.

Creation of an Accurate Algorithm to Detect Snellen Best Documented Visual Acuity from Ophthalmology Electronic Health Record Notes.

PubMed

Mbagwu, Michael; French, Dustin D; Gill, Manjot; Mitchell, Christopher; Jackson, Kathryn; Kho, Abel; Bryar, Paul J

2016-05-04

Visual acuity is the primary measure used in ophthalmology to determine how well a patient can see. Visual acuity for a single eye may be recorded in multiple ways for a single patient visit (eg, Snellen vs. Jäger units vs. font print size), and be recorded for either distance or near vision. Capturing the best documented visual acuity (BDVA) of each eye in an individual patient visit is an important step for making electronic ophthalmology clinical notes useful in research. Currently, there is limited methodology for capturing BDVA in an efficient and accurate manner from electronic health record (EHR) notes. We developed an algorithm to detect BDVA for right and left eyes from defined fields within electronic ophthalmology clinical notes. We designed an algorithm to detect the BDVA from defined fields within 295,218 ophthalmology clinical notes with visual acuity data present. About 5668 unique responses were identified and an algorithm was developed to map all of the unique responses to a structured list of Snellen visual acuities. Visual acuity was captured from a total of 295,218 ophthalmology clinical notes during the study dates. The algorithm identified all visual acuities in the defined visual acuity section for each eye and returned a single BDVA for each eye. A clinician chart review of 100 random patient notes showed a 99% accuracy detecting BDVA from these records and 1% observed error. Our algorithm successfully captures best documented Snellen distance visual acuity from ophthalmology clinical notes and transforms a variety of inputs into a structured Snellen equivalent list. Our work, to the best of our knowledge, represents the first attempt at capturing visual acuity accurately from large numbers of electronic ophthalmology notes. Use of this algorithm can benefit research groups interested in assessing visual acuity for patient centered outcome. All codes used for this study are currently available, and will be made available online at https://phekb.org.

Creation of an Accurate Algorithm to Detect Snellen Best Documented Visual Acuity from Ophthalmology Electronic Health Record Notes

PubMed Central

French, Dustin D; Gill, Manjot; Mitchell, Christopher; Jackson, Kathryn; Kho, Abel; Bryar, Paul J

2016-01-01

Background Visual acuity is the primary measure used in ophthalmology to determine how well a patient can see. Visual acuity for a single eye may be recorded in multiple ways for a single patient visit (eg, Snellen vs. Jäger units vs. font print size), and be recorded for either distance or near vision. Capturing the best documented visual acuity (BDVA) of each eye in an individual patient visit is an important step for making electronic ophthalmology clinical notes useful in research. Objective Currently, there is limited methodology for capturing BDVA in an efficient and accurate manner from electronic health record (EHR) notes. We developed an algorithm to detect BDVA for right and left eyes from defined fields within electronic ophthalmology clinical notes. Methods We designed an algorithm to detect the BDVA from defined fields within 295,218 ophthalmology clinical notes with visual acuity data present. About 5668 unique responses were identified and an algorithm was developed to map all of the unique responses to a structured list of Snellen visual acuities. Results Visual acuity was captured from a total of 295,218 ophthalmology clinical notes during the study dates. The algorithm identified all visual acuities in the defined visual acuity section for each eye and returned a single BDVA for each eye. A clinician chart review of 100 random patient notes showed a 99% accuracy detecting BDVA from these records and 1% observed error. Conclusions Our algorithm successfully captures best documented Snellen distance visual acuity from ophthalmology clinical notes and transforms a variety of inputs into a structured Snellen equivalent list. Our work, to the best of our knowledge, represents the first attempt at capturing visual acuity accurately from large numbers of electronic ophthalmology notes. Use of this algorithm can benefit research groups interested in assessing visual acuity for patient centered outcome. All codes used for this study are currently available, and will be made available online at https://phekb.org. PMID:27146002

Sleep spindles in humans: insights from intracranial EEG and unit recordings

PubMed Central

Andrillon, Thomas; Nir, Yuval; Staba, Richard J.; Ferrarelli, Fabio; Cirelli, Chiara; Tononi, Giulio; Fried, Itzhak

2012-01-01

Sleep spindles are an electroencephalographic (EEG) hallmark of non-rapid eye movement (NREM) sleep and are believed to mediate many sleep-related functions, from memory consolidation to cortical development. Spindles differ in location, frequency, and association with slow waves, but whether this heterogeneity may reflect different physiological processes and potentially serve different functional roles remains unclear. Here we utilized a unique opportunity to record intracranial depth EEG and single-unit activity in multiple brain regions of neurosurgical patients to better characterize spindle activity in human sleep. We find that spindles occur across multiple neocortical regions, and less frequently also in the parahippocampal gyrus and hippocampus. Most spindles are spatially restricted to specific brain regions. In addition, spindle frequency is topographically organized with a sharp transition around the supplementary motor area between fast (13-15Hz) centroparietal spindles often occurring with slow wave up-states, and slow (9-12Hz) frontal spindles occurring 200ms later on average. Spindle variability across regions may reflect the underlying thalamocortical projections. We also find that during individual spindles, frequency decreases within and between regions. In addition, deeper sleep is associated with a reduction in spindle occurrence and spindle frequency. Frequency changes between regions, during individual spindles, and across sleep may reflect the same phenomenon, the underlying level of thalamocortical hyperpolarization. Finally, during spindles neuronal firing rates are not consistently modulated, although some neurons exhibit phase-locked discharges. Overall, anatomical considerations can account well for regional spindle characteristics, while variable hyperpolarization levels can explain differences in spindle frequency. PMID:22159098

Effect of age on changes in motor units functional connectivity.

PubMed

Arjunan, Sridhar P; Kumar, Dinesh

2015-08-01

With age, there is a change in functional connectivity of motor units in muscle. This leads to reduced muscle strength. This study has investigated the effect of age on the changes in the motor unit recruitment by measuring the mutual information between multiple channels of surface electromyogram (sEMG) of biceps brachii muscle. It is hypothesised that with ageing, there is a reduction in number of motor units, which can lead to an increase in the dependency of remaining motor units. This increase can be observed in the mutual information between the multiple channels of the muscle activity. Two channels of sEMG were recorded during the maximum level of isometric contraction. 28 healthy subjects (Young: age range 20-35years and Old: age range - 60-70years) participated in the experiments. The normalized mutual information (NMI), a measure of dependency factor, was computed for the sEMG recordings. Statistical analysis was performed to test the effect of age on NMI. The results show that the NMI among the older cohort was significantly higher when compared with the young adults.

Evaluating the 4-hour and 30-minute rules: effects of room temperature exposure on red blood cell quality and bacterial growth.

PubMed

Ramirez-Arcos, Sandra; Mastronardi, Cherie; Perkins, Heather; Kou, Yuntong; Turner, Tracey; Mastronardi, Emily; Hansen, Adele; Yi, Qi-Long; McLaughlin, Natasha; Kahwash, Eiad; Lin, Yulia; Acker, Jason

2013-04-01

A 30-minute rule was established to limit red blood cell (RBC) exposure to uncontrolled temperatures during storage and transportation. Also, RBC units issued for transfusion should not remain at room temperature (RT) for more than 4 hours (4-hour rule). This study was aimed at determining if single or multiple RT exposures affect RBC quality and/or promote bacterial growth. Growth and RT exposure experiments were performed in RBCs inoculated with Serratia liquefaciens and Serratia marcescens. RBCs were exposed once to RT for 5 hours (S. liquefaciens) or five times to RT for 30 minutes (S. marcescens) with periodic sampling for bacterial counts. Noncontaminated units were exposed to RT once (5 hr) or five times (30 min each) and sampled to measure in vitro quality variables. RBC core temperature was monitored using mock units with temperature loggers. Growth and RT exposure experiments were repeated three and at least six times, respectively. Statistical analysis was done using mixed-model analysis. RBC core temperature ranged from 7.3 to 11.6°C during 30-minute RT exposures and the time to reach 10°C varied from 22 to 55 minutes during 5-hour RT exposures. RBC quality was preserved after single or multiple RT exposures. Increased growth of S. liquefaciens was only observed after 2 hours of continuous RT exposure. S. marcescens concentration increased significantly in multiple-exposed units compared to the controls but did not reach clinically important levels. Single or multiple RT exposures did not affect RBC quality but slightly promoted bacterial growth in contaminated units. The clinical significance of these results remains unclear and needs further investigation. © 2012 American Association of Blood Banks.

Single-beam Denisyuk holograms recording with pulsed 30Hz RGB laser

NASA Astrophysics Data System (ADS)

Zacharovas, Stanislovas; Bakanas, Ramūnas; Stankauskas, Algimantas

2016-03-01

It is well known fact that holograms can be recorded either by continuous wave (CW) laser, or by single pulse coming from pulsed laser. However, multi-pulse or multiple-exposure holograms were used only in interferometry as well as for information storage. We have used Geola's single longitudinal mode pulsed RGB laser to record Denisyuk type holograms. We successfully recorded objects situated at the distance of more than 30cm, employing the multi-pulse working regime of the laser. To record Denisyuk hologram we have used 50 ns duration 440, 660nm wavelength and 35ns duration 532nm wavelength laser pulses at the repetition rate of 30Hz. As photosensitive medium we have used Slavich-Geola PFG-03C glass photoplate. Radiations with different wavelengths were mixed into "white" beam, collimated and directed onto the photoplate. For further objects illumination an additional flat silver coated mirror was used.

Multiple environmental contexts and preterm birth risks

EPA Science Inventory

Human health is affected by simultaneous exposure to numerous stressors and amenities, but research often focuses on single exposure models. To address this, a United States county-level Multiple Environmental Domain Index (MEDI) was constructed with data representing five envir...

Triple electrical channels on a triple fluid swivel and its use to monitor intracranial temperature with a thermocouple.

PubMed

Parada, M A; Puig de Parada, M; Hernandez, L; Hoebel, B G

1995-08-01

A low-torque, bubble-free and multiple-channel fluid swivel of easy construction was recently described. This paper describes the design, construction and testing of 3 electrical channels added to the original fluid swivel. The new channels were tested monitoring intrahypothalamic temperature (T(hy)) by means of a copper-constantan thermocouple in freely moving rats, before and after a single intraperitoneal (i.p.) amphetamine injection (3 mg/kg). This test showed an increase in T(hy) after the injection and the maintenance of the electrical continuity along the whole testing period, even when the animals were hyperactive. With this improvement the original swivel was transformed in a more versatile device for experiments requiring fluid handlings and electrophysiological manipulations. Electrical stimulation as in kindling or brain self-stimulation, and electrophysiological recordings as in electroencephalography, electromiography, electrocardiography, in vivo voltammetry and even neuronal unit recording, are just examples of the electrophysiological methods that can be combined with drug self-administration and microdialysis using the present device.

36 CFR 1228.12 - How do agencies obtain approval to loan permanent or unscheduled records?

Code of Federal Regulations, 2011 CFR

2011-07-01

... duration of the loan; (5) A statement specifying any restrictions on the use of the records and how these... Archivist has signed the agreement. (b) On request, NARA may allow an agency to prepare an annual loan agreement covering multiple transfers from the same series of records to another single Federal agency. (c...

36 CFR 1228.12 - How do agencies obtain approval to loan permanent or unscheduled records?

Code of Federal Regulations, 2010 CFR

2010-07-01

... duration of the loan; (5) A statement specifying any restrictions on the use of the records and how these... Archivist has signed the agreement. (b) On request, NARA may allow an agency to prepare an annual loan agreement covering multiple transfers from the same series of records to another single Federal agency. (c...

Stable long-term chronic brain mapping at the single-neuron level.

PubMed

Fu, Tian-Ming; Hong, Guosong; Zhou, Tao; Schuhmann, Thomas G; Viveros, Robert D; Lieber, Charles M

2016-10-01

Stable in vivo mapping and modulation of the same neurons and brain circuits over extended periods is critical to both neuroscience and medicine. Current electrical implants offer single-neuron spatiotemporal resolution but are limited by such factors as relative shear motion and chronic immune responses during long-term recording. To overcome these limitations, we developed a chronic in vivo recording and stimulation platform based on flexible mesh electronics, and we demonstrated stable multiplexed local field potentials and single-unit recordings in mouse brains for at least 8 months without probe repositioning. Properties of acquired signals suggest robust tracking of the same neurons over this period. This recording and stimulation platform allowed us to evoke stable single-neuron responses to chronic electrical stimulation and to carry out longitudinal studies of brain aging in freely behaving mice. Such advantages could open up future studies in mapping and modulating changes associated with learning, aging and neurodegenerative diseases.

Auditory thresholds in the American cockroach (Orthoptera: Blattidae): estimates using single-unit and compound-action potential recordings.

PubMed

Decker, T N; Jones, T A; Gold, R E

1989-06-01

Recent commercial suggestions that insect populations can be controlled through the use of ultrasound raises the question of whether or not certain insects have receptors that are sensitive to high-frequency sound. Single neural unit discharges and compound-action potentials were recorded from the ventral nerve cord in the American cockroach, Periplaneta americana L., to constant rise time tone pulses from 100 to 40,000 hertz (Hz). Unit responses and compound-action potentials show that the cockroach is insensitive to sound above approximately 3,000 Hz. Data relating latency of the response to intensity of the stimulus suggest that the cockroach cercal system operates on the principle of energy envelope detection. Decreases in latency likely occur primarily as a result of increases in the rate of membrane depolarization in cercal dendrites.

Creating an Infrastructure for Comparative Effectiveness Research in Emergency Medical Services

PubMed Central

Seymour, Christopher W.; Kahn, Jeremy M.; Martin-Gill, Christian; Callaway, Clifton W.; Angus, Derek C.; Yealy, Donald M.

2014-01-01

Objectives Emergency medical services (EMS) providers deliver the initial care for millions of people in the United States each year. The Institute of Medicine noted a deficit in research necessary to improve prehospital care, created by the existence of data silos, absence of long-term outcomes, and limited stakeholder engagement in research. This article describes a regional effort to create a high-performing infrastructure in southwestern Pennsylvania addressing these fundamental barriers. Methods Regional EMS records from 33 agencies in January 2011 were linked to hospital-based electronic health records (EHRs) in a single nine-hospital system, with manual review of matches for accuracy. The use of community stakeholder engagement was included to guide scientific inquiry, as well as 2-year follow up for patient-centered outcomes. Results Local EMS medicine stakeholders emphasized the limits of single-agency EMS research, and suggested that studies focus on improving cross-cutting, long-term outcomes. Guided by this input, more than 95% of EMS records (2,675 out of 2,800) were linked to hospital-based EHRs. More than 80% of records were linked to 2-year mortality, with more deaths among EMS patients with prehospital hypotension (30.5%) or respiratory distress (19.5%) than chest pain (5.4%) or non-specific complaints (9.4%). Conclusions A prehospital comparative effectiveness research infrastructure composed of patient-level EMS data, EHRs at multiple hospitals, long-term outcomes, and community stakeholder perspectives is feasible and may be scalable to larger regions and networks. The lessons learned and barriers identified offer a roadmap to answering community and policy-relevant research questions in prehospital care. PMID:24842512

512-Channel and 13-Region Simultaneous Recordings Coupled with Optogenetic Manipulation in Freely Behaving Mice

PubMed Central

Xie, Kun; Fox, Grace E.; Liu, Jun; Tsien, Joe Z.

2016-01-01

The development of technologies capable of recording both single-unit activity and local field potentials (LFPs) over a wide range of brain circuits in freely behaving animals is the key to constructing brain activity maps. Although mice are the most popular mammalian genetic model, in vivo neural recording has been traditionally limited to smaller channel count and fewer brain structures because of the mouse’s small size and thin skull. Here, we describe a 512-channel tetrode system that allows us to record simultaneously over a dozen cortical and subcortical structures in behaving mice. This new technique offers two major advantages – namely, the ultra-low cost and the do-it-yourself flexibility for targeting any combination of many brain areas. We show the successful recordings of both single units and LFPs from 13 distinct neural circuits of the mouse brain, including subregions of the anterior cingulate cortices, retrosplenial cortices, somatosensory cortices, secondary auditory cortex, hippocampal CA1, dentate gyrus, subiculum, lateral entorhinal cortex, perirhinal cortex, and prelimbic cortex. This 512-channel system can also be combined with Cre-lox neurogenetics and optogenetics to further examine interactions between genes, cell types, and circuit dynamics across a wide range of brain structures. Finally, we demonstrate that complex stimuli – such as an earthquake and fear-inducing foot-shock – trigger firing changes in all of the 13 brain regions recorded, supporting the notion that neural code is highly distributed. In addition, we show that localized optogenetic manipulation in any given brain region could disrupt network oscillations and caused changes in single-unit firing patterns in a brain-wide manner, thereby raising the cautionary note of the interpretation of optogenetically manipulated behaviors. PMID:27378865

[Extension of cardiac monitoring function by used of ordinary ECG machine].

PubMed

Chen, Zhencheng; Jiang, Yong; Ni, Lili; Wang, Hongyan

2002-06-01

This paper deals with a portable monitor system on liquid crystal display (LCD) based on this available ordinary ECG machine, which is low power and suitable for China's specific condition. Apart from developing the overall scheme of the system, this paper also has completed the design of the hardware and the software. The 80c196 single chip microcomputer is taken as the central microprocessor and real time electrocardiac single is data treated and analyzed in the system. With the performance of ordinary monitor, this machine also possesses the following functions: five types of arrhythmia analysis, alarm, freeze, and record of automatic pappering, convenient in carrying, with alternate-current (AC) or direct-current (DC) powered. The hardware circuit is simplified and the software structure is optimized in this paper. Multiple low power designs and LCD unit design are adopted and completed in it. Popular in usage, low in cost price, the portable monitor system will have a valuable influence on China's monitor system field.

Single motor unit firing rate after stroke is higher on the less-affected side during stable low-level voluntary contractions

PubMed Central

McNulty, Penelope A.; Lin, Gaven; Doust, Catherine G.

2014-01-01

Muscle weakness is the most common outcome after stroke and a leading cause of adult-acquired motor disability. Single motor unit properties provide insight into the mechanisms of post-stroke motor impairment. Motor units on the more-affected side are reported to have lower peak firing rates, reduced discharge variability and a more compressed dynamic range than healthy subjects. The activity of 169 motor units was discriminated from surface electromyography in 28 stroke patients during sustained voluntary contractions 10% of maximal and compared to 110 units recorded in 16 healthy subjects. Motor units were recorded in three series: ankle dorsiflexion, wrist flexion and elbow flexion. Mean firing rates after stroke were significantly lower on the more-affected than the less-affected side (p < 0.001) with no differences between dominant and non-dominant sides for healthy subjects. When data were combined, firing rates on the less-affected side were significantly higher than those either on the more-affected side or healthy subjects (p < 0.001). Motor unit mean firing rate was higher in the upper-limb than the lower-limb (p < 0.05). The coefficient of variation of motor unit discharge rate was lower for motor units after stroke compared to controls for wrist flexion (p < 0.05) but not ankle dorsiflexion. However the dynamic range of motor units was compressed only for motor units on the more-affected side during wrist flexion. Our results show that the pathological change in motor unit firing rate occurs on the less-affected side after stroke and not the more-affected side as previously reported, and suggest that motor unit behavior recorded in a single muscle after stroke cannot be generalized to muscles acting on other joints even within the same limb. These data emphasize that the less-affected side does not provide a valid control for physiological studies on the more-affected side after stroke and that both sides should be compared to data from age- and sex-matched healthy subjects. PMID:25100969

Minimally disruptive medicine is needed for patients with multimorbidity: time to develop computerised medical record systems to meet this requirement.

PubMed

Schattner, Peter; Barker, Fiona; de Lusignan, Simon

2015-02-19

Minimally disruptive medicine (MDM) is proposed as a method for more appropriately managing people with multiple chronic disease. Much clinical management is currently single disease focussed, with people with multimorbidity being managed according to multiple single disease guidelines. Current initiatives to improve care include education about individual conditions and creating an environment where multiple guidelines might be simultaneously supported. The patient-centred medical home (PCMH) is an example of the latter. However, educational programmes and PCMH may increase the burden on patients. The cumulative workload for patients in managing the impact of multiple disease-specific guidelines is only relatively recently recognised. There is an intellectual vacuum as to how best to manage multimorbidity and how informatics might support implementing MDM. There is currently no alternative to multiple single-condition- specific guidelines and a lack of certainty, should the treatment burden need to be reduced, as to which guideline might be 'dropped'. The best information about multimorbidity is recorded in primary care computerised medical record (CMR) systems and in an increasing number of integrated care organisations. CMR systems have the potential to flag individuals who might be in greatest need. However, CMR systems may also provide insights into whether there are ameliorating factors that might make it easier for them to be resilient to the burden of care. Data from such CMR systems might be used to develop the evidence base about how to better manage multimorbidity. There is potential for these information systems to help reduce the management burden on patients and clinicians. However, substantial investment in research-driven CMR development is needed if we are to achieve this.

Effect of chronic restraint stress on inhibitory gating in the auditory cortex of rats.

PubMed

Ma, Lanlan; Li, Wai; Li, Sibin; Wang, Xuejiao; Qin, Ling

2017-05-01

A fundamental adaptive mechanism of auditory function is inhibitory gating (IG), which refers to the attenuation of neural responses to repeated sound stimuli. IG is drastically impaired in individuals with emotional and cognitive impairments (i.e. posttraumatic stress disorder). The objective of this study was to test whether chronic stress impairs the IG of the auditory cortex (AC). We used the standard two-tone stimulus paradigm and examined the parametric qualities of IG in the AC of rats by recording the electrophysiological signals of a single-unit and local field potential (LFP) simultaneously. The main results of this study were that most of the AC neurons showed a weaker response to the second tone than to the first tone, reflecting an IG of the repeated input. A fast negative wave of LFP showed consistent IG across the sampled AC sites, whereas a slow positive wave of LFP had less IG effect. IG was diminished following chronic restraint stress at both, the single-unit and LFP level, due to the increase in response to the second tone. This study provided new evidence that chronic stress disrupts the physiological function of the AC. Lay Summary The effects of chronic stress on IG were investigated by recording both, single-unit spike and LFP activities, in the AC of rats. In normal rats, most of the single-unit and N25 LFP activities in the AC showed an IG effect. IG was diminished following chronic restraint stress at both, the single-unit and LFP level.

Influence of transmucosal height in abutments of single and multiple implant-supported prostheses: a non-linear three-dimensional finite element analysis.

PubMed

Borie, Eduardo; Leal, Eduardo; Orsi, Iara Augusta; Salamanca, Carlos; Dias, Fernando José; Weber, Benjamin

2018-01-01

The aim of this study was to analyze the influence of three different transmucosal heights of the abutments in single and multiple implant-supported prostheses through the finite element method. External hexagon implants, MicroUnit, and EsthetiCone abutments were scanned and placed in an edentulous maxillary model obtained from a tomography database. The simulations were divided into two groups: (1) one implant with 3.75 × 10 mm placed in the upper central incisor, simulating a single implant-supported fixed prosthesis with an EsthetiCone abutment; and (2) two implants with 3.75 × 10 mm placed in the upper lateral incisors with MicroUnit abutments, simulating a multiple implant-supported prosthesis. Subsequently, each group was subdivided into three models according to the transmucosal height (1, 2, and 3 mm). A static oblique load at an angle of 45 degrees to the long axis of the implant in palatal-buccal direction of 150 and 75 N was applied for multiple and single implant-supported prosthesis, respectively. The implants and abutments were assessed according to the equivalent Von Mises stress analyses while the bone and ceramics were analyzed through maximum and minimum principal stresses. The total deformation values increased in all models, while the transmucosal height was augmented. The transmucosal height of the abutments influences the stress values at the bone, ceramics, implants, and abutments of both the single and multiple implant-supported prostheses, with the transmucosal height of 1 mm showing the lowest stress values.

4D multiple-cathode ultrafast electron microscopy

PubMed Central

Baskin, John Spencer; Liu, Haihua; Zewail, Ahmed H.

2014-01-01

Four-dimensional multiple-cathode ultrafast electron microscopy is developed to enable the capture of multiple images at ultrashort time intervals for a single microscopic dynamic process. The dynamic process is initiated in the specimen by one femtosecond light pulse and probed by multiple packets of electrons generated by one UV laser pulse impinging on multiple, spatially distinct, cathode surfaces. Each packet is distinctly recorded, with timing and detector location controlled by the cathode configuration. In the first demonstration, two packets of electrons on each image frame (of the CCD) probe different times, separated by 19 picoseconds, in the evolution of the diffraction of a gold film following femtosecond heating. Future elaborations of this concept to extend its capabilities and expand the range of applications of 4D ultrafast electron microscopy are discussed. The proof-of-principle demonstration reported here provides a path toward the imaging of irreversible ultrafast phenomena of materials, and opens the door to studies involving the single-frame capture of ultrafast dynamics using single-pump/multiple-probe, embedded stroboscopic imaging. PMID:25006261

4D multiple-cathode ultrafast electron microscopy.

PubMed

Baskin, John Spencer; Liu, Haihua; Zewail, Ahmed H

2014-07-22

Four-dimensional multiple-cathode ultrafast electron microscopy is developed to enable the capture of multiple images at ultrashort time intervals for a single microscopic dynamic process. The dynamic process is initiated in the specimen by one femtosecond light pulse and probed by multiple packets of electrons generated by one UV laser pulse impinging on multiple, spatially distinct, cathode surfaces. Each packet is distinctly recorded, with timing and detector location controlled by the cathode configuration. In the first demonstration, two packets of electrons on each image frame (of the CCD) probe different times, separated by 19 picoseconds, in the evolution of the diffraction of a gold film following femtosecond heating. Future elaborations of this concept to extend its capabilities and expand the range of applications of 4D ultrafast electron microscopy are discussed. The proof-of-principle demonstration reported here provides a path toward the imaging of irreversible ultrafast phenomena of materials, and opens the door to studies involving the single-frame capture of ultrafast dynamics using single-pump/multiple-probe, embedded stroboscopic imaging.

Optical encryption of multiple three-dimensional objects based on multiple interferences and single-pixel digital holography

NASA Astrophysics Data System (ADS)

Wang, Ying; Liu, Qi; Wang, Jun; Wang, Qiong-Hua

2018-03-01

We present an optical encryption method of multiple three-dimensional objects based on multiple interferences and single-pixel digital holography. By modifying the Mach–Zehnder interferometer, the interference of the multiple objects beams and the one reference beam is used to simultaneously encrypt multiple objects into a ciphertext. During decryption, each three-dimensional object can be decrypted independently without having to decrypt other objects. Since the single-pixel digital holography based on compressive sensing theory is introduced, the encrypted data of this method is effectively reduced. In addition, recording fewer encrypted data can greatly reduce the bandwidth of network transmission. Moreover, the compressive sensing essentially serves as a secret key that makes an intruder attack invalid, which means that the system is more secure than the conventional encryption method. Simulation results demonstrate the feasibility of the proposed method and show that the system has good security performance. Project supported by the National Natural Science Foundation of China (Grant Nos. 61405130 and 61320106015).

Multiple acousto-optic q-switch

DOEpatents

Deason, Vance A.

1993-01-01

An improved dynamic moire interferometer comprised of a lasing medium providing a plurality of beams of coherent light, a multiple q-switch producing multiple trains of 100,000 or more pulses per second, a combining means collimating multiple trains of pulses into substantially a single train and directing beams to specimen gratings affixed to a test material, and a controller, triggering and sequencing the emission of the pulses with the occurrence and recording of a dynamic loading event.

Multiple acousto-optic q-switch

DOEpatents

Deason, Vance A.

1993-12-07

An improved dynamic moire interferometer comprised of a lasing medium providing a plurality of beams of coherent light, a multiple q-switch producing multiple trains of 100,000 or more pulses per second, a combining means collimating multiple trains of pulses into substantially a single train and directing beams to specimen gratings affixed to a test material, and a controller, triggering and sequencing the emission of the pulses with the occurrence and recording of a dynamic loading event.

Pulse patterning effect in optical pulse division multiplexing for flexible single wavelength multiple access optical network

NASA Astrophysics Data System (ADS)

Jung, Sun-Young; Kim, Chang-Hun; Han, Sang-Kook

2018-05-01

A demand for high spectral efficiency requires multiple access within a single wavelength, but the uplink signals are significantly degraded because of optical beat interference (OBI) in intensity modulation/direct detection system. An optical pulse division multiplexing (OPDM) technique was proposed that could effectively reduce the OBI via a simple method as long as near-orthogonality is satisfied, but the condition was strict, and thus, the number of multiplexing units was very limited. We propose pulse pattern enhanced OPDM (e-OPDM) to reduce the OBI and improve the flexibility in multiple access within a single wavelength. The performance of the e-OPDM and patterning effect are experimentally verified after 23-km single mode fiber transmission. By employing pulse patterning in OPDM, the tight requirement was relaxed by extending the optical delay dynamic range. This could support more number of access with reduced OBI, which could eventually enhance a multiple access function.

Methods for automatic detection of artifacts in microelectrode recordings.

PubMed

Bakštein, Eduard; Sieger, Tomáš; Wild, Jiří; Novák, Daniel; Schneider, Jakub; Vostatek, Pavel; Urgošík, Dušan; Jech, Robert

2017-10-01

Extracellular microelectrode recording (MER) is a prominent technique for studies of extracellular single-unit neuronal activity. In order to achieve robust results in more complex analysis pipelines, it is necessary to have high quality input data with a low amount of artifacts. We show that noise (mainly electromagnetic interference and motion artifacts) may affect more than 25% of the recording length in a clinical MER database. We present several methods for automatic detection of noise in MER signals, based on (i) unsupervised detection of stationary segments, (ii) large peaks in the power spectral density, and (iii) a classifier based on multiple time- and frequency-domain features. We evaluate the proposed methods on a manually annotated database of 5735 ten-second MER signals from 58 Parkinson's disease patients. The existing methods for artifact detection in single-channel MER that have been rigorously tested, are based on unsupervised change-point detection. We show on an extensive real MER database that the presented techniques are better suited for the task of artifact identification and achieve much better results. The best-performing classifiers (bagging and decision tree) achieved artifact classification accuracy of up to 89% on an unseen test set and outperformed the unsupervised techniques by 5-10%. This was close to the level of agreement among raters using manual annotation (93.5%). We conclude that the proposed methods are suitable for automatic MER denoising and may help in the efficient elimination of undesirable signal artifacts. Copyright © 2017 Elsevier B.V. All rights reserved.

[The design of a cardiac monitoring and analysing system with low power consumption].

PubMed

Chen, Zhen-cheng; Ni, Li-li; Zhu, Yan-gao; Wang, Hong-yan; Ma, Yan

2002-07-01

The paper deals with a portable analyzing monitor system with liquid crystal display (LCD), which is low in power consumption and suitable for China's specific conditions. Apart from the development of the overall scheme of the system, the paper introduces the design of the hardware and the software. The 80196 single chip microcomputer is used as the central microprocessor to process and real-time electrocardiac signal data. The system have the following functions: five types of arrhythmia analysis, alarm, freeze, and record of automatic paperfeeding. The portable system can be operated by alternate-current (AC) or direct-current (DC). Its hardware circuit is simplified and its software structure is optimized. Multiple low power consumption and LCD unit are adopted in its modular designs.

Compressive auto-indexing in femtosecond nanocrystallography

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

Maia, Filipe; Yang, Chao; Marchesini, Stefano

2010-09-20

Ultrafast nanocrystallography has the potential to revolutionize biology by enabling structural elucidation of proteins for which it is possible to grow crystals with 10 or fewer unit cells. The success of nanocrystallography depends on robust orientation-determination procedures that allow us to average diffraction data from multiple nanocrystals to produce a 3D diffraction data volume with a high signal-to-noise ratio. Such a 3D diffraction volume can then be phased using standard crystallographic techniques."Indexing" algorithms used in crystallography enable orientation determination of a diffraction data from a single crystal when a relatively large number of reflections are recorded. Here we show thatmore » it is possible to obtain the exact lattice geometry from a smaller number of measurements than standard approaches using a basis pursuit solver.« less

Single-unit analysis of somatosensory processing in the core auditory cortex of hearing ferrets.

PubMed

Meredith, M Alex; Allman, Brian L

2015-03-01

The recent findings in several species that the primary auditory cortex processes non-auditory information have largely overlooked the possibility of somatosensory effects. Therefore, the present investigation examined the core auditory cortices (anterior auditory field and primary auditory cortex) for tactile responsivity. Multiple single-unit recordings from anesthetised ferret cortex yielded histologically verified neurons (n = 311) tested with electronically controlled auditory, visual and tactile stimuli, and their combinations. Of the auditory neurons tested, a small proportion (17%) was influenced by visual cues, but a somewhat larger number (23%) was affected by tactile stimulation. Tactile effects rarely occurred alone and spiking responses were observed in bimodal auditory-tactile neurons. However, the broadest tactile effect that was observed, which occurred in all neuron types, was that of suppression of the response to a concurrent auditory cue. The presence of tactile effects in the core auditory cortices was supported by a substantial anatomical projection from the rostral suprasylvian sulcal somatosensory area. Collectively, these results demonstrate that crossmodal effects in the auditory cortex are not exclusively visual and that somatosensation plays a significant role in modulation of acoustic processing, and indicate that crossmodal plasticity following deafness may unmask these existing non-auditory functions. © 2015 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Three dimensional metafilms with dual channel unit cells

DOE PAGES

Burckel, D. Bruce; Campione, Salvatore; Davids, Paul S.; ...

2017-04-04

Three-dimensional (3D) metafilms composed of periodic arrays of silicon unit cells containing single and multiple micrometer-scale vertical split ring resonators (SRRs) per unit cell were fabricated. In contrast to planar and stacked planar structures, these 3D metafilms have a thickness t ~λ d/4, allowing for classical thin film effects in the long wavelength limit. The infrared specular far-field scattering response was measured for metafilms containing one and two resonators per unit cell and compared to numerical simulations. Excellent agreement in the frequency region below the onset of diffractive scattering was obtained. For dense arrays of unit cells containing single SRRs,more » normally incident linearly polarized plane waves which do not excite a resonant response result in thin film interference fringes in the reflected spectra and are virtually indistinguishable from the scattering response of an undecorated array of unit cells. For the resonant linear polarization, the specular reflection for arrays is highly dependent on the SRR orientation on the vertical face for gap-up, gap-down, and gap-right orientations. For dense arrays of unit cells containing two SRRs per unit cell positioned on adjacent faces, the specular reflection spectra are slightly modified due to near-field coupling between the orthogonally oriented SRRs but otherwise exhibit reflection spectra largely representative of the corresponding single-SRR unit cell structures. Lastly, the ability to pack the unit cell with multiple inclusions which can be independently excited by choice of incident polarization suggests the construction of dual-channel films where the scattering response is selected by altering the incident polarization.« less

Effect of number and location of distant metastases on renal cell carcinoma mortality in candidates for cytoreductive nephrectomy: implications for multimodal therapy.

PubMed

Capitanio, Umberto; Abdollah, Firas; Matloob, Rayan; Salonia, Andrea; Suardi, Nazareno; Briganti, Alberto; Carenzi, Cristina; Rigatti, Patrizio; Montorsi, Francesco; Bertini, Roberto

2013-06-01

To test whether the combination of number and location of distant metastases affects cancer-specific survival in patients with metastatic renal cell carcinoma. Overall, 242 metastatic renal cell carcinoma patients with synchronous metastases at diagnosis underwent cytoreductive nephrectomy at a single institution. Combinations of number and location of distant metastases were coded as: single metastasis and single organ affected, multiple metastases and single organ affected, single metastasis for each of the multiple organs affected, and multiple metastases for each of the multiple organs affected. Covariates included age, symptoms, performance status, American Society of Anesthesiologists score, hemoglobin, lactate dehydrogenase, tumor size, Fuhrman grade, T stage, lymph node status, necrosis, sarcomatoid features and metastasectomy at the time of nephrectomy. The median survival was 34.7 versus 32.3 versus 29.6 versus 8.5 months for single metastasis and single organ affected, multiple metastases and single organ affected single metastasis for each of the multiple organs affected, and multiple metastases for each of the multiple organs affected patients, respectively. At multivariable analyses, the combination of number and location of distant metastases resulted in one of the most informative and independent predictors of cancer-specific survival in metastatic renal cell carcinoma patients. The lung was the location with the highest rate of single organ affected (50.3% vs 35.1% in other sites; P < 0.001). Considering only patients with a single metastasis, no statistically significantly different cancer-specific survival rates were recorded (P > 0.3) among different metastatic organs. Among metastatic renal cell carcinoma patients undergoing cytoreductive nephrectomy, the combination of the number and location of distant metastases is a major independent predictor of cancer-specific survival. Patients with multiple organs affected by multifocal disease are more likely to have poorer survival. © 2012 The Japanese Urological Association.

Exploring Middle School Students' Use of Inscriptions in Project-Based Science Classrooms

ERIC Educational Resources Information Center

Wu, Hsin-Kai; Krajcik, Joseph S.

2006-01-01

This study explores seventh graders' use of inscriptions in a teacher-designed project-based science unit. To investigate students' learning practices during the 8-month water quality unit, we collected multiple sources of data (e.g., classroom video recordings, student artifacts, and teacher interviews) and employed analytical methods that drew…

Motion-related resource allocation in dynamic wireless visual sensor network environments.

PubMed

Katsenou, Angeliki V; Kondi, Lisimachos P; Parsopoulos, Konstantinos E

2014-01-01

This paper investigates quality-driven cross-layer optimization for resource allocation in direct sequence code division multiple access wireless visual sensor networks. We consider a single-hop network topology, where each sensor transmits directly to a centralized control unit (CCU) that manages the available network resources. Our aim is to enable the CCU to jointly allocate the transmission power and source-channel coding rates for each node, under four different quality-driven criteria that take into consideration the varying motion characteristics of each recorded video. For this purpose, we studied two approaches with a different tradeoff of quality and complexity. The first one allocates the resources individually for each sensor, whereas the second clusters them according to the recorded level of motion. In order to address the dynamic nature of the recorded scenery and re-allocate the resources whenever it is dictated by the changes in the amount of motion in the scenery, we propose a mechanism based on the particle swarm optimization algorithm, combined with two restarting schemes that either exploit the previously determined resource allocation or conduct a rough estimation of it. Experimental simulations demonstrate the efficiency of the proposed approaches.

Evaluating single-pass catch as a tool for identifying spatial pattern in fish distribution

USGS Publications Warehouse

Bateman, Douglas S.; Gresswell, Robert E.; Torgersen, Christian E.

2005-01-01

We evaluate the efficacy of single-pass electrofishing without blocknets as a tool for collecting spatially continuous fish distribution data in headwater streams. We compare spatial patterns in abundance, sampling effort, and length-frequency distributions from single-pass sampling of coastal cutthroat trout (Oncorhynchus clarki clarki) to data obtained from a more precise multiple-pass removal electrofishing method in two mid-sized (500–1000 ha) forested watersheds in western Oregon. Abundance estimates from single- and multiple-pass removal electrofishing were positively correlated in both watersheds, r = 0.99 and 0.86. There were no significant trends in capture probabilities at the watershed scale (P > 0.05). Moreover, among-sample variation in fish abundance was higher than within-sample error in both streams indicating that increased precision of unit-scale abundance estimates would provide less information on patterns of abundance than increasing the fraction of habitat units sampled. In the two watersheds, respectively, single-pass electrofishing captured 78 and 74% of the estimated population of cutthroat trout with 7 and 10% of the effort. At the scale of intermediate-sized watersheds, single-pass electrofishing exhibited a sufficient level of precision to be effective in detecting spatial patterns of cutthroat trout abundance and may be a useful tool for providing the context for investigating fish-habitat relationships at multiple scales.

Telemetric recordings of single neuron activity and visual scenes in monkeys walking in an open field.

PubMed

Lei, Yanlin; Sun, Ninglei; Wilson, Fraser A W; Wang, Xiusong; Chen, Nanhui; Yang, Jianzhen; Peng, Yanping; Wang, Jianhong; Tian, Shaohua; Wang, Maohua; Miao, Yingda; Zhu, Weina; Qi, Hua; Ma, Yuanye

2004-05-30

This paper describes a portable recording system and methods for obtaining chronic recordings of single units and tracking rhesus monkey behavior in an open field. The integrated system consists of four major components: (1) microelectrode assembly; (2) head-stage; (3) recording station; and (4) data storage station, the first three of which are carried by the monkey and weigh 800 g. Our system provides synchronized video and electrophysiological signals, which are transmitted by a wireless system to a distance of 50 m. Its major advantages are that neuronal recordings are made in freely moving monkeys, and well-separated action potentials with amplitude five times higher than the background noise are usually recorded and readily kept for many hours. Using this system, we were able to study "place cells" in non-human primate brains. The described methods provide a new way to examine correlations between single neuron activity and primate behaviors, and can also be used to study the cellular basis of social behaviors in non-human primates.

Approximation of reliabilities for multiple-trait model with maternal effects.

PubMed

Strabel, T; Misztal, I; Bertrand, J K

2001-04-01

Reliabilities for a multiple-trait maternal model were obtained by combining reliabilities obtained from single-trait models. Single-trait reliabilities were obtained using an approximation that supported models with additive and permanent environmental effects. For the direct effect, the maternal and permanent environmental variances were assigned to the residual. For the maternal effect, variance of the direct effect was assigned to the residual. Data included 10,550 birth weight, 11,819 weaning weight, and 3,617 postweaning gain records of Senepol cattle. Reliabilities were obtained by generalized inversion and by using single-trait and multiple-trait approximation methods. Some reliabilities obtained by inversion were negative because inbreeding was ignored in calculating the inverse of the relationship matrix. The multiple-trait approximation method reduced the bias of approximation when compared with the single-trait method. The correlations between reliabilities obtained by inversion and by multiple-trait procedures for the direct effect were 0.85 for birth weight, 0.94 for weaning weight, and 0.96 for postweaning gain. Correlations for maternal effects for birth weight and weaning weight were 0.96 to 0.98 for both approximations. Further improvements can be achieved by refining the single-trait procedures.

Task-Dependent Changes in Cross-Level Coupling between Single Neurons and Oscillatory Activity in Multiscale Networks

PubMed Central

Canolty, Ryan T.; Ganguly, Karunesh; Carmena, Jose M.

2012-01-01

Understanding the principles governing the dynamic coordination of functional brain networks remains an important unmet goal within neuroscience. How do distributed ensembles of neurons transiently coordinate their activity across a variety of spatial and temporal scales? While a complete mechanistic account of this process remains elusive, evidence suggests that neuronal oscillations may play a key role in this process, with different rhythms influencing both local computation and long-range communication. To investigate this question, we recorded multiple single unit and local field potential (LFP) activity from microelectrode arrays implanted bilaterally in macaque motor areas. Monkeys performed a delayed center-out reach task either manually using their natural arm (Manual Control, MC) or under direct neural control through a brain-machine interface (Brain Control, BC). In accord with prior work, we found that the spiking activity of individual neurons is coupled to multiple aspects of the ongoing motor beta rhythm (10–45 Hz) during both MC and BC, with neurons exhibiting a diversity of coupling preferences. However, here we show that for identified single neurons, this beta-to-rate mapping can change in a reversible and task-dependent way. For example, as beta power increases, a given neuron may increase spiking during MC but decrease spiking during BC, or exhibit a reversible shift in the preferred phase of firing. The within-task stability of coupling, combined with the reversible cross-task changes in coupling, suggest that task-dependent changes in the beta-to-rate mapping play a role in the transient functional reorganization of neural ensembles. We characterize the range of task-dependent changes in the mapping from beta amplitude, phase, and inter-hemispheric phase differences to the spike rates of an ensemble of simultaneously-recorded neurons, and discuss the potential implications that dynamic remapping from oscillatory activity to spike rate and timing may hold for models of computation and communication in distributed functional brain networks. PMID:23284276

Prefrontal single-unit firing associated with deficient extinction in mice

PubMed Central

Fitzgerald, Paul J; Whittle, Nigel; Flynn, Shaun M; Graybeal, Carolyn; Pinard, Courtney; Gunduz-Cinar, Ozge; Kravitz, Alexxai; Singewald, Nicolas; Holmes, Andrew

2014-01-01

The neural circuitry mediating fear extinction has been increasingly well studied and delineated. The rodent infralimbic subregion (IL) of the ventromedial prefrontal cortex (vmPFC) has been found to promote extinction, whereas the prelimbic cortex (PL) demonstrates an opposing, pro-fear, function. Studies employing in vivo electrophysiological recordings have observed that while increased IL single-unit firing and bursting predicts robust extinction retrieval, increased PL firing can correlate with sustained fear and poor extinction. These relationships between single-unit firing and extinction do not hold under all experimental conditions, however. In the current study, we further investigated the relationship between vmPFC and PL single-unit firing and extinction using inbred mouse models of intact (C57BL/6J, B6) and deficient (129S1/SvImJ, S1) extinction strains. Simultaneous single-unit recordings were made in the PL and vmPFC (encompassing IL) as B6 and S1 mice performed extinction training and retrieval. Impaired extinction retrieval in S1 mice was associated with elevated PL single-unit firing, as compared to firing in extinguishing B6 mice, consistent with the hypothesized pro-fear contribution of PL. Analysis of local field potentials also revealed significantly higher gamma power in the PL of Sthan B6 mice during extinction training and retrieval. In the vmPFC, impaired extinction in S1 mice was also associated with exaggerated single-unit firing, relative to B6 mice. This is in apparent contradiction to evidence that IL activity promotes extinction, but could reflect a (failed) compensatory effort by the vmPFC to mitigate fear-promoting activity in other regions, such as the PL or amygdala. In support of this hypothesis, augmenting IL activity via direct infusion of the GABAA receptor antagonist picrotoxin rescued impaired extinction retrieval in S1 mice. Chronic fluoxetine treatment produced modest reductions in fear during extinction retrieval and increased the number of Zif268-labeled cells in layer II of IL, but failed to increase vmPFC single-unit firing. Collectively, these findings further support the important contribution these cortical regions play in determining the balance between robust extinction on the one hand, and sustained fear on the other. Elucidating the precise nature of these roles could help inform understanding of the pathophysiology of fear-related anxiety disorders. PMID:24231425

Assessment of NASA Dual Microstructure Heat Treatment Method for Multiple Forging Batch Heat Treatment

NASA Technical Reports Server (NTRS)

Gayda, John (Technical Monitor); Lemsky, Joe

2004-01-01

NASA dual microstructure heat treatment technology previously demonstrated on single forging heat treat batches of a generic disk shape was successfully demonstrated on a multiple disk batch of a production shape component. A group of four Rolls-Royce Corporation 3rd Stage AE2100 forgings produced from alloy ME209 were successfully dual microstructure heat treated as a single heat treat batch. The forgings responded uniformly as evidenced by part-to-part consistent thermocouple recordings and resultant macrostructures, and from ultrasonic examination. Multiple disk DMHT processing offers a low cost alternative to other published dual microstructure processing techniques.

System and Method for High-Speed Data Recording

NASA Technical Reports Server (NTRS)

Taveniku, Mikael B. (Inventor)

2017-01-01

A system and method for high speed data recording includes a control computer and a disk pack unit. The disk pack is provided within a shell that provides handling and protection for the disk packs. The disk pack unit provides cooling of the disks and connection for power and disk signaling. A standard connection is provided between the control computer and the disk pack unit. The disk pack units are self sufficient and able to connect to any computer. Multiple disk packs are connected simultaneously to the system, so that one disk pack can be active while one or more disk packs are inactive. To control for power surges, the power to each disk pack is controlled programmatically for the group of disks in a disk pack.

Assessment of National Practice for Palliative Radiation Therapy for Bone Metastases Suggests Marked Underutilization of Single-Fraction Regimens in the United States

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

Rutter, Charles E., E-mail: charles.rutter@yale.edu; Yale Cancer Center, New Haven, Connecticut; Yu, James B.

2015-03-01

Purpose: To characterize temporal trends in the application of various bone metastasis fractionations within the United States during the past decade, using the National Cancer Data Base; the primary aim was to determine whether clinical practice in the United States has changed over time to reflect the published randomized evidence and the growing movement for value-based treatment decisions. Patients and Methods: The National Cancer Data Base was used to identify patients treated to osseous metastases from breast, prostate, and lung cancer. Utilization of single-fraction versus multiple-fraction radiation therapy was compared according to demographic, disease-related, and health care system details. Results: Wemore » included 24,992 patients treated during the period 2005-2011 for bone metastases. Among patients treated to non-spinal/vertebral sites (n=9011), 4.7% received 8 Gy in 1 fraction, whereas 95.3% received multiple-fraction treatment. Over time the proportion of patients receiving a single fraction of 8 Gy increased (from 3.4% in 2005 to 7.5% in 2011). Numerous independent predictors of single-fraction treatment were identified, including older age, farther travel distance for treatment, academic treatment facility, and non-private health insurance (P<.05). Conclusions: Single-fraction palliative radiation therapy regimens are significantly underutilized in current practice in the United States. Further efforts are needed to address this issue, such that evidence-based and cost-conscious care becomes more commonplace.« less

Two-Photon Functional Imaging of the Auditory Cortex in Behaving Mice: From Neural Networks to Single Spines.

PubMed

Li, Ruijie; Wang, Meng; Yao, Jiwei; Liang, Shanshan; Liao, Xiang; Yang, Mengke; Zhang, Jianxiong; Yan, Junan; Jia, Hongbo; Chen, Xiaowei; Li, Xingyi

2018-01-01

In vivo two-photon Ca 2+ imaging is a powerful tool for recording neuronal activities during perceptual tasks and has been increasingly applied to behaving animals for acute or chronic experiments. However, the auditory cortex is not easily accessible to imaging because of the abundant temporal muscles, arteries around the ears and their lateral locations. Here, we report a protocol for two-photon Ca 2+ imaging in the auditory cortex of head-fixed behaving mice. By using a custom-made head fixation apparatus and a head-rotated fixation procedure, we achieved two-photon imaging and in combination with targeted cell-attached recordings of auditory cortical neurons in behaving mice. Using synthetic Ca 2+ indicators, we recorded the Ca 2+ transients at multiple scales, including neuronal populations, single neurons, dendrites and single spines, in auditory cortex during behavior. Furthermore, using genetically encoded Ca 2+ indicators (GECIs), we monitored the neuronal dynamics over days throughout the process of associative learning. Therefore, we achieved two-photon functional imaging at multiple scales in auditory cortex of behaving mice, which extends the tool box for investigating the neural basis of audition-related behaviors.

Two-Photon Functional Imaging of the Auditory Cortex in Behaving Mice: From Neural Networks to Single Spines

PubMed Central

Li, Ruijie; Wang, Meng; Yao, Jiwei; Liang, Shanshan; Liao, Xiang; Yang, Mengke; Zhang, Jianxiong; Yan, Junan; Jia, Hongbo; Chen, Xiaowei; Li, Xingyi

2018-01-01

In vivo two-photon Ca2+ imaging is a powerful tool for recording neuronal activities during perceptual tasks and has been increasingly applied to behaving animals for acute or chronic experiments. However, the auditory cortex is not easily accessible to imaging because of the abundant temporal muscles, arteries around the ears and their lateral locations. Here, we report a protocol for two-photon Ca2+ imaging in the auditory cortex of head-fixed behaving mice. By using a custom-made head fixation apparatus and a head-rotated fixation procedure, we achieved two-photon imaging and in combination with targeted cell-attached recordings of auditory cortical neurons in behaving mice. Using synthetic Ca2+ indicators, we recorded the Ca2+ transients at multiple scales, including neuronal populations, single neurons, dendrites and single spines, in auditory cortex during behavior. Furthermore, using genetically encoded Ca2+ indicators (GECIs), we monitored the neuronal dynamics over days throughout the process of associative learning. Therefore, we achieved two-photon functional imaging at multiple scales in auditory cortex of behaving mice, which extends the tool box for investigating the neural basis of audition-related behaviors. PMID:29740289

Additive opportunistic capture explains group hunting benefits in African wild dogs.

PubMed

Hubel, Tatjana Y; Myatt, Julia P; Jordan, Neil R; Dewhirst, Oliver P; McNutt, J Weldon; Wilson, Alan M

2016-03-29

African wild dogs (Lycaon pictus) are described as highly collaborative endurance pursuit hunters based on observations derived primarily from the grass plains of East Africa. However, the remaining population of this endangered species mainly occupies mixed woodland savannah where hunting strategies appear to differ from those previously described. We used high-resolution GPS and inertial technology to record fine-scale movement of all members of a single pack of six adult African wild dogs in northern Botswana. The dogs used multiple short-distance hunting attempts with a low individual kill rate (15.5%), but high group feeding rate due to the sharing of prey. Use of high-level cooperative chase strategies (coordination and collaboration) was not recorded. In the mixed woodland habitats typical of their current range, simultaneous, opportunistic, short-distance chasing by dogs pursuing multiple prey (rather than long collaborative pursuits of single prey by multiple individuals) could be the key to their relative success in these habitats.

Additive opportunistic capture explains group hunting benefits in African wild dogs

PubMed Central

Hubel, Tatjana Y.; Myatt, Julia P.; Jordan, Neil R.; Dewhirst, Oliver P.; McNutt, J. Weldon; Wilson, Alan M.

2016-01-01

African wild dogs (Lycaon pictus) are described as highly collaborative endurance pursuit hunters based on observations derived primarily from the grass plains of East Africa. However, the remaining population of this endangered species mainly occupies mixed woodland savannah where hunting strategies appear to differ from those previously described. We used high-resolution GPS and inertial technology to record fine-scale movement of all members of a single pack of six adult African wild dogs in northern Botswana. The dogs used multiple short-distance hunting attempts with a low individual kill rate (15.5%), but high group feeding rate due to the sharing of prey. Use of high-level cooperative chase strategies (coordination and collaboration) was not recorded. In the mixed woodland habitats typical of their current range, simultaneous, opportunistic, short-distance chasing by dogs pursuing multiple prey (rather than long collaborative pursuits of single prey by multiple individuals) could be the key to their relative success in these habitats. PMID:27023355

Relationships among low-frequency local field potentials, spiking activity, and three-dimensional reach and grasp kinematics in primary motor and ventral premotor cortices

PubMed Central

Vargas-Irwin, Carlos E.; Truccolo, Wilson; Donoghue, John P.

2011-01-01

A prominent feature of motor cortex field potentials during movement is a distinctive low-frequency local field potential (lf-LFP) (<4 Hz), referred to as the movement event-related potential (mEP). The lf-LFP appears to be a global signal related to regional synaptic input, but its relationship to nearby output signaled by single unit spiking activity (SUA) or to movement remains to be established. Previous studies comparing information in primary motor cortex (MI) lf-LFPs and SUA in the context of planar reaching tasks concluded that lf-LFPs have more information than spikes about movement. However, the relative performance of these signals was based on a small number of simultaneously recorded channels and units, or for data averaged across sessions, which could miss information of larger-scale spiking populations. Here, we simultaneously recorded LFPs and SUA from two 96-microelectrode arrays implanted in two major motor cortical areas, MI and ventral premotor (PMv), while monkeys freely reached for and grasped objects swinging in front of them. We compared arm end point and grip aperture kinematics′ decoding accuracy for lf-LFP and SUA ensembles. The results show that lf-LFPs provide enough information to reconstruct kinematics in both areas with little difference in decoding performance between MI and PMv. Individual lf-LFP channels often provided more accurate decoding of single kinematic variables than any one single unit. However, the decoding performance of the best single unit among the large population usually exceeded that of the best single lf-LFP channel. Furthermore, ensembles of SUA outperformed the pool of lf-LFP channels, in disagreement with the previously reported superiority of lf-LFP decoding. Decoding results suggest that information in lf-LFPs recorded from intracortical arrays may allow the reconstruction of reach and grasp for real-time neuroprosthetic applications, thus potentially supplementing the ability to decode these same features from spiking populations. PMID:21273313

System, Apparatus, and Method for Active Debris Removal

NASA Technical Reports Server (NTRS)

Hickey, Christopher J. (Inventor); Spehar, Peter T. (Inventor); Griffith, Sr., Anthony D. (Inventor); Kohli, Rajiv (Inventor); Burns, Susan H. (Inventor); Gruber, David J. (Inventor); Lee, David E. (Inventor); Robinson, Travis M. (Inventor); Damico, Stephen J. (Inventor); Smith, Jason T. (Inventor)

2017-01-01

Systems, apparatuses, and methods for removal of orbital debris are provided. In one embodiment, an apparatus includes a spacecraft control unit configured to guide and navigate the apparatus to a target. The apparatus also includes a dynamic object characterization unit configured to characterize movement, and a capture feature, of the target. The apparatus further includes a capture and release unit configured to capture a target and deorbit or release the target. The collection of these apparatuses is then employed as multiple, independent and individually operated vehicles launched from a single launch vehicle for the purpose of disposing of multiple debris objects.

Prediction of STN-DBS Electrode Implantation Track in Parkinson's Disease by Using Local Field Potentials

PubMed Central

Telkes, Ilknur; Jimenez-Shahed, Joohi; Viswanathan, Ashwin; Abosch, Aviva; Ince, Nuri F.

2016-01-01

Optimal electrophysiological placement of the DBS electrode may lead to better long term clinical outcomes. Inter-subject anatomical variability and limitations in stereotaxic neuroimaging increase the complexity of physiological mapping performed in the operating room. Microelectrode single unit neuronal recording remains the most common intraoperative mapping technique, but requires significant expertise and is fraught by potential technical difficulties including robust measurement of the signal. In contrast, local field potentials (LFPs), owing to their oscillatory and robust nature and being more correlated with the disease symptoms, can overcome these technical issues. Therefore, we hypothesized that multiple spectral features extracted from microelectrode-recorded LFPs could be used to automate the identification of the optimal track and the STN localization. In this regard, we recorded LFPs from microelectrodes in three tracks from 22 patients during DBS electrode implantation surgery at different depths and aimed to predict the track selected by the neurosurgeon based on the interpretation of single unit recordings. A least mean square (LMS) algorithm was used to de-correlate LFPs in each track, in order to remove common activity between channels and increase their spatial specificity. Subband power in the beta band (11–32 Hz) and high frequency range (200–450 Hz) were extracted from the de-correlated LFP data and used as features. A linear discriminant analysis (LDA) method was applied both for the localization of the dorsal border of STN and the prediction of the optimal track. By fusing the information from these low and high frequency bands, the dorsal border of STN was localized with a root mean square (RMS) error of 1.22 mm. The prediction accuracy for the optimal track was 80%. Individual beta band (11–32 Hz) and the range of high frequency oscillations (200–450 Hz) provided prediction accuracies of 72 and 68% respectively. The best prediction result obtained with monopolar LFP data was 68%. These results establish the initial evidence that LFPs can be strategically fused with computational intelligence in the operating room for STN localization and the selection of the track for chronic DBS electrode implantation. PMID:27242404

47 CFR 76.71 - Scope of application.

Code of Federal Regulations, 2010 CFR

2010-10-01

... provisions of this subpart shall apply to any corporation, partnership, association, joint-stock company, or..., they shall constitute a single employment unit. (c) Headquarters office. A multiple cable operator shall treat as a separate employment unit each headquarters office to the extent the work of that office...

Population Coding of Forelimb Joint Kinematics by Peripheral Afferents in Monkeys

PubMed Central

Umeda, Tatsuya; Seki, Kazuhiko; Sato, Masa-aki; Nishimura, Yukio; Kawato, Mitsuo; Isa, Tadashi

2012-01-01

Various peripheral receptors provide information concerning position and movement to the central nervous system to achieve complex and dexterous movements of forelimbs in primates. The response properties of single afferent receptors to movements at a single joint have been examined in detail, but the population coding of peripheral afferents remains poorly defined. In this study, we obtained multichannel recordings from dorsal root ganglion (DRG) neurons in cervical segments of monkeys. We applied the sparse linear regression (SLiR) algorithm to the recordings, which selects useful input signals to reconstruct movement kinematics. Multichannel recordings of peripheral afferents were performed by inserting multi-electrode arrays into the DRGs of lower cervical segments in two anesthetized monkeys. A total of 112 and 92 units were responsive to the passive joint movements or the skin stimulation with a painting brush in Monkey 1 and Monkey 2, respectively. Using the SLiR algorithm, we reconstructed the temporal changes of joint angle, angular velocity, and acceleration at the elbow, wrist, and finger joints from temporal firing patterns of the DRG neurons. By automatically selecting a subset of recorded units, the SLiR achieved superior generalization performance compared with a regularized linear regression algorithm. The SLiR selected not only putative muscle units that were responsive to only the passive movements, but also a number of putative cutaneous units responsive to the skin stimulation. These results suggested that an ensemble of peripheral primary afferents that contains both putative muscle and cutaneous units encode forelimb joint kinematics of non-human primates. PMID:23112841

A wireless neural recording system with a precision motorized microdrive for freely behaving animals

PubMed Central

Hasegawa, Taku; Fujimoto, Hisataka; Tashiro, Koichiro; Nonomura, Mayu; Tsuchiya, Akira; Watanabe, Dai

2015-01-01

The brain is composed of many different types of neurons. Therefore, analysis of brain activity with single-cell resolution could provide fundamental insights into brain mechanisms. However, the electrical signal of an individual neuron is very small, and precise isolation of single neuronal activity from moving subjects is still challenging. To measure single-unit signals in actively behaving states, establishment of technologies that enable fine control of electrode positioning and strict spike sorting is essential. To further apply such a single-cell recording approach to small brain areas in naturally behaving animals in large spaces or during social interaction, we developed a compact wireless recording system with a motorized microdrive. Wireless control of electrode placement facilitates the exploration of single neuronal activity without affecting animal behaviors. Because the system is equipped with a newly developed data-encoding program, the recorded data are readily compressed almost to theoretical limits and securely transmitted to a host computer. Brain activity can thereby be stably monitored in real time and further analyzed using online or offline spike sorting. Our wireless recording approach using a precision motorized microdrive will become a powerful tool for studying brain mechanisms underlying natural or social behaviors. PMID:25597933

A statistical method for predicting seizure onset zones from human single-neuron recordings

NASA Astrophysics Data System (ADS)

Valdez, André B.; Hickman, Erin N.; Treiman, David M.; Smith, Kris A.; Steinmetz, Peter N.

2013-02-01

Objective. Clinicians often use depth-electrode recordings to localize human epileptogenic foci. To advance the diagnostic value of these recordings, we applied logistic regression models to single-neuron recordings from depth-electrode microwires to predict seizure onset zones (SOZs). Approach. We collected data from 17 epilepsy patients at the Barrow Neurological Institute and developed logistic regression models to calculate the odds of observing SOZs in the hippocampus, amygdala and ventromedial prefrontal cortex, based on statistics such as the burst interspike interval (ISI). Main results. Analysis of these models showed that, for a single-unit increase in burst ISI ratio, the left hippocampus was approximately 12 times more likely to contain a SOZ; and the right amygdala, 14.5 times more likely. Our models were most accurate for the hippocampus bilaterally (at 85% average sensitivity), and performance was comparable with current diagnostics such as electroencephalography. Significance. Logistic regression models can be combined with single-neuron recording to predict likely SOZs in epilepsy patients being evaluated for resective surgery, providing an automated source of clinically useful information.

Temporal Processing in the Visual Cortex of the Awake and Anesthetized Rat.

PubMed

Aasebø, Ida E J; Lepperød, Mikkel E; Stavrinou, Maria; Nøkkevangen, Sandra; Einevoll, Gaute; Hafting, Torkel; Fyhn, Marianne

2017-01-01

The activity pattern and temporal dynamics within and between neuron ensembles are essential features of information processing and believed to be profoundly affected by anesthesia. Much of our general understanding of sensory information processing, including computational models aimed at mathematically simulating sensory information processing, rely on parameters derived from recordings conducted on animals under anesthesia. Due to the high variety of neuronal subtypes in the brain, population-based estimates of the impact of anesthesia may conceal unit- or ensemble-specific effects of the transition between states. Using chronically implanted tetrodes into primary visual cortex (V1) of rats, we conducted extracellular recordings of single units and followed the same cell ensembles in the awake and anesthetized states. We found that the transition from wakefulness to anesthesia involves unpredictable changes in temporal response characteristics. The latency of single-unit responses to visual stimulation was delayed in anesthesia, with large individual variations between units. Pair-wise correlations between units increased under anesthesia, indicating more synchronized activity. Further, the units within an ensemble show reproducible temporal activity patterns in response to visual stimuli that is changed between states, suggesting state-dependent sequences of activity. The current dataset, with recordings from the same neural ensembles across states, is well suited for validating and testing computational network models. This can lead to testable predictions, bring a deeper understanding of the experimental findings and improve models of neural information processing. Here, we exemplify such a workflow using a Brunel network model.

Temporal Processing in the Visual Cortex of the Awake and Anesthetized Rat

PubMed Central

Aasebø, Ida E. J.; Stavrinou, Maria; Nøkkevangen, Sandra; Einevoll, Gaute

2017-01-01

Abstract The activity pattern and temporal dynamics within and between neuron ensembles are essential features of information processing and believed to be profoundly affected by anesthesia. Much of our general understanding of sensory information processing, including computational models aimed at mathematically simulating sensory information processing, rely on parameters derived from recordings conducted on animals under anesthesia. Due to the high variety of neuronal subtypes in the brain, population-based estimates of the impact of anesthesia may conceal unit- or ensemble-specific effects of the transition between states. Using chronically implanted tetrodes into primary visual cortex (V1) of rats, we conducted extracellular recordings of single units and followed the same cell ensembles in the awake and anesthetized states. We found that the transition from wakefulness to anesthesia involves unpredictable changes in temporal response characteristics. The latency of single-unit responses to visual stimulation was delayed in anesthesia, with large individual variations between units. Pair-wise correlations between units increased under anesthesia, indicating more synchronized activity. Further, the units within an ensemble show reproducible temporal activity patterns in response to visual stimuli that is changed between states, suggesting state-dependent sequences of activity. The current dataset, with recordings from the same neural ensembles across states, is well suited for validating and testing computational network models. This can lead to testable predictions, bring a deeper understanding of the experimental findings and improve models of neural information processing. Here, we exemplify such a workflow using a Brunel network model. PMID:28791331

System Design and Cataloging Meet the User: User Interfaces to Online Public Access Catalogs.

ERIC Educational Resources Information Center

Yee, Martha M.

1991-01-01

Discusses features of online public access catalogs: (1) demonstration of relationships between records; (2) provision of entry vocabularies; (3) arrangement of multiple entries on the screen; (4) provision of access points; (5) display of single records; and (6) division of catalogs into separate files or indexes. User studies and other research…

Creating an infrastructure for comparative effectiveness research in emergency medical services.

PubMed

Seymour, Christopher W; Kahn, Jeremy M; Martin-Gill, Christian; Callaway, Clifton W; Angus, Derek C; Yealy, Donald M

2014-05-01

Emergency medical services (EMS) providers deliver the initial care for millions of people in the United States each year. The Institute of Medicine noted a deficit in research necessary to improve prehospital care, created by the existence of data silos, absence of long-term outcomes, and limited stakeholder engagement in research. This article describes a regional effort to create a high-performing infrastructure in southwestern Pennsylvania addressing these fundamental barriers. Regional EMS records from 33 agencies in January 2011 were linked to hospital-based electronic health records (EHRs) in a single nine-hospital system, with manual review of matches for accuracy. The use of community stakeholder engagement was included to guide scientific inquiry, as well as 2-year follow up for patient-centered outcomes. Local EMS medicine stakeholders emphasized the limits of single-agency EMS research and suggested that studies focus on improving cross-cutting, long-term outcomes. Guided by this input, more than 95% of EMS records (2,675 of 2,800) were linked to hospital-based EHRs. More than 80% of records were linked to 2-year mortality, with more deaths among EMS patients with prehospital hypotension (30.5%) or respiratory distress (19.5%) than chest pain (5.4%) or nonspecific complaints (9.4%). A prehospital comparative effectiveness research infrastructure composed of patient-level EMS data, EHRs at multiple hospitals, long-term outcomes, and community stakeholder perspectives is feasible and may be scalable to larger regions and networks. The lessons learned and barriers identified offer a roadmap to answering community and policy-relevant research questions in prehospital care. © 2014 by the Society for Academic Emergency Medicine.

Real-time database drawn from an electronic health record for a thoracic surgery unit: high-quality clinical data saving time and human resources.

PubMed

Salati, Michele; Pompili, Cecilia; Refai, Majed; Xiumè, Francesco; Sabbatini, Armando; Brunelli, Alessandro

2014-06-01

The aim of the present study was to verify whether the implementation of an electronic health record (EHR) in our thoracic surgery unit allows creation of a high-quality clinical database saving time and costs. Before August 2011, multiple individuals compiled the on-paper documents/records and a single data manager inputted selected data into the database (traditional database, tDB). Since the adoption of an EHR in August 2011, multiple individuals have been responsible for compiling the EHR, which automatically generates a real-time database (EHR-based database, eDB), without the need for a data manager. During the initial period of implementation of the EHR, periodic meetings were held with all physicians involved in the use of the EHR in order to monitor and standardize the data registration process. Data quality of the first 100 anatomical lung resections recorded in the eDB was assessed by measuring the total number of missing values (MVs: existing non-reported value) and inaccurate values (wrong data) occurring in 95 core variables. The average MV of the eDB was compared with the one occurring in the same variables of the last 100 records registered in the tDB. A learning curve was constructed by plotting the number of MVs in the electronic database and tDB with the patients arranged by the date of registration. The tDB and eDB had similar MVs (0.74 vs 1, P = 0.13). The learning curve showed an initial phase including about 35 records, where MV in the eDB was higher than that in the tDB (1.9 vs 0.74, P = 0.03), and a subsequent phase, where the MV was similar in the two databases (0.7 vs 0.74, P = 0.6). The inaccuracy rate of these two phases in the eDB was stable (0.5 vs 0.3, P = 0.3). Using EHR saved an average of 9 min per patient, totalling 15 h saved for obtaining a dataset of 100 patients with respect to the tDB. The implementation of EHR allowed streamlining the process of clinical data recording. It saved time and human resource costs, without compromising the quality of data. © The Author 2014. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Fully Integrated Silicon Probes for High-Density Recording of Neural Activity

PubMed Central

Jun, James J.; Steinmetz, Nicholas A.; Siegle, Joshua H.; Denman, Daniel J.; Bauza, Marius; Barbarits, Brian; Lee, Albert K.; Anastassiou, Costas A.; Andrei, Alexandru; Aydın, Çağatay; Barbic, Mladen; Blanche, Timothy J.; Bonin, Vincent; Couto, João; Dutta, Barundeb; Gratiy, Sergey L.; Gutnisky, Diego A.; Häusser, Michael; Karsh, Bill; Ledochowitsch, Peter; Lopez, Carolina Mora; Mitelut, Catalin; Musa, Silke; Okun, Michael; Pachitariu, Marius; Putzeys, Jan; Rich, P. Dylan; Rossant, Cyrille; Sun, Wei-lung; Svoboda, Karel; Carandini, Matteo; Harris, Kenneth D.; Koch, Christof; O'Keefe, John; Harris, Timothy D.

2018-01-01

Summary Paragraph Sensory, motor, and cognitive operations involve the coordinated action of large neuronal populations across multiple brain regions in both superficial and deep structures1,2. Existing extracellular probes record neural activity with excellent spatial and temporal (sub-millisecond) resolution but from only a few dozen neurons per shank. Optical Ca2+ imaging3–5 offers more coverage but lacks the temporal resolution to reliably distinguish individual spikes and does not measure local field potentials. To date, no technology compatible with unrestrained animals has combined high spatiotemporal resolution with large volume coverage. To satisfy this need, we designed, fabricated, and tested a new silicon probe called Neuropixels. Each probe has 384 recording channels that can programmably address 960 CMOS processing-compatible low-impedance TiN6 sites that tile a single 10 mm long, 70x20 µm cross section shank. The 6x9 mm probe base is fabricated with the shank on a single chip. Voltage signals are filtered, amplified, multiplexed, and digitized on the base, allowing noise-free digital data transmission directly from the probe. The combination of dense recording sites and high channel count yielded well-isolated spiking activity from hundreds of neurons per probe implanted in mice and rats. Using two probes, more than 700 well-isolated single neurons were simultaneously recorded from five brain structures in an awake mouse. The fully integrated functionality and small size of Neuropixels probes allowed recording large populations of neurons from multiple brain structures in freely moving animals. This combination of high-performance electrode technology and scalable chip fabrication methods opens the path to record brain-wide neural activity during behavior. PMID:29120427

Neuronal Assemblies Evidence Distributed Interactions within a Tactile Discrimination Task in Rats

PubMed Central

Deolindo, Camila S.; Kunicki, Ana C. B.; da Silva, Maria I.; Lima Brasil, Fabrício; Moioli, Renan C.

2018-01-01

Accumulating evidence suggests that neural interactions are distributed and relate to animal behavior, but many open questions remain. The neural assembly hypothesis, formulated by Hebb, states that synchronously active single neurons may transiently organize into functional neural circuits—neuronal assemblies (NAs)—and that would constitute the fundamental unit of information processing in the brain. However, the formation, vanishing, and temporal evolution of NAs are not fully understood. In particular, characterizing NAs in multiple brain regions over the course of behavioral tasks is relevant to assess the highly distributed nature of brain processing. In the context of NA characterization, active tactile discrimination tasks with rats are elucidative because they engage several cortical areas in the processing of information that are otherwise masked in passive or anesthetized scenarios. In this work, we investigate the dynamic formation of NAs within and among four different cortical regions in long-range fronto-parieto-occipital networks (primary somatosensory, primary visual, prefrontal, and posterior parietal cortices), simultaneously recorded from seven rats engaged in an active tactile discrimination task. Our results first confirm that task-related neuronal firing rate dynamics in all four regions is significantly modulated. Notably, a support vector machine decoder reveals that neural populations contain more information about the tactile stimulus than the majority of single neurons alone. Then, over the course of the task, we identify the emergence and vanishing of NAs whose participating neurons are shown to contain more information about animal behavior than randomly chosen neurons. Taken together, our results further support the role of multiple and distributed neurons as the functional unit of information processing in the brain (NA hypothesis) and their link to active animal behavior. PMID:29375324

Action potential propagation recorded from single axonal arbors using multi-electrode arrays.

PubMed

Tovar, Kenneth R; Bridges, Daniel C; Wu, Bian; Randall, Connor; Audouard, Morgane; Jang, Jiwon; Hansma, Paul K; Kosik, Kenneth S

2018-04-11

We report the presence of co-occurring extracellular action potentials (eAPs) from cultured mouse hippocampal neurons among groups of planar electrodes on multi-electrode arrays (MEAs). The invariant sequences of eAPs among co-active electrode groups, repeated co-occurrences and short inter-electrode latencies are consistent with action potential propagation in unmyelinated axons. Repeated eAP co-detection by multiple electrodes was widespread in all our data records. Co-detection of eAPs confirms they result from the same neuron and allows these eAPs to be isolated from all other spikes independently of spike sorting algorithms. We averaged co-occurring events and revealed additional electrodes with eAPs that would otherwise be below detection threshold. We used these eAP cohorts to explore the temperature sensitivity of action potential propagation and the relationship between voltage-gated sodium channel density and propagation velocity. The sequence of eAPs among co-active electrodes 'fingerprints' neurons giving rise to these events and identifies them within neuronal ensembles. We used this property and the non-invasive nature of extracellular recording to monitor changes in excitability at multiple points in single axonal arbors simultaneously over several hours, demonstrating independence of axonal segments. Over several weeks, we recorded changes in inter-electrode propagation latencies and ongoing changes in excitability in different regions of single axonal arbors. Our work illustrates how repeated eAP co-occurrences can be used to extract physiological data from single axons with low electrode density MEAs. However, repeated eAP co-occurrences leads to over-sampling spikes from single neurons and thus can confound traditional spike-train analysis.

Three-dimensional volume containing multiple two-dimensional information patterns

NASA Astrophysics Data System (ADS)

Nakayama, Hirotaka; Shiraki, Atsushi; Hirayama, Ryuji; Masuda, Nobuyuki; Shimobaba, Tomoyoshi; Ito, Tomoyoshi

2013-06-01

We have developed an algorithm for recording multiple gradated two-dimensional projection patterns in a single three-dimensional object. When a single pattern is observed, information from the other patterns can be treated as background noise. The proposed algorithm has two important features: the number of patterns that can be recorded is theoretically infinite and no meaningful information can be seen outside of the projection directions. We confirmed the effectiveness of the proposed algorithm by performing numerical simulations of two laser crystals: an octagonal prism that contained four patterns in four projection directions and a dodecahedron that contained six patterns in six directions. We also fabricated and demonstrated an actual prototype laser crystal from a glass cube engraved by a laser beam. This algorithm has applications in various fields, including media art, digital signage, and encryption technology.

30 CFR 75.506 - Electric face equipment; requirements for permissibility.

Code of Federal Regulations, 2012 CFR

2012-07-01

...' approval schedules, and if it is in permissible condition: (1) Multiple-Shot Blasting Units, part 7 subpart...; (4) Flame Safety Lamps; (5) Portable Methane Detectors, part 22; (6) Telephone and Signaling Devices, part 23; (7) Single-Shot Blasting Units; (8) Lighting Equipment for Illuminating Underground Workings...

30 CFR 75.506 - Electric face equipment; requirements for permissibility.

Code of Federal Regulations, 2013 CFR

2013-07-01

...' approval schedules, and if it is in permissible condition: (1) Multiple-Shot Blasting Units, part 7 subpart...; (4) Flame Safety Lamps; (5) Portable Methane Detectors, part 22; (6) Telephone and Signaling Devices, part 23; (7) Single-Shot Blasting Units; (8) Lighting Equipment for Illuminating Underground Workings...

30 CFR 75.506 - Electric face equipment; requirements for permissibility.

Code of Federal Regulations, 2014 CFR

2014-07-01

...' approval schedules, and if it is in permissible condition: (1) Multiple-Shot Blasting Units, part 7 subpart...; (4) Flame Safety Lamps; (5) Portable Methane Detectors, part 22; (6) Telephone and Signaling Devices, part 23; (7) Single-Shot Blasting Units; (8) Lighting Equipment for Illuminating Underground Workings...

Innovation Diffusion: Implications for Evaluation

ERIC Educational Resources Information Center

Ashley, Shena R.

2009-01-01

Whether looking at the spread and adoption of an intervention across a community, across multiple units, or within a single unit, an understanding of diffusion theory can help evaluators uncover patterns and impacts that might otherwise be overlooked. The theory alerts evaluators to examine why uptake of an intervention appeared different in…

48 CFR 1408.802 - Policy.

Code of Federal Regulations, 2014 CFR

2014-10-01

... PLANNING REQUIRED SOURCES OF SUPPLIES AND SERVICES Acquisition of Printing and Related Supplies 1408.802... copiers. Volumes are of sufficient mass quantities up to 5,000 single-page and 25,000 production units in... to 2,500 production units in the aggregate of multiple pages. This volume standard is referred to as...

48 CFR 1408.802 - Policy.

Code of Federal Regulations, 2011 CFR

2011-10-01

... PLANNING REQUIRED SOURCES OF SUPPLIES AND SERVICES Acquisition of Printing and Related Supplies 1408.802... copiers. Volumes are of sufficient mass quantities up to 5,000 single-page and 25,000 production units in... to 2,500 production units in the aggregate of multiple pages. This volume standard is referred to as...

48 CFR 1408.802 - Policy.

Code of Federal Regulations, 2012 CFR

2012-10-01

... PLANNING REQUIRED SOURCES OF SUPPLIES AND SERVICES Acquisition of Printing and Related Supplies 1408.802... copiers. Volumes are of sufficient mass quantities up to 5,000 single-page and 25,000 production units in... to 2,500 production units in the aggregate of multiple pages. This volume standard is referred to as...

48 CFR 1408.802 - Policy.

Code of Federal Regulations, 2013 CFR

2013-10-01

... PLANNING REQUIRED SOURCES OF SUPPLIES AND SERVICES Acquisition of Printing and Related Supplies 1408.802... copiers. Volumes are of sufficient mass quantities up to 5,000 single-page and 25,000 production units in... to 2,500 production units in the aggregate of multiple pages. This volume standard is referred to as...

30 CFR 75.506 - Electric face equipment; requirements for permissibility.

Code of Federal Regulations, 2010 CFR

2010-07-01

...' approval schedules, and if it is in permissible condition: (1) Multiple-Shot Blasting Units, part 7 subpart...; (4) Flame Safety Lamps; (5) Portable Methane Detectors, part 22; (6) Telephone and Signaling Devices, part 23; (7) Single-Shot Blasting Units; (8) Lighting Equipment for Illuminating Underground Workings...

30 CFR 75.506 - Electric face equipment; requirements for permissibility.

Code of Federal Regulations, 2011 CFR

2011-07-01

...' approval schedules, and if it is in permissible condition: (1) Multiple-Shot Blasting Units, part 7 subpart...; (4) Flame Safety Lamps; (5) Portable Methane Detectors, part 22; (6) Telephone and Signaling Devices, part 23; (7) Single-Shot Blasting Units; (8) Lighting Equipment for Illuminating Underground Workings...

A novel methodology to reproduce previously recorded six-degree of freedom kinematics on the same diarthrodial joint.

PubMed

Moore, Susan M; Thomas, Maribeth; Woo, Savio L-Y; Gabriel, Mary T; Kilger, Robert; Debski, Richard E

2006-01-01

The objective of this study was to develop a novel method to more accurately reproduce previously recorded 6-DOF kinematics of the tibia with respect to the femur using robotic technology. Furthermore, the effect of performing only a single or multiple registrations and the effect of robot joint configuration were investigated. A single registration consisted of registering the tibia and femur with respect to the robot at full extension and reproducing all kinematics while multiple registrations consisted of registering the bones at each flexion angle and reproducing only the kinematics of the corresponding flexion angle. Kinematics of the knee in response to an anterior (134 N) and combined internal/external (+/-10 N m) and varus/valgus (+/-5 N m) loads were collected at 0 degrees , 15 degrees , 30 degrees , 60 degrees , and 90 degrees of flexion. A six axes, serial-articulated robotic manipulator (PUMA Model 762) was calibrated and the working volume was reduced to improve the robot's accuracy. The effect of the robot joint configuration was determined by performing single and multiple registrations for three selected configurations. For each robot joint configuration, the accuracy in position of the reproduced kinematics improved after multiple registrations (0.7+/-0.3, 1.2+/-0.5, and 0.9+/-0.2 mm, respectively) when compared to only a single registration (1.3+/-0.9, 2.0+/-1.0, and 1.5+/-0.7 mm, respectively) (p<0.05). The accuracy in position of each robot joint configuration was unique as significant differences were detected between each of the configurations. These data demonstrate that the number of registrations and the robot joint configuration both affect the accuracy of the reproduced kinematics. Therefore, when using robotic technology to reproduce previously recorded kinematics, it may be necessary to perform these analyses for each individual robotic system and for each diarthrodial joint, as different joints will require the robot to be placed in different robot joint configurations.

Motor unit number estimation based on high-density surface electromyography decomposition.

PubMed

Peng, Yun; He, Jinbao; Yao, Bo; Li, Sheng; Zhou, Ping; Zhang, Yingchun

2016-09-01

To advance the motor unit number estimation (MUNE) technique using high density surface electromyography (EMG) decomposition. The K-means clustering convolution kernel compensation algorithm was employed to detect the single motor unit potentials (SMUPs) from high-density surface EMG recordings of the biceps brachii muscles in eight healthy subjects. Contraction forces were controlled at 10%, 20% and 30% of the maximal voluntary contraction (MVC). Achieved MUNE results and the representativeness of the SMUP pools were evaluated using a high-density weighted-average method. Mean numbers of motor units were estimated as 288±132, 155±87, 107±99 and 132±61 by using the developed new MUNE at 10%, 20%, 30% and 10-30% MVCs, respectively. Over 20 SMUPs were obtained at each contraction level, and the mean residual variances were lower than 10%. The new MUNE method allows a convenient and non-invasive collection of a large size of SMUP pool with great representativeness. It provides a useful tool for estimating the motor unit number of proximal muscles. The present new MUNE method successfully avoids the use of intramuscular electrodes or multiple electrical stimuli which is required in currently available MUNE techniques; as such the new MUNE method can minimize patient discomfort for MUNE tests. Copyright © 2016 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Multipulsed dynamic moire interferometer

DOEpatents

Deason, Vance A.

1991-01-01

An improved dynamic moire interferometer comprised of a lasing medium providing a plurality of beams of coherent light, a multiple q-switch producing multiple trains of 100,000 or more pulses per second, a combining means collimating multiple trains of pulses into substantially a single train and directing beams to specimen gratings affixed to a test material, and a controller, triggering and sequencing the emission of the pulses with the occurrence and recording of a dynamic loading event.

Surface-modified CMOS IC electrochemical sensor array targeting single chromaffin cells for highly parallel amperometry measurements.

PubMed

Huang, Meng; Delacruz, Joannalyn B; Ruelas, John C; Rathore, Shailendra S; Lindau, Manfred

2018-01-01

Amperometry is a powerful method to record quantal release events from chromaffin cells and is widely used to assess how specific drugs modify quantal size, kinetics of release, and early fusion pore properties. Surface-modified CMOS-based electrochemical sensor arrays allow simultaneous recordings from multiple cells. A reliable, low-cost technique is presented here for efficient targeting of single cells specifically to the electrode sites. An SU-8 microwell structure is patterned on the chip surface to provide insulation for the circuitry as well as cell trapping at the electrode sites. A shifted electrode design is also incorporated to increase the flexibility of the dimension and shape of the microwells. The sensitivity of the electrodes is validated by a dopamine injection experiment. Microwells with dimensions slightly larger than the cells to be trapped ensure excellent single-cell targeting efficiency, increasing the reliability and efficiency for on-chip single-cell amperometry measurements. The surface-modified device was validated with parallel recordings of live chromaffin cells trapped in the microwells. Rapid amperometric spikes with no diffusional broadening were observed, indicating that the trapped and recorded cells were in very close contact with the electrodes. The live cell recording confirms in a single experiment that spike parameters vary significantly from cell to cell but the large number of cells recorded simultaneously provides the statistical significance.

Interhemispheric correlations of slow spontaneous neuronal fluctuations revealed in human sensory cortex

PubMed Central

Nir, Yuval; Mukamel, Roy; Dinstein, Ilan; Privman, Eran; Harel, Michal; Fisch, Lior; Gelbard-Sagiv, Hagar; Kipervasser, Svetlana; Andelman, Fani; Neufeld, Miri Y; Kramer, Uri; Arieli, Amos; Fried, Itzhak; Malach, Rafael

2009-01-01

Animal studies have shown robust electrophysiological activity in the sensory cortex in the absence of stimuli or tasks. Similarly, recent human functional magnetic resonance imaging (fMRI) revealed widespread, spontaneously emerging cortical fluctuations. However, it is unknown what neuronal dynamics underlie this spontaneous activity in the human brain. Here we studied this issue by combining bilateral single-unit, local field potentials (LFPs) and intracranial electrocorticography (ECoG) recordings in individuals undergoing clinical monitoring. We found slow (<0.1 Hz, following 1/f-like profiles) spontaneous fluctuations of neuronal activity with significant interhemispheric correlations. These fluctuations were evident mainly in neuronal firing rates and in gamma (40–100 Hz) LFP power modulations. Notably, the interhemispheric correlations were enhanced during rapid eye movement and stage 2 sleep. Multiple intracranial ECoG recordings revealed clear selectivity for functional networks in the spontaneous gamma LFP power modulations. Our results point to slow spontaneous modulations in firing rate and gamma LFP as the likely correlates of spontaneous fMRI fluctuations in the human sensory cortex. PMID:19160509

A low noise remotely controllable wireless telemetry system for single-unit recording in rats navigating in a vertical maze.

PubMed

Chen, Hsin-Yung; Wu, Jin-Shang; Hyland, Brian; Lu, Xiao-Dong; Chen, Jia Jin Jason

2008-08-01

The use of cables for recording neural activity limits the scope of behavioral tests used in conscious free-moving animals. Particularly, cable attachments make it impossible to record in three-dimensional (3D) mazes where levels are vertically stacked or in enclosed spaces. Such environments are of particular interest in investigations of hippocampal place cells, in which neural activity is correlated with spatial position in the environment. We developed a flexible miniaturized Bluetooth-based wireless data acquisition system. The wireless module included an 8-channel analogue front end, digital controller, and Bluetooth transceiver mounted on a backpack. Our bidirectional wireless design allowed all data channels to be previewed at 1 kHz sample rate, and one channel, selected by remote control, to be sampled at 10 kHz. Extracellular recordings of neuronal activity are highly susceptible to ambient electrical noise due to the high electrode impedance. Through careful design of appropriate shielding and hardware configuration to avoid ground loops, mains power and Bluetooth hopping frequency noise were reduced sufficiently to yield signal quality comparable to those recorded by wired systems. With this system we were able to obtain single-unit recordings of hippocampal place cells in rats running an enclosed vertical maze, over a range of 5 m.

Effects of single-family rooms on nurse-parent and nurse-infant interaction in neonatal intensive care unit.

PubMed

Toivonen, Mirka; Lehtonen, Liisa; Löyttyniemi, Eliisa; Axelin, Anna

Single-family rooms in neonatal intensive care unit can provide longer interaction between family and staff. On the other hand, separation in private rooms has been shown detrimental to child development if parents are not present. To examine the effects of single-family rooms on nurse-family, nurse-parent and nurse-infant interaction time in neonatal intensive care unit. A quantitative, comparative, observational study was conducted before and after a move to a neonatal intensive care unit with single-family rooms. A total of 194 observation hours were conducted before the move and 194h after the move. The differences were analyzed using a hierarchical linear mixed model. Nurses working in one neonatal intensive care unit were recruited to study. The duration and number of nurse-parent and nurse-infant interaction episodes were recorded. The nurse-family and the nurse-parent interaction were longer in the unit with single-family rooms compared with the unit before the move (mean 261 vs. 138min per shift, p<0.0001 and 117 vs. 35, p=0.001, respectively). The duration of the nurse-infant interaction did not change after the move. The frequency of the nurse-parent or the nurse-infant interactions did not change between the time periods. Neonatal intensive care unit with single-family rooms supported an increase in nurse-parent interaction time. Importantly, nurse-infant interaction time did not decrease. Copyright © 2017 Elsevier B.V. All rights reserved.

Motor control differs for increasing and releasing force

PubMed Central

Park, Seoung Hoon; Kwon, MinHyuk; Solis, Danielle; Lodha, Neha

2016-01-01

Control of the motor output depends on our ability to precisely increase and release force. However, the influence of aging on force increase and release remains unknown. The purpose of this study, therefore, was to determine whether force control differs while increasing and releasing force in young and older adults. Sixteen young adults (22.5 ± 4 yr, 8 females) and 16 older adults (75.7 ± 6.4 yr, 8 females) increased and released force at a constant rate (10% maximum voluntary contraction force/s) during an ankle dorsiflexion isometric task. We recorded the force output and multiple motor unit activity from the tibialis anterior (TA) muscle and quantified the following outcomes: 1) variability of force using the SD of force; 2) mean discharge rate and variability of discharge rate of multiple motor units; and 3) power spectrum of the multiple motor units from 0–4, 4–10, 10–35, and 35–60 Hz. Participants exhibited greater force variability while releasing force, independent of age (P < 0.001). Increased force variability during force release was associated with decreased modulation of multiple motor units from 35 to 60 Hz (R2 = 0.38). Modulation of multiple motor units from 35 to 60 Hz was further correlated to the change in mean discharge rate of multiple motor units (r = 0.66) and modulation from 0 to 4 Hz (r = −0.64). In conclusion, these findings suggest that force control is altered while releasing due to an altered modulation of the motor units. PMID:26961104

A Multi-Trait, Meta-analysis for Detecting Pleiotropic Polymorphisms for Stature, Fatness and Reproduction in Beef Cattle

PubMed Central

Bolormaa, Sunduimijid; Pryce, Jennie E.; Reverter, Antonio; Zhang, Yuandan; Barendse, William; Kemper, Kathryn; Tier, Bruce; Savin, Keith; Hayes, Ben J.; Goddard, Michael E.

2014-01-01

Polymorphisms that affect complex traits or quantitative trait loci (QTL) often affect multiple traits. We describe two novel methods (1) for finding single nucleotide polymorphisms (SNPs) significantly associated with one or more traits using a multi-trait, meta-analysis, and (2) for distinguishing between a single pleiotropic QTL and multiple linked QTL. The meta-analysis uses the effect of each SNP on each of n traits, estimated in single trait genome wide association studies (GWAS). These effects are expressed as a vector of signed t-values (t) and the error covariance matrix of these t values is approximated by the correlation matrix of t-values among the traits calculated across the SNP (V). Consequently, t'V−1t is approximately distributed as a chi-squared with n degrees of freedom. An attractive feature of the meta-analysis is that it uses estimated effects of SNPs from single trait GWAS, so it can be applied to published data where individual records are not available. We demonstrate that the multi-trait method can be used to increase the power (numbers of SNPs validated in an independent population) of GWAS in a beef cattle data set including 10,191 animals genotyped for 729,068 SNPs with 32 traits recorded, including growth and reproduction traits. We can distinguish between a single pleiotropic QTL and multiple linked QTL because multiple SNPs tagging the same QTL show the same pattern of effects across traits. We confirm this finding by demonstrating that when one SNP is included in the statistical model the other SNPs have a non-significant effect. In the beef cattle data set, cluster analysis yielded four groups of QTL with similar patterns of effects across traits within a group. A linear index was used to validate SNPs having effects on multiple traits and to identify additional SNPs belonging to these four groups. PMID:24675618

Characteristics of infants admitted with hypoglycemia to a neonatal unit.

PubMed

Van Haltren, Karen; Malhotra, Atul

2013-01-01

Neonatal hypoglycemia is a common symptom in early infant life. The currently available literature identifies the risk factors but not the degree to which each factor lends itself to the development or severity of an ensuing hypoglycemia. A retrospective electronic chart review of near-term and term infants (>35 weeks' gestation) admitted to a tertiary-level neonatal unit over 16 months was carried out from the initiation of electronic record keeping. Ninety-five infants admitted with hypoglycemia to the unit were identified with complete records available. Fifty-eight percent of the infants were males, and the median gestation was 38 weeks. Twenty-two percent of the infants were premature, whereas 18% were macrosomic. Maternal diabetes was present in 27% infants. Comorbidities were common in this cohort, with approximately two-thirds of infants having multiple morbidities. The majority of which were jaundice and infection, whereas the minor ones were respiratory distress, initial lactic acidosis, feeding issues, and temperature instability. Neonatal hypoglycemia continues to be a significant morbidity in near-term and term infants. The presence of multiple morbidities is common in the setting of hypoglycemia and is the main determinant of the length of stay in the neonatal unit in this study population.

Recruitment and rate coding organisation for soleus motor units across entire range of voluntary isometric plantar flexions.

PubMed

Oya, Tomomichi; Riek, Stephan; Cresswell, Andrew G

2009-10-01

Unlike upper limb muscles, it remains undocumented as to how motor units in the soleus muscle are organised in terms of recruitment range and discharge rates with respect to their recruitment and de-recruitment thresholds. The possible influence of neuromodulation, such as persistent inward currents (PICs) on lower limb motor unit recruitment and discharge rates has also yet to be reported. To address these issues, electromyographic (EMG) activities from the soleus muscle were recorded using selective branched-wire intramuscular electrodes during ramp-and-hold contractions with intensities up to maximal voluntary contraction (MVC). The multiple single motor unit activities were then derived using a decomposition technique. The onset-offset hysteresis of motor unit discharge, i.e. a difference between recruitment and de-recruitment thresholds, as well as PIC magnitude calculated by a paired motor unit analysis were used to examine the neuromodulatory effects on discharge behaviours, such as minimum firing rate, peak firing rate and degree of increase in firing rate. Forty-two clearly identified motor units from five subjects revealed that soleus motor units are recruited progressively from rest to contraction strengths close to 95% of MVC, with low-threshold motor units discharging action potentials slower at their recruitment and with a lower peak rate than later recruited high-threshold units. This observation is in contrast to the 'onion skin phenomenon' often reported for the upper limb muscles. Based on positive correlations of the peak discharge rates, initial rates and recruitment order of the units with the magnitude of the onset-offset hysteresis and not PIC contribution, we conclude that discharge behaviours among motor units appear to be related to a variation in an intrinsic property other than PICs.

Adaptive Estimation and Heuristic Optimization of Nonlinear Spacecraft Attitude Dynamics

DTIC Science & Technology

2016-09-15

Algorithm GPS Global Positioning System HOUF Higher Order Unscented Filter IC initial conditions IMM Interacting Multiple Model IMU Inertial Measurement Unit ...sources ranging from inertial measurement units to star sensors are used to construct observations for attitude estimation algorithms. The sensor...parameters. A single vector measurement will provide two independent parameters, as a unit vector constraint removes a DOF making the problem underdetermined

Generalization of the Lyot filter and its application to snapshot spectral imaging.

PubMed

Gorman, Alistair; Fletcher-Holmes, David William; Harvey, Andrew Robert

2010-03-15

A snapshot multi-spectral imaging technique is described which employs multiple cascaded birefringent interferometers to simultaneously spectrally filter and demultiplex multiple spectral images onto a single detector array. Spectral images are recorded directly without the need for inversion and without rejection of light and so the technique offers the potential for high signal-to-noise ratio. An example of an eight-band multi-spectral movie sequence is presented; we believe this is the first such demonstration of a technique able to record multi-spectral movie sequences without the need for computer reconstruction.

Qualitative differences in the guidance of attention during single-color and multiple-color visual search: behavioral and electrophysiological evidence.

PubMed

Grubert, Anna; Eimer, Martin

2013-10-01

To find out whether attentional target selection can be effectively guided by top-down task sets for multiple colors, we measured behavioral and ERP markers of attentional target selection in an experiment where participants had to identify color-defined target digits that were accompanied by a single gray distractor object in the opposite visual field. In the One Color task, target color was constant. In the Two Color task, targets could have one of two equally likely colors. Color-guided target selection was less efficient during multiple-color relative to single-color search, and this was reflected by slower response times and delayed N2pc components. Nontarget-color items that were presented in half of all trials captured attention and gained access to working memory when participants searched for two colors, but were excluded from attentional processing in the One Color task. Results demonstrate qualitative differences in the guidance of attentional target selection between single-color and multiple-color visual search. They suggest that top-down attentional control can be applied much more effectively when it is based on a single feature-specific attentional template. PsycINFO Database Record (c) 2013 APA, all rights reserved.

Novel microbial fuel cell design to operate with different wastewaters simultaneously.

PubMed

Mathuriya, Abhilasha Singh

2016-04-01

A novel single cathode chamber and multiple anode chamber microbial fuel cell design (MAC-MFC) was developed by incorporating multiple anode chambers into a single unit and its performance was checked. During 60 days of operation, performance of MAC-MFC was assessed and compared with standard single anode/cathode chamber microbial fuel cell (SC-MFC). The tests showed that MAC-MFC generated stable and higher power outputs compared with SC-MFC and each anode chamber contributed efficiently. Further, MAC-MFCs were incorporated with different wastewaters in different anode chambers and their behavior in MFC performance was observed. MAC-MFC efficiently treated multiple wastewaters simultaneously at low cost and small space, which claims its candidature for future possible scale-up applications. Copyright © 2015. Published by Elsevier B.V.

A Phloem Sandwich Unit for Observing Bark Beetles, Associated Predators, and Parasites

Treesearch

Donald N. Kim; Mitchel C. Miller

1981-01-01

This paper describes a phloem sandwich that allows observation of parent beetles, their brood, and associates within the inner bark, and permits observation of predator and parasite behavior on the bark surface. The construction of the unit permits the introduction of multiple pairs of beetles into a single sandwich.

Conformity of commercial oral single solid unit dose packages in hospital pharmacy practice.

PubMed

Thibault, Maxime; Prot-Labarthe, Sonia; Bussières, Jean-François; Lebel, Denis

2008-06-01

There are limited published data on the labelling of single unit dose packages in hospitals. The study was conducted in three large hospitals (two adult and one paediatric) in the metropolitan Montreal area, Quebec, Canada. The objective is to evaluate the labelling of commercial oral single solid unit dose packages available in Canadian urban hospital pharmacy practice. The study endpoint was the labelling conformity of each unit dose package for each criterion and overall for each manufacturer. Complete labelling of unit dose packages should include the following information: (1) brand name, (2) international non-proprietary name or generic name, (3) dosage, (4) pharmaceutical form, (5) manufacturer's name, (6) expiry date, (7) batch number and (8) drug identification number. We also evaluated the ease with which a single unit dose package is detached from a multiple unit dose package for quick, easy and safe use by pharmacy staff. Conformity levels were compared between brand-name and generic packages. A total of 124 different unit dose packages were evaluated. The level of conformity of each criterion varied between 19 and 50%. Only 43% of unit dose packages provided an easy-to-detach system for single doses. Among the 14 manufacturers with three or more unit dose packages evaluated, eight (57%) had a conformity level less than 50%. This study describes the conformity of commercial oral single solid unit dose packages in hospital pharmacy practice in Quebec. A large proportion of unit dose packages do not conform to a set of nine criteria set out in the guidelines of the American Society of Health-System Pharmacists and the Canadian Society of Hospital Pharmacists.

Recruitment of single human low-threshold motor units with increasing loads at different muscle lengths.

PubMed

McNulty, P A; Cresswell, A G

2004-06-01

We investigated the recruitment behaviour of low threshold motor units in flexor digitorum superficialis by altering two biomechanical constraints: the load against which the muscle worked and the initial muscle length. The load was increased using isotonic (low load), loaded dynamic (intermediate load) and isometric (high load) contractions in two studies. The initial muscle position reflected resting muscle length in series A, and a longer length with digit III fully extended in series B. Intramuscular EMG was recorded from 48 single motor units in 10 experiments on five healthy subjects, 21 units in series A and 27 in series B, while subjects performed ramp up, hold and ramp down contractions. Increasing the load on the muscle decreased the force, displacement and firing rate of single motor units at recruitment at shorter muscle lengths (P<0.001, dependent t-test). At longer muscle lengths this recruitment pattern was observed between loaded dynamic and isotonic contractions, but not between isometric and loaded dynamic contractions. Thus, the recruitment properties of single motor units in human flexor digitorum superficialis are sensitive to changes in both imposed external loads and the initial length of the muscle.

Two are not better than one: Combining unitization and relational encoding strategies.

PubMed

Tu, Hsiao-Wei; Diana, Rachel A

2016-01-01

In recognition memory, recollection is defined as retrieval of the context associated with an event, whereas familiarity is defined as retrieval based on item strength alone. Recent studies have shown that conventional recollection-based tasks, in which context details are manipulated for source memory assessment at test, can also rely on familiarity when context information is "unitized" with the relevant item information at encoding. Unlike naturalistic episodic memories that include many context details encoded in different ways simultaneously, previous studies have focused on unitization and its effect on the recognition of a single context detail. To further understand how various encoding strategies operate on item and context representations, we independently assigned unitization and relational association to 2 context details (size and color) of each item and tested the contribution of recollection and familiarity to source recognition of each detail. The influence of familiarity on retrieval of each context detail was compared as a function of the encoding strategy used for each detail. Receiver operating characteristic curves suggested that the unitization effect was not additive and that similar levels of familiarity occurred for 1 or multiple details when unitization was the only strategy applied during encoding. On the other hand, a detrimental effect was found when relational encoding and unitization were simultaneously applied to 1 item such that a salient nonunitized context detail interfered with the effortful processing required to unitize an accompanying context detail. However, this detrimental effect was not reciprocal and possibly dependent on the nature of individual context details. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Single Versus Multiple Parenting: Implications for Infancy.

ERIC Educational Resources Information Center

Eiduson, Bernice T.; And Others

This study, part of a naturalistic longitudinal study of infants being reared in a variety of family life styles, attempted to establish the extent to which differing parenting patterns affected early developmental outcomes. Subjects were 200 infants: 50 of single mothers who headed their family units, 50 of mothers in communal living groups, and…

Neurons in cat V1 show significant clustering by degree of tuning

PubMed Central

Ziskind, Avi J.; Emondi, Al A.; Kurgansky, Andrei V.; Rebrik, Sergei P.

2015-01-01

Neighboring neurons in cat primary visual cortex (V1) have similar preferred orientation, direction, and spatial frequency. How diverse is their degree of tuning for these properties? To address this, we used single-tetrode recordings to simultaneously isolate multiple cells at single recording sites and record their responses to flashed and drifting gratings of multiple orientations, spatial frequencies, and, for drifting gratings, directions. Orientation tuning width, spatial frequency tuning width, and direction selectivity index (DSI) all showed significant clustering: pairs of neurons recorded at a single site were significantly more similar in each of these properties than pairs of neurons from different recording sites. The strength of the clustering was generally modest. The percent decrease in the median difference between pairs from the same site, relative to pairs from different sites, was as follows: for different measures of orientation tuning width, 29–35% (drifting gratings) or 15–25% (flashed gratings); for DSI, 24%; and for spatial frequency tuning width measured in octaves, 8% (drifting gratings). The clusterings of all of these measures were much weaker than for preferred orientation (68% decrease) but comparable to that seen for preferred spatial frequency in response to drifting gratings (26%). For the above properties, little difference in clustering was seen between simple and complex cells. In studies of spatial frequency tuning to flashed gratings, strong clustering was seen among simple-cell pairs for tuning width (70% decrease) and preferred frequency (71% decrease), whereas no clustering was seen for simple-complex or complex-complex cell pairs. PMID:25652921

Feasibility of one-shot-per-crystal structure determination using Laue diffraction

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

Cornaby, Sterling; CHESS; Szebenyi, Doletha M. E.

Structure determination was successfully carried out using single Laue exposures from a group of lysozyme crystals. The Laue method may be a viable option for collection of one-shot-per-crystal data from microcrystals. Crystal size is an important factor in determining the number of diffraction patterns which may be obtained from a protein crystal before severe radiation damage sets in. As crystal dimensions decrease this number is reduced, eventually falling to one, at which point a complete data set must be assembled using data from multiple crystals. When only a single exposure is to be collected from each crystal, the polychromatic Lauemore » technique may be preferable to monochromatic methods owing to its simultaneous recording of a large number of fully recorded reflections per image. To assess the feasibility of solving structures using single Laue images from multiple crystals, data were collected using a ‘pink’ beam at the CHESS D1 station from groups of lysozyme crystals with dimensions of the order of 20–30 µm mounted on MicroMesh grids. Single-shot Laue data were used for structure determination by molecular replacement and correct solutions were obtained even when as few as five crystals were used.« less

Patterns of wounding in hamadryas baboons (Papio hamadryas) in North American zoos.

PubMed

Wiley, Jodi N; Leeds, Austin; Carpenter, Kamisha D; Kendall, Corinne J

2018-03-01

In North American zoos, hamadryas baboons (Papio hamadryas) have traditionally been housed as single one-male units (single male groups). In recent years, efforts have been made to house hamadryas in groups composed of multiple one-male units (multi-male groups) to more closely mirror their natural social structure, in addition to all-male or bachelor groups to manage surplus males. Given that the majority of social conflict in hamadryas occurs between males during the acquisition and defense of females, it was thought that managing hamadryas in these multi-male groups would result in increased rates of wounding. To assess this, incidences of wounding were recorded over one year across seven zoos (10 social groups, 59 individuals). Overall, we found no difference in wounding rates between group types, or by sex, and group type. These data provide evidence that managing hamadryas in multi-male and bachelor groups is an effective husbandry practice that does not negatively impact the welfare of the individuals, in addition to providing a more species-appropriate social setting for hamadryas in zoos. As the management of hamadryas in multi-male and bachelor groups continues and expands, additional research will be needed to understand what factors contribute to optimal cohesion, and welfare of groups and if wounding rates change as group size continues to increase. © 2018 Wiley Periodicals, Inc.

The Breadth of Coarticulatory Units in Children and Adults

ERIC Educational Resources Information Center

Goffman, Lisa; Smith, Anne; Heisler, Lori; Ho, Michael

2008-01-01

Purpose: To assess, in children and adults, the breadth of coarticulatory movements associated with a single rounded vowel. Method: Upper and lower lip movements were recorded from 8 young adults and 8 children (aged 4-5 years). A single rounded versus unrounded vowel was embedded in the medial position of pairs of 7-word/7-syllable sentences.…

Microprobe array with low impedance electrodes and highly flexible polyimide cables for acute neural recording.

PubMed

Kisban, S; Herwik, S; Seidl, K; Rubehn, B; Jezzini, A; Umiltà, M A; Fogassi, L; Stieglitz, T; Paul, O; Ruther, P

2007-01-01

This paper reports on a novel type of silicon-based microprobes with linear, two and three dimensional (3D) distribution of their recording sites. The microprobes comprise either single shafts, combs with multiple shafts or 3D arrays combining two combs with 9, 36 or 72 recording sites, respectively. The electrical interconnection of the probes is achieved through highly flexible polyimide ribbon cables attached using the MicroFlex Technology which allows a connection part of small lateral dimensions. For an improved handling, probes can be secured by a protecting canula. Low-impedance electrodes are achieved by the deposition of platinum black. First in vivo experiments proved the capability to record single action potentials in the motor cortex from electrodes close to the tip as well as body electrodes along the shaft.

Trends Analysis of rhBMP2 Utilization in Single-Level Anterior Lumbar Interbody Fusion in the United States

PubMed Central

Lao, Lifeng; Cohen, Jeremiah R.; Buser, Zorica; Brodke, Darrel S.; Yoon, S. Tim; Youssef, Jim A.; Park, Jong-Beom; Meisel, Hans-Joerg; Wang, Jeffrey C.

2017-01-01

Study Design: Retrospective case study. Objective: To evaluate the trends and demographics of recombinant human bone morphogenetic protein 2 (rhBMP2) utilization in single-level anterior lumbar interbody fusion (ALIF) in the United States. Methods: Patients who underwent single-level ALIF from 2005 to 2011 were identified by searching ICD-9 diagnosis and procedure codes in the PearlDiver Patient Records Database (PearlDiver Technologies, Fort Wayne, IN), a national database of orthopedic insurance records. The year of procedure, age, gender, and region of the United States were analyzed for each patient. Results: A total of 921 patients were identified who underwent a single-level ALIF in this study. The average rate of single-level ALIF with rhBMP2 utilization increased (35%-48%) from 2005 to 2009, but sharply decreased to 16.7% in 2010 and 15.0% in 2011. The overall incidence of single-level ALIF without rhBMP2 (0.20 cases per 100 000 patients) was more than twice of the incidence of single-level ALIF with rhBMP2 (0.09 cases per 100 000 patients). The average rate of single-level ALIF with rhBMP2 utilization is highest in West (41.4%), followed by Midwest (33.3%), South (26.5%) and Northeast (22.2%). The highest incidence of single-level ALIF with rhBMP2 was observed in the group aged less than 65 years (compared with any other age groups, P < .001), with an incidence of 0.21 per 100 000 patients. Conclusions: The incidence of rhBMP2 utilization in single-level ALIF increased from 2006 to 2009, but decreased in 2010 and 2011. The Northeast region had the lowest incidence of rhBMP2 utilization. The group aged less than 65 years trended to have the higher incidence of single-level ALIF with rhBMP2 utilization. PMID:29662743

Trends Analysis of rhBMP2 Utilization in Single-Level Anterior Lumbar Interbody Fusion in the United States.

PubMed

Lao, Lifeng; Cohen, Jeremiah R; Buser, Zorica; Brodke, Darrel S; Yoon, S Tim; Youssef, Jim A; Park, Jong-Beom; Meisel, Hans-Joerg; Wang, Jeffrey C

2018-04-01

Retrospective case study. To evaluate the trends and demographics of recombinant human bone morphogenetic protein 2 (rhBMP2) utilization in single-level anterior lumbar interbody fusion (ALIF) in the United States. Patients who underwent single-level ALIF from 2005 to 2011 were identified by searching ICD-9 diagnosis and procedure codes in the PearlDiver Patient Records Database (PearlDiver Technologies, Fort Wayne, IN), a national database of orthopedic insurance records. The year of procedure, age, gender, and region of the United States were analyzed for each patient. A total of 921 patients were identified who underwent a single-level ALIF in this study. The average rate of single-level ALIF with rhBMP2 utilization increased (35%-48%) from 2005 to 2009, but sharply decreased to 16.7% in 2010 and 15.0% in 2011. The overall incidence of single-level ALIF without rhBMP2 (0.20 cases per 100 000 patients) was more than twice of the incidence of single-level ALIF with rhBMP2 (0.09 cases per 100 000 patients). The average rate of single-level ALIF with rhBMP2 utilization is highest in West (41.4%), followed by Midwest (33.3%), South (26.5%) and Northeast (22.2%). The highest incidence of single-level ALIF with rhBMP2 was observed in the group aged less than 65 years (compared with any other age groups, P < .001), with an incidence of 0.21 per 100 000 patients. The incidence of rhBMP2 utilization in single-level ALIF increased from 2006 to 2009, but decreased in 2010 and 2011. The Northeast region had the lowest incidence of rhBMP2 utilization. The group aged less than 65 years trended to have the higher incidence of single-level ALIF with rhBMP2 utilization.

Spatio-Temporal Data Model for Integrating Evolving Nation-Level Datasets

NASA Astrophysics Data System (ADS)

Sorokine, A.; Stewart, R. N.

2017-10-01

Ability to easily combine the data from diverse sources in a single analytical workflow is one of the greatest promises of the Big Data technologies. However, such integration is often challenging as datasets originate from different vendors, governments, and research communities that results in multiple incompatibilities including data representations, formats, and semantics. Semantics differences are hardest to handle: different communities often use different attribute definitions and associate the records with different sets of evolving geographic entities. Analysis of global socioeconomic variables across multiple datasets over prolonged time is often complicated by the difference in how boundaries and histories of countries or other geographic entities are represented. Here we propose an event-based data model for depicting and tracking histories of evolving geographic units (countries, provinces, etc.) and their representations in disparate data. The model addresses the semantic challenge of preserving identity of geographic entities over time by defining criteria for the entity existence, a set of events that may affect its existence, and rules for mapping between different representations (datasets). Proposed model is used for maintaining an evolving compound database of global socioeconomic and environmental data harvested from multiple sources. Practical implementation of our model is demonstrated using PostgreSQL object-relational database with the use of temporal, geospatial, and NoSQL database extensions.

Single- and multiple-dose pharmacokinetics and absolute bioavailability of tedizolid.

PubMed

Flanagan, Shawn; Fang, Edward; Muñoz, Kelly A; Minassian, Sonia L; Prokocimer, Philippe G

2014-09-01

Tedizolid phosphate is a novel antibacterial under investigation for the treatment of gram-positive infections. This study was conducted to assess the pharmacokinetics, safety, and tolerability of intravenous tedizolid phosphate as well as the oral bioavailability of tedizolid phosphate. Double-blind, single-ascending dose, multiple-dose pharmacokinetics study, as well as tolerability and open-label crossover studies. Single center in the United States (Covance Clinical Research Unit, Madison, WI) between September 2009 and January 2010. Ninety healthy volunteers. Single intravenous (IV) doses of tedizolid phosphate 50 mg (lead-in) and 100-400 mg. Single oral and IV dose of tedizolid phosphate 200 mg in crossover fashion. Multiple IV doses of tedizolid phosphate 200 and 300 mg for up to 7 days. A dose-dependent increase was observed in the maximum plasma concentration (1.2-5.1 μg/ml) and the area under the concentration-time curve (17.4-58.7 μg × hr/ml) of tedizolid (the microbiologically active moiety of tedizolid phosphate) after single IV doses of tedizolid phosphate 100-400 mg. Administration of IV tedizolid phosphate 200 mg once/day for 7 days resulted in minimal (28%) tedizolid accumulation. The absolute oral bioavailability of tedizolid after a single 200-mg dose of tedizolid phosphate was 91%; pharmacokinetic parameters of tedizolid were similar with oral and IV administration. Treatment-related adverse events occurred in 41% of subjects. Most adverse events were related to infusion site and became more frequent with multiple dosing. In an additional 3-day tolerability study, IV tedizolid phosphate 200 mg and placebo were similarly tolerated, based on visual infusion phlebitis scores. These results from a population of healthy volunteers support once/day dosing of tedizolid phosphate 200 mg with both the oral and IV formulations, without the need for dose adjustment when switching administration routes. © 2014 Cubist Pharmaceuticals. Pharmacotherapy published by Wiley Periodicals, Inc. on behalf of Pharmacotherapy Publications, Inc.

Outcomes of multiple wire localization for larger breast cancers: when can mastectomy be avoided?

PubMed

Kirstein, Laurie J; Rafferty, Elizabeth; Specht, Michelle C; Moore, Richard H; Taghian, Alphonse G; Hughes, Kevin S; Gadd, Michele A; Smith, Barbara L

2008-09-01

Mastectomy is often recommended when mammography shows a breast cancer with extensive calcifications. We wished to determine whether the use of multiple localizing wires to guide lumpectomy in this setting was associated with increased rates of breast conservation. We also wanted to identify factors that predicted a poor chance of successful lumpectomy, to avoid multiple lumpectomy attempts in a patient who would ultimately require mastectomy. Records of 153 women with breast cancer who underwent lumpectomy for larger lesions that required multiple wire localization and 196 controls who required only single wire localization were reviewed retrospectively. The number of localizing wires, specimen volume, largest specimen dimension, number of surgical procedures, and rates of breast conservation were scored. Seventy-seven percent of patients requiring multiple wire localization had successful breast conservation, compared with 90% of those needing only single wire localization. Only 28% of multiple wire patients required more than 1 excision to achieve clear margins, compared with 36% of single wire patients (p < 0.01). Breast conservation is possible in the great majority of breast cancer patients whose mammographic lesions require multiple localizing wires for excision. The use of multiple wires can decrease the number of procedures required to obtain clear lumpectomy margins.

A placebo-controlled, double-blind, dose-escalation study to assess the safety, tolerability and pharmacokinetics/pharmacodynamics of single and multiple intravenous infusions of AZD9773 in patients with severe sepsis and septic shock

PubMed Central

2012-01-01

Introduction Tumor necrosis factor-alpha (TNF-α), an early mediator in the systemic inflammatory response to infection, is a potential therapeutic target in sepsis. The primary objective of this study was to determine the safety and tolerability of AZD9773, an ovine, polyclonal, anti-human TNF-α Fab preparation, in patients with severe sepsis. Secondary outcomes related to pharmacokinetic (PK) and pharmacodynamic (PD) parameters. Methods In this double-blind, placebo-controlled, multicenter Phase IIa study, patients were sequentially enrolled into five escalating-dose cohorts (single doses of 50 or 250 units/kg; multiple doses of 250 units/kg loading and 50 units/kg maintenance, 500 units/kg loading and 100 units/kg maintenance, or 750 units/kg loading and 250 units/kg maintenance). In each cohort, patients were randomized 2:1 to receive AZD9773 or placebo. Results Seventy patients received AZD9773 (n = 47) or placebo (n = 23). Baseline characteristics were similar across cohorts. Mean baseline APACHE score was 25.9. PK data demonstrated an approximately proportional increase in concentration with increasing dose and a terminal half-life of 20 hours. For the multiple-dose cohorts, serum TNF-α concentrations decreased to near-undetectable levels within two hours of commencing AZD9773 infusion. This suppression was maintained in most patients for the duration of treatment. AZD9773 was well tolerated. Most adverse events were of mild-to-moderate intensity and considered by the reporting investigator as unrelated to study treatment. Conclusions The safety, PK and PD data support the continued evaluation of AZD9773 in larger Phase IIb/III studies. PMID:22340283

Administering Multiple Injectable Vaccines During a Single Visit-Summary of Findings From the Accelerated Introduction of Inactivated Polio Vaccine Globally.

PubMed

Dolan, Samantha B; Patel, Manish; Hampton, Lee M; Burnett, Eleanor; Ehlman, Daniel C; Garon, Julie; Cloessner, Emily; Chmielewski, Elizabeth; Hyde, Terri B; Mantel, Carsten; Wallace, Aaron S

2017-07-01

In 2013, the World Health Organization's (WHO's) Strategic Advisory Group of Experts (SAGE) recommended that all 126 countries using only oral polio vaccine (OPV) introduce at least 1 dose of inactivated polio vaccine (IPV) into their routine immunization schedules by the end of 2015. In many countries, the addition of IPV would necessitate delivery of multiple injectable vaccines (hereafter, "multiple injections") during a single visit, with infants receiving IPV alongside pentavalent vaccine (which covers diphtheria, tetanus, and whole-cell pertussis; hepatitis B; and Haemophilus influenzae type b) and pneumococcal vaccine. Unanticipated concerns emerged from countries over acceptability of multiple injections, sites of administration, and safety. We contextualized the issues surrounding multiple injections by documenting concerns associated with administration of ≥3 injections, existing evidence in the published literature, and findings of a systematic review on administration practices and techniques. Concerns associated with multiple-injection visits were documented from meetings and personal communications with immunization program managers. Published literature on the acceptability of multiple injections by providers and caregivers was summarized, and a systematic review of the literature on administration practices was completed on the following topics: spacing between injection sites (ie, vaccine spacing), site of injection, route of injection, and procedural preparedness. WHO and United Nations Children's Fund data from 2013-2015 were used to assess multiple-injection visits included in national immunization schedules. Healthcare provider and caregiver attitudes and practices indicated concerns about infant pain, potential adverse effects, and uncertainty about vaccine effectiveness with multiple-injection visits. Published literature reinforced the record of safety and acceptance of the recommended schedule of IPV by the SAGE, but the evidence was largely from developed countries. Parental acceptance of multiple injections was associated with a positive provider recommendation to the caregiver. Findings of the systematic review identified that the intramuscular route is preferred over the subcutaneous route for vaccine administration and that the vastus lateralis muscle is preferred over the deltoid muscle for intramuscular injections. Recommendations on vaccine spacing and procedural preparedness were based on practical necessities, but comparative evidence was not identified. During 2013-2015, 85 countries added IPV to their immunization schedules, 46 (55%) of which adopted a schedule resulting in 3 injectable vaccines being administered in a single visit. The multiple-injection experience identified gaps in guidance for future vaccine introductions. Global partner organizations quickly mobilized to assess, document, and communicate the existing global experience on multiple-injection visits. This evidence-based approach provided reassurance to opinion leaders, health workers, and professional societies, thus encouraging uptake of IPV as a second or third injection in an accelerated manner globally. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America.

Administering Multiple Injectable Vaccines During a Single Visit—Summary of Findings From the Accelerated Introduction of Inactivated Polio Vaccine Globally

PubMed Central

Patel, Manish; Hampton, Lee M.; Burnett, Eleanor; Ehlman, Daniel C.; Garon, Julie; Cloessner, Emily; Chmielewski, Elizabeth; Hyde, Terri B.; Mantel, Carsten; Wallace, Aaron S.

2017-01-01

Abstract Background. In 2013, the World Health Organization’s (WHO’s) Strategic Advisory Group of Experts (SAGE) recommended that all 126 countries using only oral polio vaccine (OPV) introduce at least 1 dose of inactivated polio vaccine (IPV) into their routine immunization schedules by the end of 2015. In many countries, the addition of IPV would necessitate delivery of multiple injectable vaccines (hereafter, “multiple injections”) during a single visit, with infants receiving IPV alongside pentavalent vaccine (which covers diphtheria, tetanus, and whole-cell pertussis; hepatitis B; and Haemophilus influenzae type b) and pneumococcal vaccine. Unanticipated concerns emerged from countries over acceptability of multiple injections, sites of administration, and safety. We contextualized the issues surrounding multiple injections by documenting concerns associated with administration of ≥3 injections, existing evidence in the published literature, and findings of a systematic review on administration practices and techniques. Methods. Concerns associated with multiple-injection visits were documented from meetings and personal communications with immunization program managers. Published literature on the acceptability of multiple injections by providers and caregivers was summarized, and a systematic review of the literature on administration practices was completed on the following topics: spacing between injection sites (ie, vaccine spacing), site of injection, route of injection, and procedural preparedness. WHO and United Nations Children’s Fund data from 2013–2015 were used to assess multiple-injection visits included in national immunization schedules. Results. Healthcare provider and caregiver attitudes and practices indicated concerns about infant pain, potential adverse effects, and uncertainty about vaccine effectiveness with multiple-injection visits. Published literature reinforced the record of safety and acceptance of the recommended schedule of IPV by the SAGE, but the evidence was largely from developed countries. Parental acceptance of multiple injections was associated with a positive provider recommendation to the caregiver. Findings of the systematic review identified that the intramuscular route is preferred over the subcutaneous route for vaccine administration and that the vastus lateralis muscle is preferred over the deltoid muscle for intramuscular injections. Recommendations on vaccine spacing and procedural preparedness were based on practical necessities, but comparative evidence was not identified. During 2013–2015, 85 countries added IPV to their immunization schedules, 46 (55%) of which adopted a schedule resulting in 3 injectable vaccines being administered in a single visit. Conclusion. The multiple-injection experience identified gaps in guidance for future vaccine introductions. Global partner organizations quickly mobilized to assess, document, and communicate the existing global experience on multiple-injection visits. This evidence-based approach provided reassurance to opinion leaders, health workers, and professional societies, thus encouraging uptake of IPV as a second or third injection in an accelerated manner globally. PMID:28838188

The microcomputer scientific software series 9: user's guide to Geo-CLM: geostatistical interpolation of the historical climatic record in the Lake States.

Treesearch

Margaret R. Holdaway

1994-01-01

Describes Geo-CLM, a computer application (for Mac or DOS) whose primary aim is to perform multiple kriging runs to interpolate the historic climatic record at research plots in the Lake States. It is an exploration and analysis tool. Addition capabilities include climatic databases, a flexible test mode, cross validation, lat/long conversion, English/metric units,...

Diagnostic and psychosocial differences in psychiatrically hospitalized military service members with single versus multiple suicide attempts.

PubMed

Kochanski-Ruscio, Kristen M; Carreno-Ponce, Jaime T; DeYoung, Kathryn; Grammer, Geoffrey; Ghahramanlou-Holloway, Marjan

2014-04-01

Individuals with multiple versus single suicide attempts present a more severe clinical picture and may be at greater risk for suicide. Yet group differences within military samples have been vastly understudied. The objective is to determine demographic, diagnostic, and psychosocial differences, based on suicide attempt status, among military inpatients admitted for suicide-related events. A retrospective chart review design was used with a total of 423 randomly selected medical records of psychiatric admissions to a military hospital from 2001 to 2006. Chi-square analyses indicated that individuals with multiple versus single suicide attempts were significantly more likely to have documented childhood sexual abuse (p =.025); problem substance use (p=.001); mood disorder diagnosis (p=.005); substance disorder diagnosis (p =.050); personality disorder not otherwise specified diagnosis (p =.018); and Axis II traits or diagnosis (p=.038) when compared to those with a single attempt history. Logistic regression analyses showed that males with multiple suicide attempts were more likely to have problem substance use (p=.005) and a mood disorder diagnosis (p =.002), while females with a multiple attempt history were more likely to have a history of childhood sexual (p =.027). Clinically meaningful differences among military inpatients with single versus multiple suicide attempts exist. Targeted Department of Defense suicide prevention and intervention efforts that address the unique needs of these two specific at-risk subgroups are additionally needed. Published by Elsevier Inc.

Theta coupling between V4 and prefrontal cortex predicts visual short-term memory performance.

PubMed

Liebe, Stefanie; Hoerzer, Gregor M; Logothetis, Nikos K; Rainer, Gregor

2012-01-29

Short-term memory requires communication between multiple brain regions that collectively mediate the encoding and maintenance of sensory information. It has been suggested that oscillatory synchronization underlies intercortical communication. Yet, whether and how distant cortical areas cooperate during visual memory remains elusive. We examined neural interactions between visual area V4 and the lateral prefrontal cortex using simultaneous local field potential (LFP) recordings and single-unit activity (SUA) in monkeys performing a visual short-term memory task. During the memory period, we observed enhanced between-area phase synchronization in theta frequencies (3-9 Hz) of LFPs together with elevated phase locking of SUA to theta oscillations across regions. In addition, we found that the strength of intercortical locking was predictive of the animals' behavioral performance. This suggests that theta-band synchronization coordinates action potential communication between V4 and prefrontal cortex that may contribute to the maintenance of visual short-term memories.

Single-shot optical recording with sub-picosecond resolution spans record nanosecond lengths

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

Muir, Ryan; Heebner, John

With the advent of electronics, oscilloscopes and photodiodes are now routinely capable of measuring events well below nanosecond resolution. However, these electronic instruments do not currently measure events below 10 ps resolution. From Walden’s observation that there is an engineering tradeoff between electronic bit depth and temporal resolution in analog-to-digital converters, this technique is projected to have extremely poor fidelity if it is extended to record single events with picosecond resolution. While this constraint may be circumvented with extensive signal averaging or other multiple measurements approaches, rare events and nonrepetitive events cannot be observed with this technique. Techniques capable ofmore » measuring information in a single shot are often required. There is a general lack of available technologies that are easily scalable to long records with sub-picosecond resolution, and are simultaneously versatile in wavelength of operation. Since it is difficult to scale electronic methods to shorter resolutions, we instead aim to scale optical methods to longer records. Demonstrated optical recording methods that have achieved 1 ps resolution and long recording lengths rely on either time scaling to slow down the temporal information or, like Wien, perform time-to-space mapping so that fast events may be captured with a conventional camera.« less

Single-shot optical recording with sub-picosecond resolution spans record nanosecond lengths

DOE PAGES

Muir, Ryan; Heebner, John

2018-01-18

With the advent of electronics, oscilloscopes and photodiodes are now routinely capable of measuring events well below nanosecond resolution. However, these electronic instruments do not currently measure events below 10 ps resolution. From Walden’s observation that there is an engineering tradeoff between electronic bit depth and temporal resolution in analog-to-digital converters, this technique is projected to have extremely poor fidelity if it is extended to record single events with picosecond resolution. While this constraint may be circumvented with extensive signal averaging or other multiple measurements approaches, rare events and nonrepetitive events cannot be observed with this technique. Techniques capable ofmore » measuring information in a single shot are often required. There is a general lack of available technologies that are easily scalable to long records with sub-picosecond resolution, and are simultaneously versatile in wavelength of operation. Since it is difficult to scale electronic methods to shorter resolutions, we instead aim to scale optical methods to longer records. Demonstrated optical recording methods that have achieved 1 ps resolution and long recording lengths rely on either time scaling to slow down the temporal information or, like Wien, perform time-to-space mapping so that fast events may be captured with a conventional camera.« less

Endodontic flare-ups: comparison of incidence between single and multiple visits procedures in patients attending a Nigerian teaching hospital.

PubMed

Oginni, Ao; Udoye, C I

2004-12-01

The present study was performed to compare the incidence of endodontic flare ups in single with multiple visits treatment procedures, to establish the relationship between pre-operative and post obturation pain in patients attending for endodontic therapy in a Nigerian teaching Hospital. Patients were randomly assigned to either single visit or multiple visits group. Data collected at root canal treatment appointment and recall visits (1st, 7th and 30th day post obturation) include pulp vitality status, the presence or absence of pre-operative pain, presence and degree of post obturation pain. Presence of endodontic flare-ups (defined as either patient's report of pain not controlled with over the counter medication and or increasing swelling). The compiled data were analyzed using chi-square where applicable. P level < 0.05 was taken as significant. Ten endodontic flare-ups (8.1 %) were recorded in the multiple visits group compared to 19 (18,3%) flare-ups for the single visit group, P = 0.02. For both single and multiple visits procedures, there were statistically significant correlations between pre operative and post obturation pain (P = 0.002 and P = 0.0004 respectively). Teeth with vital pulps reported the lowest frequency of post obturation pain (48.8%), while those with non vital pulps were found to have the highest frequency oh post obturation pain (50,3%), P = 0.9. Although the present study reported higher incidences for post obturation pain and flare-ups following the single visit procedures, single visit endodontic therapy has been shown to be a safe and effective alternative to multiple visits treatment.

Morbidity following Mexico City's 1985 earthquakes: clinical and epidemiologic findings from hospitals and emergency units.

PubMed

Sánchez-Carrillo, C I

1989-01-01

Medical records of 822 inpatients and outpatients cared for by the Department of the Federal District medical services during the 1985 Mexico City earthquakes were reviewed. Record incompleteness varied between 92.8 percent and 14.0 percent for the various study variables. No gender differences were detected among the groups; more than 70.0 percent of the patients were ages 15 to 64 years. Multiple traumatic injuries were frequent for inpatients across age groups, while simple contusions were more frequent among outpatients. Multiple head traumas, thorax-abdomen multiple traumas, and simple fractures of an arm or leg were more frequently recorded for inpatients than for outpatients. Head wounds with contusions; simple contusion of the thorax-abdomen, arms, and legs; and psychological trauma were more frequently recorded for outpatients. Although a great many records were incomplete, the data may reflect what actually happened to these patients, given the similarity of the findings with other reports of disasters. Improved record keeping during emergencies is needed to standardize the quantity and the reliability of the data so that statistical and medical care requirements are soundly based. The use of standard questionnaires for data collection is stressed to facilitate the management of clinical and epidemiologic activities. Longitudinal studies are needed to determine patterns of physical injuries, psychological trauma, and survival.

Sources and Radiation Patterns of Volcano-Acoustic Signals Investigated with Field-Scale Chemical Explosions

NASA Astrophysics Data System (ADS)

Bowman, D. C.; Lees, J. M.; Taddeucci, J.; Graettinger, A. H.; Sonder, I.; Valentine, G.

2014-12-01

We investigate the processes that give rise to complex acoustic signals during volcanic blasts by monitoring buried chemical explosions with infrasound and audio range microphones, strong motion sensors, and high speed imagery. Acoustic waveforms vary with scaled depth of burial (SDOB, units in meters per cube root of joules), ranging from high amplitude, impulsive, gas expansion dominated signals at low SDOB to low amplitude, longer duration, ground motion dominated signals at high SDOB. Typically, the sudden upward acceleration of the substrate above the blast produces the first acoustic arrival, followed by a second pulse due to the eruption of pressurized gas at the surface. Occasionally, a third overpressure occurs when displaced material decelerates upon impact with the ground. The transition between ground motion dominated and gas release dominated acoustics ranges between 0.0038-0.0018 SDOB, respectively. For example, one explosion registering an SDOB=0.0031 produced two overpressure pulses of approximately equal amplitude, one due to ground motion, the other to gas release. Recorded volcano infrasound has also identified distinct ground motion and gas release components during explosions at Sakurajima, Santiaguito, and Karymsky volcanoes. Our results indicate that infrasound records may provide a proxy for the depth and energy of these explosions. Furthermore, while magma fragmentation models indicate the possibility of several explosions during a single vulcanian eruption (Alidibirov, Bull Volc., 1994), our results suggest that a single explosion can also produce complex acoustic signals. Thus acoustic records alone cannot be used to distinguish between single explosions and multiple closely-spaced blasts at volcanoes. Results from a series of lateral blasts during the 2014 field experiment further indicates whether vent geometry can produce directional acoustic radiation patterns like those observed at Tungarahua volcano (Kim et al., GJI, 2012). Beside infrasonic radiation, our multiparametric dataset also allowed us to investigate other acoustic processes relevant for explosive eruptions, including shock-wave generation and audible sound radiation, and to link them to the starting conditions and evolution of the blasts.

8 CFR 210.1 - Definition of terms used in this part.

Code of Federal Regulations, 2010 CFR

2010-01-01

...-month periods ending on May 1, 1984, 1985, and 1986, and who have resided in the United States for six... employment records relating to an alien applicant show only piece rate units completed, then any day in which piece rate work was performed shall be counted as a man-day. Work for more than one employer in a single...

Methods for implantation of micro-wire bundles and optimization of single/multiunit recordings from human mesial temporal lobe

PubMed Central

Misra, A; Burke, JF; Ramayya, A; Jacobs, J; Sperling, MR; Moxon, KA; Kahana, MJ; Evans, JJ; Sharan, AD

2014-01-01

Objective The authors report methods developed for the implantation of micro-wire bundles into mesial temporal lobe structures and subsequent single neuron recording in epileptic patients undergoing in-patient diagnostic monitoring. This is done with the intention of lowering the perceived barriers to routine single neuron recording from deep brain structures in the clinical setting. Approach Over a 15 month period, 11 patients were implanted with platinum micro-wire bundles into mesial temporal structures. Protocols were developed for A) monitoring electrode integrity through impedance testing, B) ensuring continuous 24-7 recording, C) localizing micro-wire position and “splay” pattern and D) monitoring grounding and referencing to maintain the quality of recordings. Main Result Five common modes of failure were identified: 1) broken micro-wires from acute tensile force, 2) broken micro-wires from cyclic fatigue at stress points, 3) poor in-vivo micro-electrode separation, 4) motion artifact and 5) deteriorating ground connection and subsequent drop in common mode noise rejection. Single neurons have been observed up to 14 days post implantation and on 40% of micro-wires. Significance Long-term success requires detailed review of each implant by both the clinical and research teams to identify failure modes, and appropriate refinement of techniques while moving forward. This approach leads to reliable unit recordings without prolonging operative times, which will help increase the availability and clinical viability of human single neuron data. PMID:24608589

Involvement of the human midbrain and thalamus in auditory deviance detection.

PubMed

Cacciaglia, Raffaele; Escera, Carles; Slabu, Lavinia; Grimm, Sabine; Sanjuán, Ana; Ventura-Campos, Noelia; Ávila, César

2015-02-01

Prompt detection of unexpected changes in the sensory environment is critical for survival. In the auditory domain, the occurrence of a rare stimulus triggers a cascade of neurophysiological events spanning over multiple time-scales. Besides the role of the mismatch negativity (MMN), whose cortical generators are located in supratemporal areas, cumulative evidence suggests that violations of auditory regularities can be detected earlier and lower in the auditory hierarchy. Recent human scalp recordings have shown signatures of auditory mismatch responses at shorter latencies than those of the MMN. Moreover, animal single-unit recordings have demonstrated that rare stimulus changes cause a release from stimulus-specific adaptation in neurons of the primary auditory cortex, the medial geniculate body (MGB), and the inferior colliculus (IC). Although these data suggest that change detection is a pervasive property of the auditory system which may reside upstream cortical sites, direct evidence for the involvement of subcortical stages in the human auditory novelty system is lacking. Using event-related functional magnetic resonance imaging during a frequency oddball paradigm, we here report that auditory deviance detection occurs in the MGB and the IC of healthy human participants. By implementing a random condition controlling for neural refractoriness effects, we show that auditory change detection in these subcortical stations involves the encoding of statistical regularities from the acoustic input. These results provide the first direct evidence of the existence of multiple mismatch detectors nested at different levels along the human ascending auditory pathway. Copyright © 2015 Elsevier Ltd. All rights reserved.

Salicylate-induced changes in spontaneous activity of single units in the inferior colliculus of the guinea pig.

PubMed

Jastreboff, P J; Sasaki, C T

1986-11-01

Changes in spontaneous neuronal activity of the inferior colliculus in albino guinea pigs before and after administration of sodium salicylate were analyzed. Animals were anesthetized with pentobarbital, and two microelectrodes separated by a few hundred microns were driven through the inferior colliculus. After collecting a sufficiently large sample of cells, sodium salicylate (450 mg/kg) was injected i.p. and recordings again made 2 h after the injection. Comparison of spontaneous activity recorded before and after salicylate administration revealed highly statistically significant differences (p less than 0.001). After salicylate, the mean rate of the cell population increased from 29 to 83 Hz and the median from 26 to 74 Hz. Control experiments in which sodium salicylate was replaced by saline injection revealed no statistically significant differences in cell discharges. Recordings made during the same experiments from lobulus V of the cerebellar vermis revealed no changes in response to salicylate. The observed changes in single-unit activity due to salicylate administration may represent the first systematic evidence of a tinnituslike phenomenon in animals.

Balanced Crystalloids versus Saline in the Intensive Care Unit. The SALT Randomized Trial.

PubMed

Semler, Matthew W; Wanderer, Jonathan P; Ehrenfeld, Jesse M; Stollings, Joanna L; Self, Wesley H; Siew, Edward D; Wang, Li; Byrne, Daniel W; Shaw, Andrew D; Bernard, Gordon R; Rice, Todd W

2017-05-15

Saline is the intravenous fluid most commonly administered to critically ill adults, but it may be associated with acute kidney injury and death. Whether use of balanced crystalloids rather than saline affects patient outcomes remains unknown. To pilot a cluster-randomized, multiple-crossover trial using software tools within the electronic health record to compare saline to balanced crystalloids. This was a cluster-randomized, multiple-crossover trial among 974 adults admitted to a tertiary medical intensive care unit from February 3, 2015 to May 31, 2015. The intravenous crystalloid used in the unit alternated monthly between saline (0.9% sodium chloride) and balanced crystalloids (lactated Ringer's solution or Plasma-Lyte A). Enrollment, fluid delivery, and data collection were performed using software tools within the electronic health record. The primary outcome was the difference between study groups in the proportion of isotonic crystalloid administered that was saline. The secondary outcome was major adverse kidney events within 30 days (MAKE30), a composite of death, dialysis, or persistent renal dysfunction. Patients assigned to saline (n = 454) and balanced crystalloids (n = 520) were similar at baseline and received similar volumes of crystalloid by 30 days (median [interquartile range]: 1,424 ml [500-3,377] vs. 1,617 ml [500-3,628]; P = 0.40). Saline made up a larger proportion of the isotonic crystalloid given in the saline group than in the balanced crystalloid group (91% vs. 21%; P < 0.001). MAKE30 did not differ between groups (24.7% vs. 24.6%; P = 0.98). An electronic health record-embedded, cluster-randomized, multiple-crossover trial comparing saline with balanced crystalloids can produce well-balanced study groups and separation in crystalloid receipt. Clinical trial registered with www.clinicaltrials.gov (NCT 02345486).

Multi-species detection using multi-mode absorption spectroscopy (MUMAS)

NASA Astrophysics Data System (ADS)

Northern, J. H.; Thompson, A. W. J.; Hamilton, M. L.; Ewart, P.

2013-06-01

The detection of multiple species using a single laser and single detector employing multi-mode absorption spectroscopy (MUMAS) is reported. An in-house constructed, diode-pumped, Er:Yb:glass micro-laser operating at 1,565 nm with 10 modes separated by 18 GHz was used to record MUMAS signals in a gas mixture containing C2H2, N2O and CO. The components of the mixture were detected simultaneously by identifying multiple transitions in each of the species. By using temperature- and pressure-dependent modelled spectral fits to the data, partial pressures of each species in the mixture were determined with an uncertainty of ±2 %.

In search of real autonomy for fertility patients.

PubMed

Johnston, Josephine; Gusmano, Michael K; Patrizio, Pasquale

2015-07-01

Nearly one in eight infants in the United States is born preterm. A variety of factors are associated with preterm birth, including multiplicity. In the United States fertility treatments are currently associated with high rates of multiplicity, but these rates could be reduced significantly if changes can be made to fertility treatment policy and practice. These include reducing the financial pressure on patients to prioritize pregnancy chances over safety by expanding insurance coverage and altering the way we calculate success rates and insurance benefits so that two consecutive single embryo transfers is equivalent to one double embryo transfer.

Improved multiple-pass Raman spectrometer

NASA Astrophysics Data System (ADS)

Kc, Utsav; Silver, Joel A.; Hovde, David C.; Varghese, Philip L.

2011-08-01

An improved Raman gain spectrometer for flame measurements of gas temperature and species concentrations is described. This instrument uses a multiple-pass optical cell to enhance the incident light intensity in the measurement volume. The Raman signal is 83 times larger than from a single pass, and the Raman signal-to-noise ratio (SNR) in room-temperature air of 153 is an improvement over that from a single-pass cell by a factor of 9.3 when the cell is operated with 100 passes and the signal is integrated over 20 laser shots. The SNR improvement with the multipass cell is even higher for flame measurements at atmospheric pressure, because detector readout noise is more significant for single-pass measurements when the gas density is lower. Raman scattering is collected and dispersed in a spectrograph with a transmission grating and recorded with a fast gated CCD array detector to help eliminate flame interferences. The instrument is used to record spontaneous Raman spectra from N2, CO2, O2, and CO in a methane--air flame. Curve fits of the recorded Raman spectra to detailed simulations of nitrogen spectra are used to determine the flame temperature from the shapes of the spectral signatures and from the ratio of the total intensities of the Stokes and anti-Stokes signals. The temperatures measured are in good agreement with radiation-corrected thermocouple measurements for a range of equivalence ratios.

The Development of a Subdivision Within the Parkway School District. Environmental Ecological Education Project. Revised.

ERIC Educational Resources Information Center

Parkway School District, Chesterfield, MO.

This unit, designed for use with junior high school students, focuses on the factors involved in subdivision design and planning. Although it is specifically constructed for use in the Parkway School District, Chesterfield, Missouri, it could be adapted for use in any suburban area where subdivisions (multiple and/or single family units) exist. It…

Single and multiple food allergies in infants with proctocolitis.

PubMed

Koksal, B T; Barıs, Z; Ozcay, F; Yilmaz Ozbek, O

Food protein-induced allergic proctocolitis is a frequent cause of rectal bleeding in infants. Characteristics of infants with multiple food allergies have not been defined. This study aimed to identify characteristics of infants with proctocolitis and compare infants with single and multiple food allergies. A total of 132 infants with proctocolitis were evaluated retrospectively. All of the infants were diagnosed by a paediatric allergist and/or a paediatric gastroenterologist according to guidelines. Clinical features of the infants, as well as results of a complete blood count, skin prick test, specific immunoglobulin E, and stool examinations or colonoscopy were recorded. Cow's milk (97.7%) was the most common allergen, followed by egg (22%). Forty-five (34.1%) infants had allergies to more than one food. Infants with multiple food allergies had a higher eosinophil count (613±631.2 vs. 375±291.9) and a higher frequency of positive specific IgE and/or positive skin prick test results than that of patients with a single food allergy. Most of the patients whose symptoms persisted after two years of age had multiple food allergies. There is no difference in clinical presentations between infants with single and multiple food allergies. However, infants with multiple food allergies have a high blood total eosinophil count and are more likely to have a positive skin prick test and/or positive specific IgE results. Copyright © 2017 SEICAP. Published by Elsevier España, S.L.U. All rights reserved.

The Physiology of Bone Pain. How Much Do We Really Know?

PubMed Central

Nencini, Sara; Ivanusic, Jason J.

2016-01-01

Pain is associated with most bony pathologies. Clinical and experimental observations suggest that bone pain can be derived from noxious stimulation of the periosteum or bone marrow. Sensory neurons are known to innervate the periosteum and marrow cavity, and most of these have a morphology and molecular phenotype consistent with a role in nociception. However, little is known about the physiology of these neurons, and therefore information about mechanisms that generate and maintain bone pain is lacking. The periosteum has received greater attention relative to the bone marrow, reflecting the easier access of the periosteum for experimental assessment. With the electrophysiological preparations used, investigators have been able to record from single periosteal units in isolation, and there is a lot of information available about how they respond to different stimuli, including those that are noxious. In contrast, preparations used to study sensory neurons that innervate the bone marrow have been limited to recording multi-unit activity in whole nerves, and whilst they clearly report responses to noxious stimulation, it is not possible to define responses for single sensory neurons that innervate the bone marrow. There is only limited evidence that peripheral sensory neurons that innervate bone can be sensitized or that they can be activated by multiple stimulus types, and at present this only exists in part for periosteal units. In the central nervous system, it is clear that spinal dorsal horn neurons can be activated by noxious stimuli applied to bone. Some can be sensitized under pathological conditions and may contribute in part to secondary or referred pain associated with bony pathology. Activity related to stimulation of sensory nerves that innervate bone has also been reported in neurons of the spinoparabrachial pathway and the somatosensory cortices, both known for roles in coding information about pain. Whilst these provide some clues as to the way information about bone pain is centrally coded, they need to be expanded to further our understanding of other central territories involved. There is a lot more to learn about the physiology of peripheral sensory neurons that innervate bone and their central projections. PMID:27199772

Wavelength-selective mid-infrared metamaterial absorbers with multiple tungsten cross resonators.

PubMed

Li, Zhigang; Stan, Liliana; Czaplewski, David A; Yang, Xiaodong; Gao, Jie

2018-03-05

Wavelength-selective metamaterial absorbers in the mid-infrared range are demonstrated by using multiple tungsten cross resonators. By adjusting the geometrical parameters of cross resonators in single-sized unit cells, near-perfect absorption with single absorption peak tunable from 3.5 µm to 5.5 µm is realized. The combination of two, three, or four cross resonators of different sizes in one unit cell enables broadband near-perfect absorption at mid-infrared range. The obtained absorption spectra exhibit omnidirectionality and weak dependence on incident polarization. The underlying mechanism of near-perfect absorption with cross resonators is further explained by the optical mode analysis, dispersion relation and equivalent RLC circuit model. Moreover, thermal analysis is performed to study the heat generation and temperature increase in the cross resonator absorbers, while the energy conversion efficiency is calculated for the thermophotovoltaic system made of the cross resonator thermal emitters and low-bandgap semiconductors.

Real-time separation of multineuron recordings with a DSP32C signal processor.

PubMed

Gädicke, R; Albus, K

1995-04-01

We have developed a hardware and software package for real-time discrimination of multiple-unit activities recorded simultaneously from multiple microelectrodes using a VME-Bus system. Compared with other systems cited in literature or commercially available, our system has the following advantages. (1) Each electrode is served by its own preprocessor (DSP32C); (2) On-line spike discrimination is performed independently for each electrode. (3) The VME-bus allows processing of data received from 16 electrodes. The digitized (62.5 kHz) spike form is itself used as the model spike; the algorithm allows for comparing and sorting complete wave forms in real time into 8 different models per electrode.

6C polarization analysis - seismic direction finding in coherent noise, automated event identification, and wavefield separation

NASA Astrophysics Data System (ADS)

Schmelzbach, C.; Sollberger, D.; Greenhalgh, S.; Van Renterghem, C.; Robertsson, J. O. A.

2017-12-01

Polarization analysis of standard three-component (3C) seismic data is an established tool to determine the propagation directions of seismic waves recorded by a single station. A major limitation of seismic direction finding methods using 3C recordings, however, is that a correct propagation-direction determination is only possible if the wave mode is known. Furthermore, 3C polarization analysis techniques break down in the presence of coherent noise (i.e., when more than one event is present in the analysis time window). Recent advances in sensor technology (e.g., fibre-optical, magnetohydrodynamic angular rate sensors, and ring laser gyroscopes) have made it possible to accurately measure all three components of rotational ground motion exhibited by seismic waves, in addition to the conventionally recorded three components of translational motion. Here, we present an extension of the theory of single station 3C polarization analysis to six-component (6C) recordings of collocated translational and rotational ground motions. We demonstrate that the information contained in rotation measurements can help to overcome some of the main limitations of standard 3C seismic direction finding, such as handling multiple arrivals simultaneously. We show that the 6C polarisation of elastic waves measured at the Earth's free surface does not only depend on the seismic wave type and propagation direction, but also on the local P- and S-wave velocities just beneath the recording station. Using an adaptation of the multiple signal classification algorithm (MUSIC), we demonstrate how seismic events can univocally be identified and characterized in terms of their wave type. Furthermore, we show how the local velocities can be inferred from single-station 6C data, in addition to the direction angles (inclination and azimuth) of seismic arrivals. A major benefit of our proposed 6C method is that it also allows the accurate recovery of the wave type, propagation directions, and phase velocities of multiple, interfering arrivals in one time window. We demonstrate how this property can be exploited to separate the wavefield into its elastic wave-modes and to isolate or suppress waves arriving from specific directions (directional filtering), both in a fully automated fashion.

Neural decoding of treadmill walking from noninvasive electroencephalographic signals

PubMed Central

Presacco, Alessandro; Goodman, Ronald; Forrester, Larry

2011-01-01

Chronic recordings from ensembles of cortical neurons in primary motor and somatosensory areas in rhesus macaques provide accurate information about bipedal locomotion (Fitzsimmons NA, Lebedev MA, Peikon ID, Nicolelis MA. Front Integr Neurosci 3: 3, 2009). Here we show that the linear and angular kinematics of the ankle, knee, and hip joints during both normal and precision (attentive) human treadmill walking can be inferred from noninvasive scalp electroencephalography (EEG) with decoding accuracies comparable to those from neural decoders based on multiple single-unit activities (SUAs) recorded in nonhuman primates. Six healthy adults were recorded. Participants were asked to walk on a treadmill at their self-selected comfortable speed while receiving visual feedback of their lower limbs (i.e., precision walking), to repeatedly avoid stepping on a strip drawn on the treadmill belt. Angular and linear kinematics of the left and right hip, knee, and ankle joints and EEG were recorded, and neural decoders were designed and optimized with cross-validation procedures. Of note, the optimal set of electrodes of these decoders were also used to accurately infer gait trajectories in a normal walking task that did not require subjects to control and monitor their foot placement. Our results indicate a high involvement of a fronto-posterior cortical network in the control of both precision and normal walking and suggest that EEG signals can be used to study in real time the cortical dynamics of walking and to develop brain-machine interfaces aimed at restoring human gait function. PMID:21768121

Time-dependent Increase in the Network Response to the Stimulation of Neuronal Cell Cultures on Micro-electrode Arrays.

PubMed

Gertz, Monica L; Baker, Zachary; Jose, Sharon; Peixoto, Nathalia

2017-05-29

Micro-electrode arrays (MEAs) can be used to investigate drug toxicity, design paradigms for next-generation personalized medicine, and study network dynamics in neuronal cultures. In contrast with more traditional methods, such as patch-clamping, which can only record activity from a single cell, MEAs can record simultaneously from multiple sites in a network, without requiring the arduous task of placing each electrode individually. Moreover, numerous control and stimulation configurations can be easily applied within the same experimental setup, allowing for a broad range of dynamics to be explored. One of the key dynamics of interest in these in vitro studies has been the extent to which cultured networks display properties indicative of learning. Mouse neuronal cells cultured on MEAs display an increase in response following training induced by electrical stimulation. This protocol demonstrates how to culture neuronal cells on MEAs; successfully record from over 95% of the plated dishes; establish a protocol to train the networks to respond to patterns of stimulation; and sort, plot, and interpret the results from such experiments. The use of a proprietary system for stimulating and recording neuronal cultures is demonstrated. Software packages are also used to sort neuronal units. A custom-designed graphical user interface is used to visualize post-stimulus time histograms, inter-burst intervals, and burst duration, as well as to compare the cellular response to stimulation before and after a training protocol. Finally, representative results and future directions of this research effort are discussed.

A phase I study to assess the single and multiple dose pharmacokinetics of THC/CBD oromucosal spray.

PubMed

Stott, C G; White, L; Wright, S; Wilbraham, D; Guy, G W

2013-05-01

A Phase I study to assess the single and multipledose pharmacokinetics (PKs) and safety and tolerability of oromucosally administered Δ(9)-tetrahydrocannabinol (THC)/cannabidiol (CBD) spray, an endocannabinoid system modulator, in healthy male subjects. Subjects received either single doses of THC/CBD spray as multiple sprays [2 (5.4 mg THC and 5.0 mg CBD), 4 (10.8 mg THC and 10.0 mg CBD) or 8 (21.6 mg THC and 20.0 mg CBD) daily sprays] or multiple doses of THC/CBD spray (2, 4 or 8 sprays once daily) for nine consecutive days, following fasting for a minimum of 10 h overnight prior to each dosing. Plasma samples were analyzed by gas chromatography-mass spectrometry for CBD, THC, and its primary metabolite 11-hydroxy-THC, and various PK parameters were investigated. Δ(9)-Tetrahydrocannabinol and CBD were rapidly absorbed following single-dose administration. With increasing single and multiple doses of THC/CBD spray, the mean peak plasma concentration (Cmax) increased for all analytes. There was evidence of dose-proportionality in the single but not the multiple dosing data sets. The bioavailability of THC was greater than CBD at single and multiple doses, and there was no evidence of accumulation for any analyte with multiple dosing. Inter-subject variability ranged from moderate to high for all PK parameters in this study. The time to peak plasma concentration (Tmax) was longest for all analytes in the eight spray group, but was similar in the two and four spray groups. THC/CBD spray was well-tolerated in this study and no serious adverse events were reported. The mean Cmax values (<12 ng/mL) recorded in this study were well below those reported in patients who smoked/inhaled cannabis, which is reassuring since elevated Cmax values are linked to significant psychoactivity. There was also no evidence of accumulation on repeated dosing.

Decoding Speech With Integrated Hybrid Signals Recorded From the Human Ventral Motor Cortex.

PubMed

Ibayashi, Kenji; Kunii, Naoto; Matsuo, Takeshi; Ishishita, Yohei; Shimada, Seijiro; Kawai, Kensuke; Saito, Nobuhito

2018-01-01

Restoration of speech communication for locked-in patients by means of brain computer interfaces (BCIs) is currently an important area of active research. Among the neural signals obtained from intracranial recordings, single/multi-unit activity (SUA/MUA), local field potential (LFP), and electrocorticography (ECoG) are good candidates for an input signal for BCIs. However, the question of which signal or which combination of the three signal modalities is best suited for decoding speech production remains unverified. In order to record SUA, LFP, and ECoG simultaneously from a highly localized area of human ventral sensorimotor cortex (vSMC), we fabricated an electrode the size of which was 7 by 13 mm containing sparsely arranged microneedle and conventional macro contacts. We determined which signal modality is the most capable of decoding speech production, and tested if the combination of these signals could improve the decoding accuracy of spoken phonemes. Feature vectors were constructed from spike frequency obtained from SUAs and event-related spectral perturbation derived from ECoG and LFP signals, then input to the decoder. The results showed that the decoding accuracy for five spoken vowels was highest when features from multiple signals were combined and optimized for each subject, and reached 59% when averaged across all six subjects. This result suggests that multi-scale signals convey complementary information for speech articulation. The current study demonstrated that simultaneous recording of multi-scale neuronal activities could raise decoding accuracy even though the recording area is limited to a small portion of cortex, which is advantageous for future implementation of speech-assisting BCIs.

Decoding Speech With Integrated Hybrid Signals Recorded From the Human Ventral Motor Cortex

PubMed Central

Ibayashi, Kenji; Kunii, Naoto; Matsuo, Takeshi; Ishishita, Yohei; Shimada, Seijiro; Kawai, Kensuke; Saito, Nobuhito

2018-01-01

Restoration of speech communication for locked-in patients by means of brain computer interfaces (BCIs) is currently an important area of active research. Among the neural signals obtained from intracranial recordings, single/multi-unit activity (SUA/MUA), local field potential (LFP), and electrocorticography (ECoG) are good candidates for an input signal for BCIs. However, the question of which signal or which combination of the three signal modalities is best suited for decoding speech production remains unverified. In order to record SUA, LFP, and ECoG simultaneously from a highly localized area of human ventral sensorimotor cortex (vSMC), we fabricated an electrode the size of which was 7 by 13 mm containing sparsely arranged microneedle and conventional macro contacts. We determined which signal modality is the most capable of decoding speech production, and tested if the combination of these signals could improve the decoding accuracy of spoken phonemes. Feature vectors were constructed from spike frequency obtained from SUAs and event-related spectral perturbation derived from ECoG and LFP signals, then input to the decoder. The results showed that the decoding accuracy for five spoken vowels was highest when features from multiple signals were combined and optimized for each subject, and reached 59% when averaged across all six subjects. This result suggests that multi-scale signals convey complementary information for speech articulation. The current study demonstrated that simultaneous recording of multi-scale neuronal activities could raise decoding accuracy even though the recording area is limited to a small portion of cortex, which is advantageous for future implementation of speech-assisting BCIs. PMID:29674950

Low driving voltage simplified tandem organic light-emitting devices by using exciplex-forming hosts

NASA Astrophysics Data System (ADS)

Zhou, Dong-Ying; Cui, Lin-Song; Zhang, Ying-Jie; Liao, Liang-Sheng; Aziz, Hany

2014-10-01

Tandem organic light-emitting devices (OLEDs), i.e., OLEDs containing multiple electroluminescence (EL) units that are vertically stacked, are attracting significant interest because of their ability to realize high current efficiency and long operational lifetime. However, stacking multiple EL units in tandem OLEDs increases driving voltage and complicates fabrication process relative to their standard single unit counterparts. In this paper, we demonstrate low driving voltage tandem OLEDs via utilizing exciplex-forming hosts in the EL units instead of conventional host materials. The use of exciplex-forming hosts reduces the charge injection barriers and the trapping of charges on guest molecules, resulting in the lower driving voltage. The use of exciplex-forming hosts also allows using fewer layers, hence simpler EL configuration which is beneficial for reducing the fabrication complexity of tandem OLEDs.

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

Alfonso Hernandez, Laura; Nelson, Tammie Renee; Gelin, Maxim F.

The interchromophoric energy-transfer pathways between weakly coupled units in a π-conjugated phenylene–ethynylene macrocycle and its half-ring analogue have been investigated using the nonadiabatic excited-state molecular dynamics approach. To track the flow of electronic transition density between macrocycle units, we formulate a transition density flux analysis adapted from the statistical minimum flow method previously developed to investigate vibrational energy flow. Following photoexcitation, transition density is primarily delocalized on two chromophore units and the system undergoes ultrafast energy transfer, creating a localized excited state on a single unit. In the macrocycle, distinct chromophore units donate transition density to a single acceptor unitmore » but do not interchange transition density among each other. We find that energy transfer in the macrocycle is slower than in the corresponding half ring because of the presence of multiple interfering energy-transfer pathways. Finally, simulation results are validated by modeling the fluorescence anisotropy decay.« less

Interference of interchromophoric energy-transfer pathways in π-conjugated macrocycles

DOE PAGES

Alfonso Hernandez, Laura; Nelson, Tammie Renee; Gelin, Maxim F.; ...

2016-11-10

The interchromophoric energy-transfer pathways between weakly coupled units in a π-conjugated phenylene–ethynylene macrocycle and its half-ring analogue have been investigated using the nonadiabatic excited-state molecular dynamics approach. To track the flow of electronic transition density between macrocycle units, we formulate a transition density flux analysis adapted from the statistical minimum flow method previously developed to investigate vibrational energy flow. Following photoexcitation, transition density is primarily delocalized on two chromophore units and the system undergoes ultrafast energy transfer, creating a localized excited state on a single unit. In the macrocycle, distinct chromophore units donate transition density to a single acceptor unitmore » but do not interchange transition density among each other. We find that energy transfer in the macrocycle is slower than in the corresponding half ring because of the presence of multiple interfering energy-transfer pathways. Finally, simulation results are validated by modeling the fluorescence anisotropy decay.« less

Differentially Variable Component Analysis (dVCA): Identifying Multiple Evoked Components using Trial-to-Trial Variability

NASA Technical Reports Server (NTRS)

Knuth, Kevin H.; Shah, Ankoor S.; Truccolo, Wilson; Ding, Ming-Zhou; Bressler, Steven L.; Schroeder, Charles E.

2003-01-01

Electric potentials and magnetic fields generated by ensembles of synchronously active neurons in response to external stimuli provide information essential to understanding the processes underlying cognitive and sensorimotor activity. Interpreting recordings of these potentials and fields is difficult as each detector records signals simultaneously generated by various regions throughout the brain. We introduce the differentially Variable Component Analysis (dVCA) algorithm, which relies on trial-to-trial variability in response amplitude and latency to identify multiple components. Using simulations we evaluate the importance of response variability to component identification, the robustness of dVCA to noise, and its ability to characterize single-trial data. Finally, we evaluate the technique using visually evoked field potentials recorded at incremental depths across the layers of cortical area VI, in an awake, behaving macaque monkey.

Phase retrieval without unwrapping by single-shot dual-wavelength digital holography

NASA Astrophysics Data System (ADS)

Min, Junwei; Yao, Baoli; Zhou, Meiling; Guo, Rongli; Lei, Ming; Yang, Yanlong; Dan, Dan; Yan, Shaohui; Peng, Tong

2014-12-01

A phase retrieval method by using single-shot dual-wavelength digital holography is proposed. Each single wavelength hologram is extracted from the color CCD recorded hologram at one exposure, and the unwrapped phase image of object can be reconstructed directly. Different from the traditional multiple wavelength phase unwrapping techniques, any single complex wave-fronts at different wavelengths have no need to be calculated any more. Thus, the phase retrieval is computationally fast and straightforward, and the limitations on the total optical path difference are significantly relaxed. The practicability of the proposed method is demonstrated by both simulated and experimental results.

Detection of ventricular fibrillation from multiple sensors

NASA Astrophysics Data System (ADS)

Lindsley, Stephanie A.; Ludeman, Lonnie C.

1992-07-01

Ventricular fibrillation is a potentially fatal medical condition in which the flow of blood through the body is terminated due to the lack of an organized electric potential in the heart. Automatic implantable defibrillators are becoming common as a means for helping patients confronted with repeated episodes of ventricular fibrillation. Defibrillators must first accurately detect ventricular fibrillation and then provide an electric shock to the heart to allow a normal sinus rhythm to resume. The detection of ventricular fibrillation by using an array of multiple sensors to distinguish between signals recorded from single (normal sinus rhythm) or multiple (ventricular fibrillation) sources is presented. An idealistic model is presented and the analysis of data generated by this model suggests that the method is promising as a method for accurately and quickly detecting ventricular fibrillation from signals recorded from sensors placed on the epicardium.

Ubiquitous health monitoring system for multiple users using a ZigBee and WLAN dual-network.

PubMed

Cha, Yong Dae; Yoon, Gilwon

2009-11-01

A ubiquitous health monitoring system for multiple users was developed based on a ZigBee and wireless local area network (WLAN) dual-network. A compact biosignal monitoring unit (BMU) for measuring electrocardiogram (ECG), photoplethysmogram (PPG), and temperature was also developed. A single 8-bit microcontroller operated the BMU including most of digital filtering and wireless communication. The BMU with its case was reduced to 55 x 35 x 15 mm and 33 g. In routine use, vital signs of 6 bytes/sec (heart rate, temperature, pulse transit time) per each user were transmitted through a ZigBee module even though all the real-time data were recorded in a secure digital memory of the BMU. In an emergency or when need arises, a channel of a particular user was switched to another ZigBee module, called the emergency module, that sent all ECG and PPG waveforms in real time. Each emergency ZigBee module handled up to a few users. Data from multiple users were wirelessly received by the ZigBee receiver modules in a controller called ZigBee-WLAN gateway, where the ZigBee modules were connected to a WLAN module. This WLAN module sent all data wirelessly to a monitoring center. Operating the dual modes of ZigBee/WLAN utilized an advantage of ZigBee by handling multiple users with minimum power consumption, and overcame the ZigBee limitation of low data rate. This dual-network system for LAN is economically competitive and reliable.

Faster processing of multiple spatially-heterodyned direct to digital holograms

DOEpatents

Hanson, Gregory R.; Bingham, Philip R.

2006-10-03

Systems and methods are described for faster processing of multiple spatially-heterodyned direct to digital holograms. A method includes of obtaining multiple spatially-heterodyned holograms, includes: digitally recording a first spatially-heterodyned hologram including spatial heterodyne fringes for Fourier analysis; digitally recording a second spatially-heterodyned hologram including spatial heterodyne fringes for Fourier analysis; Fourier analyzing the recorded first spatially-heterodyned hologram by shifting a first original origin of the recorded first spatially-heterodyned hologram including spatial heterodyne fringes in Fourier space to sit on top of a spatial-heterodyne carrier frequency defined as a first angle between a first reference beam and a first, object beam; applying a first digital filter to cut off signals around the first original origin and performing an inverse Fourier transform on the result; Fourier analyzing the recorded second spatially-heterodyned hologram by shifting a second original origin of the recorded second spatially-heterodyned hologram including spatial heterodyne fringes in Fourier space to sit on top of a spatial-heterodyne carrier frequency defined as a second angle between a second reference beam and a second object beam; and applying a second digital filter to cut off signals around the second original origin and performing an inverse Fourier transform on the result, wherein digitally recording the first spatially-heterodyned hologram is completed before digitally recording the second spatially-heterodyned hologram and a single digital image includes both the first spatially-heterodyned hologram and the second spatially-heterodyned hologram.

Faster processing of multiple spatially-heterodyned direct to digital holograms

DOEpatents

Hanson, Gregory R [Clinton, TN; Bingham, Philip R [Knoxville, TN

2008-09-09

Systems and methods are described for faster processing of multiple spatially-heterodyned direct to digital holograms. A method includes of obtaining multiple spatially-heterodyned holograms, includes: digitally recording a first spatially-heterodyned hologram including spatial heterodyne fringes for Fourier analysis; digitally recording a second spatially-heterodyned hologram including spatial heterodyne fringes for Fourier analysis; Fourier analyzing the recorded first spatially-heterodyned hologram by shifting a first original origin of the recorded first spatially-heterodyned hologram including spatial heterodyne fringes in Fourier space to sit on top of a spatial-heterodyne carrier frequency defined as a first angle between a first reference beam and a first object beam; applying a first digital filter to cut off signals around the first original origin and performing an inverse Fourier transform on the result; Fourier analyzing the recorded second spatially-heterodyned hologram by shifting a second original origin of the recorded second spatially-heterodyned hologram including spatial heterodyne fringes in Fourier space to sit on top of a spatial-heterodyne carrier frequency defined as a second angle between a second reference beam and a second object beam; and applying a second digital filter to cut off signals around the second original origin and performing an inverse Fourier transform on the result, wherein digitally recording the first spatially-heterodyned hologram is completed before digitally recording the second spatially-heterodyned hologram and a single digital image includes both the first spatially-heterodyned hologram and the second spatially-heterodyned hologram.

AMOS Phase 3 Program. Volume 1

DTIC Science & Technology

1978-03-01

master and are therefore always connected to the same net, VDL or dial line that the master unit has selected. Binaural headsets are provided which...to the reentry vehicle. The recorded and reduced data is compared to a Beat Estimate of Trajectory (BET) as derived from multiple radar sources

10 CFR 20.2101 - General provisions.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 10 Energy 1 2012-01-01 2012-01-01 false General provisions. 20.2101 Section 20.2101 Energy NUCLEAR REGULATORY COMMISSION STANDARDS FOR PROTECTION AGAINST RADIATION Records § 20.2101 General provisions. (a) Each licensee shall use the units: curie, rad, rem, including multiples and subdivisions, and shall...

10 CFR 20.2101 - General provisions.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 1 2010-01-01 2010-01-01 false General provisions. 20.2101 Section 20.2101 Energy NUCLEAR REGULATORY COMMISSION STANDARDS FOR PROTECTION AGAINST RADIATION Records § 20.2101 General provisions. (a) Each licensee shall use the units: curie, rad, rem, including multiples and subdivisions, and shall...

10 CFR 20.2101 - General provisions.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 10 Energy 1 2013-01-01 2013-01-01 false General provisions. 20.2101 Section 20.2101 Energy NUCLEAR REGULATORY COMMISSION STANDARDS FOR PROTECTION AGAINST RADIATION Records § 20.2101 General provisions. (a) Each licensee shall use the units: curie, rad, rem, including multiples and subdivisions, and shall...

10 CFR 20.2101 - General provisions.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 10 Energy 1 2011-01-01 2011-01-01 false General provisions. 20.2101 Section 20.2101 Energy NUCLEAR REGULATORY COMMISSION STANDARDS FOR PROTECTION AGAINST RADIATION Records § 20.2101 General provisions. (a) Each licensee shall use the units: curie, rad, rem, including multiples and subdivisions, and shall...

10 CFR 20.2101 - General provisions.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 10 Energy 1 2014-01-01 2014-01-01 false General provisions. 20.2101 Section 20.2101 Energy NUCLEAR REGULATORY COMMISSION STANDARDS FOR PROTECTION AGAINST RADIATION Records § 20.2101 General provisions. (a) Each licensee shall use the units: curie, rad, rem, including multiples and subdivisions, and shall...

Trends Analysis of rhBMP Utilization in Single-Level Posterior Lumbar Interbody Fusion in the United States

PubMed Central

Lao, Lifeng; Cohen, Jeremiah R.; Brodke, Darrel S.; Youssef, Jim A.; Park, Jong-Beom; Yoon, S. Tim; Wang, Jeffrey C.; Meisel, Hans-Joerg

2017-01-01

Study Design: Retrospective study. Objectives: Recombinant human bone morphogenetic protein-2 (rhBMP-2) has been widely used in spinal fusion surgery, but there is little information on rhBMP-2 utilization in single-level posterior lumbar interbody fusion (PLIF). The purpose of our study was to evaluate the trends and demographics of rhBMP-2 utilization in single-level PLIF. Methods: Patients who underwent single-level PLIF from 2005 to 2011 were identified by searching ICD-9 diagnosis and procedure codes in the PearlDiver Patient Records Database, a national database of orthopedic insurance records. The year of procedure, age, gender, and region of the United States were recorded for each patient. Results were reported for each variable as the incidence of procedures identified per 100 000 patients searched in the database. Results: A total of 2735 patients had single-level PLIF. The average rate of single-level PLIF with rhBMP-2 maintained at a relatively stable level (28% to 31%) from 2005 to 2009, but decreased in 2010 (9.9%) and 2011 (11.8%). The overall incidence of single-level PLIF without rhBMP-2 (0.68 cases per 100 000 patients) was statistically higher (P < .01) compared to single-level PLIF with rhBMP-2 (0.21 cases per 100 000 patients). The average rate of single-level PLIF with rhBMP-2 utilization was the highest in West (30.1%), followed by Midwest (26.9%), South (20.5%), and Northeast (17.8%). The highest incidence of single-level PLIF with rhBMP-2 was observed in the age group <65 years (0.3 per 100 000 patients). Conclusions: To our knowledge, this is the first study to report on the demographics associated with rhBMP-2 use in single-level PLIF. There was a 3-fold increase in the rate of PLIF without rhBMP-2 compared to PLIF with rhBMP-2, with both procedures being mainly done in patients less than 65 years of age. PMID:28989840

Trends Analysis of rhBMP Utilization in Single-Level Posterior Lumbar Interbody Fusion in the United States.

PubMed

Lao, Lifeng; Cohen, Jeremiah R; Buser, Zorica; Brodke, Darrel S; Youssef, Jim A; Park, Jong-Beom; Yoon, S Tim; Wang, Jeffrey C; Meisel, Hans-Joerg

2017-10-01

Retrospective study. Recombinant human bone morphogenetic protein-2 (rhBMP-2) has been widely used in spinal fusion surgery, but there is little information on rhBMP-2 utilization in single-level posterior lumbar interbody fusion (PLIF). The purpose of our study was to evaluate the trends and demographics of rhBMP-2 utilization in single-level PLIF. Patients who underwent single-level PLIF from 2005 to 2011 were identified by searching ICD-9 diagnosis and procedure codes in the PearlDiver Patient Records Database, a national database of orthopedic insurance records. The year of procedure, age, gender, and region of the United States were recorded for each patient. Results were reported for each variable as the incidence of procedures identified per 100 000 patients searched in the database. A total of 2735 patients had single-level PLIF. The average rate of single-level PLIF with rhBMP-2 maintained at a relatively stable level (28% to 31%) from 2005 to 2009, but decreased in 2010 (9.9%) and 2011 (11.8%). The overall incidence of single-level PLIF without rhBMP-2 (0.68 cases per 100 000 patients) was statistically higher ( P < .01) compared to single-level PLIF with rhBMP-2 (0.21 cases per 100 000 patients). The average rate of single-level PLIF with rhBMP-2 utilization was the highest in West (30.1%), followed by Midwest (26.9%), South (20.5%), and Northeast (17.8%). The highest incidence of single-level PLIF with rhBMP-2 was observed in the age group <65 years (0.3 per 100 000 patients). To our knowledge, this is the first study to report on the demographics associated with rhBMP-2 use in single-level PLIF. There was a 3-fold increase in the rate of PLIF without rhBMP-2 compared to PLIF with rhBMP-2, with both procedures being mainly done in patients less than 65 years of age.

How many neurons can we see with current spike sorting algorithms?

PubMed Central

Pedreira, Carlos; Martinez, Juan; Ison, Matias J.; Quian Quiroga, Rodrigo

2012-01-01

Recent studies highlighted the disagreement between the typical number of neurons observed with extracellular recordings and the ones to be expected based on anatomical and physiological considerations. This disagreement has been mainly attributed to the presence of sparsely firing neurons. However, it is also possible that this is due to limitations of the spike sorting algorithms used to process the data. To address this issue, we used realistic simulations of extracellular recordings and found a relatively poor spike sorting performance for simulations containing a large number of neurons. In fact, the number of correctly identified neurons for single-channel recordings showed an asymptotic behavior saturating at about 8–10 units, when up to 20 units were present in the data. This performance was significantly poorer for neurons with low firing rates, as these units were twice more likely to be missed than the ones with high firing rates in simulations containing many neurons. These results uncover one of the main reasons for the relatively low number of neurons found in extracellular recording and also stress the importance of further developments of spike sorting algorithms. PMID:22841630

Validating silicon polytrodes with paired juxtacellular recordings: method and dataset.

PubMed

Neto, Joana P; Lopes, Gonçalo; Frazão, João; Nogueira, Joana; Lacerda, Pedro; Baião, Pedro; Aarts, Arno; Andrei, Alexandru; Musa, Silke; Fortunato, Elvira; Barquinha, Pedro; Kampff, Adam R

2016-08-01

Cross-validating new methods for recording neural activity is necessary to accurately interpret and compare the signals they measure. Here we describe a procedure for precisely aligning two probes for in vivo "paired-recordings" such that the spiking activity of a single neuron is monitored with both a dense extracellular silicon polytrode and a juxtacellular micropipette. Our new method allows for efficient, reliable, and automated guidance of both probes to the same neural structure with micrometer resolution. We also describe a new dataset of paired-recordings, which is available online. We propose that our novel targeting system, and ever expanding cross-validation dataset, will be vital to the development of new algorithms for automatically detecting/sorting single-units, characterizing new electrode materials/designs, and resolving nagging questions regarding the origin and nature of extracellular neural signals. Copyright © 2016 the American Physiological Society.

A Multi-Functional Microelectrode Array Featuring 59760 Electrodes, 2048 Electrophysiology Channels, Stimulation, Impedance Measurement and Neurotransmitter Detection Channels.

PubMed

Dragas, Jelena; Viswam, Vijay; Shadmani, Amir; Chen, Yihui; Bounik, Raziyeh; Stettler, Alexander; Radivojevic, Milos; Geissler, Sydney; Obien, Marie; Müller, Jan; Hierlemann, Andreas

2017-06-01

Biological cells are characterized by highly complex phenomena and processes that are, to a great extent, interdependent. To gain detailed insights, devices designed to study cellular phenomena need to enable tracking and manipulation of multiple cell parameters in parallel; they have to provide high signal quality and high spatiotemporal resolution. To this end, we have developed a CMOS-based microelectrode array system that integrates six measurement and stimulation functions, the largest number to date. Moreover, the system features the largest active electrode array area to date (4.48×2.43 mm 2 ) to accommodate 59,760 electrodes, while its power consumption, noise characteristics, and spatial resolution (13.5 μm electrode pitch) are comparable to the best state-of-the-art devices. The system includes: 2,048 action-potential (AP, bandwidth: 300 Hz to 10 kHz) recording units, 32 local-field-potential (LFP, bandwidth: 1 Hz to 300 Hz) recording units, 32 current recording units, 32 impedance measurement units, and 28 neurotransmitter detection units, in addition to the 16 dual-mode voltage-only or current/voltage-controlled stimulation units. The electrode array architecture is based on a switch matrix, which allows for connecting any measurement/stimulation unit to any electrode in the array and for performing different measurement/stimulation functions in parallel.

Chronic multiunit recordings in behaving animals: advantages and limitations.

PubMed

Supèr, Hans; Roelfsema, Pieter R

2005-01-01

By simultaneous recording from neural responses at many different loci at the same time, we can understand the interaction between neurons, and thereby gain insight into the network properties of neural processing, instead of the functioning of individual neurons. Here we will discuss a method for recording in behaving animals that uses chronically implanted micro-electrodes that allow one to track neural responses over a long period of time. In a majority of cases, multiunit activity, which is the aggregate spiking activity of a number of neurons in the vicinity of an electrode tip, is recorded through these electrodes, and occasionally single neurons can be isolated. Here we compare the properties of multiunit responses to the responses of single neurons in the primary visual cortex. We also discuss the advantages and disadvantages of the multiunit signal as opposed to a signal of single neurons. We demonstrate that multiunit recording provides a reliable and useful technique in cases where the neurons at the electrodes have similar response properties. Multiunit recording is therefore especially valuable when task variables have an effect that is consistent across the population of neurons. In the primary visual cortex, this is the case for figure-ground segregation and visual attention. Multiunit recording also has clear advantages for cross-correlation analysis. We show that the cross-correlation function between multiunit signals gives a reliable estimate of the average single-unit cross-correlation function. By the use of multiunit recording, it becomes much easier to detect relatively weak interactions between neurons at different cortical locations.

Intrapulmonary receptors in the Tegu lizard: II. Functional characteristics and localization;.

PubMed

Scheid, P; Kuhlmann, W D; Fedde, M R

1977-02-01

Intrapulmonary receptors identified in the Tegu lizard by single-unit vagal recording (Fedde et al., 1977) were subjected to a number of stimuli and localized within the lung. Some carbon dioxide receptors could follow periodic changes in intrapulmonary CO2 concentrations as rapidly as 1.3 Hz; No oxygen sensitivity was observed with this receptor type, and halothane markedly depressed the discharge frequency. In response to intravenously injected acetazolamide they increased their discharge frequency and became almost totally insensitive to CO2, suggesting molecular per se is not the direct controller of receptor discharge; These receptors show many of the functional characteristics described for those in the avian lung. Afferent activity from both CO2 and mechanoreceptors could be elicited by electrically stimulating the lung surface. The CO2 receptors appeared to be organized in a receptive field covering more than 1 cm2 of lung surface, multiple receptors being innervated by a single afferent fiber. Activity in afferent fibers from mechanoreceptors could be evoked from only one distinct spot on the lung surface. Conduction velocities of afferent fibers from CO2 receptors ranged from 1 to 3 m-sec-1; from mechanoreceptors, from 1.9 to 5.2 m-sec-1.

A simple and effective process for noise reduction of multichannel cortical field potential recordings in freely moving rats.

PubMed

Shaw, Fu-Zen; Yen, Chen Tung; Chen, Ruei Feng

2003-04-15

Simple and useful steps, i.e. placing a grounded plate under the recording chamber as well as using multiple reference electrodes, are introduced here for obtaining reliable low-noise recordings of brain activity in freely moving rats. A general circuit model was built to analyze the electrical interference of both single-grounded and two-reference ground-free recording configurations. In both simulated and realistic conditions under two recording states, 60-Hz magnitude was in the microvolt range. Moreover, the noise was significantly reduced by shortening the distance between the subject and the grounded plate under the recording chamber. Furthermore, in chronically implanted rats, average 60-Hz interference of multichannel electroencephalograms of two-reference ground-free recordings (3.74 +/- 0.18 microV) was significantly smaller than that of the single-grounded condition (9.03 +/- 1.98 microV). Thus, we demonstrated that a lower-noise recording can be achieved by a two-reference configuration and a closely-placed metal grounded plate in an open-field circumstance. As compared to the use of a Faraday cage, this simple procedure is of benefit for long-term behavioral tracking with a video camera and for pharmacological experiments.

Morbidity following Mexico City's 1985 earthquakes: clinical and epidemiologic findings from hospitals and emergency units.

PubMed Central

Sánchez-Carrillo, C I

1989-01-01

Medical records of 822 inpatients and outpatients cared for by the Department of the Federal District medical services during the 1985 Mexico City earthquakes were reviewed. Record incompleteness varied between 92.8 percent and 14.0 percent for the various study variables. No gender differences were detected among the groups; more than 70.0 percent of the patients were ages 15 to 64 years. Multiple traumatic injuries were frequent for inpatients across age groups, while simple contusions were more frequent among outpatients. Multiple head traumas, thorax-abdomen multiple traumas, and simple fractures of an arm or leg were more frequently recorded for inpatients than for outpatients. Head wounds with contusions; simple contusion of the thorax-abdomen, arms, and legs; and psychological trauma were more frequently recorded for outpatients. Although a great many records were incomplete, the data may reflect what actually happened to these patients, given the similarity of the findings with other reports of disasters. Improved record keeping during emergencies is needed to standardize the quantity and the reliability of the data so that statistical and medical care requirements are soundly based. The use of standard questionnaires for data collection is stressed to facilitate the management of clinical and epidemiologic activities. Longitudinal studies are needed to determine patterns of physical injuries, psychological trauma, and survival. PMID:2508177

Quantitative evaluation of apically extruded debris with different single-file systems: Reciproc, F360 and OneShape versus Mtwo.

PubMed

Bürklein, S; Benten, S; Schäfer, E

2014-05-01

To assess in a laboratory setting the amount of apically extruded debris associated with different single-file nickel-titanium instrumentation systems compared to one multiple-file rotary system. Eighty human mandibular central incisors were randomly assigned to four groups (n = 20 teeth per group). The root canals were instrumented according to the manufacturers' instructions using the reciprocating single-file system Reciproc, the single-file rotary systems F360 and OneShape and the multiple-file rotary Mtwo instruments. The apically extruded debris was collected and dried in pre-weighed glass vials. The amount of debris was assessed with a micro balance and statistically analysed using anova and post hoc Student-Newman-Keuls test. The time required to prepare the canals with the different instruments was also recorded. Reciproc produced significantly more debris compared to all other systems (P < 0.05). No significant difference was noted between the two single-file rotary systems and the multiple-file rotary system (P > 0.05). Instrumentation with the three single-file systems was significantly faster than with Mtwo (P < 0.05). Under the condition of this study, all systems caused apical debris extrusion. Rotary instrumentation was associated with less debris extrusion compared to reciprocal instrumentation. © 2013 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Global Trends in Chlorophyll Concentration Observed with the Satellite Ocean Colour Data Record

NASA Astrophysics Data System (ADS)

Melin, F.; Vantrepotte, V.; Chuprin, A.; Grant, M.; Jackson, T.; Sathyendranath, S.

2016-08-01

To detect climate change signals in the data records derived from remote sensing of ocean colour, combining data from multiple missions is required, which implies that the existence of inter-mission differences be adequately addressed prior to undertaking trend studies. Trend distributions associated with merged products are compared with those obtained from single-mission data sets in order to evaluate their suitability for climate studies. Merged products originally developed for operational applications such as near-real time distribution (GlobColour) do not appear to be proper climate data records, showing large parts of the ocean with trends significantly different from trends obtained with SeaWiFS, MODIS or MERIS. On the other hand, results obtained from the Climate Change Initiative (CCI) data are encouraging, showing a good consistency with single-mission products.

Multifunctional and Context-Dependent Control of Vocal Acoustics by Individual Muscles

PubMed Central

Srivastava, Kyle H.; Elemans, Coen P.H.

2015-01-01

The relationship between muscle activity and behavioral output determines how the brain controls and modifies complex skills. In vocal control, ensembles of muscles are used to precisely tune single acoustic parameters such as fundamental frequency and sound amplitude. If individual vocal muscles were dedicated to the control of single parameters, then the brain could control each parameter independently by modulating the appropriate muscle or muscles. Alternatively, if each muscle influenced multiple parameters, a more complex control strategy would be required to selectively modulate a single parameter. Additionally, it is unknown whether the function of single muscles is fixed or varies across different vocal gestures. A fixed relationship would allow the brain to use the same changes in muscle activation to, for example, increase the fundamental frequency of different vocal gestures, whereas a context-dependent scheme would require the brain to calculate different motor modifications in each case. We tested the hypothesis that single muscles control multiple acoustic parameters and that the function of single muscles varies across gestures using three complementary approaches. First, we recorded electromyographic data from vocal muscles in singing Bengalese finches. Second, we electrically perturbed the activity of single muscles during song. Third, we developed an ex vivo technique to analyze the biomechanical and acoustic consequences of single-muscle perturbations. We found that single muscles drive changes in multiple parameters and that the function of single muscles differs across vocal gestures, suggesting that the brain uses a complex, gesture-dependent control scheme to regulate vocal output. PMID:26490859

Correlates of a single cortical action potential in the epidural EEG

PubMed Central

Teleńczuk, Bartosz; Baker, Stuart N; Kempter, Richard; Curio, Gabriel

2015-01-01

To identify the correlates of a single cortical action potential in surface EEG, we recorded simultaneously epidural EEG and single-unit activity in the primary somatosensory cortex of awake macaque monkeys. By averaging over EEG segments coincident with more than hundred thousand single spikes, we found short-lived (≈ 0.5 ms) triphasic EEG deflections dominated by high-frequency components > 800 Hz. The peak-to-peak amplitude of the grand-averaged spike correlate was 80 nV, which matched theoretical predictions, while single-neuron amplitudes ranged from 12 to 966 nV. Combining these estimates with post-stimulus-time histograms of single-unit responses to median-nerve stimulation allowed us to predict the shape of the evoked epidural EEG response and to estimate the number of contributing neurons. These findings establish spiking activity of cortical neurons as a primary building block of high-frequency epidural EEG, which thus can serve as a quantitative macroscopic marker of neuronal spikes. PMID:25554430

Records of Triassic volcanism in Pangean Great Lakes, and implications for reconstructing the distal effects of Large Igneous Provinces

NASA Astrophysics Data System (ADS)

Whiteside, J. H.; Percival, L.; Kinney, S.; Olsen, P. E.; Mather, T. A.; Philpotts, A.

2017-12-01

Documentation of the precise timing of volcanic eruptions in sedimentary records is key for linking volcanic activity to both historical and geological episodes of environmental change. Deposition of tuffs in sediments, and sedimentary enrichment of trace metals linked to igneous processes, are both commonly used for such correlations. In particular, sedimentary mercury (Hg) enrichments have been used as a marker for volcanic activity from Large Igneous Provinces (LIPs) to support their link to episodes of major climate change and mass extinction in the geological record. However, linking such enrichments to a specific eruption or eruption products is often challenging or impossible. In this study, the mercury records from two exactly contemporaneous latest Triassic-earliest Jurassic rift lakes are presented. Both sedimentary records feature igneous units proposed to be related to the later (Early Jurassic) stages of volcanism of the Central Atlantic Magmatic Province (CAMP). These CAMP units include a small tuff unit identified by thin-section petrology and identified at 10 localities over a distance of over 200 km, and a major CAMP basalt flow overlying this tuff (and dated at 200.916±0.064 Ma) which is also known across multiple sedimentary basins in both North America and Morocco and is thought to have been emplaced about 120 kyr after the tuff. A potential stratigraphic correlation between Hg enrichments and the igneous units is considered, and compared to the established records of mercury enrichments from the latest Triassic that are thought to be coeval with the earlier stages of CAMP volcanism. Investigating the Hg records of sedimentary successions containing tuffs and basalt units is an important step for demonstrating whether the mercury emissions from specific individual volcanic eruptions in the deep past can be identified in the geological record, and are thus important tools for interpreting the causes of associated past geological events, such as mass extinctions.

Volumetric display containing multiple two-dimensional color motion pictures

NASA Astrophysics Data System (ADS)

Hirayama, R.; Shiraki, A.; Nakayama, H.; Kakue, T.; Shimobaba, T.; Ito, T.

2014-06-01

We have developed an algorithm which can record multiple two-dimensional (2-D) gradated projection patterns in a single three-dimensional (3-D) object. Each recorded pattern has the individual projected direction and can only be seen from the direction. The proposed algorithm has two important features: the number of recorded patterns is theoretically infinite and no meaningful pattern can be seen outside of the projected directions. In this paper, we expanded the algorithm to record multiple 2-D projection patterns in color. There are two popular ways of color mixing: additive one and subtractive one. Additive color mixing used to mix light is based on RGB colors and subtractive color mixing used to mix inks is based on CMY colors. We made two coloring methods based on the additive mixing and subtractive mixing. We performed numerical simulations of the coloring methods, and confirmed their effectiveness. We also fabricated two types of volumetric display and applied the proposed algorithm to them. One is a cubic displays constructed by light-emitting diodes (LEDs) in 8×8×8 array. Lighting patterns of LEDs are controlled by a microcomputer board. The other one is made of 7×7 array of threads. Each thread is illuminated by a projector connected with PC. As a result of the implementation, we succeeded in recording multiple 2-D color motion pictures in the volumetric displays. Our algorithm can be applied to digital signage, media art and so forth.

Solar heating and cooling systems design and development

NASA Technical Reports Server (NTRS)

1977-01-01

The development and delivery of eight prototype solar heating and cooling systems for installation and operational test was reported. Two heating and six heating and cooling units will be delivered for single family residences, multiple family residences and commercial applications.

Support for non-locking parallel reception of packets belonging to a single memory reception FIFO

DOEpatents

Chen, Dong [Yorktown Heights, NY; Heidelberger, Philip [Yorktown Heights, NY; Salapura, Valentina [Yorktown Heights, NY; Senger, Robert M [Yorktown Heights, NY; Steinmacher-Burow, Burkhard [Boeblingen, DE; Sugawara, Yutaka [Yorktown Heights, NY

2011-01-27

A method and apparatus for distributed parallel messaging in a parallel computing system. A plurality of DMA engine units are configured in a multiprocessor system to operate in parallel, one DMA engine unit for transferring a current packet received at a network reception queue to a memory location in a memory FIFO (rmFIFO) region of a memory. A control unit implements logic to determine whether any prior received packet destined for that rmFIFO is still in a process of being stored in the associated memory by another DMA engine unit of the plurality, and prevent the one DMA engine unit from indicating completion of storing the current received packet in the reception memory FIFO (rmFIFO) until all prior received packets destined for that rmFIFO are completely stored by the other DMA engine units. Thus, there is provided non-locking support so that multiple packets destined for a single rmFIFO are transferred and stored in parallel to predetermined locations in a memory.

Tunable optical frequency comb enabled scalable and cost-effective multiuser orthogonal frequency-division multiple access passive optical network with source-free optical network units.

PubMed

Chen, Chen; Zhang, Chongfu; Liu, Deming; Qiu, Kun; Liu, Shuang

2012-10-01

We propose and experimentally demonstrate a multiuser orthogonal frequency-division multiple access passive optical network (OFDMA-PON) with source-free optical network units (ONUs), enabled by tunable optical frequency comb generation technology. By cascading a phase modulator (PM) and an intensity modulator and dynamically controlling the peak-to-peak voltage of a PM driven signal, a tunable optical frequency comb source can be generated. It is utilized to assist the configuration of a multiple source-free ONUs enhanced OFDMA-PON where simultaneous and interference-free multiuser upstream transmission over a single wavelength can be efficiently supported. The proposed multiuser OFDMA-PON is scalable and cost effective, and its feasibility is successfully verified by experiment.

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

PubMed Central

Schwendicke, Falk; Göstemeyer, Gerd

2017-01-01

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

Real-time Seizure Detection System Using Multiple Single-Neuron Recordings

DTIC Science & Technology

2001-10-25

electrodes were implanted bilaterally into the temporal lobe of each rat. The rats were anesthetized with nebutal (50mg/kg). Small craniotomies were...1997. [9] Fanselow, E.E., Reid, A.P., Nicolelis, M.A.L., Reduction of pentylenetetrazole-induced seizure activity in awake rats by seizure-triggered

Molecular epidemiology and spatiotemporal analysis of hospital-acquired Acinetobacter baumannii infection in a tertiary care hospital in southern Thailand.

PubMed

Chusri, S; Chongsuvivatwong, V; Rivera, J I; Silpapojakul, K; Singkhamanan, K; McNeil, E; Doi, Y

2017-01-01

Acinetobacter baumannii is a major hospital-acquired pathogen in Thailand that has a negative effect on patient survival. The nature of its transmission is poorly understood. To investigate the genotypic and spatiotemporal pattern of A. baumannii infection at a hospital in Thailand. The medical records of patients infected with A. baumannii at an 800-bed tertiary care hospital in southern Thailand between January 2010 and December 2011 were reviewed retrospectively. A. baumannii was identified at the genomospecies level. Carbapenemase genes were identified among carbapenem-resistant isolates associated with A. baumannii infection. A spatiotemporal analysis was performed by admission ward, time of infection and pulsed-field gel electrophoresis (PFGE) groups of A. baumannii. Nine PFGE groups were identified among the 197 A. baumannii infections. All A. baumannii isolates were assigned to International Clonal Lineage II. bla OXA-23 was the most prevalent carbapenemase gene. Outbreaks were observed mainly in respiratory and intensive care units. The association between PFGE group and hospital unit was significant. Spatiotemporal analysis identified 20 clusters of single PFGE group infections. Approximately half of the clusters involved multiple hospital units simultaneously. A. baumannii transmitted both within and between hospital wards. Better understanding and control of the transmission of A. baumannii are needed. Copyright © 2016 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

Multiple-hypothesis multiple-model line tracking

NASA Astrophysics Data System (ADS)

Pace, Donald W.; Owen, Mark W.; Cox, Henry

2000-07-01

Passive sonar signal processing generally includes tracking of narrowband and/or broadband signature components observed on a Lofargram or on a Bearing-Time-Record (BTR) display. Fielded line tracking approaches to date have been recursive and single-hypthesis-oriented Kalman- or alpha-beta filters, with no mechanism for considering tracking alternatives beyond the most recent scan of measurements. While adaptivity is often built into the filter to handle changing track dynamics, these approaches are still extensions of single target tracking solutions to multiple target tracking environment. This paper describes an application of multiple-hypothesis, multiple target tracking technology to the sonar line tracking problem. A Multiple Hypothesis Line Tracker (MHLT) is developed which retains the recursive minimum-mean-square-error tracking behavior of a Kalman Filter in a maximum-a-posteriori delayed-decision multiple hypothesis context. Multiple line track filter states are developed and maintained using the interacting multiple model (IMM) state representation. Further, the data association and assignment problem is enhanced by considering line attribute information (line bandwidth and SNR) in addition to beam/bearing and frequency fit. MHLT results on real sonar data are presented to demonstrate the benefits of the multiple hypothesis approach. The utility of the system in cluttered environments and particularly in crossing line situations is shown.

Interstage Outcomes in Infants With Single Ventricle Heart Disease Comparing Home Monitoring Technology to Three-Ring Binder Documentation: A Randomized Crossover Study.

PubMed

Bingler, Michael; Erickson, Lori A; Reid, Kimberly J; Lee, Brian; O'Brien, James; Apperson, Johnathan; Goggin, Kathy; Shirali, Girish

2018-05-01

Interstage outcomes for infants with single ventricle remain suboptimal. We have previously described a tablet PC-based platform Cardiac High Acuity Monitoring Program (CHAMP) for remote monitoring which provides immediate access to data, videos, and instant alerts to our single ventricle care team. This study compares traditional three-ring binder monitoring (Binder) to CHAMP using a randomized crossover design to evaluate mortality, resource utilization, and caregiver experience. At discharge, all single ventricle infants were monitored using Binder and randomized to receive CHAMP at either one or two months postdischarge. One month after randomization, caregivers could choose either Binder or CHAMP for the remainder of the interstage period. Caregivers experience was recorded using surveys. Enrollment included 31 single ventricle infants from May 2014 to June 2015. There was no interstage mortality over 4,911 total interstage days (median: 144/patient). Of 73 readmissions, 45 were unplanned. Of the initial 23 unplanned readmissions, 13 were found to have been based on data obtained exclusively through CHAMP (as instant alerts or based on data review) rather than caregiver concerns. Due to concerns regarding patient safety, additional enrollment was stopped. The CHAMP use was associated with significantly fewer unplanned intensive care unit days/100 interstage days, shorter delays in care, lower resource utilization at readmissions, and lower incidence of interstage growth failure and was preferred by a majority of caregivers. These findings suggest that CHAMP may offer benefits over Binder (improved interstage outcomes, delays in care, and caregiver experience). These findings should be tested across multiple centers in larger populations.

Multiple film plane diagnostic for shocked lattice measurements (invited)

NASA Astrophysics Data System (ADS)

Kalantar, Daniel H.; Bringa, E.; Caturla, M.; Colvin, J.; Lorenz, K. T.; Kumar, M.; Stölken, J.; Allen, A. M.; Rosolankova, K.; Wark, J. S.; Meyers, M. A.; Schneider, M.; Boehly, T. R.

2003-03-01

Laser-based shock experiments have been conducted in thin Si and Cu crystals at pressures above the Hugoniot elastic limit. In these experiments, static film and x-ray streak cameras recorded x rays diffracted from lattice planes both parallel and perpendicular to the shock direction. These data showed uniaxial compression of Si(100) along the shock direction and three-dimensional compression of Cu(100). In the case of the Si diffraction, there was a multiple wave structure observed, which may be due to a one-dimensional phase transition or a time variation in the shock pressure. A new film-based detector has been developed for these in situ dynamic diffraction experiments. This large-angle detector consists of three film cassettes that are positioned to record x rays diffracted from a shocked crystal anywhere within a full π steradian. It records x rays that are diffracted from multiple lattice planes both parallel and at oblique angles with respect to the shock direction. It is a time-integrating measurement, but time-resolved data may be recorded using a short duration laser pulse to create the diffraction source x rays. This new instrument has been fielded at the OMEGA and Janus lasers to study single-crystal materials shock compressed by direct laser irradiation. In these experiments, a multiple wave structure was observed on many different lattice planes in Si. These data provide information on the structure under compression.

Estimating food portions. Influence of unit number, meal type and energy density.

PubMed

Almiron-Roig, Eva; Solis-Trapala, Ivonne; Dodd, Jessica; Jebb, Susan A

2013-12-01

Estimating how much is appropriate to consume can be difficult, especially for foods presented in multiple units, those with ambiguous energy content and for snacks. This study tested the hypothesis that the number of units (single vs. multi-unit), meal type and food energy density disrupts accurate estimates of portion size. Thirty-two healthy weight men and women attended the laboratory on 3 separate occasions to assess the number of portions contained in 33 foods or beverages of varying energy density (1.7-26.8 kJ/g). Items included 12 multi-unit and 21 single unit foods; 13 were labelled "meal", 4 "drink" and 16 "snack". Departures in portion estimates from reference amounts were analysed with negative binomial regression. Overall participants tended to underestimate the number of portions displayed. Males showed greater errors in estimation than females (p=0.01). Single unit foods and those labelled as 'meal' or 'beverage' were estimated with greater error than multi-unit and 'snack' foods (p=0.02 and p<0.001 respectively). The number of portions of high energy density foods was overestimated while the number of portions of beverages and medium energy density foods were underestimated by 30-46%. In conclusion, participants tended to underestimate the reference portion size for a range of food and beverages, especially single unit foods and foods of low energy density and, unexpectedly, overestimated the reference portion of high energy density items. There is a need for better consumer education of appropriate portion sizes to aid adherence to a healthy diet. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

Single-channel recordings of RyR1 at microsecond resolution in CMOS-suspended membranes.

PubMed

Hartel, Andreas J W; Ong, Peijie; Schroeder, Indra; Giese, M Hunter; Shekar, Siddharth; Clarke, Oliver B; Zalk, Ran; Marks, Andrew R; Hendrickson, Wayne A; Shepard, Kenneth L

2018-02-20

Single-channel recordings are widely used to explore functional properties of ion channels. Typically, such recordings are performed at bandwidths of less than 10 kHz because of signal-to-noise considerations, limiting the temporal resolution available for studying fast gating dynamics to greater than 100 µs. Here we present experimental methods that directly integrate suspended lipid bilayers with high-bandwidth, low-noise transimpedance amplifiers based on complementary metal-oxide-semiconductor (CMOS) integrated circuits (IC) technology to achieve bandwidths in excess of 500 kHz and microsecond temporal resolution. We use this CMOS-integrated bilayer system to study the type 1 ryanodine receptor (RyR1), a Ca 2+ -activated intracellular Ca 2+ -release channel located on the sarcoplasmic reticulum. We are able to distinguish multiple closed states not evident with lower bandwidth recordings, suggesting the presence of an additional Ca 2+ binding site, distinct from the site responsible for activation. An extended beta distribution analysis of our high-bandwidth data can be used to infer closed state flicker events as fast as 35 ns. These events are in the range of single-file ion translocations.

Distributing digital video to multiple computers

PubMed Central

Murray, James A.

2004-01-01

Video is an effective teaching tool, and live video microscopy is especially helpful in teaching dissection techniques and the anatomy of small neural structures. Digital video equipment is more affordable now and allows easy conversion from older analog video devices. I here describe a simple technique for bringing digital video from one camera to all of the computers in a single room. This technique allows students to view and record the video from a single camera on a microscope. PMID:23493464

Optic probe for multiple angle image capture and optional stereo imaging

DOEpatents

Malone, Robert M.; Kaufman, Morris I.

2016-11-29

A probe including a multiple lens array is disclosed to measure velocity distribution of a moving surface along many lines of sight. Laser light, directed to the moving surface is reflected back from the surface and is Doppler shifted, collected into the array, and then directed to detection equipment through optic fibers. The received light is mixed with reference laser light and using photonic Doppler velocimetry, a continuous time record of the surface movement is obtained. An array of single-mode optical fibers provides an optic signal to the multiple lens array. Numerous fibers in a fiber array project numerous rays to establish many measurement points at numerous different locations. One or more lens groups may be replaced with imaging lenses so a stereo image of the moving surface can be recorded. Imaging a portion of the surface during initial travel can determine whether the surface is breaking up.

Multiple-, But Not Single-, Dose of Parecoxib Reduces Shoulder Pain after Gynecologic Laparoscopy

PubMed Central

Zhang, Hufei; Shu, Haihua; Yang, Lu; Cao, Minghui; Zhang, Jingjun; Liu, Kexuan; Xiao, Liangcan; Zhang, Xuyu

2012-01-01

Background: The aim of this study was to investigate effect of single- and multiple-dose of parecoxib on shoulder pain after gynecologic laparoscopy. Methods: 126 patients requiring elective gynecologic laparoscopy were randomly allocated to three groups. Group M (multiple-dose): receiving parecoxib 40mg at 30min before the end of surgery, at 8 and 20hr after surgery, respectively; Group S (single-dose): receiving parecoxib 40mg at 30min before the end of surgery and normal saline at the corresponding time points; Group C (control): receiving normal saline at the same three time points. The shoulder pain was evaluated, both at rest and with motion, at postoperative 6, 24 and 48hr. The impact of shoulder pain on patients' recovery (activity, mood, walking and sleep) was also evaluated. Meanwhile, rescue analgesics and complications were recorded. Results: The overall incidence of shoulder pain in group M (37.5%) was lower than that in group C (61.9%) (difference=-24.4%; 95% CI: 3.4~45.4%; P=0.023). Whereas, single-dose regimen (61.0%) showed no significant reduction (difference with control=-0.9%; 95% CI: -21.9~20.0%; P=0.931). Moreover, multiple-dose regimen reduced the maximal intensity of shoulder pain and the impact for activity and mood in comparison to the control. Multiple-dose of parecoxib decreased the consumption of rescue analgesics. The complications were similar among all groups and no severe complications were observed. Conclusions: Multiple-, but not single-, dose of parecoxib may attenuate the incidence and intensity of shoulder pain and thereby improve patients' quality of recovery following gynecologic laparoscopy. PMID:23136538

Hydra multiple head star sensor and its in-flight self-calibration of optical heads alignment

NASA Astrophysics Data System (ADS)

Majewski, L.; Blarre, L.; Perrimon, N.; Kocher, Y.; Martinez, P. E.; Dussy, S.

2017-11-01

HYDRA is EADS SODERN new product line of APS-based autonomous star trackers. The baseline is a multiple head sensor made of three separated optical heads and one electronic unit. Actually the concept which was chosen offers more than three single-head star trackers working independently. Since HYDRA merges all fields of view the result is a more accurate, more robust and completely autonomous multiple-head sensor, releasing the AOCS from the need to manage the outputs of independent single-head star trackers. Specific to the multiple head architecture and the underlying data fusion, is the calibration of the relative alignments between the sensor optical heads. The performance of the sensor is related to its estimation of such alignments. HYDRA design is first reminded in this paper along with simplification it can bring at system level (AOCS). Then self-calibration of optical heads alignment is highlighted through descriptions and simulation results, thus demonstrating the performances of a key part of HYDRA multiple-head concept.

Wavelet methodology to improve single unit isolation in primary motor cortex cells

PubMed Central

Ortiz-Rosario, Alexis; Adeli, Hojjat; Buford, John A.

2016-01-01

The proper isolation of action potentials recorded extracellularly from neural tissue is an active area of research in the fields of neuroscience and biomedical signal processing. This paper presents an isolation methodology for neural recordings using the wavelet transform (WT), a statistical thresholding scheme, and the principal component analysis (PCA) algorithm. The effectiveness of five different mother wavelets was investigated: biorthogonal, Daubachies, discrete Meyer, symmetric, and Coifman; along with three different wavelet coefficient thresholding schemes: fixed form threshold, Stein’s unbiased estimate of risk, and minimax; and two different thresholding rules: soft and hard thresholding. The signal quality was evaluated using three different statistical measures: mean-squared error, root-mean squared, and signal to noise ratio. The clustering quality was evaluated using two different statistical measures: isolation distance, and L-ratio. This research shows that the selection of the mother wavelet has a strong influence on the clustering and isolation of single unit neural activity, with the Daubachies 4 wavelet and minimax thresholding scheme performing the best. PMID:25794461

Investigation of genotype x environment interactions for weaning weight for Herefords in three countries.

PubMed

de Mattos, D; Bertrand, J K; Misztal, I

2000-08-01

The objective of this study was to investigate the possibility of genotype x environment interactions for weaning weight (WWT) between different regions of the United States (US) and between Canada (CA), Uruguay (UY), and US for populations of Hereford cattle. Original data were composed of 487,661, 102,986, and 2,322,722 edited weaning weight records from CA, UY, and US, respectively. A total of 359 sires were identified as having progeny across all three countries; 240 of them had at least one progeny with a record in each environment. The data sets within each country were reduced by retaining records from herds with more than 500 WWT records, with an average contemporary group size of greater than nine animals, and that contained WWT records from progeny or maternal grand-progeny of the across-country sires. Data sets within each country were further reduced by randomly selecting among remaining herds. Four regions within US were defined: Upper Plains (UP), Cornbelt (CB), South (S), and Gulf Coast (GC). Similar sampling criteria and common international sires were used to form the within-US regional data sets. A pairwise analysis was done between countries and regions within US (UP-CB vs S-GC, UP vs CB, and S vs GC) for the estimation of (co)variance components and genetic correlation between environments. An accelerated EM-REML algorithm and a multiple-trait animal model that considered WWT as a different trait in each environment were used to estimate parameters in each pairwise analysis. Direct and maternal (in parentheses) estimated genetic correlations for CA vs UY, CA vs US, US vs UY, UP-CB vs S-GC, UP vs CB, and S vs GC were .88 (.84), .86 (.82), .90 (.85), .88 (.87), .88 (.84), and .87 (.85), respectively. The general absence of genotype x country interactions observed in this study, together with a prior study that showed the similarity of genetic and environmental parameters across the three countries, strongly indicates that a joint WWT genetic evaluation for Hereford cattle could be conducted using a model that treated the information from CA, UY, and US as a single population using single population-wide genetic parameters.

Select spinal lesions reveal multiple ascending pathways in the rat conveying input from the male genitalia

PubMed Central

Hubscher, C H; Reed, W R; Kaddumi, E G; Armstrong, J E; Johnson, R D

2010-01-01

The specific white matter location of all the spinal pathways conveying penile input to the rostral medulla is not known. Our previous studies using rats demonstrated the loss of low but not high threshold penile inputs to medullary reticular formation (MRF) neurons after acute and chronic dorsal column (DC) lesions of the T8 spinal cord and loss of all penile inputs after lesioning the dorsal three-fifths of the cord. In the present study, select T8 lesions were made and terminal electrophysiological recordings were performed 45–60 days later in a limited portion of the nucleus reticularis gigantocellularis (Gi) and Gi pars alpha. Lesions included subtotal dorsal hemisections that spared only the lateral half of the dorsal portion of the lateral funiculus on one side, dorsal and over-dorsal hemisections, and subtotal transections that spared predominantly just the ventromedial white matter. Electrophysiological data for 448 single unit recordings obtained from 32 urethane-anaesthetized rats, when analysed in groups based upon histological lesion reconstructions, revealed (1) ascending bilateral projections in the dorsal, dorsolateral and ventrolateral white matter of the spinal cord conveying information from the male external genitalia to MRF, and (2) ascending bilateral projections in the ventrolateral white matter conveying information from the pelvic visceral organs (bladder, descending colon, urethra) to MRF. Multiple spinal pathways from the penis to the MRF may correspond to different functions, including those processing affective/pleasure/motivational, nociception, and mating-specific (such as for erection and ejaculation) inputs. PMID:20142271

Validating silicon polytrodes with paired juxtacellular recordings: method and dataset

PubMed Central

Lopes, Gonçalo; Frazão, João; Nogueira, Joana; Lacerda, Pedro; Baião, Pedro; Aarts, Arno; Andrei, Alexandru; Musa, Silke; Fortunato, Elvira; Barquinha, Pedro; Kampff, Adam R.

2016-01-01

Cross-validating new methods for recording neural activity is necessary to accurately interpret and compare the signals they measure. Here we describe a procedure for precisely aligning two probes for in vivo “paired-recordings” such that the spiking activity of a single neuron is monitored with both a dense extracellular silicon polytrode and a juxtacellular micropipette. Our new method allows for efficient, reliable, and automated guidance of both probes to the same neural structure with micrometer resolution. We also describe a new dataset of paired-recordings, which is available online. We propose that our novel targeting system, and ever expanding cross-validation dataset, will be vital to the development of new algorithms for automatically detecting/sorting single-units, characterizing new electrode materials/designs, and resolving nagging questions regarding the origin and nature of extracellular neural signals. PMID:27306671

Estimating Uncertainty in Long Term Total Ozone Records from Multiple Sources

NASA Technical Reports Server (NTRS)

Frith, Stacey M.; Stolarski, Richard S.; Kramarova, Natalya; McPeters, Richard D.

2014-01-01

Total ozone measurements derived from the TOMS and SBUV backscattered solar UV instrument series cover the period from late 1978 to the present. As the SBUV series of instruments comes to an end, we look to the 10 years of data from the AURA Ozone Monitoring Instrument (OMI) and two years of data from the Ozone Mapping Profiler Suite (OMPS) on board the Suomi National Polar-orbiting Partnership satellite to continue the record. When combining these records to construct a single long-term data set for analysis we must estimate the uncertainty in the record resulting from potential biases and drifts in the individual measurement records. In this study we present a Monte Carlo analysis used to estimate uncertainties in the Merged Ozone Dataset (MOD), constructed from the Version 8.6 SBUV2 series of instruments. We extend this analysis to incorporate OMI and OMPS total ozone data into the record and investigate the impact of multiple overlapping measurements on the estimated error. We also present an updated column ozone trend analysis and compare the size of statistical error (error from variability not explained by our linear regression model) to that from instrument uncertainty.

The influence of multiple ownership interests and decision-making networks on the management of family forest lands: evidence from the United States

Treesearch

Stephanie A. Snyder; Michael A. Kilgore

2018-01-01

A national assessment of how the number of parcel owners influence family forest land management and use decisions in the US was conducted using a subset of the US Forest Service's National Woodland Owner Survey Dataset. Seventy-two percent of single parcel family forest land ownership respondents of at least 4.05 ha had multiple owners. The extent to which past...

Dose rate effect on micronuclei induction in human blood lymphocytes exposed to single pulse and multiple pulses of electrons.

PubMed

Acharya, Santhosh; Bhat, N N; Joseph, Praveen; Sanjeev, Ganesh; Sreedevi, B; Narayana, Y

2011-05-01

The effects of single pulses and multiple pulses of 7 MV electrons on micronuclei (MN) induction in cytokinesis-blocked human peripheral blood lymphocytes (PBLs) were investigated over a wide range of dose rates per pulse (instantaneous dose rate). PBLs were exposed to graded doses of 2, 3, 4, 6, and 8 Gy of single electron pulses of varying pulse widths at different dose rates per pulse, ranging from 1 × 10(6) Gy s(-1) to 3.2 × 10(8) Gy s(-1). Different dose rates per pulse were achieved by changing the dose per electron pulse by adjusting the beam current and pulse width. MN yields per unit absorbed dose after irradiation with single electron pulses were compared with those of multiple pulses of electrons. A significant decrease in the MN yield with increasing dose rates per pulse was observed, when dose was delivered by a single electron pulse. However, no reduction in the MN yield was observed when dose was delivered by multiple pulses of electrons. The decrease in the yield at high dose rates per pulse suggests possible radical recombination, which leads to decreased biological damage. Cellular response to the presence of very large numbers of chromosomal breaks may also alter the damage.

Variability of wildland fire emissions across the contiguous United States

Treesearch

YongQiang Liu

2004-01-01

This study analyzes spatial and temporal variability of emissions from wildland fires across the contiguous US. The emissions are estimates based on a recently constructed dataset of historical fire records collected by multiple US governlnental agencies. Both wildfire and prescribed fires have the highest emissions over the Pacific coastal states. Prescribed fire...

Multidose Botulinum Toxin A for Intralaryngeal Injection: A Cost Analysis.

PubMed

Gilbert, Mark R; Young, VyVy N; Smith, Libby J; Rosen, Clark A

2018-01-04

Botulinum toxin A (BtxA) injection is the mainstay treatment for laryngeal dystonias. BtxA product labeling states that reconstituted toxin should be used within 4 hours on a single patient despite several studies that have demonstrated multidose BtxA to be safe and effective. Many insurance carriers mandate the use of an outside pharmacy which necessitates a single-use approach. This study compares the cost savings of multidose BtxA for laryngeal dystonia compared to single-use. This is a retrospective review and projected cost savings analysis. Records and billing information were reviewed for patients receiving BtxA for intralaryngeal injection at a single laryngology division in 2015. Inclusion criteria included CPT 64617 or J0585; exclusion criteria included CPT 64616. The price of BtxA 100 unit vial for calculation was $670. A total of 142 patients were seen for intralaryngeal BtxA injection resulting in 337 visits over 1 year. The average BtxA dose per visit was 2.86 units with an average of 3.06 procedure visits per year. The calculated cost of BtxA treatment using a single vial approach was found to be $2,050 per patient per year. If billed instead for $7/unit with 5 units wastage charge per visit, the yearly per patient charge is $168. Single vial-use of BtxA injection thus represents a 1,118% price increase versus multidose use. When estimated for yearly prevalence of spasmodic dysphonia, multidose BtxA use would save almost $100 million annually. Multidose botulinum toxin A application utilizing per unit billing is significantly less expensive than per single-use vial billing and would save the health-care system significant amount of money without any sacrifice in safety or effectiveness. Copyright © 2018. Published by Elsevier Inc.

Multiple versus single virus respiratory infections: viral load and clinical disease severity in hospitalized children

PubMed Central

Martin, Emily T.; Kuypers, Jane; Wald, Anna; Englund, Janet A.

2011-01-01

Please cite this paper as: Martin et al. (2012) Multiple versus single virus respiratory infections: viral load and clinical disease severity in hospitalized children. Influenza and Other Respiratory Viruses 6(1), 71–77. Background  Molecular testing for viral pathogens has resulted in increasing detection of multiple viruses in respiratory secretions of ill children. The clinical impact of multiple virus infections on clinical presentation and outcome is unclear. Objectives  To compare clinical characteristics and viral load between children with multiple virus versus single virus illnesses. Patients/methods  Eight hundred and ninety‐three residual nasal wash samples from children treated for respiratory illness at Children’s Hospital, Seattle, from September 2003 to September 2004 were evaluated by quantitative PCR for respiratory syncytial virus (RSV), human metapneumovirus (hMPV), influenza (Flu), parainfluenza, adenoviruses, and coronaviruses (CoV). Illness severity and patient characteristics were abstracted from medical charts. Results  Coinfections were identified in 103 (18%) of 566 virus‐positive samples. Adenovirus was most commonly detected in coinfections (52%), followed by CoV (50%). Illnesses with a single virus had increased risk of oxygen requirement (P = 0·02), extended hospital stays (P = 0·002), and admissions to the inpatient (P = 0·02) or intensive care units (P = 0·04). For Adv and PIV‐1, multiple virus illnesses had a significantly lower viral load (log10 copies/ml) than single virus illnesses (4·2 versus 5·6, P = 0·007 and 4·2 versus 6·9, P < 0·001, respectively). RSV, Flu‐A, PIV‐3, and hMPV viral loads were consistently high whether or not another virus was detected. Conclusions  Illnesses with multiple virus detections were correlated with less severe disease. The relationship between viral load and multiple virus infections was virus specific, and this may serve as a way to differentiate viruses in multiple virus infections. PMID:21668660

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

None, None

The most common method of measuring air leakage is to perform single (or solo) blower door pressurization and/or depressurization test. In detached housing, the single blower door test measures leakage to the outside. In attached housing, however, this "solo" test method measures both air leakage to the outside and air leakage between adjacent units through common surfaces. Although minimizing leakage to neighboring units is highly recommended to avoid indoor air quality issues between units, reduce pressure differentials between units, and control stack effect, the energy benefits of air sealing can be significantly overpredicted if the solo air leakage number ismore » used in the energy analysis. Guarded blower door testing is more appropriate for isolating and measuring leakage to the outside in attached housing. This method uses multiple blower doors to depressurize adjacent spaces to the same level as the unit being tested. Maintaining a neutral pressure across common walls, ceilings, and floors acts as a "guard" against air leakage between units. The resulting measured air leakage in the test unit is only air leakage to the outside. Although preferred for assessing energy impacts, the challenges of performing guarded testing can be daunting.« less

LFPy: a tool for biophysical simulation of extracellular potentials generated by detailed model neurons.

PubMed

Lindén, Henrik; Hagen, Espen; Lęski, Szymon; Norheim, Eivind S; Pettersen, Klas H; Einevoll, Gaute T

2013-01-01

Electrical extracellular recordings, i.e., recordings of the electrical potentials in the extracellular medium between cells, have been a main work-horse in electrophysiology for almost a century. The high-frequency part of the signal (≳500 Hz), i.e., the multi-unit activity (MUA), contains information about the firing of action potentials in surrounding neurons, while the low-frequency part, the local field potential (LFP), contains information about how these neurons integrate synaptic inputs. As the recorded extracellular signals arise from multiple neural processes, their interpretation is typically ambiguous and difficult. Fortunately, a precise biophysical modeling scheme linking activity at the cellular level and the recorded signal has been established: the extracellular potential can be calculated as a weighted sum of all transmembrane currents in all cells located in the vicinity of the electrode. This computational scheme can considerably aid the modeling and analysis of MUA and LFP signals. Here, we describe LFPy, an open source Python package for numerical simulations of extracellular potentials. LFPy consists of a set of easy-to-use classes for defining cells, synapses and recording electrodes as Python objects, implementing this biophysical modeling scheme. It runs on top of the widely used NEURON simulation environment, which allows for flexible usage of both new and existing cell models. Further, calculation of extracellular potentials using the line-source-method is efficiently implemented. We describe the theoretical framework underlying the extracellular potential calculations and illustrate by examples how LFPy can be used both for simulating LFPs, i.e., synaptic contributions from single cells as well a populations of cells, and MUAs, i.e., extracellular signatures of action potentials.

Vegetation change and pollen geochronology from the Atlantic Coast of the United States during the last Millennium

NASA Astrophysics Data System (ADS)

Christie, M.; Bernhardt, C. E.; Clear, J.; Corbett, D. R.; Horton, B.

2017-12-01

Vegetation changes related to anthropogenic and climatic change have been reconstructed at many locations. Synthesizing observations from multiple locations improves our understanding of the regionality of these impacts and drivers. Human alterations to the plant communities vary spatially in timing and impact. For example, deforestation occurred at different times, rates, and magnitudes along the Atlantic Coast of the United States, while of the introduction of non-native plants into ecosystems varies by region. Gradual climate shifts cause the appearance of migration in sensitive plants, so climate-related transitions can be traced from one location to another. Here, we combine new and published pollen data from Florida to Connecticut to produce a regional synthesis of vegetation changes for the last 1000 years. We have produced detailed reconstructions of vegetation changes in response to anthropogenic and climatic forcing. Our database contains pollen assemblages from more than 10 locations along the Atlantic coast of the United States, including new reconstructions from the Florida Keys, Delaware Estuary, and northern New Jersey. All pollen assemblages are placed in a geochronological framework with as fine as decadal resolution using composite chronologies of radiocarbon, pollution histories and cesium isotopes. Anthropogenic impacts, including deforestation from European settlement and the introduction of non-native plants, are observed in the pollen record and serve as useful markers of time. For example, the abrupt increase in Ambrosia pollen in the mid-Atlantic corresponds to 18th Century deforestation. Climate transitions that can be seen in the pollen record during the last millennium include the Medieval Climate Optimum, Little Ice Age, and human-induced warming following industrialization in the 20th century. Plant communities of the United States Atlantic Coast adapted to the evolving climate. For example, Picea and Tsuga are indicative of cooler, moister conditions and disappear from regions as conditions become warmer or drier. We combine the various histories of vegetation change from pollen assemblages into a single source for researchers to use when attempting to understand geochronology and impacts of climate change along the Atlantic coast of the United States.

Overestimation of infant and toddler energy intake by 24-h recall compared with weighed food records.

PubMed

Fisher, Jennifer O; Butte, Nancy F; Mendoza, Patricia M; Wilson, Theresa A; Hodges, Eric A; Reidy, Kathleen C; Deming, Denise

2008-08-01

Twenty-four-hour dietary recalls have been used in large surveys of infant and toddler energy intake, but the accuracy of the method for young children is not well documented. We aimed to determine the accuracy of infant and toddler energy intakes by a single, telephone-administered, multiple-pass 24-h recall as compared with 3-d weighed food records. A within-subjects design was used in which a 24-h recall and 3-d weighed food records were completed within 2 wk by 157 mothers (56 non-Hispanic white, 51 non-Hispanic black, and 50 Hispanic) of 7-11-mo-old infants or 12-24-mo-old toddlers. Child and caregiver anthropometrics, child eating patterns, and caregiver demographics and social desirability were evaluated as correlates of reporting bias. Intakes based on 3-d weighed food records were within 5% of estimated energy requirements. Compared with the 3-d weighed food records, the 24-h recall overestimated energy intake by 13% among infants (740 +/- 154 and 833 +/- 255 kcal, respectively) and by 29% among toddlers (885 +/- 197 and 1140 +/- 299 kcal, respectively). Eating patterns (ie, frequency and location) did not differ appreciably between methods. Macronutrient and micronutrient intakes were higher by 24-h recall than by 3-d weighed food record. Dairy and grains contributed the most energy to the diet and accounted for 74% and 54% of the overestimation seen in infants and toddlers, respectively. Greater overestimation was associated with a greater number of food items reported by the caregiver and lower child weight-for-length z scores. The use of a single, telephone-administered, multiple-pass 24-h recall may significantly overestimate infant or toddler energy and nutrient intakes because of portion size estimation errors.

Accelerating the Gillespie Exact Stochastic Simulation Algorithm using hybrid parallel execution on graphics processing units.

PubMed

Komarov, Ivan; D'Souza, Roshan M

2012-01-01

The Gillespie Stochastic Simulation Algorithm (GSSA) and its variants are cornerstone techniques to simulate reaction kinetics in situations where the concentration of the reactant is too low to allow deterministic techniques such as differential equations. The inherent limitations of the GSSA include the time required for executing a single run and the need for multiple runs for parameter sweep exercises due to the stochastic nature of the simulation. Even very efficient variants of GSSA are prohibitively expensive to compute and perform parameter sweeps. Here we present a novel variant of the exact GSSA that is amenable to acceleration by using graphics processing units (GPUs). We parallelize the execution of a single realization across threads in a warp (fine-grained parallelism). A warp is a collection of threads that are executed synchronously on a single multi-processor. Warps executing in parallel on different multi-processors (coarse-grained parallelism) simultaneously generate multiple trajectories. Novel data-structures and algorithms reduce memory traffic, which is the bottleneck in computing the GSSA. Our benchmarks show an 8×-120× performance gain over various state-of-the-art serial algorithms when simulating different types of models.

How many neurons can we see with current spike sorting algorithms?

PubMed

Pedreira, Carlos; Martinez, Juan; Ison, Matias J; Quian Quiroga, Rodrigo

2012-10-15

Recent studies highlighted the disagreement between the typical number of neurons observed with extracellular recordings and the ones to be expected based on anatomical and physiological considerations. This disagreement has been mainly attributed to the presence of sparsely firing neurons. However, it is also possible that this is due to limitations of the spike sorting algorithms used to process the data. To address this issue, we used realistic simulations of extracellular recordings and found a relatively poor spike sorting performance for simulations containing a large number of neurons. In fact, the number of correctly identified neurons for single-channel recordings showed an asymptotic behavior saturating at about 8-10 units, when up to 20 units were present in the data. This performance was significantly poorer for neurons with low firing rates, as these units were twice more likely to be missed than the ones with high firing rates in simulations containing many neurons. These results uncover one of the main reasons for the relatively low number of neurons found in extracellular recording and also stress the importance of further developments of spike sorting algorithms. Copyright © 2012 Elsevier B.V. All rights reserved.

Motor unit size estimation: confrontation of surface EMG with macro EMG.

PubMed

Roeleveld, K; Stegeman, D F; Falck, B; Stålberg, E V

1997-06-01

Surface EMG (SEMG) is little used for diagnostic purposes in clinical neurophysiology, mainly because it provides little direct information on individual motor units (MUs). One of the techniques to estimate the MU size is intra-muscular Macro EMG. The present study compares SEMG with Macro EMG. Fifty-eight channel SEMG was recorded simultaneously with Macro EMG. Individual MUPs were obtained by single fiber triggered averaging. All recordings were made from the biceps brachii of healthy subjects during voluntary contraction at low force. High positive correlations were found between all Macro and Surface motor unit potential (MUP) parameters: area, peak-to-peak amplitude, negative peak amplitude and positive peak amplitude. The MUPs recorded with SEMG were dependent on the distance between the MU and the skin surface. Normalizing the SEMG parameters for MU location did not improve the correlation coefficient between the parameters of both techniques. The two measurement techniques had almost the same relative range in MUP parameters in any individual subject compared to the others, especially after normalizing the surface MUP parameters for MU location. MUPs recorded with this type of SEMG provide useful information about the MU size.

Fatigue reduction during aggregated and distributed sequential stimulation.

PubMed

Bergquist, Austin J; Babbar, Vishvek; Ali, Saima; Popovic, Milos R; Masani, Kei

2017-08-01

Transcutaneous neuromuscular electrical stimulation (NMES) can generate muscle contractions for rehabilitation and exercise. However, NMES-evoked contractions are limited by fatigue when they are delivered "conventionally" (CONV) using a single active electrode. Researchers have developed "sequential" (SEQ) stimulation, involving rotation of pulses between multiple "aggregated" (AGGR-SEQ) or "distributed" (DISTR-SEQ) active electrodes, to reduce fatigue (torque-decline) by reducing motor unit discharge rates. The primary objective was to compare fatigue-related outcomes, "potentiation," "variability," and "efficiency" between CONV, AGGR-SEQ, and DISTR-SEQ stimulation of knee extensors in healthy participants. Torque and current were recorded during testing with fatiguing trains using each NMES type under isometric and isokinetic (180°/s) conditions. Compared with CONV stimulation, SEQ techniques reduced fatigue-related outcomes, increased potentiation, did not affect variability, and reduced efficiency. SEQ techniques hold promise for reducing fatigue during NMES-based rehabilitation and exercise; however, optimization is required to improve efficiency. Muscle Nerve 56: 271-281, 2017. © 2016 Wiley Periodicals, Inc.

A Fully Automated Approach to Spike Sorting.

PubMed

Chung, Jason E; Magland, Jeremy F; Barnett, Alex H; Tolosa, Vanessa M; Tooker, Angela C; Lee, Kye Y; Shah, Kedar G; Felix, Sarah H; Frank, Loren M; Greengard, Leslie F

2017-09-13

Understanding the detailed dynamics of neuronal networks will require the simultaneous measurement of spike trains from hundreds of neurons (or more). Currently, approaches to extracting spike times and labels from raw data are time consuming, lack standardization, and involve manual intervention, making it difficult to maintain data provenance and assess the quality of scientific results. Here, we describe an automated clustering approach and associated software package that addresses these problems and provides novel cluster quality metrics. We show that our approach has accuracy comparable to or exceeding that achieved using manual or semi-manual techniques with desktop central processing unit (CPU) runtimes faster than acquisition time for up to hundreds of electrodes. Moreover, a single choice of parameters in the algorithm is effective for a variety of electrode geometries and across multiple brain regions. This algorithm has the potential to enable reproducible and automated spike sorting of larger scale recordings than is currently possible. Copyright © 2017 Elsevier Inc. All rights reserved.

Surface Dimming by the 2013 Rim Fire Simulated by a Sectional Aerosol Model

NASA Technical Reports Server (NTRS)

Yu, Pengfei; Toon, Owen B.; Bardeen, Charles G; Bucholtz, Anthony; Rosenlof, Karen; Saide, Pablo E.; Da Silva, Arlindo M.; Ziemba, Luke D.; Thornhill, Kenneth L.; Jimenez, Jose-Luis;

Surface dimming by the 2013 Rim Fire simulated by a sectional aerosol model.

PubMed

Yu, Pengfei; Toon, Owen B; Bardeen, Charles G; Bucholtz, Anthony; Rosenlof, Karen H; Saide, Pablo E; Da Silva, Arlindo; Ziemba, Luke D; Thornhill, Kenneth L; Jimenez, Jose-Luis; Campuzano-Jost, Pedro; Schwarz, Joshua P; Perring, Anne E; Froyd, Karl D; Wagner, N L; Mills, Michael J; Reid, Jeffrey S

2016-06-27

The Rim Fire of 2013, the third largest area burned by fire recorded in California history, is simulated by a climate model coupled with a size-resolved aerosol model. Modeled aerosol mass, number, and particle size distribution are within variability of data obtained from multiple-airborne in situ measurements. Simulations suggest that Rim Fire smoke may block 4-6% of sunlight energy reaching the surface, with a dimming efficiency around 120-150 W m -2 per unit aerosol optical depth in the midvisible at 13:00-15:00 local time. Underestimation of simulated smoke single scattering albedo at midvisible by 0.04 suggests that the model overestimates either the particle size or the absorption due to black carbon. This study shows that exceptional events like the 2013 Rim Fire can be simulated by a climate model with 1° resolution with overall good skill, although that resolution is still not sufficient to resolve the smoke peak near the source region.

Frequency-Domain Tomography for Single-shot, Ultrafast Imaging of Evolving Laser-Plasma Accelerators

NASA Astrophysics Data System (ADS)

Li, Zhengyan; Zgadzaj, Rafal; Wang, Xiaoming; Downer, Michael

2011-10-01

Intense laser pulses propagating through plasma create plasma wakefields that often evolve significantly, e.g. by expanding and contracting. However, such dynamics are known in detail only through intensive simulations. Laboratory visualization of evolving plasma wakes in the ``bubble'' regime is important for optimizing and scaling laser-plasma accelerators. Recently snap-shots of quasi-static wakes were recorded using frequency-domain holography (FDH). To visualize the wake's evolution, we have generalized FDH to frequency-domain tomography (FDT), which uses multiple probes propagating at different angles with respect to the pump pulse. Each probe records a phase streak, imprinting a partial record of the evolution of pump-created structures. We then topographically reconstruct the full evolution from all phase streaks. To prove the concept, a prototype experiment visualizing nonlinear index evolution in glass is demonstrated. Four probes propagating at 0, 0.6, 2, 14 degrees to the index ``bubble'' are angularly and temporally multiplexed to a single spectrometer to achieve cost-effective FDT. From these four phase streaks, an FDT algorithm analogous to conventional CT yields a single-shot movie of the pump's self-focusing dynamics.

Technology as friend or foe? Do electronic health records increase burnout?

PubMed

Ehrenfeld, Jesse M; Wanderer, Jonathan P

2018-06-01

To summarize recent relevant studies regarding the use of electronic health records and physician burnout. Recently acquired knowledge regarding the relationship between electronic health record use, professional satisfaction, burnout, and desire to leave clinical practice are discussed. Adoption of electronic health records has increased across the United States and worldwide. Although electronic health records have many benefits, there is growing concern about the adverse consequences of their use on physician satisfaction and burnout. Poor usability, incongruent workflows, and the addition of clerical tasks to physician documentation requirements have been previously highlighted as ongoing concerns with electronic health record adoption. In multiple recent studies, electronic health records have been shown to decrease professional satisfaction, increase burnout, and the likelihood that a physician will reduce or leave clinical practice. One interventional study demonstrated a positive effect of a dedicated electronic health record entry clerk on physicians working in an outpatient practice.

Clinical outcome of single plastic stent treatment of benign iatrogenic biliary strictures: is the outcome predetermined?

PubMed

Rajab, Murad A; Go, Jorge; Silverman, William B

2014-12-01

Endoscopic retrograde cholangiopancreatography (ERCP) is used for the management of benign iatrogenic biliary strictures after cholecystectomy and liver transplantation. Multiple stents can injure biliary circulation. If resolution of reversible ductal edema and/or ischemia is the mechanism for successful therapy then single stent placement for benign biliary stricture should work. Retrospectively reviewed ERCP records between November 1999 and 2012 provided 25 patients with repeat ERCPs performed at 10-week intervals or if symptoms of stent occlusion were present. If strictures did not improve between stent changes and if removal was not an option, hepaticojejunostomy was used. Strictures resolved in 72% of patients. Seven patients underwent hepaticojejunostomy. Three had ERCP-related complications. No stricture recurrence occurred during the follow-up period. Endoscopic single plastic stent treatment of benign biliary iatrogenic strictures has comparable success to multiple stenting. Many postsurgical strictures may have reversible ischemic/edematous component with stenting to maintain bile drainage.

Diversity of coding profiles of mechanoreceptors in glabrous skin of kittens.

PubMed

Gibson, J M; Beitel, R E; Welker, W

1975-03-21

We examined stimulul-response (S-R) profiles of 35 single mechanoreceptive afferent units having small receptive fields in glabrous forepaw skin of 24 anesthetized domestic kittens. Single unit activity was recorded with tungsten microelectrodes from cervical dorsal root ganglia. The study was designed to be as quantitatively descriptive as possible. We indented each unit's receptive field with a broad battery of simple, carefully controlled stimuli whose major parameters, including amplitude, velocity, acceleration, duration, and interstimulus interval were systematically varied. Stimuli were delivered by a small probe driven by a feedback-controlled axial displacement generator. Single unit discharge data were analyzed by a variety of direct and derived measures including dot patterns, peristimulus histograms, instantaneous and mean instantaneous firing rates, tuning curves, thresholds for amplitude and velocity, adaptation rates, dynamic and static sensitivities, and others. We found that with respect to any of the S-R transactions examined, the properties of our sample of units were continuously and broadly distributed. Any one unit might exhibit either a slow or rapid rate of adaptation, or might superficially appear to preferentially code a single stimulus parameter such as amplitude or velocity. But when the entire range of responsiveness of units to the entire stimulus battery was surveyed by a variety of analytic techniques, we were unable to find any justifiable basis for designation of discrete categories of S-R profiles. Intermediate response types were always found, and in general, all units were both broadly tuned and capable of responding to integrals of several stimulus parameters, our data argue against the usefulness of evaluating a unit's S-R coding capabilities by means of a limited ste of stimulation of response analysis procedures.

Encoding of speed and direction of movement in the human supplementary motor area

PubMed Central

Tankus, Ariel; Yeshurun, Yehezkel; Flash, Tamar; Fried, Itzhak

2010-01-01

Object The supplementary motor area (SMA) plays an important role in planning, initiation, and execution of motor acts. Patients with SMA lesions are impaired in various kinematic parameters, such as velocity and duration of movement. However, the relationships between neuronal activity and these parameters in the human brain have not been fully characterized. This is a study of single-neuron activity during a continuous volitional motor task, with the goal of clarifying these relationships for SMA neurons and other frontal lobe regions in humans. Methods The participants were 7 patients undergoing evaluation for epilepsy surgery requiring implantation of intracranial depth electrodes. Single-unit recordings were conducted while the patients played a computer game involving movement of a cursor in a simple maze. Results In the SMA proper, most of the recorded units exhibited a monotonic relationship between the unit firing rate and hand motion speed. The vast majority of SMA proper units with this property showed an inverse relation, that is, firing rate decrease with speed increase. In addition, most of the SMA proper units were selective to the direction of hand motion. These relationships were far less frequent in the pre-SMA, anterior cingulate gyrus, and orbitofrontal cortex. Conclusions The findings suggest that the SMA proper takes part in the control of kinematic parameters of end-effector motion, and thus lend support to the idea of connecting neuroprosthetic devices to the human SMA. PMID:19231930

Automatic Rejection Of Multimode Laser Pulses

NASA Technical Reports Server (NTRS)

Tratt, David M.; Menzies, Robert T.; Esproles, Carlos

1991-01-01

Characteristic modulation detected, enabling rejection of multimode signals. Monitoring circuit senses multiple longitudinal mode oscillation of transversely excited, atmospheric-pressure (TEA) CO2 laser. Facility developed for inclusion into coherent detection laser radar (LIDAR) system. However, circuit described of use in any experiment where desireable to record data only when laser operates in single longitudinal mode.

Automatic Word Sense Disambiguation of Acronyms and Abbreviations in Clinical Texts

ERIC Educational Resources Information Center

Moon, Sungrim

2012-01-01

The use of acronyms and abbreviations is increasing profoundly in the clinical domain in large part due to the greater adoption of electronic health record (EHR) systems and increased electronic documentation within healthcare. A single acronym or abbreviation may have multiple different meanings or senses. Comprehending the proper meaning of an…

Achieving Consistent Multiple Daily Low-Dose Bacillus anthracis Spore Inhalation Exposures in the Rabbit Model

PubMed Central

Barnewall, Roy E.; Comer, Jason E.; Miller, Brian D.; Gutting, Bradford W.; Wolfe, Daniel N.; Director-Myska, Alison E.; Nichols, Tonya L.; Taft, Sarah C.

2012-01-01

Repeated low-level exposures to biological agents could occur before or after the remediation of an environmental release. This is especially true for persistent agents such as B. anthracis spores, the causative agent of anthrax. Studies were conducted to examine aerosol methods needed for consistent daily low aerosol concentrations to deliver a low-dose (less than 106 colony forming units (CFU) of B. anthracis spores) and included a pilot feasibility characterization study, acute exposure study, and a multiple 15 day exposure study. This manuscript focuses on the state-of-the-science aerosol methodologies used to generate and aerosolize consistent daily low aerosol concentrations and resultant low inhalation doses to rabbits. The pilot feasibility characterization study determined that the aerosol system was consistent and capable of producing very low aerosol concentrations. In the acute, single day exposure experiment, targeted inhaled doses of 1 × 102, 1 × 103, 1 × 104, and 1 × 105 CFU were used. In the multiple daily exposure experiment, rabbits were exposed multiple days to targeted inhaled doses of 1 × 102, 1 × 103, and 1 × 104 CFU. In all studies, targeted inhaled doses remained consistent from rabbit-to-rabbit and day-to-day. The aerosol system produced aerosolized spores within the optimal mass median aerodynamic diameter particle size range to reach deep lung alveoli. Consistency of the inhaled dose was aided by monitoring and recording respiratory parameters during the exposure with real-time plethysmography. Overall, the presented results show that the animal aerosol system was stable and highly reproducible between different studies and over multiple exposure days. PMID:22919662

Chronic In Vivo Stability Assessment of Carbon Fiber Microelectrode Arrays

PubMed Central

Patel, Paras R.; Zhang, Huanan; Robbins, Matthew T.; Nofar, Justin B.; Marshall, Shaun P.; Kobylarek, Michael J.; Kozai, Takashi D. Y.; Kotov, Nicholas A.; Chestek, Cynthia A.

2016-01-01

Objective Individual carbon fiber microelectrodes can record unit activity in both acute and semi-chronic (∼1 month) implants. Additionally, new methods have been developed to insert a 16 channel array of carbon fiber microelectrodes. Before assessing the in vivo long-term viability of these arrays, accelerated soak tests were carried out to determine the most stable site coating material. Next, a multi-animal, multi-month, chronic implantation study was carried out with carbon fiber microelectrode arrays and silicon electrodes. Approach Carbon fibers were first functionalized with one of two different formulations of PEDOT and subjected to accelerated aging in a heated water bath. After determining the best PEDOT formula to use, carbon fiber arrays were chronically implanted in rat motor cortex. Some rodents were also implanted with a single silicon electrode, while others received both. At the end of the study a subset of animals were perfused and the brain tissue sliced. Tissue sections were stained for astrocytes, microglia, and neurons. The local reactive responses were assessed using qualitative and quantitative methods. Main results Electrophysiology recordings showed the carbon fibers detecting unit activity for at least 3 months with average amplitudes of ∼200 μV. Histology analysis showed the carbon fiber arrays with a minimal to non-existent glial scarring response with no adverse effects on neuronal density. Silicon electrodes showed large glial scarring that impacted neuronal counts. Significance This study has validated the use of carbon fiber microelectrode arrays as a chronic neural recording technology. These electrodes have demonstrated the ability to detect single units with high amplitude over 3 months, and show the potential to record for even longer periods. In addition, the minimal reactive response should hold stable indefinitely, as any response by the immune system may reach a steady state after 12 weeks. PMID:27705958

Chronic in vivo stability assessment of carbon fiber microelectrode arrays

NASA Astrophysics Data System (ADS)

Patel, Paras R.; Zhang, Huanan; Robbins, Matthew T.; Nofar, Justin B.; Marshall, Shaun P.; Kobylarek, Michael J.; Kozai, Takashi D. Y.; Kotov, Nicholas A.; Chestek, Cynthia A.

2016-12-01

Objective. Individual carbon fiber microelectrodes can record unit activity in both acute and semi-chronic (∼1 month) implants. Additionally, new methods have been developed to insert a 16 channel array of carbon fiber microelectrodes. Before assessing the in vivo long-term viability of these arrays, accelerated soak tests were carried out to determine the most stable site coating material. Next, a multi-animal, multi-month, chronic implantation study was carried out with carbon fiber microelectrode arrays and silicon electrodes. Approach. Carbon fibers were first functionalized with one of two different formulations of PEDOT and subjected to accelerated aging in a heated water bath. After determining the best PEDOT formula to use, carbon fiber arrays were chronically implanted in rat motor cortex. Some rodents were also implanted with a single silicon electrode, while others received both. At the end of the study a subset of animals were perfused and the brain tissue sliced. Tissue sections were stained for astrocytes, microglia, and neurons. The local reactive responses were assessed using qualitative and quantitative methods. Main results. Electrophysiology recordings showed the carbon fibers detecting unit activity for at least 3 months with average amplitudes of ∼200 μV. Histology analysis showed the carbon fiber arrays with a minimal to non-existent glial scarring response with no adverse effects on neuronal density. Silicon electrodes showed large glial scarring that impacted neuronal counts. Significance. This study has validated the use of carbon fiber microelectrode arrays as a chronic neural recording technology. These electrodes have demonstrated the ability to detect single units with high amplitude over 3 months, and show the potential to record for even longer periods. In addition, the minimal reactive response should hold stable indefinitely, as any response by the immune system may reach a steady state after 12 weeks.

Chronic recording of regenerating VIIIth nerve axons with a sieve electrode

NASA Technical Reports Server (NTRS)

Mensinger, A. F.; Anderson, D. J.; Buchko, C. J.; Johnson, M. A.; Martin, D. C.; Tresco, P. A.; Silver, R. B.; Highstein, S. M.

2000-01-01

A micromachined silicon substrate sieve electrode was implanted within transected toadfish (Opsanus tau) otolith nerves. High fidelity, single unit neural activity was recorded from seven alert and unrestrained fish 30 to 60 days after implantation. Fibrous coatings of genetically engineered bioactive protein polymers and nerve guide tubes increased the number of axons regenerating through the electrode pores when compared with controls. Sieve electrodes have potential as permanent interfaces to the nervous system and to bridge missing connections between severed or damaged nerves and muscles. Recorded impulses might also be amplified and used to control prosthetic devices.

One Small Step for a Man: Estimation of Gender, Age and Height from Recordings of One Step by a Single Inertial Sensor

PubMed Central

Riaz, Qaiser; Vögele, Anna; Krüger, Björn; Weber, Andreas

2015-01-01

A number of previous works have shown that information about a subject is encoded in sparse kinematic information, such as the one revealed by so-called point light walkers. With the work at hand, we extend these results to classifications of soft biometrics from inertial sensor recordings at a single body location from a single step. We recorded accelerations and angular velocities of 26 subjects using integrated measurement units (IMUs) attached at four locations (chest, lower back, right wrist and left ankle) when performing standardized gait tasks. The collected data were segmented into individual walking steps. We trained random forest classifiers in order to estimate soft biometrics (gender, age and height). We applied two different validation methods to the process, 10-fold cross-validation and subject-wise cross-validation. For all three classification tasks, we achieve high accuracy values for all four sensor locations. From these results, we can conclude that the data of a single walking step (6D: accelerations and angular velocities) allow for a robust estimation of the gender, height and age of a person. PMID:26703601

An ambulatory recording system for the assessment of autonomic changes across multiple days

NASA Astrophysics Data System (ADS)

Sollers, John J., III; Yonezawa, Yoshiharu; Silver, Rebecca A.; Merritt, Marcellus M.; Thayer, Julian F.

2005-05-01

Recent evidence indicates that poor autonomic regulation, indexed by decreased heart period variability (HPV), is associated with decreased working memory. HPV analyses are computed on the interbeat interval time series derived from the electrocardiogram (EKG). Unfortunately, the duration of the data collection and the issue of the size of ambulatory monitors with sufficient storage capacity for multi-day records is somewhat problematic. In the present paper we describe a system that allows for the collection of large amounts of high quality data using a small data collection device. The recording system consists of a miniature, single-module electrocardiogram-recording device. This module consists of an integrated three-electrode device that is attached to the chest of the subject. A low power 8-bit micro-controller detects the R-spike and stores the time between R-spikes in milliseconds on a 512 KB EEPROM. This system can record continuously for over four days. This system will allow the recording of cardio-dynamics in the field and provide highly reliable data across multiple days. The use of this device to assess physiological function in military operations would allow researchers to examine longer data records across several contexts and to understand the role of changes in autonomic function as they relate to performance.

The risk of disciplinary action by state medical boards against physicians prescribing opioids.

PubMed

Richard, Jack; Reidenberg, Marcus M

2005-02-01

Concern of physicians about being disciplined for prescribing opioids for patients in pain is one cause for undertreatment of pain. This study was done to assess the actual risk of being disciplined by state medical boards. A review of records of actions by the New York State Board for Professional Medical Misconduct for 3 years and of all medical boards in the United States for 9 months was done to determine this risk. New York State, with 7.8% of U.S. physicians, had 10 physicians disciplined annually related to overprescribing opioids, while the total for the entire U.S. was 120 physicians annually. Most physicians disciplined had multiple violations in addition to overprescribing controlled substances. In the national sample, 43% were prescribing for themselves or for nonpatients, 12% prescribed for addicts without addressing the patients' problems of addiction, 42% had inadequate records, 19% prescribed without indication for opioids, 13% were incompetent in additional ways, and 8% were having sexual activity with patients. Not a single physician, for whom information was available, was disciplined solely for overprescribing opioids. The actual risk of an American physician being disciplined by a state medical board for treating a real patient with opioids for a painful medical condition is virtually nonexistent.

Neurodevelopmental Biology Associated with Childhood Sexual Abuse

ERIC Educational Resources Information Center

De Bellis, Michael D.; Spratt, Eve G.; Hooper, Stephen R.

2011-01-01

Child maltreatment appears to be the single most preventable cause of mental illness and behavioral dysfunction in the United States. Few published studies examine the developmental and the psychobiological consequences of sexual abuse. There are multiple mechanisms through which sexual abuse can cause post-traumatic stress disorder, activate…

Classroom sound can be used to classify teaching practices in college science courses.

PubMed

Owens, Melinda T; Seidel, Shannon B; Wong, Mike; Bejines, Travis E; Lietz, Susanne; Perez, Joseph R; Sit, Shangheng; Subedar, Zahur-Saleh; Acker, Gigi N; Akana, Susan F; Balukjian, Brad; Benton, Hilary P; Blair, J R; Boaz, Segal M; Boyer, Katharyn E; Bram, Jason B; Burrus, Laura W; Byrd, Dana T; Caporale, Natalia; Carpenter, Edward J; Chan, Yee-Hung Mark; Chen, Lily; Chovnick, Amy; Chu, Diana S; Clarkson, Bryan K; Cooper, Sara E; Creech, Catherine; Crow, Karen D; de la Torre, José R; Denetclaw, Wilfred F; Duncan, Kathleen E; Edwards, Amy S; Erickson, Karen L; Fuse, Megumi; Gorga, Joseph J; Govindan, Brinda; Green, L Jeanette; Hankamp, Paul Z; Harris, Holly E; He, Zheng-Hui; Ingalls, Stephen; Ingmire, Peter D; Jacobs, J Rebecca; Kamakea, Mark; Kimpo, Rhea R; Knight, Jonathan D; Krause, Sara K; Krueger, Lori E; Light, Terrye L; Lund, Lance; Márquez-Magaña, Leticia M; McCarthy, Briana K; McPheron, Linda J; Miller-Sims, Vanessa C; Moffatt, Christopher A; Muick, Pamela C; Nagami, Paul H; Nusse, Gloria L; Okimura, Kristine M; Pasion, Sally G; Patterson, Robert; Pennings, Pleuni S; Riggs, Blake; Romeo, Joseph; Roy, Scott W; Russo-Tait, Tatiane; Schultheis, Lisa M; Sengupta, Lakshmikanta; Small, Rachel; Spicer, Greg S; Stillman, Jonathon H; Swei, Andrea; Wade, Jennifer M; Waters, Steven B; Weinstein, Steven L; Willsie, Julia K; Wright, Diana W; Harrison, Colin D; Kelley, Loretta A; Trujillo, Gloriana; Domingo, Carmen R; Schinske, Jeffrey N; Tanner, Kimberly D

2017-03-21

Active-learning pedagogies have been repeatedly demonstrated to produce superior learning gains with large effect sizes compared with lecture-based pedagogies. Shifting large numbers of college science, technology, engineering, and mathematics (STEM) faculty to include any active learning in their teaching may retain and more effectively educate far more students than having a few faculty completely transform their teaching, but the extent to which STEM faculty are changing their teaching methods is unclear. Here, we describe the development and application of the machine-learning-derived algorithm Decibel Analysis for Research in Teaching (DART), which can analyze thousands of hours of STEM course audio recordings quickly, with minimal costs, and without need for human observers. DART analyzes the volume and variance of classroom recordings to predict the quantity of time spent on single voice (e.g., lecture), multiple voice (e.g., pair discussion), and no voice (e.g., clicker question thinking) activities. Applying DART to 1,486 recordings of class sessions from 67 courses, a total of 1,720 h of audio, revealed varied patterns of lecture (single voice) and nonlecture activity (multiple and no voice) use. We also found that there was significantly more use of multiple and no voice strategies in courses for STEM majors compared with courses for non-STEM majors, indicating that DART can be used to compare teaching strategies in different types of courses. Therefore, DART has the potential to systematically inventory the presence of active learning with ∼90% accuracy across thousands of courses in diverse settings with minimal effort.

Classroom sound can be used to classify teaching practices in college science courses

PubMed Central

Seidel, Shannon B.; Wong, Mike; Bejines, Travis E.; Lietz, Susanne; Perez, Joseph R.; Sit, Shangheng; Subedar, Zahur-Saleh; Acker, Gigi N.; Akana, Susan F.; Balukjian, Brad; Benton, Hilary P.; Blair, J. R.; Boaz, Segal M.; Boyer, Katharyn E.; Bram, Jason B.; Burrus, Laura W.; Byrd, Dana T.; Caporale, Natalia; Carpenter, Edward J.; Chan, Yee-Hung Mark; Chen, Lily; Chovnick, Amy; Chu, Diana S.; Clarkson, Bryan K.; Cooper, Sara E.; Creech, Catherine; Crow, Karen D.; de la Torre, José R.; Denetclaw, Wilfred F.; Duncan, Kathleen E.; Edwards, Amy S.; Erickson, Karen L.; Fuse, Megumi; Gorga, Joseph J.; Govindan, Brinda; Green, L. Jeanette; Hankamp, Paul Z.; Harris, Holly E.; He, Zheng-Hui; Ingalls, Stephen; Ingmire, Peter D.; Jacobs, J. Rebecca; Kamakea, Mark; Kimpo, Rhea R.; Knight, Jonathan D.; Krause, Sara K.; Krueger, Lori E.; Light, Terrye L.; Lund, Lance; Márquez-Magaña, Leticia M.; McCarthy, Briana K.; McPheron, Linda J.; Miller-Sims, Vanessa C.; Moffatt, Christopher A.; Muick, Pamela C.; Nagami, Paul H.; Nusse, Gloria L.; Okimura, Kristine M.; Pasion, Sally G.; Patterson, Robert; Riggs, Blake; Romeo, Joseph; Roy, Scott W.; Russo-Tait, Tatiane; Schultheis, Lisa M.; Sengupta, Lakshmikanta; Small, Rachel; Spicer, Greg S.; Stillman, Jonathon H.; Swei, Andrea; Wade, Jennifer M.; Waters, Steven B.; Weinstein, Steven L.; Willsie, Julia K.; Wright, Diana W.; Harrison, Colin D.; Kelley, Loretta A.; Trujillo, Gloriana; Domingo, Carmen R.; Schinske, Jeffrey N.; Tanner, Kimberly D.

2017-01-01

Active-learning pedagogies have been repeatedly demonstrated to produce superior learning gains with large effect sizes compared with lecture-based pedagogies. Shifting large numbers of college science, technology, engineering, and mathematics (STEM) faculty to include any active learning in their teaching may retain and more effectively educate far more students than having a few faculty completely transform their teaching, but the extent to which STEM faculty are changing their teaching methods is unclear. Here, we describe the development and application of the machine-learning–derived algorithm Decibel Analysis for Research in Teaching (DART), which can analyze thousands of hours of STEM course audio recordings quickly, with minimal costs, and without need for human observers. DART analyzes the volume and variance of classroom recordings to predict the quantity of time spent on single voice (e.g., lecture), multiple voice (e.g., pair discussion), and no voice (e.g., clicker question thinking) activities. Applying DART to 1,486 recordings of class sessions from 67 courses, a total of 1,720 h of audio, revealed varied patterns of lecture (single voice) and nonlecture activity (multiple and no voice) use. We also found that there was significantly more use of multiple and no voice strategies in courses for STEM majors compared with courses for non-STEM majors, indicating that DART can be used to compare teaching strategies in different types of courses. Therefore, DART has the potential to systematically inventory the presence of active learning with ∼90% accuracy across thousands of courses in diverse settings with minimal effort. PMID:28265087

Behavior of motor units in human biceps brachii during a submaximal fatiguing contraction.

PubMed

Garland, S J; Enoka, R M; Serrano, L P; Robinson, G A

1994-06-01

The activity of 50 single motor units was recorded in the biceps brachii muscle of human subjects while they performed submaximal isometric elbow flexion contractions that were sustained to induce fatigue. The purposes of this study were to examine the influence of fatigue on motor unit threshold force and to determine the relationship between the threshold force of recruitment and the initial interimpulse interval on the discharge rates of single motor units during a fatiguing contraction. The discharge rate of most motor units that were active from the beginning of the contraction declined during the fatiguing contraction, whereas the discharge rates of most newly recruited units were either constant or increased slightly. The absolute threshold forces of recruitment and derecruitment decreased, and the variability of interimpulse intervals increased after the fatigue task. The change in motor unit discharge rate during the fatigue task was related to the initial rate, but the direction of the change in discharge rate could not be predicted from the threshold force of recruitment or the variability in the interimpulse intervals. The discharge rate of most motor units declined despite an increase in the excitatory drive to the motoneuron pool during the fatigue task.

Measuring multiple spike train synchrony.

PubMed

Kreuz, Thomas; Chicharro, Daniel; Andrzejak, Ralph G; Haas, Julie S; Abarbanel, Henry D I

2009-10-15

Measures of multiple spike train synchrony are essential in order to study issues such as spike timing reliability, network synchronization, and neuronal coding. These measures can broadly be divided in multivariate measures and averages over bivariate measures. One of the most recent bivariate approaches, the ISI-distance, employs the ratio of instantaneous interspike intervals (ISIs). In this study we propose two extensions of the ISI-distance, the straightforward averaged bivariate ISI-distance and the multivariate ISI-diversity based on the coefficient of variation. Like the original measure these extensions combine many properties desirable in applications to real data. In particular, they are parameter-free, time scale independent, and easy to visualize in a time-resolved manner, as we illustrate with in vitro recordings from a cortical neuron. Using a simulated network of Hindemarsh-Rose neurons as a controlled configuration we compare the performance of our methods in distinguishing different levels of multi-neuron spike train synchrony to the performance of six other previously published measures. We show and explain why the averaged bivariate measures perform better than the multivariate ones and why the multivariate ISI-diversity is the best performer among the multivariate methods. Finally, in a comparison against standard methods that rely on moving window estimates, we use single-unit monkey data to demonstrate the advantages of the instantaneous nature of our methods.

Recovery Act - CAREER: Sustainable Silicon -- Energy-Efficient VLSI Interconnect for Extreme-Scale Computing

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

Chiang, Patrick

2014-01-31

The research goal of this CAREER proposal is to develop energy-efficient, VLSI interconnect circuits and systems that will facilitate future massively-parallel, high-performance computing. Extreme-scale computing will exhibit massive parallelism on multiple vertical levels, from thou­ sands of computational units on a single processor to thousands of processors in a single data center. Unfortunately, the energy required to communicate between these units at every level (on­ chip, off-chip, off-rack) will be the critical limitation to energy efficiency. Therefore, the PI's career goal is to become a leading researcher in the design of energy-efficient VLSI interconnect for future computing systems.

State Dependency of Chemosensory Coding in the Gustatory Thalamus (VPMpc) of Alert Rats

PubMed Central

Liu, Haixin

2015-01-01

The parvicellular portion of the ventroposteromedial nucleus (VPMpc) is the part of the thalamus that processes gustatory information. Anatomical evidence shows that the VPMpc receives ascending gustatory inputs from the parabrachial nucleus (PbN) in the brainstem and sends projections to the gustatory cortex (GC). Although taste processing in PbN and GC has been the subject of intense investigation in behaving rodents, much less is known on how VPMpc neurons encode gustatory information. Here we present results from single-unit recordings in the VPMpc of alert rats receiving multiple tastants. Thalamic neurons respond to taste with time-varying modulations of firing rates, consistent with those observed in GC and PbN. These responses encode taste quality as well as palatability. Comparing responses to tastants either passively delivered, or self-administered after a cue, unveiled the effects of general expectation on taste processing in VPMpc. General expectation led to an improvement of taste coding by modulating response dynamics, and single neuron ability to encode multiple tastants. Our results demonstrate that the time course of taste coding as well as single neurons' ability to encode for multiple qualities are not fixed but rather can be altered by the state of the animal. Together, the data presented here provide the first description that taste coding in VPMpc is dynamic and state-dependent. SIGNIFICANCE STATEMENT Over the past years, a great deal of attention has been devoted to understanding taste coding in the brainstem and cortex of alert rodents. Thanks to this research, we now know that taste coding is dynamic, distributed, and context-dependent. Alas, virtually nothing is known on how the gustatory thalamus (VPMpc) processes gustatory information in behaving rats. This manuscript investigates taste processing in the VPMpc of behaving rats. Our results show that thalamic neurons encode taste and palatability with time-varying patterns of activity and that thalamic coding of taste is modulated by general expectation. Our data will appeal not only to researchers interested in taste, but also to a broader audience of sensory and systems neuroscientists interested in the thalamocortical system. PMID:26609147

Flexible multielectrodes can resolve multiple muscles in an insect appendage.

PubMed

Spence, Andrew J; Neeves, Keith B; Murphy, Devon; Sponberg, Simon; Land, Bruce R; Hoy, Ronald R; Isaacson, Michael S

2007-01-15

Research into the neuromechanical basis of behavior, either in biomechanics, neuroethology, or neuroscience, is frequently limited by methods of data collection. Two of the most pressing needs are for methods with which to (1) record from multiple neurons or muscles simultaneously and (2) perform this recording in intact, behaving animals. In this paper we present the fabrication and testing of flexible multielectrode arrays (fMEAs) that move us significantly towards these goals. The fMEAs were used to record the activity of several distinct units in the coxa of the cockroach Blaberus discoidalis. The devices fabricated here address the first goal in two ways: (1) their flexibility allows them to be inserted into an animal and guided through internal tissues in order to access distinct groups of neurons and muscles and (2) their recording site geometry has been tuned to suit the anatomy under study, yielding multichannel spike waveforms that are easily separable under conditions of spike overlap. The flexible nature of the devices simultaneously addresses the second goal, in that it is less likely to interfere with the natural movement of the animal.

Multi-stage accretion of high pressure rocks and thermal changes in a subduction channel: evidence from Diego de Almagro Island (Chilean Patagonia)

NASA Astrophysics Data System (ADS)

Hyppolito, Thais; Angiboust, Samuel; Juliani, Caetano; Glodny, Johannes; Garcia-Casco, Antonio; Calderon, Mauricio; Chopin, Christian

2016-04-01

The remote Diego de Almagro Island, Chile (51° 30' S) exposes one of the rare vestiges of the Cretaceous paleo-subduction system of western South America. It is constituted by two main tectonic units formed by mafic rocks and metasediments: the high temperature/middle pressure Lázaro unit to the East and the high pressure-low temperature Almagro Complex to the West. We herein focus on the Almagro Complex, a pluri-kilometer thick subducted sequence comprising dominantly metatuffs, but also Grt-micaschists, meta-pillow lavas (showing MORB and OIB signatures) and metacherts (transformed to quartz+garnet-rich layers). Despite its apparent homogeneity, the Almagro Complex is actually composed of two distinct units (Willner et al., 2004) with distinct pressure-temperature-time paths. The Garnet Amphibolite unit (GA) shows three chemically and microstructurally distinct garnet generations that grew and (re)-equilibrated between 1.1 GPa and 1.7 GPa (35-55 km) and between 500°C and 600°C. We report for the first time in Chilean Patagonia the presence of rare relicts of omphacite in equilibrium with garnet in mafic layers together with the finding of chloritoid inclusions in garnet from metasediments, and omphacite and glaucophane inclusions in metatuffs. Our P-T estimates, based on pseudosection modeling, single/multi-equilibrium estimates and Raman spectroscopy of organic matter, demonstrate that rocks from the GA unit reached eclogite facies at around 1.7 to 1.8 GPa. Rb-Sr mineral data for Grt-amphibolites indicates that the amphibolitization overprint - which varies in intensity throughout the GA unit - took place at c. 120 Ma. The Blueschist unit, structurally below the GA unit, comprises lithologies similar to the GA unit but finer grained than the former. On other hand, the Blueschist unit (i) does not show garnet with multiple overgrowths and omphacite crystals as seen in the in GA unit; (ii) exhibits slightly lower peak metamorphic conditions than the GA unit (c. 500 °C, 1.4 GPa); (iii) has not suffered the strong amphibolitization visible in the GA unit, and (iv) records blueschist facies deformation at ~80 Ma (Rb-Sr mineral data). Importantly, this cool 80 Ma old event heterogeneously overprinted the GA rocks as shown by silica-rich (Si = 3.5 pfu) rims around phengite (Si = 3.33 pfu) crystals and glaucophane overgrowths around amphibolite-facies hornblende. The amphibolitization stage recorded by GA unit reveals the presence of a transient warming up of the subduction thermal gradient from 9 °C/ km to c. 14 °C/km at c. 120 Ma. We propose that the GA unit has been subsequently cooled down at around 80 Ma coevally with peak metamorphism in the blueschist unit. Dissolution-overgrowth patterns visible in GA unit garnets may be viewed as the record of short-lived thermal pulses associated with discrete basal accretion events. Lately, GA and blueschist units have been tectonically juxtaposed near the root of the accretionary wedge (at c. 30 km depth) and exhumed coherently. Our P-T-t reconstructions for Diego de Almagro rocks bear implications for reconstructing the physical nature of the subduction interface as well as for the understanding of transient, deep accretionary processes taking place near the roots of the seismogenic zone.

Active Vibration Control for Helicopter Interior Noise Reduction Using Power Minimization

NASA Technical Reports Server (NTRS)

Mendoza, J.; Chevva, K.; Sun, F.; Blanc, A.; Kim, S. B.

2014-01-01

This report describes work performed by United Technologies Research Center (UTRC) for NASA Langley Research Center (LaRC) under Contract NNL11AA06C. The objective of this program is to develop technology to reduce helicopter interior noise resulting from multiple gear meshing frequencies. A novel active vibration control approach called Minimum Actuation Power (MAP) is developed. MAP is an optimal control strategy that minimizes the total input power into a structure by monitoring and varying the input power of controlling sources. MAP control was implemented without explicit knowledge of the phasing and magnitude of the excitation sources by driving the real part of the input power from the controlling sources to zero. It is shown that this occurs when the total mechanical input power from the excitation and controlling sources is a minimum. MAP theory is developed for multiple excitation sources with arbitrary relative phasing for single or multiple discrete frequencies and controlled by a single or multiple controlling sources. Simulations and experimental results demonstrate the feasibility of MAP for structural vibration reduction of a realistic rotorcraft interior structure. MAP control resulted in significant average global vibration reduction of a single frequency and multiple frequency excitations with one controlling actuator. Simulations also demonstrate the potential effectiveness of the observed vibration reductions on interior radiated noise.

Inferring time-varying recharge from inverse analysis of long-term water levels

NASA Astrophysics Data System (ADS)

Dickinson, Jesse E.; Hanson, R. T.; Ferré, T. P. A.; Leake, S. A.

2004-07-01

Water levels in aquifers typically vary in response to time-varying rates of recharge, suggesting the possibility of inferring time-varying recharge rates on the basis of long-term water level records. Presumably, in the southwestern United States (Arizona, Nevada, New Mexico, southern California, and southern Utah), rates of mountain front recharge to alluvial aquifers depend on variations in precipitation rates due to known climate cycles such as the El Niño-Southern Oscillation index and the Pacific Decadal Oscillation. This investigation examined the inverse application of a one-dimensional analytical model for periodic flow described by Lloyd R. Townley in 1995 to estimate periodic recharge variations on the basis of variations in long-term water level records using southwest aquifers as the case study. Time-varying water level records at various locations along the flow line were obtained by simulation of forward models of synthetic basins with applied sinusoidal recharge of either a single period or composite of multiple periods of length similar to known climate cycles. Periodic water level components, reconstructed using singular spectrum analysis (SSA), were used to calibrate the analytical model to estimate each recharge component. The results demonstrated that periodic recharge estimates were most accurate in basins with nearly uniform transmissivity and the accuracy of the recharge estimates depends on monitoring well location. A case study of the San Pedro Basin, Arizona, is presented as an example of calibrating the analytical model to real data.

Inferring time‐varying recharge from inverse analysis of long‐term water levels

USGS Publications Warehouse

Dickinson, Jesse; Hanson, R.T.; Ferré, T.P.A.; Leake, S.A.

2004-01-01

Water levels in aquifers typically vary in response to time‐varying rates of recharge, suggesting the possibility of inferring time‐varying recharge rates on the basis of long‐term water level records. Presumably, in the southwestern United States (Arizona, Nevada, New Mexico, southern California, and southern Utah), rates of mountain front recharge to alluvial aquifers depend on variations in precipitation rates due to known climate cycles such as the El Niño‐Southern Oscillation index and the Pacific Decadal Oscillation. This investigation examined the inverse application of a one‐dimensional analytical model for periodic flow described by Lloyd R. Townley in 1995 to estimate periodic recharge variations on the basis of variations in long‐term water level records using southwest aquifers as the case study. Time‐varying water level records at various locations along the flow line were obtained by simulation of forward models of synthetic basins with applied sinusoidal recharge of either a single period or composite of multiple periods of length similar to known climate cycles. Periodic water level components, reconstructed using singular spectrum analysis (SSA), were used to calibrate the analytical model to estimate each recharge component. The results demonstrated that periodic recharge estimates were most accurate in basins with nearly uniform transmissivity and the accuracy of the recharge estimates depends on monitoring well location. A case study of the San Pedro Basin, Arizona, is presented as an example of calibrating the analytical model to real data.

Site term from single-station sigma analysis of S-waves in western Turkey

NASA Astrophysics Data System (ADS)

Akyol, Nihal

2018-05-01

The main aim of this study is to obtain site terms from single-station sigma analysis and to compare them with the site functions resulting from different techniques. The dataset consists of 1764 records from 322 micro- and moderate-size local earthquakes recorded by 29 stations in western Turkey. Median models were derived from S-wave Fourier amplitude spectra for selected 22 frequencies, by utilizing the MLR procedure which performs the maximum likelihood (ML) estimation of mixed models where the fixed effects are treated as random (R) effects with infinite variance. At this stage, b (geometrical spreading coefficient) and Q (quality factor) values were decomposed, simultaneously. The residuals of the median models were examined by utilizing the single-station sigma analysis to obtain the site terms of 29 stations. Sigma for the median models is about 0.422 log10 units and decreases to about 0.308, when the site terms from the single-station sigma analysis were considered (27% reduction). The event-corrected within-event standard deviations for each frequency are rather stable, in the range 0.19-0.23 log10 units with an average value of 0.20 (± 0.01). The site terms from single-station sigma analysis were compared with the site function estimates from the horizontal-to-vertical-spectral-ratio (HVSR) and generalized inversion (INV) techniques by Akyol et al. (2013) and Kurtulmuş and Akyol (2015), respectively. Consistency was observed between the single-station sigma site terms and the INV site transfer functions. The results imply that the single-station sigma analysis could separate the site terms with respect to the median models.

Large-scale analysis reveals populational contributions of cortical spike rate and synchrony to behavioural functions.

PubMed

Kimura, Rie; Saiki, Akiko; Fujiwara-Tsukamoto, Yoko; Sakai, Yutaka; Isomura, Yoshikazu

2017-01-01

There have been few systematic population-wide analyses of relationships between spike synchrony within a period of several milliseconds and behavioural functions. In this study, we obtained a large amount of spike data from > 23,000 neuron pairs by multiple single-unit recording from deep layer neurons in motor cortical areas in rats performing a forelimb movement task. The temporal changes of spike synchrony in the whole neuron pairs were statistically independent of behavioural changes during the task performance, although some neuron pairs exhibited correlated changes in spike synchrony. Mutual information analyses revealed that spike synchrony made a smaller contribution than spike rate to behavioural functions. The strength of spike synchrony between two neurons was statistically independent of the spike rate-based preferences of the pair for behavioural functions. Spike synchrony within a period of several milliseconds in presynaptic neurons enables effective integration of functional information in the postsynaptic neuron. However, few studies have systematically analysed the population-wide relationships between spike synchrony and behavioural functions. Here we obtained a sufficiently large amount of spike data among regular-spiking (putatively excitatory) and fast-spiking (putatively inhibitory) neuron subtypes (> 23,000 pairs) by multiple single-unit recording from deep layers in motor cortical areas (caudal forelimb area, rostral forelimb area) in rats performing a forelimb movement task. After holding a lever, rats pulled the lever either in response to a cue tone (external-trigger trials) or spontaneously without any cue (internal-trigger trials). Many neurons exhibited functional spike activity in association with forelimb movements, and the preference of regular-spiking neurons in the rostral forelimb area was more biased toward externally triggered movement than that in the caudal forelimb area. We found that a population of neuron pairs with spike synchrony does exist, and that some neuron pairs exhibit a dependence on movement phase during task performance. However, the population-wide analysis revealed that spike synchrony was statistically independent of the movement phase and the spike rate-based preferences of the pair for behavioural functions, whereas spike rates were clearly dependent on the movement phase. In fact, mutual information analyses revealed that the contribution of spike synchrony to the behavioural functions was small relative to the contribution of spike rate. Our large-scale analysis revealed that cortical spike rate, rather than spike synchrony, contributes to population coding for movement. © 2016 The Authors. The Journal of Physiology © 2016 The Physiological Society.

Rotational scanning and multiple-spot focusing through a multimode fiber based on digital optical phase conjugation

NASA Astrophysics Data System (ADS)

Ma, Chaojie; Di, Jianglei; Li, Ying; Xiao, Fajun; Zhang, Jiwei; Liu, Kaihui; Bai, Xuedong; Zhao, Jianlin

2018-06-01

We demonstrate, for the first time, the rotational memory effect of a multimode fiber (MMF) based on digital optical phase conjugation (DOPC) to achieve multiple-spot focusing. An implementation interferometer is used to address the challenging alignments in DOPC. By rotating the acquired phase conjugate pattern, rotational scanning through a MMF could be achieved by recording a single off-axis hologram. The generation of two focal spots through a MMF is also demonstrated by combining the rotational memory effect with the superposition principle. The results may be useful for ultrafast scanning imaging and optical manipulation of multiple objects through a MMF.

Conditional spectrum computation incorporating multiple causal earthquakes and ground-motion prediction models

USGS Publications Warehouse

Lin, Ting; Harmsen, Stephen C.; Baker, Jack W.; Luco, Nicolas

2013-01-01

The conditional spectrum (CS) is a target spectrum (with conditional mean and conditional standard deviation) that links seismic hazard information with ground-motion selection for nonlinear dynamic analysis. Probabilistic seismic hazard analysis (PSHA) estimates the ground-motion hazard by incorporating the aleatory uncertainties in all earthquake scenarios and resulting ground motions, as well as the epistemic uncertainties in ground-motion prediction models (GMPMs) and seismic source models. Typical CS calculations to date are produced for a single earthquake scenario using a single GMPM, but more precise use requires consideration of at least multiple causal earthquakes and multiple GMPMs that are often considered in a PSHA computation. This paper presents the mathematics underlying these more precise CS calculations. Despite requiring more effort to compute than approximate calculations using a single causal earthquake and GMPM, the proposed approach produces an exact output that has a theoretical basis. To demonstrate the results of this approach and compare the exact and approximate calculations, several example calculations are performed for real sites in the western United States. The results also provide some insights regarding the circumstances under which approximate results are likely to closely match more exact results. To facilitate these more precise calculations for real applications, the exact CS calculations can now be performed for real sites in the United States using new deaggregation features in the U.S. Geological Survey hazard mapping tools. Details regarding this implementation are discussed in this paper.

Multiple Perceptions of Science Concepts: A Qualitative Study in a Swamp.

ERIC Educational Resources Information Center

Hulland, Carol Marie

This study focuses on how students make sense of and understand concepts related to the study of a wetland. The analyses of students' talk and drawings recorded during a 2-week wetland unit were divided into two levels. The first level examined students' understandings and explored student traits that contributed to a clear, stable understanding…

40 CFR 75.72 - Determination of NOX mass emissions for common stack and multiple stack configurations.

Code of Federal Regulations, 2010 CFR

2010-07-01

... the hourly stack flow rate (in scfh). Only one methodology for determining NOX mass emissions shall be...-diluent continuous emissions monitoring system and a flow monitoring system in the common stack, record... maintain a flow monitoring system and diluent monitor in the duct to the common stack from each unit; or...

76 FR 71353 - Notice of Availability of the Record of Decision for the DesertXpress Enterprises, LLC High-Speed...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-17

..., LLC High-Speed Passenger Train Project AGENCY: Bureau of Land Management, Interior. ACTION: Notice of... (ROD) for the DesertXpress Enterprises, LLC High-Speed Passenger Train Project (DesertXpress Project...-managed lands to build an Electrical Multiple Unit (EMU) high-speed passenger rail line in compliance with...

Deciphering the contribution of intrinsic and synaptic currents to the effects of transient synaptic inputs on human motor unit discharge

PubMed Central

Powers, Randall K.; Türker, Kemal S.

2010-01-01

The amplitude and time course of synaptic potentials in human motoneurons can be estimated in tonically discharging motor units by measuring stimulus-evoked changes in the rate and probability of motor unit action potentials. However, in spite of the fact that some of these techniques have been used for over thirty years, there is still no consensus on the best way to estimate the characteristics of synaptic potentials or on the accuracy of these estimates. In this review, we compare different techniques for estimating synaptic potentials from human motor unit discharge and also discuss relevant animal models in which estimated synaptic potentials can be compared to those directly measured from intracellular recordings. We also review the experimental evidence on how synaptic noise and intrinsic motoneuron properties influence their responses to synaptic inputs. Finally, we consider to what extent recordings of single motor unit discharge in humans can be used to distinguish the contribution of changes in synaptic inputs versus changes in intrinsic motoneuron properties to altered motoneuron responses following CNS injury. PMID:20427230

Understanding Horizontal Governance. Research Brief

ERIC Educational Resources Information Center

Ferguson, Daniel

2009-01-01

Horizontal governance is an umbrella term that covers a range of approaches to policy development, service delivery issues, and management practices. A horizontal initiative may take place across levels of government, across boundaries between units of a single department or agency or among multiple departments or agencies, or across public,…

Solar thermal collectors using planar reflector

NASA Technical Reports Server (NTRS)

Espy, P. N.

1978-01-01

Specular reflectors have been used successfully with flat-plate collectors to achieve exceptionally high operating temperatures and high delivered energy per unit collector area. Optimal orientation of collectors and reflectors can result in even higher performance with an improved relationship between energy demand and supply. This paper reports on a study providing first order optimization of collector-reflector arrays in which single- and multiple-faceted reflectors in fixed or singly adjustable configurations provide delivered energy maxima in either summer or winter.

Measurement of the multiple-muon charge ratio in the MINOS Far Detector

DOE PAGES

Adamson, P.; Anghel, I.; Aurisano, A.; ...

2016-03-30

The charge ratio, R μ = N μ+/N μ-, for cosmogenic multiple-muon events observed at an underground depth of 2070 mwe has been measured using the magnetized MINOS Far Detector. The multiple-muon events, recorded nearly continuously from August 2003 until April 2012, comprise two independent data sets imaged with opposite magnetic field polarities, the comparison of which allows the systematic uncertainties of the measurement to be minimized. The multiple-muon charge ratio is determined to be R μ = 1.104±0.006(stat)more » $$+0.009\\atop{-0.010}$$(syst). As a result, this measurement complements previous determinations of single-muon and multiple-muon charge ratios at underground sites and serves to constrain models of cosmic-ray interactions at TeV energies.« less

Differential co-promoting activities of alpha, beta and gamma interferons in the murine skin two-stage carcinogenesis model.

PubMed

Reiners, J J; Cantu, A; Thai, G; Pavone, A

1993-03-01

SENCAR mice develop more papillomas in two-stage skin carcinogenesis protocols if gamma interferon (IFN-gamma) is co-administered with 12-O-tetradecanoylphorbol-13-acetate (TPA) during the promotion phase. In the current study preparations of murine alpha, beta and gamma IFNs were surveyed for their abilities to modulate TPA-dependent promotion and induction of epidermal hyperplasia, inflammation and ornithine decarboxylase activity (ODC). Single or multiple i.p. administrations of IFN-alpha, -beta or -gamma (< or = 2500 units) did not induce epidermal hyperplasia, inflammation or ODC activity. Single or multiple i.p. administrations of IFN-alpha, -beta or -gamma (2500 units) to mice being topically promoted with 0.1 or 1 microgram of TPA did not alter the epidermal hyperplasia induced by the phorbol ester. The vascular permeability of the skin, as evaluated by the extravasation of Evans blue dye, was increased in a dose-dependent fashion by TPA over the range of 0.1-1 microgram. Treatment of mice promoted with 0.1 microgram of TPA with IFN-gamma (> or = 2500 units) significantly increased the skin's vascular permeability. Comparable effects were not obtained with IFN-beta (IFN-alpha not tested). Treatment of TPA-promoted mice with IFN-gamma, and to a lesser extent IFN-beta, weakly potentiated the TPA-dependent induction of epidermal ODC activity. Under conditions in which IFN-gamma had co-promoting activities in an initiation-promotion protocol, co-treatment of initiated mice with 1 microgram of TPA and IFN-alpha or -beta (100-5000 units) did not reproducibly alter tumor latency., or papilloma and carcinoma multiplicities. These findings suggest that the co-promoting activities of IFNs are restricted to the gamma class, and are not uniformly reflected by parameters commonly employed as short-term markers of tumor promotion.

Aetiology of obstructive azoospermia in Chinese infertility patients.

PubMed

Han, H; Liu, S; Zhou, X-G; Tian, L; Zhang, X-D

2016-09-01

To explore the aetiology of obstructive azoospermia (OA) in Chinese infertility patients, 133 OA patients was included in this study diagnosed and evaluated by one major specialist trained urological infertility. We retrospected the medical records to collect relative information. All of the patients had been underwent physical examination, ultrasound scan to the urogenital system, serum hormone tests, genetic tests and two separate semen analyses. The mean age of all 133 patients was 32.7 ± 6.8 years. A total of 266 reproductive tract units (two/patient) were classified into four categories: no causes (Idiopathic) for 74 units (27.8%), single cause for 173 units (65.0%), double causes for 17 units (6.4%) and triple causes for two units (0.8%). As to single cause of OA, there were four types: trauma for 0 unit (0%), infection for 125 units (47.0%), dysplasia for 11 units (4.1%) and surgeries for 37 units (13.9%). As to total cause of OA, there were five types: infection for 144 units (54.1%), orchitis for 51 units (19.2%), epididymitis for 54 units (20.3%), gonorrhoea for 28 units (10.5%) and inguinal hernia repair surgery for 18 units (6.8%). The most frequent cause of obstructive azoospermia was infection revealed in these Chinese infertility populations, followed by idiopathic reason. © 2015 Blackwell Verlag GmbH.

Towards component-based validation of GATE: aspects of the coincidence processor

PubMed Central

Moraes, Eder R.; Poon, Jonathan K.; Balakrishnan, Karthikayan; Wang, Wenli; Badawi, Ramsey D.

2014-01-01

GATE is public domain software widely used for Monte Carlo simulation in emission tomography. Validations of GATE have primarily been performed on a whole-system basis, leaving the possibility that errors in one sub-system may be offset by errors in others. We assess the accuracy of the GATE PET coincidence generation sub-system in isolation, focusing on the options most closely modeling the majority of commercially available scanners. Independent coincidence generators were coded by teams at Toshiba Medical Research Unit (TMRU) and UC Davis. A model similar to the Siemens mCT scanner was created in GATE. Annihilation photons interacting with the detectors were recorded. Coincidences were generated using GATE, TMRU and UC Davis code and results compared to “ground truth” obtained from the history of the photon interactions. GATE was tested twice, once with every qualified single event opening a time window and initiating a coincidence check (the “multiple window method”), and once where a time window is opened and a coincidence check initiated only by the first single event to occur after the end of the prior time window (the “single window method”). True, scattered and random coincidences were compared. Noise equivalent count rates were also computed and compared. The TMRU and UC Davis coincidence generators agree well with ground truth. With GATE, reasonable accuracy can be obtained if the single window method option is chosen and random coincidences are estimated without use of the delayed coincidence option. However in this GATE version, other parameter combinations can result in significant errors. PMID:25240897

The use of MP3 recorders to log data from equine hoof mounted accelerometers.

PubMed

Parsons, K J; Wilson, A M

2006-11-01

MP3 recorders are readily available, small, lightweight and low cost, providing the potential for logging analogue hoof mounted accelerometer signals for the characterisation of equine locomotion. These, however, require testing in practice. To test whether 1) multiple MP3 recorders can maintain synchronisation, giving the ability to synchronise independent recorders for the logging of multiple limbs simultaneously; and 2) features of a foot mounted accelerometer signal attributable to foot-on and foot-off can be accurately identified from horse foot mounted accelerometers logged directly into an MP3 recorder. Three experiments were performed: 1) Maintenance of synchronisation was assessed by counting the number of samples recorded by each of 4 MP3 recorders while mounted on a trotting horse and over 2 consecutive 30 min periods in 8 recorders on a bench. 2) Foot-on and foot-off times obtained from manual transcription of MP3 logged data and directly logged accelerometer signal were compared. 3) MP3/accelerometer acquisition units were used to log accelerometer signals from racehorses during extended training sessions. Mean absolute error of synchronisation between MP3 recorders was 10 samples per million (compared to mean number of samples, range 1-32 samples per million). Error accumulation showed a linear correlation with time. Features attributable to foot on and foot off were equally identifiable from the MP3 recorded signal over a range of equine gaits. Multiple MP3 recorders can be synchronised and used as a relatively cheap, robust, reliable and accurate logging system when combined with an accelerometer and external battery for the specific application of the measurement of stride timing variables across the range of equine gaits during field locomotion. Footfall timings can be used to identify intervals between the fore and hind contacts, the identification of diagonal advanced placement and to calculate stride timing variables (stance time, protraction time and stride time). These parameters are invaluable for the characterisation and assessment of equine locomotion.

Response inhibition rapidly increases single-neuron responses in the subthalamic nucleus of patients with Parkinson's disease.

PubMed

Benis, Damien; David, Olivier; Piallat, Brigitte; Kibleur, Astrid; Goetz, Laurent; Bhattacharjee, Manik; Fraix, Valérie; Seigneuret, Eric; Krack, Paul; Chabardès, Stéphan; Bastin, Julien

2016-11-01

The subthalamic nucleus (STN) plays a critical role during action inhibition, perhaps by acting like a fast brake on the motor system when inappropriate responses have to be rapidly suppressed. However, the mechanisms involving the STN during motor inhibition are still unclear, particularly because of a relative lack of single-cell responses reported in this structure in humans. In this study, we used extracellular microelectrode recordings during deep brain stimulation surgery in patients with Parkinson's disease (PD) to study STN neurophysiological correlates of inhibitory control during a stop signal task. We found two neuronal subpopulations responding either during motor execution (GO units) or during motor inhibition (STOP units). GO units fired selectively before patients' motor responses whereas STOP units fired selectively when patients successfully withheld their move at a latency preceding the duration of the inhibition process. These results provide electrophysiological evidence for the hypothesized role of the STN in current models of response inhibition. Copyright © 2016. Published by Elsevier Ltd.

[Comparison of the factors influencing children's self-esteem between two parent families and single parent families].

PubMed

Sok, Sohyune R; Shin, Sung Hee

2010-06-01

This study was done to compare factors influencing children's self-esteem between two parent families and single parent families. The participants were 692 children aged 11 to 13 yr (388 in two parent families and 304 in single parent families) recruited from 20 community agencies and 5 elementary schools in Gyeonggi Province and Seoul City, South Korea. Data were collected from May to July, 2007 using a survey questionnaire containing items on self-esteem, internal control, problematic behavior, school record, family hardiness, parent-child communication and social support. The data were analyzed using SPSS 15.0 program and factors affecting children's self-esteem were analyzed by stepwise multiple regression. Scores for the study variables were significantly different between the two groups. The factors influencing children's self-esteem were also different according to family type. For two parent families, internal control, problematic behavior, school record, and parent-child communication significantly predicted the level of self-esteem (adjusted R(2)=.505, p<.001). For single parent families, social support, family hardiness, internal control, problematic behavior, school record, and parent-child communication significantly predicted the level of self-esteem (adjusted R(2)=.444, p<.001). Nurse working with children should consider family type-specific factors influencing their self-esteem.

Overestimation of infant and toddler energy intake by 24-h recall compared with weighed food records

USDA-ARS?s Scientific Manuscript database

Twenty-four-hour dietary recalls have been used in large surveys of infant and toddler energy intake, but the accuracy of the method for young children is not well documented. We aimed to determine the accuracy of infant and toddler energy intakes by a single, telephone-administered, multiple-pass 2...

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

PubMed

Schwendicke, Falk; Göstemeyer, Gerd

2017-02-01

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

Differential recruitment of brain networks in single-digit addition and multiplication: Evidence from EEG oscillations in theta and lower alpha bands.

PubMed

Wang, Lihan; Gan, John Q; Zhang, Li; Wang, Haixian

2018-06-01

Previous neuroimaging research investigating dissociation between single-digit addition and multiplication has suggested that the former placed more reliance on the visuo-spatial processing whereas the latter on the verbal processing. However, there has been little exploration into the disassociation in spatio-temporal dynamics of the oscillatory brain activity in specific frequency bands during the two arithmetic operations. To address this issue, the electroencephalogram (EEG) data were recorded from 19 participants engaged in a delayed verification arithmetic task. By analyzing oscillatory EEG activity in theta (5-7 Hz) and lower alpha frequency (9-10 Hz) bands, we found different patterns of oscillatory brain activity between single-digit addition and multiplication during the early processing stage (0-400 ms post-operand onset). Experiment results in this study showed a larger phasic increase of theta-band power for addition than for multiplication in the midline and the right frontal and central regions during the operator and operands presentation intervals, which was extended to the right parietal and the right occipito-temporal regions during the interval immediately after the operands presentation. In contrast, during multiplication higher phase-locking in lower alpha band was evident in the centro-parietal regions during the operator presentation, which was extended to the left fronto-central and anterior regions during the operands presentation. Besides, we found stronger theta phase synchrony between the parietal areas and the right occipital areas for single-digit addition than for multiplication during operands encoding. These findings of oscillatory brain activity extend the previous observations on functional dissociation between the two arithmetic operations. Copyright © 2018 Elsevier B.V. All rights reserved.

Automatic feedback to promote safe walking and speech loudness control in persons with multiple disabilities: two single-case studies.

PubMed

Lancioni, Giulio E; Singh, Nirbhay N; O'Reilly, Mark F; Green, Vanessa A; Alberti, Gloria; Boccasini, Adele; Smaldone, Angela; Oliva, Doretta; Bosco, Andrea

2014-08-01

Assessing automatic feedback technologies to promote safe travel and speech loudness control in two men with multiple disabilities, respectively. The men were involved in two single-case studies. In Study I, the technology involved a microprocessor, two photocells, and a verbal feedback device. The man received verbal alerting/feedback when the photocells spotted an obstacle in front of him. In Study II, the technology involved a sound-detecting unit connected to a throat and an airborne microphone, and to a vibration device. Vibration occurred when the man's speech loudness exceeded a preset level. The man included in Study I succeeded in using the automatic feedback in substitution of caregivers' alerting/feedback for safe travel. The man of Study II used the automatic feedback to successfully reduce his speech loudness. Automatic feedback can be highly effective in helping persons with multiple disabilities improve their travel and speech performance.

The image of motor units architecture in the mechanomyographic signal during the single motor unit contraction: in vivo and simulation study.

PubMed

Kaczmarek, P; Celichowski, J; Drzymała-Celichowska, H; Kasiński, A

2009-08-01

The mechanomyographic (MMG) signal analysis has been performed during single motor unit (MU) contractions of the rat medial gastrocnemius muscle. The MMG has been recorded as a muscle surface displacement by using a laser distance sensor. The profiles of the MMG signal let to categorize these signals for particular MUs into three classes. Class MMG-P (positive) comprises MUs with the MMG signal similar to the force signal profile, where the distance between the muscle surface and the laser sensor increases with the force increase. The class MMG-N (negative) has also the MMG profile similar to the force profile, however the MMG is inverted in comparison to the force signal and the distance measured by using laser sensor decreases with the force increase. The third class MMG-M (mixed) characterize the MMG which initially increases with the force increases and when the force exceeds some level it starts to decrease towards the negative values. The semi-pennate muscle model has been proposed, enabling estimation of the MMG generated by a single MU depending on its localization. The analysis have shown that in the semi-pennate muscle the localization of the MU and the relative position of the laser distance sensor determine the MMG profile and amplitude. Thus, proposed classification of the MMG recordings is not related to the physiological types of MUs, but only to the MU localization and mentioned sensor position. When the distance sensor is located over the middle of the muscle belly, a part of the muscle fibers have endings near the location of the sensor beam. For the MU MMG of class MMG-N the deflection of the muscle surface proximal to the sensor mainly influences the MMG recording, whereas for the MU MMG class MMG-P, it is mainly the distal muscle surface deformation. For the MU MMG of MMG-M type the effects of deformation within the proximal and distal muscle surfaces overlap. The model has been verified with experimental recordings, and its responses are consistent and adequate in comparison to the experimental data.

Single-Trial Classification of Multi-User P300-Based Brain-Computer Interface Using Riemannian Geometry.

PubMed

Korczowski, L; Congedo, M; Jutten, C

2015-08-01

The classification of electroencephalographic (EEG) data recorded from multiple users simultaneously is an important challenge in the field of Brain-Computer Interface (BCI). In this paper we compare different approaches for classification of single-trials Event-Related Potential (ERP) on two subjects playing a collaborative BCI game. The minimum distance to mean (MDM) classifier in a Riemannian framework is extended to use the diversity of the inter-subjects spatio-temporal statistics (MDM-hyper) or to merge multiple classifiers (MDM-multi). We show that both these classifiers outperform significantly the mean performance of the two users and analogous classifiers based on the step-wise linear discriminant analysis. More importantly, the MDM-multi outperforms the performance of the best player within the pair.

Acquisition of electroencephalographic data in a large regional hospital - Bringing the brain waves to the computer.

NASA Technical Reports Server (NTRS)

Low, M. D.; Baker, M.; Ferguson, R.; Frost, J. D., Jr.

1972-01-01

This paper describes a complete electroencephalographic acquisition and transmission system, designed to meet the needs of a large hospital with multiple critical care patient monitoring units. The system provides rapid and prolonged access to a centralized recording and computing area from remote locations within the hospital complex, and from locations in other hospitals and other cities. The system includes quick-on electrode caps, amplifier units and cable transmission for access from within the hospital, and EEG digitization and telephone transmission for access from other hospitals or cities.

Correlating Polymer Crystals via Self-Induced Nucleation

NASA Astrophysics Data System (ADS)

Reiter, Günter

Crystallizable polymers often form multiple stacks of uniquely oriented lamellae, which have good registry despite being separated by amorphous fold surfaces. These correlations require multiple synchronized, yet unidentified, nucleation events. Here, we demonstrate that in thin films of isotactic polystyrene, the probability of generating correlated lamellae is controlled by the branched morphology of a single primary lamella. The nucleation density ns of secondary lamellae is found to be dependent on the width of the branches of the primary lamella. This relation is independent of molecular weight, crystallization temperature, and film thickness. We propose a nucleation mechanism based on the insertion of polymers into a branched primary lamellar crystal. Even in single crystals, characterized by faceted structures with a well-defined envelope reflecting the underlying crystal unit cell, polymers are folded and thus in a meta-stable state. Annealing such meta-stable single crystals allowed to unveil the initial morphological framework of a dendritic single crystal, i.e. the initial stages of growth.

3D motion picture of transparent gas flow by parallel phase-shifting digital holography

NASA Astrophysics Data System (ADS)

Awatsuji, Yasuhiro; Fukuda, Takahito; Wang, Yexin; Xia, Peng; Kakue, Takashi; Nishio, Kenzo; Matoba, Osamu

2018-03-01

Parallel phase-shifting digital holography is a technique capable of recording three-dimensional (3D) motion picture of dynamic object, quantitatively. This technique can record single hologram of an object with an image sensor having a phase-shift array device and reconstructs the instantaneous 3D image of the object with a computer. In this technique, a single hologram in which the multiple holograms required for phase-shifting digital holography are multiplexed by using space-division multiplexing technique pixel by pixel. We demonstrate 3D motion picture of dynamic and transparent gas flow recorded and reconstructed by the technique. A compressed air duster was used to generate the gas flow. A motion picture of the hologram of the gas flow was recorded at 180,000 frames/s by parallel phase-shifting digital holography. The phase motion picture of the gas flow was reconstructed from the motion picture of the hologram. The Abel inversion was applied to the phase motion picture and then the 3D motion picture of the gas flow was obtained.

Follow-up of serious offender patients in the community: multiple methods of tracing.

PubMed

Jamieson, Elizabeth; Taylor, Pamela J

2002-01-01

Longitudinal studies of people with mental disorder are important in understanding outcome and intervention effects but attrition rates can be high. This study aimed to evaluate use of multiple record sources to trace, over 12 years, a one-year discharge cohort of high-security hospital patients. Everyone leaving such a hospital in 1984 was traced until a census date of 31 December 1995. Data were collected from several national databases (Office for National Statistics (ONS), Home Office (HO) Offenders' Index, Police National Computer Records, the Electoral Roll) and by hand-searching responsible agency records (HO, National Health Service). Using all methods, only three of the 204 patients had no follow-up information. Home Office Mental Health Unit data were an excellent source, but only for people still under discharge restrictions (<50% after eight years). Sequential tracing of hospital placements for people never or no longer under such restrictions was laborious and also produced only group-specific yield. The best indicator of community residence was ONS information on general practitioner (GP/primary care) registration. The electoral roll was useful when other sources were exhausted. Follow-up of offenders/offender-patients has generally focused on event data, such as re-offending. People untraced by that method alone, however, are unlikely to be lost to follow-up on casting a wider records net. Using multiple records, attrition at the census was 38%, but, after certain assumptions, reduced further to 5%.

Phase discriminating capacitive array sensor system

NASA Technical Reports Server (NTRS)

Vranish, John M. (Inventor); Rahim, Wadi (Inventor)

1993-01-01

A phase discriminating capacitive sensor array system which provides multiple sensor elements which are maintained at a phase and amplitude based on a frequency reference provided by a single frequency stabilized oscillator. Sensor signals provided by the multiple sensor elements are controlled by multiple phase control units, which correspond to the multiple sensor elements, to adjust the sensor signals from the multiple sensor elements based on the frequency reference. The adjustment made to the sensor signals is indicated by output signals which indicate the proximity of the object. The output signals may also indicate the closing speed of the object based on the rate of change of the adjustment made, and the edges of the object based on a sudden decrease in the adjustment made.

Systems and methods to control multiple peripherals with a single-peripheral application code

DOEpatents

Ransom, Ray M.

2013-06-11

Methods and apparatus are provided for enhancing the BIOS of a hardware peripheral device to manage multiple peripheral devices simultaneously without modifying the application software of the peripheral device. The apparatus comprises a logic control unit and a memory in communication with the logic control unit. The memory is partitioned into a plurality of ranges, each range comprising one or more blocks of memory, one range being associated with each instance of the peripheral application and one range being reserved for storage of a data pointer related to each peripheral application of the plurality. The logic control unit is configured to operate multiple instances of the control application by duplicating one instance of the peripheral application for each peripheral device of the plurality and partitioning a memory device into partitions comprising one or more blocks of memory, one partition being associated with each instance of the peripheral application. The method then reserves a range of memory addresses for storage of a data pointer related to each peripheral device of the plurality, and initializes each of the plurality of peripheral devices.

78 FR 30392 - Notice of Application for Special Permits

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-22

... the table below as follows: 1--Motor vehicle, 2--Rail freight, 3--Cargo vessel, 4--Cargo aircraft only... available for inspection in the Records Center, East Building, PHH-30, 1200 New Jersey Avenue Southeast..., 4.3, 5.1, 6.1, and Class 3 and Class 8 materials in a single Container Transport Unit (CTU...

Grave Songs in Stone.

ERIC Educational Resources Information Center

Hunter, J. Mark

A survey of images on gravestones yields a fascinating array of symbols and visual communication. This paper describes a project in which over 300 symbols in graveyards of the southeastern United States were examined. The method of recording the images and information about them was to photograph the symbol with a 35mm single lens reflex (SLR) and…

Wavelet methodology to improve single unit isolation in primary motor cortex cells.

PubMed

Ortiz-Rosario, Alexis; Adeli, Hojjat; Buford, John A

2015-05-15

The proper isolation of action potentials recorded extracellularly from neural tissue is an active area of research in the fields of neuroscience and biomedical signal processing. This paper presents an isolation methodology for neural recordings using the wavelet transform (WT), a statistical thresholding scheme, and the principal component analysis (PCA) algorithm. The effectiveness of five different mother wavelets was investigated: biorthogonal, Daubachies, discrete Meyer, symmetric, and Coifman; along with three different wavelet coefficient thresholding schemes: fixed form threshold, Stein's unbiased estimate of risk, and minimax; and two different thresholding rules: soft and hard thresholding. The signal quality was evaluated using three different statistical measures: mean-squared error, root-mean squared, and signal to noise ratio. The clustering quality was evaluated using two different statistical measures: isolation distance, and L-ratio. This research shows that the selection of the mother wavelet has a strong influence on the clustering and isolation of single unit neural activity, with the Daubachies 4 wavelet and minimax thresholding scheme performing the best. Copyright © 2015. Published by Elsevier B.V.

Holographic Reciprocity Law Failure, with Applications to the Three-Dimensional Display of Medical Data

NASA Astrophysics Data System (ADS)

Johnson, Kristina Mary

In 1973 the computerized tomography (CT) scanner revolutionized medical imaging. This machine can isolate and display in two-dimensional cross-sections, internal lesions and organs previously impossible to visualize. The possibility of three-dimensional imaging however is not yet exploited by present tomographic systems. Using multiple-exposure holography, three-dimensional displays can be synthesizing from two-dimensional CT cross -sections. A multiple-exposure hologram is an incoherent superposition of many individual holograms. Intuitively it is expected that holograms recorded with equal energy will reconstruct images with equal brightness. It is found however, that holograms recorded first are brighter than holograms recorded later in the superposition. This phenomena is called Holographic Reciprocity Law Failure (HRLF). Computer simulations of latent image formation in multiple-exposure holography are one of the methods used to investigate HRLF. These simulations indicate that it is the time between individual exposures in the multiple -exposure hologram that is responsible for HRLF. This physical parameter introduces an asymmetry into the latent image formation process that favors the signal of previously recorded holograms over holograms recorded later in the superposition. The origin of this asymmetry lies in the dynamics of latent image formation, and in particular in the decay of single-atom latent image specks, which have lifetimes that are short compared to typical times between exposures. An analytical model is developed for a double exposure hologram that predicts a decrease in the brightness of the second exposure as compared to the first exposure as the time between exposures increases. These results are consistent with the computer simulations. Experiments investigating the influence of this parameter on the diffraction efficiency of reconstructed images in a double exposure hologram are also found to be consistent with the computer simulations and analytical results. From this information, two techniques are presented that correct for HRLF, and succeed in reconstructing multiple holographic images of CT cross-sections with equal brightness. The multiple multiple-exposure hologram is a new hologram that increases the number of equally bright images that can be superimposed on one photographic plate.

Simultaneous estimation of multiple phases in digital holographic interferometry using state space analysis

NASA Astrophysics Data System (ADS)

Kulkarni, Rishikesh; Rastogi, Pramod

2018-05-01

A new approach is proposed for the multiple phase estimation from a multicomponent exponential phase signal recorded in multi-beam digital holographic interferometry. It is capable of providing multidimensional measurements in a simultaneous manner from a single recording of the exponential phase signal encoding multiple phases. Each phase within a small window around each pixel is appproximated with a first order polynomial function of spatial coordinates. The problem of accurate estimation of polynomial coefficients, and in turn the unwrapped phases, is formulated as a state space analysis wherein the coefficients and signal amplitudes are set as the elements of a state vector. The state estimation is performed using the extended Kalman filter. An amplitude discrimination criterion is utilized in order to unambiguously estimate the coefficients associated with the individual signal components. The performance of proposed method is stable over a wide range of the ratio of signal amplitudes. The pixelwise phase estimation approach of the proposed method allows it to handle the fringe patterns that may contain invalid regions.

Suppression of optical beat interference-noise in orthogonal frequency division multiple access-passive optical network link using self-homodyne balanced detection

NASA Astrophysics Data System (ADS)

Won, Yong-Yuk; Jung, Sang-Min; Han, Sang-Kook

2014-08-01

A new technique, which reduces optical beat interference (OBI) noise in orthogonal frequency division multiple access-passive optical network (OFDMA-PON) links, is proposed. A self-homodyne balanced detection, which uses a single laser for the optical line terminal (OLT) as well as for the optical network unit (ONU), reduces OBI noise and also improves the signal to noise ratio (SNR) of the discrete multi-tone (DMT) signal. The proposed scheme is verified by transmitting quadrature phase shift keying (QPSK)-modulated DMT signal over a 20-km single mode fiber. The optical signal to noise ratio (OSNR), that is required for BER of 10-5, is reduced by 2 dB in the balanced detection compared with a single channel due to the cancellation of OBI noise in conjunction with the local laser.

Transmission-Type 2-Bit Programmable Metasurface for Single-Sensor and Single-Frequency Microwave Imaging

PubMed Central

Li, Yun Bo; Li, Lian Lin; Xu, Bai Bing; Wu, Wei; Wu, Rui Yuan; Wan, Xiang; Cheng, Qiang; Cui, Tie Jun

2016-01-01

The programmable and digital metamaterials or metasurfaces presented recently have huge potentials in designing real-time-controlled electromagnetic devices. Here, we propose the first transmission-type 2-bit programmable coding metasurface for single-sensor and single- frequency imaging in the microwave frequency. Compared with the existing single-sensor imagers composed of active spatial modulators with their units controlled independently, we introduce randomly programmable metasurface to transform the masks of modulators, in which their rows and columns are controlled simultaneously so that the complexity and cost of the imaging system can be reduced drastically. Different from the single-sensor approach using the frequency agility, the proposed imaging system makes use of variable modulators under single frequency, which can avoid the object dispersion. In order to realize the transmission-type 2-bit programmable metasurface, we propose a two-layer binary coding unit, which is convenient for changing the voltages in rows and columns to switch the diodes in the top and bottom layers, respectively. In our imaging measurements, we generate the random codes by computer to achieve different transmission patterns, which can support enough multiple modes to solve the inverse-scattering problem in the single-sensor imaging. Simple experimental results are presented in the microwave frequency, validating our new single-sensor and single-frequency imaging system. PMID:27025907

Transmission-Type 2-Bit Programmable Metasurface for Single-Sensor and Single-Frequency Microwave Imaging.

PubMed

Li, Yun Bo; Li, Lian Lin; Xu, Bai Bing; Wu, Wei; Wu, Rui Yuan; Wan, Xiang; Cheng, Qiang; Cui, Tie Jun

2016-03-30

The programmable and digital metamaterials or metasurfaces presented recently have huge potentials in designing real-time-controlled electromagnetic devices. Here, we propose the first transmission-type 2-bit programmable coding metasurface for single-sensor and single- frequency imaging in the microwave frequency. Compared with the existing single-sensor imagers composed of active spatial modulators with their units controlled independently, we introduce randomly programmable metasurface to transform the masks of modulators, in which their rows and columns are controlled simultaneously so that the complexity and cost of the imaging system can be reduced drastically. Different from the single-sensor approach using the frequency agility, the proposed imaging system makes use of variable modulators under single frequency, which can avoid the object dispersion. In order to realize the transmission-type 2-bit programmable metasurface, we propose a two-layer binary coding unit, which is convenient for changing the voltages in rows and columns to switch the diodes in the top and bottom layers, respectively. In our imaging measurements, we generate the random codes by computer to achieve different transmission patterns, which can support enough multiple modes to solve the inverse-scattering problem in the single-sensor imaging. Simple experimental results are presented in the microwave frequency, validating our new single-sensor and single-frequency imaging system.

Visualization of Cortical Dynamics

NASA Astrophysics Data System (ADS)

Grinvald, Amiram

2003-03-01

Recent progress in studies of cortical dynamics will be reviewed including the combination of real time optical imaging based on voltage sensitive dyes, single and multi- unit recordings, LFP, intracellular recordings and microstimulation. To image the flow of neuronal activity from one cortical site to the next, in real time, we have used optical imaging based on newly designed voltage sensitive dyes and a Fuji 128x 128 fast camera which we modified. A factor of 20-40 fold improvement in the signal to noise ratio was obtained with the new dye during in vivo imaging experiments. This improvements has facilitates the exploration of cortical dynamics without signal averaging in the millisecond time domain. We confirmed that the voltage sensitive dye signal indeed reflects membrane potential changes in populations of neurons by showing that the time course of the intracellular activity recorded intracellularly from a single neuron was highly correlated in many cases with the optical signal from a small patch of cortex recorded nearby. We showed that the firing of single cortical neurons is not a random process but occurs when the on-going pattern of million of neurons is similar to the functional architecture map which correspond to the tuning properties of that neuron. Chronic optical imaging, combined with electrical recordings and microstimulation, over a long period of times of more than a year, was successfully applied also to the study of higher brain functions in the behaving macaque monkey.

Comparison of drug treatment histories of single and multiple drug abusers in detox.

PubMed

Greberman, S B; Jasinski, D

2001-01-01

This study was undertaken to determine differences in previous treatment patterns in individuals currently using different numbers of substances. Medical records of 1198 inpatient detoxification (detox) admissions were analyzed. Numbers of past admissions to completed detox, methadone, or other types of drug abuse treatment were totaled and ranked to determine most frequent type. Within gender, treatment histories of single and multiple drug abusers usually do not differ. The one exception is male multiple drug abusers ages 26-30, who show increased admissions. Possible explanations are that men do not seek treatment before developing medical complications of addiction or until external factors influence admission. There were differences in treatment histories between genders in multiple drug abusers only. Before age 30, women reported increased treatment of certain types. Possible explanations are that treatment priority is given to women who are, or may be, pregnant. Also, younger men may not enter or complete treatment. Previous treatment history may influence many behaviors. The results of this study delineate several valuable indicators for assessing past history.

Single stab injuries.

PubMed

Burke, Michael P; Baber, Yeliena; Cheung, Zoe; Fitzgerald, Mark

2018-05-01

Determining the manner of death in cases involving multiple stab injuries from a knife is generally straightforward. The medico-legal investigation of a stabbing death caused by a single stab injury from a knife comprises a smaller but potentially more problematic subset of forensic cases. We reviewed our institute's experience with single stab injuries and endeavored to identify features identified at the post-mortem examination which may aid in the differentiation between cases of homicide, suicide and accidental death. The single stab injury was to the left chest in the majority of deaths from homicide and from suicide. Clothing was nearly always involved in cases of homicide, but was also seen in cases of suicide. The knife was found in situ in 9 of the 11 cases of suicide involving a chest injury, but was not seen in any of the cases of homicide. There were no cases of an accidental single stab death from a knife in our records. Clinical data on accidental stab injuries was sought via a search of the medical records of a major tertiary referral hospital. A single non-fatal case of an accidental single stab injury from a knife was identified after the conclusion of our study period. Accidental stab injuries from a knife causing injury or death are rare.

Late Pliocene cooling, sea ice and the establishment of a Ross Sea polynya: Geochemical and diatom assemblage constraints from McMurdo Sound, Antarctica

NASA Astrophysics Data System (ADS)

Riesselman, C.; Dunbar, R. B.; Sjunneskog, C. M.; Mucciarone, D. A.; Winter, D.; Olney, M.; Tuzzi, E.; McKay, R. M.; Scherer, R. P.

2010-12-01

The marine sediment cores collected by the Antarctic Geological Drilling (ANDRILL) Program from sites beneath the McMurdo Ice Shelf (MIS; Core AND-1B) and in Southern McMurdo Sound (SMS; Core AND-2A) represent the most complete record to date of Neogene climate evolution proximal to the Antarctic continent. Diatom-rich lithologic units alternate with glacial sediments throughout the Pliocene and early Pleistocene of AND-1B; each diatom-rich unit within this oscillating record has distinctive geochemical and diatom assemblage characteristics and most are interpreted to preserve single interglacial intervals of 40-thousand-year glacial/interglacial cycles. Though the dramatic Pliocene glacial/interglacial oscillations recorded at the MIS site are absent in the shallower SMS record, AND-2A preserves a single diverse late Pliocene diatom assemblage, providing an additional constraint on Ross Sea Pliocene climate. Here, we focus on the reconstruction of sea surface conditions from four discrete AND-1B interglacial units deposited ~3.2, 3.0, 2.9, and 2.6 Ma. Diatom assemblages record the onset of Plio-Pleistocene cooling in the Ross Sea at 3.2 Ma, intensifying at 3.0 Ma, and suggest spring blooms in a surface ocean seasonally stratified by sea ice melt. Following the initial cooling, an increase in warm-water species at 2.9 and 2.6 Ma records a temporary late Pliocene reversal in the cooling trend. The Pliocene diatom-bearing interval in AND-2A is equivalent to the 2.6 Ma diatomite, providing further evidence for late Pliocene reversion to warmer open ocean conditions. Cooling resumes in the early Pleistocene, but sea-ice related diatoms, which dominate late Pleistocene and recent Antarctic sediments, are present only as minor components throughout the ANDRILL records. Sedimentary δ13C and δ15N in the AND-1B diatomite units provide additional insights into Pliocene evolution of sea ice, stratification, and primary productivity. For AND-1B diatomite units younger than 3.2 Ma, δ13C and δ15N vary in phase, the amplitude of δ13C fluctuations increases progressively up section, and peak interglacial δ15N trends toward more positive values, reflecting increasing variability in surface-water stratification within individual glacial minima. During the peaks of Late Pliocene glacial minima, negative δ13C values likely indicate enhanced wind mixing and summer polynya formation over AND-1B, while more positive values during the start and end of glacial minima indicate increased stratification due to sea ice melt or reduced wind stress. In sequence, these units offer a unique perspective on the changing character of the interglacial environment in the Ross Embayment spanning the transition from the mid-Pliocene climatic optimum into modern cold-polar conditions.

Process for removing an organic compound from water

DOEpatents

Baker, Richard W.; Kaschemekat, Jurgen; Wijmans, Johannes G.; Kamaruddin, Henky D.

1993-12-28

A process for removing organic compounds from water is disclosed. The process involves gas stripping followed by membrane separation treatment of the stripping gas. The stripping step can be carried out using one or multiple gas strippers and using air or any other gas as stripping gas. The membrane separation step can be carried out using a single-stage membrane unit or a multistage unit. Apparatus for carrying out the process is also disclosed. The process is particularly suited for treatment of contaminated groundwater or industrial wastewater.

Onshore industrial wind turbine locations for the United States up to March 2014

USGS Publications Warehouse

Diffendorfer, James E.; Kramer, Louisa; Ancona, Zachary H.; Garrity, Christopher P.

2015-01-01

Wind energy is a rapidly growing form of renewable energy in the United States. While summary information on the total amounts of installed capacity are available by state, a free, centralized, national, turbine-level, geospatial dataset useful for scientific research, land and resource management, and other uses did not exist. Available in multiple formats and in a web application, these public domain data provide industrial-scale onshore wind turbine locations in the United States up to March 2014, corresponding facility information, and turbine technical specifications. Wind turbine records have been collected and compiled from various public sources, digitized or position verified from aerial imagery, and quality assured and quality controlled. Technical specifications for turbines were assigned based on the wind turbine make and model as described in public literature. In some cases, turbines were not seen in imagery or turbine information did not exist or was difficult to obtain. Uncertainty associated with these is recorded in a confidence rating.

Onshore industrial wind turbine locations for the United States up to March 2014.

PubMed

Diffendorfer, Jay E; Kramer, Louisa A; Ancona, Zach H; Garrity, Christopher P

2015-11-24

Wind energy is a rapidly growing form of renewable energy in the United States. While summary information on the total amounts of installed capacity are available by state, a free, centralized, national, turbine-level, geospatial dataset useful for scientific research, land and resource management, and other uses did not exist. Available in multiple formats and in a web application, these public domain data provide industrial-scale onshore wind turbine locations in the United States up to March 2014, corresponding facility information, and turbine technical specifications. Wind turbine records have been collected and compiled from various public sources, digitized or position verified from aerial imagery, and quality assured and quality controlled. Technical specifications for turbines were assigned based on the wind turbine make and model as described in public literature. In some cases, turbines were not seen in imagery or turbine information did not exist or was difficult to obtain. Uncertainty associated with these is recorded in a confidence rating.

Onshore industrial wind turbine locations for the United States up to March 2014

PubMed Central

Diffendorfer, Jay E.; Kramer, Louisa A.; Ancona, Zach H.; Garrity, Christopher P.

2015-01-01

Wind energy is a rapidly growing form of renewable energy in the United States. While summary information on the total amounts of installed capacity are available by state, a free, centralized, national, turbine-level, geospatial dataset useful for scientific research, land and resource management, and other uses did not exist. Available in multiple formats and in a web application, these public domain data provide industrial-scale onshore wind turbine locations in the United States up to March 2014, corresponding facility information, and turbine technical specifications. Wind turbine records have been collected and compiled from various public sources, digitized or position verified from aerial imagery, and quality assured and quality controlled. Technical specifications for turbines were assigned based on the wind turbine make and model as described in public literature. In some cases, turbines were not seen in imagery or turbine information did not exist or was difficult to obtain. Uncertainty associated with these is recorded in a confidence rating. PMID:26601687

Feasibility of Floating Platform Systems for Wind Turbines: Preprint

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

Musial, W.; Butterfield, S.; Boone, A.

This paper provides a general technical description of several types of floating platforms for wind turbines. Platform topologies are classified into multiple- or single-turbine floaters and by mooring method. Platforms using catenary mooring systems are contrasted to vertical mooring systems and the advantages and disadvantages are discussed. Specific anchor types are described in detail. A rough cost comparison is performed for two different platform architectures using a generic 5-MW wind turbine. One platform is a Dutch study of a tri-floater platform using a catenary mooring system, and the other is a mono-column tension-leg platform developed at the National Renewable Energymore » Laboratory. Cost estimates showed that single unit production cost is $7.1 M for the Dutch tri-floater, and $6.5 M for the NREL TLP concept. However, value engineering, multiple unit series production, and platform/turbine system optimization can lower the unit platform costs to $4.26 M and $2.88 M, respectively, with significant potential to reduce cost further with system optimization. These foundation costs are within the range necessary to bring the cost of energy down to the DOE target range of $0.05/kWh for large-scale deployment of offshore floating wind turbines.« less

Single and Multiple Scattered Solar Radiation

DTIC Science & Technology

1982-08-30

so that factor can be expected to vary considerably from one scattering point to the next. The monochromatic intensity at the observer due to all of...the single scattering sources within the line-of-sight is obtained by summing over the optical path the product of the source function and the...the observer. Using a dot product 1)etwecen position_ vectors on the unit sphere, it can be Chown that cosA cost coss cost) cos4o + 0 S 0 0 "+ cost

Single-Specimen Technique to Establish the J-Resistance of Linear Viscoelastic Solids with Constant Poisson's Ratio

NASA Technical Reports Server (NTRS)

Gutierrez-Lemini, Danton; McCool, Alex (Technical Monitor)

2001-01-01

A method is developed to establish the J-resistance function for an isotropic linear viscoelastic solid of constant Poisson's ratio using the single-specimen technique with constant-rate test data. The method is based on the fact that, for a test specimen of fixed crack size under constant rate, the initiation J-integral may be established from the crack size itself, the actual external load and load-point displacement at growth initiation, and the relaxation modulus of the viscoelastic solid, without knowledge of the complete test record. Since crack size alone, of the required data, would be unknown at each point of the load-vs-load-point displacement curve of a single-specimen test, an expression is derived to estimate it. With it, the physical J-integral at each point of the test record may be established. Because of its basis on single-specimen testing, not only does the method not require the use of multiple specimens with differing initial crack sizes, but avoids the need for tracking crack growth as well.

Building a Web in Science Instruction: Using Multiple Resources in a Swedish Multilingual Middle School Class

ERIC Educational Resources Information Center

Jakobson, Britt; Axelsson, Monica

2017-01-01

This study, on the unit measuring time, examines classroom use of different resources and their affordances for students' meaning-making. The data, comprising audio and video recordings, fieldnotes, photographs and student texts, were collected during a lesson in a multilingual Swedish grade 5 classroom (students aged 11-12). In order to analyse…

Task-Dependent Intermuscular Motor Unit Synchronization between Medial and Lateral Vastii Muscles during Dynamic and Isometric Squats.

PubMed

Mohr, Maurice; Nann, Marius; von Tscharner, Vinzenz; Eskofier, Bjoern; Nigg, Benno Maurus

2015-01-01

Motor unit activity is coordinated between many synergistic muscle pairs but the functional role of this coordination for the motor output is unclear. The purpose of this study was to investigate the short-term modality of coordinated motor unit activity-the synchronized discharge of individual motor units across muscles within time intervals of 5ms-for the Vastus Medialis (VM) and Lateralis (VL). Furthermore, we studied the task-dependency of intermuscular motor unit synchronization between VM and VL during static and dynamic squatting tasks to provide insight into its functional role. Sixteen healthy male and female participants completed four tasks: Bipedal squats, single-leg squats, an isometric squat, and single-leg balance. Monopolar surface electromyography (EMG) was used to record motor unit activity of VM and VL. For each task, intermuscular motor unit synchronization was determined using a coherence analysis between the raw EMG signals of VM and VL and compared to a reference coherence calculated from two desynchronized EMG signals. The time shift between VM and VL EMG signals was estimated according to the slope of the coherence phase angle spectrum. For all tasks, except for singe-leg balance, coherence between 15-80Hz significantly exceeded the reference. The corresponding time shift between VM and VL was estimated as 4ms. Coherence between 30-60Hz was highest for the bipedal squat, followed by the single-leg squat and the isometric squat. There is substantial short-term motor unit synchronization between VM and VL. Intermuscular motor unit synchronization is enhanced for contractions during dynamic activities, possibly to facilitate a more accurate control of the joint torque, and reduced during single-leg tasks that require balance control and thus, a more independent muscle function. It is proposed that the central nervous system scales the degree of intermuscular motor unit synchronization according to the requirements of the movement task at hand.

Task-Dependent Intermuscular Motor Unit Synchronization between Medial and Lateral Vastii Muscles during Dynamic and Isometric Squats

PubMed Central

Mohr, Maurice; Nann, Marius; von Tscharner, Vinzenz; Eskofier, Bjoern; Nigg, Benno Maurus

2015-01-01

Purpose Motor unit activity is coordinated between many synergistic muscle pairs but the functional role of this coordination for the motor output is unclear. The purpose of this study was to investigate the short-term modality of coordinated motor unit activity–the synchronized discharge of individual motor units across muscles within time intervals of 5ms–for the Vastus Medialis (VM) and Lateralis (VL). Furthermore, we studied the task-dependency of intermuscular motor unit synchronization between VM and VL during static and dynamic squatting tasks to provide insight into its functional role. Methods Sixteen healthy male and female participants completed four tasks: Bipedal squats, single-leg squats, an isometric squat, and single-leg balance. Monopolar surface electromyography (EMG) was used to record motor unit activity of VM and VL. For each task, intermuscular motor unit synchronization was determined using a coherence analysis between the raw EMG signals of VM and VL and compared to a reference coherence calculated from two desynchronized EMG signals. The time shift between VM and VL EMG signals was estimated according to the slope of the coherence phase angle spectrum. Results For all tasks, except for singe-leg balance, coherence between 15–80Hz significantly exceeded the reference. The corresponding time shift between VM and VL was estimated as 4ms. Coherence between 30–60Hz was highest for the bipedal squat, followed by the single-leg squat and the isometric squat. Conclusion There is substantial short-term motor unit synchronization between VM and VL. Intermuscular motor unit synchronization is enhanced for contractions during dynamic activities, possibly to facilitate a more accurate control of the joint torque, and reduced during single-leg tasks that require balance control and thus, a more independent muscle function. It is proposed that the central nervous system scales the degree of intermuscular motor unit synchronization according to the requirements of the movement task at hand. PMID:26529604

Exploring middle school students' use of inscriptions in project-based science classrooms

NASA Astrophysics Data System (ADS)

Wu, Hsin-Kai; Krajcik, Joseph S.

2006-09-01

This study explores seventh graders' use of inscriptions in a teacher-designed project-based science unit. To investigate students' learning practices during the 8-month water quality unit, we collected multiple sources of data (e.g., classroom video recordings, student artifacts, and teacher interviews) and employed analytical methods that drew from a naturalistic approach. The findings showed that throughout the unit, provided with the teachers' scaffold and social, conceptual, and material resources, the seventh graders were able to use various inscriptions (e.g., digital pictures, Web pages, and models) to demonstrate meaningful inscriptional practices such as creating and using inscriptions to make arguments, to represent conceptual understandings, and to engage in thoughtful discussions. Inscriptions and associated practices provided students with experiences and understandings about certain ways to organize, transform, and link data or scientific ideas. However, when constructing inscriptions, students did not consider how the inscriptions could serve certain reasoning purposes. In addition, more scaffolds were needed to help students use multiple inscriptions to make a coherent argument.

The unit event of sliding of the chemo-mechanical enzyme composed of myosin and actin with regulatory proteins.

PubMed

Oosawa, Fumio

2008-04-25

Various myosin-actin systems do not always show the same sliding behaviors. To make the situation clear, discussions are concentrated on the unit event of sliding of the chemo-mechanical enzyme composed of a single myosin head and a single actin filament with regulatory proteins. The popular idea of the one-to-one correspondence between the chemical state and the physical state or between the chemical reaction step and the physical conformational change is reexamined. It is likely that the sites and the modes of interaction between myosin head and actin filament during the ATP hydrolysis are more multiple and variable, and the input-output coupling in the chemo-mechanical enzyme is loose.

Estimation of energy requirements for mechanically ventilated, critically ill patients using nutritional status

PubMed Central

Kan, Mee-Nin; Chang, Han-Hsin; Sheu, Woei-Fen; Cheng, Chien-Hsiang; Lee, Bor-Jen; Huang, Yi-Chia

2003-01-01

Background There is very little information on what is considered an adequate energy intake for mechanically ventilated, critically ill patients. The purpose of the present study was to determine this energy requirement by making use of patients' nutritional status. Methods The study was conducted in a multidisciplinary intensive care unit of Taichung Veterans General Hospital, Taiwan. Patients were hemodynamically stable and not comatose, and were requiring at least 7 days of mechanical ventilation. Fifty-four patients successfully completed this study. The resting energy expenditure was measured using indirect calorimetry. The total energy requirement was considered 120% of the measured energy expenditure. The daily nutrient intake was recorded. Nutritional status was assessed using single and multiple parameters, nitrogen balance, and medical records, and was performed within 24 hours of admission and after 7 days in the intensive care unit. Results Fifteen patients were being underfed (<90% of total energy requirement), 20 patients were in the appropriate feeding (AF) group (within ± 10% of total energy requirement), and 19 patients received overfeeding (>110% of total energy requirement). Patients in the underfeeding group received only 68.3% of their energy requirement, while the overfeeding group patients received up to 136.5% of their required calories. Only patients in the AF group had a positive nitrogen balance (0.04 ± 5.1) on day 7. AF group patients had a significantly higher Nutritional Risk Index value at day 7 than at day 1. Conclusion AF patients had more improvement in nutritional status than patients in the other feeding groups. To provide at least 120% of the resting energy expenditure seemed adequate to meet the caloric energy needs of hemodynamically stable, mechanically ventilated, critically ill patients. PMID:12974978

Evidence for Early Pleistocene Glaciation obtained from borecores collected in East-Central Alberta, Canada

NASA Astrophysics Data System (ADS)

Barendregt, R. W.; Andriashek, L. D.; Jackson, L. E.

2014-12-01

Borecores collected from the east-central region of Alberta, Canada have recently been sub-sampled and studied for paleomagnetic remanence characteristics. A preliminary magnetostratigraphy has been established for sediments previously assumed to represent multiple continental (Laurentide) glaciations, but for which no geochronology was available for the pre-late Wisconsin units. Comprised primarily of tills and lesser thicknesses of interbedded glacio-lacustrine and outwash sediments, the record is extensive, reaching to thicknesses of 300 metres within buried valleys. Most of the sampled units are not accessible from outcrop, and their sedimentology and stratigraphy is derived from core data only. The lowermost tills are reversely magnetized in the majority of borecores sampled to date. These tills are underlain by Empress Formation sediments and/or Colorado Group shales, and overlain by normally magnetized sediments. Both tills contain substantial weathering horizons at their surface, suggesting that interglacial or nonglacial conditions persisted for some time after each period of till deposition. Whether these tills represent a single Early Pleistocene glaciation, or perhaps two, will require additional borecore measurements. This new record of Early Pleistocene glaciation(s) in east-central Alberta places the westernmost extent of earliest Laurentide ice some 300 km farther westward from its previously established limit in the Saskatoon to Regina region of the western Canadian prairies, but still well short of the all-time limit and elevation reached during the Late Wisconsin (Late Pleistocene) in the foothills of the Alberta and Montana Rocky Mountains. Key Words: East-Central Alberta glacial history, Early Pleistocene (Laurentide) glaciation, till magnetostratigraphy, Quaternary history of Western Canadian Prairies, continental glaciations of North America.

Engineering challenges of BioNEMS: the integration of microfluidics, micro- and nanodevices, models and external control for systems biology.

PubMed

Wikswo, J P; Prokop, A; Baudenbacher, F; Cliffel, D; Csukas, B; Velkovsky, M

2006-08-01

Systems biology, i.e. quantitative, postgenomic, postproteomic, dynamic, multiscale physiology, addresses in an integrative, quantitative manner the shockwave of genetic and proteomic information using computer models that may eventually have 10(6) dynamic variables with non-linear interactions. Historically, single biological measurements are made over minutes, suggesting the challenge of specifying 10(6) model parameters. Except for fluorescence and micro-electrode recordings, most cellular measurements have inadequate bandwidth to discern the time course of critical intracellular biochemical events. Micro-array expression profiles of thousands of genes cannot determine quantitative dynamic cellular signalling and metabolic variables. Major gaps must be bridged between the computational vision and experimental reality. The analysis of cellular signalling dynamics and control requires, first, micro- and nano-instruments that measure simultaneously multiple extracellular and intracellular variables with sufficient bandwidth; secondly, the ability to open existing internal control and signalling loops; thirdly, external BioMEMS micro-actuators that provide high bandwidth feedback and externally addressable intracellular nano-actuators; and, fourthly, real-time, closed-loop, single-cell control algorithms. The unravelling of the nested and coupled nature of cellular control loops requires simultaneous recording of multiple single-cell signatures. Externally controlled nano-actuators, needed to effect changes in the biochemical, mechanical and electrical environment both outside and inside the cell, will provide a major impetus for nanoscience.

Single-transducer dual-frequency ultrasound generation to enhance acoustic cavitation.

PubMed

Liu, Hao-Li; Hsieh, Chao-Ming

2009-03-01

Dual- or multiple-frequency ultrasound stimulation is capable of effectively enhancing the acoustic cavitation effect over single-frequency ultrasound. Potential application of this sonoreactor design has been widely proposed such as on sonoluminescence, sonochemistry enhancement, and transdermal drug release enhancement. All currently available sonoreactor designs employed multiple piezoelectric transducers for generating single-frequency ultrasonic waves separately and then these waves were mixed and interfered in solutions. The purpose of this research is to propose a novel design of generating dual-frequency ultrasonic waves with single piezoelectric elements, thereby enhancing acoustic cavitation. Macroscopic bubbles were detected optically, and they were quantified at either a single-frequency or for different frequency combinations for determining their efficiency for enhancing acoustic cavitation. Visible bubbles were optically detected and hydrogen peroxide was measured to quantify acoustic cavitation. Test water samples with different gas concentrations and different power levels were used to determine the efficacy of enhancing acoustic cavitation of this design. The spectrum obtained from the backscattered signals was also recorded and examined to confirm the occurrence of stable cavitation. The results confirmed that single-element dual-frequency ultrasound stimulation can enhance acoustic cavitation. Under certain testing conditions, the generation of bubbles can be enhanced up to a level of five times higher than the generation of bubbles in single-frequency stimulation, and can increase the hydrogen peroxide production up to an increase of one fold. This design may serve as a useful alternative for future sonoreactor design owing to its simplicity to produce dual- or multiple-frequency ultrasound.

Lake sediment records as earthquake catalogues: A compilation from Swiss lakes - Limitations and possibilities

NASA Astrophysics Data System (ADS)

Kremer, Katrina; Reusch, Anna; Wirth, Stefanie B.; Anselmetti, Flavio S.; Girardclos, Stéphanie; Strasser, Michael

2016-04-01

Intraplate settings are characterized by low deformation rates and recurrence intervals of strong earthquakes that often exceed the time span covered by instrumental records. Switzerland, as an example for such settings, shows a low instrumentally recorded seismicity, in contrast to strong earthquakes (e.g. 1356 Basel earthquake, Mw=6.6 and 1601 Unterwalden earthquake, Mw=5.9) mentioned in the historical archives. As such long recurrence rates do not allow for instrumental identification of earthquake sources of these strong events, and as intense geomorphologic alterations prevent preservation of surface expressions of faults, the knowledge of active faults is very limited. Lake sediments are sensitive to seismic shaking and thus, can be used to extend the regional earthquake catalogue if the sedimentary deposits or deformation structures can be linked to an earthquake. Single lake records allow estimating local intensities of shaking while multiple lake records can furthermore be used to compare temporal and spatial distribution of earthquakes. In this study, we compile a large dataset of dated sedimentary event deposits recorded in Swiss lakes available from peer-reviewed publications and unpublished master theses. We combine these data in order to detect large prehistoric regional earthquake events or periods of intense shaking that might have affected multiple lake settings. In a second step, using empirical seismic attenuation equations, we test if lake records can be used to reconstruct magnitudes and epicentres of identified earthquakes.

Integrating artificial intelligence with real-time intracranial EEG monitoring to automate interictal identification of seizure onset zones in focal epilepsy.

PubMed

Varatharajah, Yogatheesan; Berry, Brent; Cimbalnik, Jan; Kremen, Vaclav; Van Gompel, Jamie; Stead, Matt; Brinkmann, Benjamin; Iyer, Ravishankar; Worrell, Gregory

2018-08-01

An ability to map seizure-generating brain tissue, i.e. the seizure onset zone (SOZ), without recording actual seizures could reduce the duration of invasive EEG monitoring for patients with drug-resistant epilepsy. A widely-adopted practice in the literature is to compare the incidence (events/time) of putative pathological electrophysiological biomarkers associated with epileptic brain tissue with the SOZ determined from spontaneous seizures recorded with intracranial EEG, primarily using a single biomarker. Clinical translation of the previous efforts suffers from their inability to generalize across multiple patients because of (a) the inter-patient variability and (b) the temporal variability in the epileptogenic activity. Here, we report an artificial intelligence-based approach for combining multiple interictal electrophysiological biomarkers and their temporal characteristics as a way of accounting for the above barriers and show that it can reliably identify seizure onset zones in a study cohort of 82 patients who underwent evaluation for drug-resistant epilepsy. Our investigation provides evidence that utilizing the complementary information provided by multiple electrophysiological biomarkers and their temporal characteristics can significantly improve the localization potential compared to previously published single-biomarker incidence-based approaches, resulting in an average area under ROC curve (AUC) value of 0.73 in a cohort of 82 patients. Our results also suggest that recording durations between 90 min and 2 h are sufficient to localize SOZs with accuracies that may prove clinically relevant. The successful validation of our approach on a large cohort of 82 patients warrants future investigation on the feasibility of utilizing intra-operative EEG monitoring and artificial intelligence to localize epileptogenic brain tissue. Broadly, our study demonstrates the use of artificial intelligence coupled with careful feature engineering in augmenting clinical decision making.

Flat bands in fractal-like geometry

NASA Astrophysics Data System (ADS)

Pal, Biplab; Saha, Kush

2018-05-01

We report the presence of multiple flat bands in a class of two-dimensional lattices formed by Sierpinski gasket (SPG) fractal geometries as the basic unit cells. Solving the tight-binding Hamiltonian for such lattices with different generations of a SPG network, we find multiple degenerate and nondegenerate completely flat bands, depending on the configuration of parameters of the Hamiltonian. Moreover, we establish a generic formula to determine the number of such bands as a function of the generation index ℓ of the fractal geometry. We show that the flat bands and their neighboring dispersive bands have remarkable features, the most interesting one being the spin-1 conical-type spectrum at the band center without any staggered magnetic flux, in contrast to the kagome lattice. We furthermore investigate the effect of magnetic flux in these lattice settings and show that different combinations of fluxes through such fractal unit cells lead to a richer spectrum with a single isolated flat band or gapless electron- or holelike flat bands. Finally, we discuss a possible experimental setup to engineer such a fractal flat-band network using single-mode laser-induced photonic waveguides.

Chlorhexidine allergy in four specialist allergy centres in the United Kingdom, 2009–13: clinical features and diagnostic tests

PubMed Central

Helbert, M.; Sargur, R.; Swallow, K.; Harper, N.; Garcez, T.; Savic, S.; Savic, L.; Eren, E.

2017-01-01

Summary We describe an observational survey of diagnostic pathways in 104 patients attending four specialist allergy clinics in the United Kingdom following perioperative hypersensitivity reactions to chlorhexidine reactions. The majority were life‐threatening. Men undergoing urological or cardiothoracic surgery predominated. Skin prick testing and specific immunoglobulin (sIg)E testing were the most common tests used for diagnosis. Fifty‐three per cent of diagnoses were made on the basis of a single positive test. Where multiple tests were performed the sensitivity of intradermal, basophil activation and skin prick testing was 68% (50–86%), 50% (10–90%) and 35% (17–55%), respectively. Seven per cent were negative on screening tests initially, and 12 cases were only positive for a single test despite multiple testing. Intradermal tests appeared most sensitive in this context. Additional sensitization to other substances used perioperatively, particularly neuromuscular blocking agents (NMBA), was found in 28 patients, emphasizing the need to test for possible allergy to all drugs to which the patient was exposed even where chlorhexidine is positive. PMID:28194756

Real-time electroholography using a multiple-graphics processing unit cluster system with a single spatial light modulator and the InfiniBand network

NASA Astrophysics Data System (ADS)

Niwase, Hiroaki; Takada, Naoki; Araki, Hiromitsu; Maeda, Yuki; Fujiwara, Masato; Nakayama, Hirotaka; Kakue, Takashi; Shimobaba, Tomoyoshi; Ito, Tomoyoshi

2016-09-01

Parallel calculations of large-pixel-count computer-generated holograms (CGHs) are suitable for multiple-graphics processing unit (multi-GPU) cluster systems. However, it is not easy for a multi-GPU cluster system to accomplish fast CGH calculations when CGH transfers between PCs are required. In these cases, the CGH transfer between the PCs becomes a bottleneck. Usually, this problem occurs only in multi-GPU cluster systems with a single spatial light modulator. To overcome this problem, we propose a simple method using the InfiniBand network. The computational speed of the proposed method using 13 GPUs (NVIDIA GeForce GTX TITAN X) was more than 3000 times faster than that of a CPU (Intel Core i7 4770) when the number of three-dimensional (3-D) object points exceeded 20,480. In practice, we achieved ˜40 tera floating point operations per second (TFLOPS) when the number of 3-D object points exceeded 40,960. Our proposed method was able to reconstruct a real-time movie of a 3-D object comprising 95,949 points.

Demographics of the gay and lesbian population in the United States: evidence from available systematic data sources.

PubMed

Black, D; Gates, G; Sanders, S; Taylor, L

2000-05-01

This work provides an overview of standard social science data sources that now allow some systematic study of the gay and lesbian population in the United States. For each data source, we consider how sexual orientation can be defined, and we note the potential sample sizes. We give special attention to the important problem of measurement error, especially the extent to which individuals recorded as gay and lesbian are indeed recorded correctly. Our concern is that because gays and lesbians constitute a relatively small fraction of the population, modest measurement problems could lead to serious errors in inference. In examining gays and lesbians in multiple data sets we also achieve a second objective: We provide a set of statistics about this population that is relevant to several current policy debates.

Does clinical governance influence the appropriateness of hospital stay?

PubMed

Specchia, Maria Lucia; Poscia, Andrea; Volpe, Massimo; Parente, Paolo; Capizzi, Silvio; Cambieri, Andrea; Damiani, Gianfranco; Ricciardi, Walter; De Belvis, Antonio Giulio

2015-04-03

Clinical Governance provides a framework for assessing and improving clinical quality through a single coherent program. Organizational appropriateness is aimed at achieving the best health outcomes and the most appropriate use of resources. The goal of the present study is to verify the likely relationship between Clinical Governance and appropriateness of hospital stay. A cross-sectional study was conducted in 2012 in an Italian Teaching Hospital. The OPTIGOV(©) (Optimizing Health Care Governance) methodology was used to quantify the level of implementation of Clinical Governance globally and in its main dimensions. Organizational appropriateness was measured retrospectively using the Italian version of the Appropriateness Evaluation Protocol to analyze a random sample of medical records for each clinical unit. Pearson-correlation and multiple linear regression were used to test the relationship between the percentage of inappropriate days of hospital stay and the Clinical Governance implementation levels. 47 Units were assessed. The percentage of inappropriate days of hospital stay showed an inverse correlation with almost all the main Clinical Governance dimensions. Adjusted multiple regression analysis resulted in a significant association between the percentage of inappropriate days and the overall Clinical Governance score (β = -0.28; p < 0.001; R-squared = 0.8). EBM and Clinical Audit represented the Clinical Governance dimensions which had the strongest association with organizational appropriateness. This study suggests that the evaluation of both Clinical Governance and organizational appropriateness through standardized and repeatable tools, such as OPTIGOV(©) and AEP, is a key strategy for healthcare quality. The relationship between the two underlines the central role of Clinical Governance, and especially of EBM and Clinical Audit, in determining a rational improvement of appropriateness levels.

Chronic, Wireless Recordings of Large Scale Brain Activity in Freely Moving Rhesus Monkeys

PubMed Central

Schwarz, David A.; Lebedev, Mikhail A.; Hanson, Timothy L.; Dimitrov, Dragan F.; Lehew, Gary; Meloy, Jim; Rajangam, Sankaranarayani; Subramanian, Vivek; Ifft, Peter J.; Li, Zheng; Ramakrishnan, Arjun; Tate, Andrew; Zhuang, Katie; Nicolelis, Miguel A.L.

2014-01-01

Advances in techniques for recording large-scale brain activity contribute to both the elucidation of neurophysiological principles and the development of brain-machine interfaces (BMIs). Here we describe a neurophysiological paradigm for performing tethered and wireless large-scale recordings based on movable volumetric three-dimensional (3D) multielectrode implants. This approach allowed us to isolate up to 1,800 units per animal and simultaneously record the extracellular activity of close to 500 cortical neurons, distributed across multiple cortical areas, in freely behaving rhesus monkeys. The method is expandable, in principle, to thousands of simultaneously recorded channels. It also allows increased recording longevity (5 consecutive years), and recording of a broad range of behaviors, e.g. social interactions, and BMI paradigms in freely moving primates. We propose that wireless large-scale recordings could have a profound impact on basic primate neurophysiology research, while providing a framework for the development and testing of clinically relevant neuroprostheses. PMID:24776634

Multiple signal classification algorithm for super-resolution fluorescence microscopy

PubMed Central

Agarwal, Krishna; Macháň, Radek

2016-01-01

Single-molecule localization techniques are restricted by long acquisition and computational times, or the need of special fluorophores or biologically toxic photochemical environments. Here we propose a statistical super-resolution technique of wide-field fluorescence microscopy we call the multiple signal classification algorithm which has several advantages. It provides resolution down to at least 50 nm, requires fewer frames and lower excitation power and works even at high fluorophore concentrations. Further, it works with any fluorophore that exhibits blinking on the timescale of the recording. The multiple signal classification algorithm shows comparable or better performance in comparison with single-molecule localization techniques and four contemporary statistical super-resolution methods for experiments of in vitro actin filaments and other independently acquired experimental data sets. We also demonstrate super-resolution at timescales of 245 ms (using 49 frames acquired at 200 frames per second) in samples of live-cell microtubules and live-cell actin filaments imaged without imaging buffers. PMID:27934858

Using pupil size and heart rate to infer affective states during behavioral neurophysiology and neuropsychology experiments

PubMed Central

Mitz, Andrew R.; Chacko, Ravi V.; Putnam, Philip T.; Rudebeck, Peter H.; Murray, Elisabeth A.

2017-01-01

Background Nonhuman primates (NHPs) are a valuable research model because of their behavioral, physiological and neuroanatomical similarities to humans. In the absence of language, autonomic activity can provide crucial information about cognitive and affective states during single-unit recording, inactivation and lesion studies. Methods standardized for use in humans are not easily adapted to NHPs and detailed guidance has been lacking. New Method We provide guidance for monitoring heart rate and pupil size in the behavioral neurophysiology setting by addressing the methodological issues, pitfalls and solutions for NHP studies. The methods are based on comparative physiology to establish a rationale for each solution. We include examples from both electrophysiological and lesion studies. Results Single-unit recording, pupil responses and heart rate changes represent a range of decreasing temporal resolution, a characteristic that impacts experimental design and analysis. We demonstrate the unexpected result that autonomic measures acquired before and after amygdala lesions are comparable despite disruption of normal autonomic function. Comparison with Existing Methods Species and study design differences can render standard techniques used in human studies inappropriate for NHP studies. We show how to manage data from small groups typical of NHP studies, data from the short behavioral trials typical of neurophysiological studies, issues associated with longitudinal studies, and differences in anatomy and physiology. Conclusions Autonomic measurement to infer cognitive and affective states in NHP is neither off-the-shelf nor onerous. Familiarity with the issues and solutions will broaden the use of autonomic signals in NHP single unit and lesion studies. PMID:28089759

Namibia’s transition from whole blood–derived pooled platelets to single-donor apheresis platelet collections

PubMed Central

Pitman, John P.; Basavaraju, Sridhar V.; Shiraishi, Ray W.; Wilkinson, Robert; von Finckenstein, Bjorn; Lowrance, David W.; Marfin, Anthony A.; Postma, Maarten; Mataranyika, Mary; Sibinga, Cees Th. Smit

2015-01-01

BACKGROUND Few African countries separate blood donations into components; however, demand for platelets (PLTs) is increasing as regional capacity to treat causes of thrombocytopenia, including chemotherapy, increases. Namibia introduced single-donor apheresis PLT collections in 2007 to increase PLT availability while reducing exposure to multiple donors via pooling. This study describes the impact this transition had on PLT availability and safety in Namibia. STUDY DESIGN AND METHODS Annual national blood collections and PLT units issued data were extracted from a database maintained by the Blood Transfusion Service of Namibia (NAMBTS). Production costs and unit prices were analyzed. RESULTS In 2006, NAMBTS issued 771 single and pooled PLT doses from 3054 whole blood (WB) donations (drawn from 18,422 WB donations). In 2007, NAMBTS issued 486 single and pooled PLT doses from 1477 WB donations (drawn from 18,309 WB donations) and 131 single-donor PLT doses. By 2011, NAMBTS issued 837 single-donor PLT doses per year, 99.1% of all PLT units. Of 5761 WB donations from which PLTs were made in 2006 to 2011, a total of 20 (0.35%) were from donors with confirmed test results for human immunodeficiency virus or other transfusion-transmissible infections (TTIs). Of 2315 single-donor apheresis donations between 2007 and 2011, none of the 663 donors had a confirmed positive result for any pathogen. As apheresis replaced WB-derived PLTs, apheresis production costs dropped by a mean of 8.2% per year, while pooled PLT costs increased by an annual mean of 21.5%. Unit prices paid for apheresis- and WB-derived PLTs increased by 9 and 7.4% per year on average, respectively. CONCLUSION Namibia’s PLT transition shows that collections from repeat apheresis donors can reduce TTI risk and production costs. PMID:25727921

Ultraflexible nanoelectronic probes form reliable, glial scar–free neural integration

PubMed Central

Luan, Lan; Wei, Xiaoling; Zhao, Zhengtuo; Siegel, Jennifer J.; Potnis, Ojas; Tuppen, Catherine A; Lin, Shengqing; Kazmi, Shams; Fowler, Robert A.; Holloway, Stewart; Dunn, Andrew K.; Chitwood, Raymond A.; Xie, Chong

2017-01-01

Implanted brain electrodes construct the only means to electrically interface with individual neurons in vivo, but their recording efficacy and biocompatibility pose limitations on scientific and clinical applications. We showed that nanoelectronic thread (NET) electrodes with subcellular dimensions, ultraflexibility, and cellular surgical footprints form reliable, glial scar–free neural integration. We demonstrated that NET electrodes reliably detected and tracked individual units for months; their impedance, noise level, single-unit recording yield, and the signal amplitude remained stable during long-term implantation. In vivo two-photon imaging and postmortem histological analysis revealed seamless, subcellular integration of NET probes with the local cellular and vasculature networks, featuring fully recovered capillaries with an intact blood-brain barrier and complete absence of chronic neuronal degradation and glial scar. PMID:28246640

Acute adaptation of the vestibuloocular reflex: signal processing by floccular and ventral parafloccular Purkinje cells.

PubMed

Hirata, Y; Highstein, S M

2001-05-01

The gain of the vertical vestibuloocular reflex (VVOR), defined as eye velocity/head velocity was adapted in squirrel monkeys by employing visual-vestibular mismatch stimuli. VVOR gain, measured in the dark, could be trained to values between 0.4 and 1.5. Single-unit activity of vertical zone Purkinje cells was recorded from the flocculus and ventral paraflocculus in alert squirrel monkeys before and during the gain change training. Our goal was to evaluate the site(s) of learning of the gain change. To aid in the evaluation, a model of the vertical optokinetic reflex (VOKR) and VVOR was constructed consisting of floccular and nonfloccular systems divided into subsystems based on the known anatomy and input and output parameters. Three kinds of input to floccular Purkinje cells via mossy fibers were explicitly described, namely vestibular, visual (retinal slip), and efference copy of eye movement. The characteristics of each subsystem (gain and phase) were identified at different VOR gains by reconstructing single-unit activity of Purkinje cells during VOKR and VVOR with multiple linear regression models consisting of sensory input and motor output signals. Model adequacy was checked by evaluating the residual following the regressions and by predicting Purkinje cells' activity during visual-vestibular mismatch paradigms. As a result, parallel changes in identified characteristics with VVOR adaptation were found in the prefloccular/floccular subsystem that conveys vestibular signals and in the nonfloccular subsystem that conveys vestibular signals, while no change was found in other subsystems, namely prefloccular/floccular subsystems conveying efference copy or visual signals, nonfloccular subsystem conveying visual signals, and postfloccular subsystem transforming Purkinje cell activity to eye movements. The result suggests multiple sites for VVOR motor learning including both flocculus and nonflocculus pathways. The gain change in the nonfloccular vestibular subsystem was in the correct direction to cause VOR gain adaptation while the change in the prefloccular/floccular vestibular subsystem was incorrect (anti-compensatory). This apparent incorrect directional change might serve to prevent instability of the VOR caused by positive feedback via the efference copy pathway.

Single- or multiple-visit endodontics: which technique results in fewest postoperative problems?

PubMed

Balto, Khaled

2009-01-01

The Cochrane Central Register of Controlled Trials, Medline, Embase, six thesis databases (Networked Digital Library of Theses and Dissertations, Proquest Digital Dissertations, OAIster, Index to Theses, Australian Digital Thesis Program and Dissertation.com) and one conference report database (BIOSIS Previews) were searched. There were no language restrictions. Studies were included if subjects had a noncontributory medical history; underwent nonsurgical root canal treatment during the study; there was comparison between single- and multiple-visit root canal treatment; and if outcome was measured in terms of pain degree or prevalence of flare-up. Data were extracted using a standard data extraction sheet. Because of variations in recorded outcomes and methodological and clinical heterogeneity, a meta-analysis was not carried out, although a qualitative synthesis was presented. Sixteen studies fitted the inclusion criteria in the review, with sample size varying from 60-1012 cases. The prevalence of postoperative pain ranged from 3-58%. The heterogeneity of the included studies was far too great to yield meaningful results from a meta-analysis. Compelling evidence is lacking to indicate any significantly different prevalence of postoperative pain or flare-up following either single- or multiple-visit root canal treatment.

Multiple Component Event-Related Potential (mcERP) Estimation

NASA Technical Reports Server (NTRS)

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

2002-01-01

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

Stratification of a cityscape using census and land use variables for inventory of building materials

USGS Publications Warehouse

Rosenfield, G.H.; Fitzpatrick-Lins, K.; Johnson, T.L.

1987-01-01

A cityscape (or any landscape) can be stratified into environmental units using multiple variables of information. For the purposes of sampling building materials, census and land use variables were used to identify similar strata. In the Metropolitan Statistical Area of a cityscape, the census tract is the smallest unit for which census data are summarized and digitized boundaries are available. For purposes of this analysis, census data on total population, total number of housing units, and number of singleunit dwellings were aggregated into variables of persons per square kilometer and proportion of housing units in single-unit dwellings. The level 2 categories of the U.S. Geological Survey's land use and land cover data base were aggregated into variables of proportion of residential land with buildings, proportion of nonresidential land with buildings, and proportion of open land. The cityscape was stratified, from these variables, into environmental strata of Urban Central Business District, Urban Livelihood Industrial Commercial, Urban Multi-Family Residential, Urban Single Family Residential, Non-Urban Suburbanizing, and Non-Urban Rural. The New England region was chosen as a region with commonality of building materials, and a procedure developed for trial classification of census tracts into one of the strata. Final stratification was performed by discriminant analysis using the trial classification and prior probabilities as weights. The procedure was applied to several cities, and the results analyzed by correlation analysis from a field sample of building materials. The methodology developed for stratification of a cityscape using multiple variables has application to many other types of environmental studies, including forest inventory, hydrologic unit management, waste disposal, transportation studies, and other urban studies. Multivariate analysis techniques have recently been used for urban stratification in England. ?? 1987 Annals of Regional Science.

Bringing quality improvement into the intensive care unit.

PubMed

McMillan, Tracy R; Hyzy, Robert C

2007-02-01

During the last several years, many governmental and nongovernmental organizations have championed the application of the principles of quality improvement to the practice of medicine, particularly in the area of critical care. To review the breadth of approaches to quality improvement in the intensive care unit, including measures such as mortality and length of stay, and the use of protocols, bundles, and the role of large, multiple-hospital collaboratives. Several agencies have participated in the application of the quality movement to medicine, culminating in the development of standards such as the intensive care unit core measures of the Joint Commission on Accreditation of Healthcare Organizations. Although "zero defects" may not be possible in all measurable variables of quality in the intensive care unit, several measures, such as catheter-related bloodstream infections, can be significantly reduced through the implementation of improved processes of care, such as care bundles. Large, multiple-center, quality improvement collaboratives, such as the Michigan Keystone Intensive Care Unit Project, may be particularly effective in improving the quality of care by creating a "bandwagon effect" within a geographic region. The quality revolution is having a significant effect in the critical care unit and is likely to be facilitated by the transition to the electronic medical record.

Implementation of a single sign-on system between practice, research and learning systems.

PubMed

Purkayastha, Saptarshi; Gichoya, Judy W; Addepally, Siva Abhishek

2017-03-29

Multiple specialized electronic medical systems are utilized in the health enterprise. Each of these systems has their own user management, authentication and authorization process, which makes it a complex web for navigation and use without a coherent process workflow. Users often have to remember multiple passwords, login/logout between systems that disrupt their clinical workflow. Challenges exist in managing permissions for various cadres of health care providers. This case report describes our experience of implementing a single sign-on system, used between an electronic medical records system and a learning management system at a large academic institution with an informatics department responsible for student education and a medical school affiliated with a hospital system caring for patients and conducting research. At our institution, we use OpenMRS for research registry tracking of interventional radiology patients as well as to provide access to medical records to students studying health informatics. To provide authentication across different users of the system with different permissions, we developed a Central Authentication Service (CAS) module for OpenMRS, released under the Mozilla Public License and deployed it for single sign-on across the academic enterprise. The module has been in implementation since August 2015 to present, and we assessed usability of the registry and education system before and after implementation of the CAS module. 54 students and 3 researchers were interviewed. The module authenticates users with appropriate privileges in the medical records system, providing secure access with minimal disruption to their workflow. No passwords requests were sent and users reported ease of use, with streamlined workflow. The project demonstrates that enterprise-wide single sign-on systems should be used in healthcare to reduce complexity like "password hell", improve usability and user navigation. We plan to extend this to work with other systems used in the health care enterprise.

Twin-Mirrored-Galvanometer Laser-Light-Sheet Generator

NASA Technical Reports Server (NTRS)

Rhodes, David B.; Franke, John M.; Jones, Stephen B.; Leighty, Bradley D.

1991-01-01

Multiple, rotating laser-light sheets generated to illuminate flows in wind tunnels. Designed and developed to provide flexibility and adaptability to wide range of applications. Design includes capability to control size and location of laser-light sheet in real time, to generate horizontal or vertical sheets, to sweep sheet repeatedly through volume, to generate multiple sheets with controllable separation, and to rotate single or multiple laser-light sheets. Includes electronic equipment and laser mounted on adjustable-height platform. Twin-mirrored galvanometer unit supported by tripod to reduce vibration. Other possible applications include use in construction industry to align beams of building. Artistic or display applications also possible.

Tools for probing local circuits: high-density silicon probes combined with optogenetics

PubMed Central

Buzsáki, György; Stark, Eran; Berényi, Antal; Khodagholy, Dion; Kipke, Daryl R.; Yoon, Euisik; Wise, Kensall

2015-01-01

To understand how function arises from the interactions between neurons, it is necessary to use methods that allow the monitoring of brain activity at the single-neuron, single-spike level and the targeted manipulation of the diverse neuron types selectively in a closed-loop manner. Large-scale recordings of neuronal spiking combined with optogenetic perturbation of identified individual neurons has emerged as a suitable method for such tasks in behaving animals. To fully exploit the potential power of these methods, multiple steps of technical innovation are needed. We highlight the current state-of-the-art in electrophysiological recording methods, combined with optogenetics, and discuss directions for progress. In addition, we point to areas where rapid development is in progress and discuss topics where near-term improvements are possible and needed. PMID:25856489

Single Concept Film Clip Project; Parts One and Two.

ERIC Educational Resources Information Center

Miller, Elwood E., Director

This project had a two-fold objective, namely to record on film aspects of a significant period in the history of education in the United States which had been reported almost entirely in print heretofore, and to organize and structure this information so as to link theory with practice, to the improvement of instruction generally when used in…

Fully integrated silicon probes for high-density recording of neural activity.

PubMed

Jun, James J; Steinmetz, Nicholas A; Siegle, Joshua H; Denman, Daniel J; Bauza, Marius; Barbarits, Brian; Lee, Albert K; Anastassiou, Costas A; Andrei, Alexandru; Aydın, Çağatay; Barbic, Mladen; Blanche, Timothy J; Bonin, Vincent; Couto, João; Dutta, Barundeb; Gratiy, Sergey L; Gutnisky, Diego A; Häusser, Michael; Karsh, Bill; Ledochowitsch, Peter; Lopez, Carolina Mora; Mitelut, Catalin; Musa, Silke; Okun, Michael; Pachitariu, Marius; Putzeys, Jan; Rich, P Dylan; Rossant, Cyrille; Sun, Wei-Lung; Svoboda, Karel; Carandini, Matteo; Harris, Kenneth D; Koch, Christof; O'Keefe, John; Harris, Timothy D

2017-11-08

Sensory, motor and cognitive operations involve the coordinated action of large neuronal populations across multiple brain regions in both superficial and deep structures. Existing extracellular probes record neural activity with excellent spatial and temporal (sub-millisecond) resolution, but from only a few dozen neurons per shank. Optical Ca 2+ imaging offers more coverage but lacks the temporal resolution needed to distinguish individual spikes reliably and does not measure local field potentials. Until now, no technology compatible with use in unrestrained animals has combined high spatiotemporal resolution with large volume coverage. Here we design, fabricate and test a new silicon probe known as Neuropixels to meet this need. Each probe has 384 recording channels that can programmably address 960 complementary metal-oxide-semiconductor (CMOS) processing-compatible low-impedance TiN sites that tile a single 10-mm long, 70 × 20-μm cross-section shank. The 6 × 9-mm probe base is fabricated with the shank on a single chip. Voltage signals are filtered, amplified, multiplexed and digitized on the base, allowing the direct transmission of noise-free digital data from the probe. The combination of dense recording sites and high channel count yielded well-isolated spiking activity from hundreds of neurons per probe implanted in mice and rats. Using two probes, more than 700 well-isolated single neurons were recorded simultaneously from five brain structures in an awake mouse. The fully integrated functionality and small size of Neuropixels probes allowed large populations of neurons from several brain structures to be recorded in freely moving animals. This combination of high-performance electrode technology and scalable chip fabrication methods opens a path towards recording of brain-wide neural activity during behaviour.

Temporal Correlation Mechanisms and Their Role in Feature Selection: A Single-Unit Study in Primate Somatosensory Cortex

PubMed Central

Gomez-Ramirez, Manuel; Trzcinski, Natalie K.; Mihalas, Stefan; Niebur, Ernst

2014-01-01

Studies in vision show that attention enhances the firing rates of cells when it is directed towards their preferred stimulus feature. However, it is unknown whether other sensory systems employ this mechanism to mediate feature selection within their modalities. Moreover, whether feature-based attention modulates the correlated activity of a population is unclear. Indeed, temporal correlation codes such as spike-synchrony and spike-count correlations (rsc) are believed to play a role in stimulus selection by increasing the signal and reducing the noise in a population, respectively. Here, we investigate (1) whether feature-based attention biases the correlated activity between neurons when attention is directed towards their common preferred feature, (2) the interplay between spike-synchrony and rsc during feature selection, and (3) whether feature attention effects are common across the visual and tactile systems. Single-unit recordings were made in secondary somatosensory cortex of three non-human primates while animals engaged in tactile feature (orientation and frequency) and visual discrimination tasks. We found that both firing rate and spike-synchrony between neurons with similar feature selectivity were enhanced when attention was directed towards their preferred feature. However, attention effects on spike-synchrony were twice as large as those on firing rate, and had a tighter relationship with behavioral performance. Further, we observed increased rsc when attention was directed towards the visual modality (i.e., away from touch). These data suggest that similar feature selection mechanisms are employed in vision and touch, and that temporal correlation codes such as spike-synchrony play a role in mediating feature selection. We posit that feature-based selection operates by implementing multiple mechanisms that reduce the overall noise levels in the neural population and synchronize activity across subpopulations that encode the relevant features of sensory stimuli. PMID:25423284

Intensive care unit depth of sleep: proof of concept of a simple electroencephalography index in the non-sedated

PubMed Central

2014-01-01

Introduction Intensive care unit (ICU) patients are known to experience severely disturbed sleep, with possible detrimental effects on short- and long- term outcomes. Investigation into the exact causes and effects of disturbed sleep has been hampered by cumbersome and time consuming methods of measuring and staging sleep. We introduce a novel method for ICU depth of sleep analysis, the ICU depth of sleep index (IDOS index), using single channel electroencephalography (EEG) and apply it to outpatient recordings. A proof of concept is shown in non-sedated ICU patients. Methods Polysomnographic (PSG) recordings of five ICU patients and 15 healthy outpatients were analyzed using the IDOS index, based on the ratio between gamma and delta band power. Manual selection of thresholds was used to classify data as either wake, sleep or slow wave sleep (SWS). This classification was compared to visual sleep scoring by Rechtschaffen & Kales criteria in normal outpatient recordings and ICU recordings to illustrate face validity of the IDOS index. Results When reduced to two or three classes, the scoring of sleep by IDOS index and manual scoring show high agreement for normal sleep recordings. The obtained overall agreements, as quantified by the kappa coefficient, were 0.84 for sleep/wake classification and 0.82 for classification into three classes (wake, non-SWS and SWS). Sensitivity and specificity were highest for the wake state (93% and 93%, respectively) and lowest for SWS (82% and 76%, respectively). For ICU recordings, agreement was similar to agreement between visual scorers previously reported in literature. Conclusions Besides the most satisfying visual resemblance with manually scored normal PSG recordings, the established face-validity of the IDOS index as an estimator of depth of sleep was excellent. This technique enables real-time, automated, single channel visualization of depth of sleep, facilitating the monitoring of sleep in the ICU. PMID:24716479

Quantitating the multiplicity of infection with human immunodeficiency virus type 1 subtype C reveals a non-poisson distribution of transmitted variants.

PubMed

Abrahams, M-R; Anderson, J A; Giorgi, E E; Seoighe, C; Mlisana, K; Ping, L-H; Athreya, G S; Treurnicht, F K; Keele, B F; Wood, N; Salazar-Gonzalez, J F; Bhattacharya, T; Chu, H; Hoffman, I; Galvin, S; Mapanje, C; Kazembe, P; Thebus, R; Fiscus, S; Hide, W; Cohen, M S; Karim, S Abdool; Haynes, B F; Shaw, G M; Hahn, B H; Korber, B T; Swanstrom, R; Williamson, C

2009-04-01

Identifying the specific genetic characteristics of successfully transmitted variants may prove central to the development of effective vaccine and microbicide interventions. Although human immunodeficiency virus transmission is associated with a population bottleneck, the extent to which different factors influence the diversity of transmitted viruses is unclear. We estimate here the number of transmitted variants in 69 heterosexual men and women with primary subtype C infections. From 1,505 env sequences obtained using a single genome amplification approach we show that 78% of infections involved single variant transmission and 22% involved multiple variant transmissions (median of 3). We found evidence for mutations selected for cytotoxic-T-lymphocyte or antibody escape and a high prevalence of recombination in individuals infected with multiple variants representing another potential escape pathway in these individuals. In a combined analysis of 171 subtype B and C transmission events, we found that infection with more than one variant does not follow a Poisson distribution, indicating that transmission of individual virions cannot be seen as independent events, each occurring with low probability. While most transmissions resulted from a single infectious unit, multiple variant transmissions represent a significant fraction of transmission events, suggesting that there may be important mechanistic differences between these groups that are not yet understood.

A randomized controlled trial of single versus multiple health behavior change: promoting physical activity and nutrition among adolescents.

PubMed

Prochaska, Judith J; Sallis, James F

2004-05-01

Targeting multiple behaviors for change may provide significant health benefits. This study compared interventions targeting physical activity and nutrition (PAN) concurrently versus physical activity (PA) alone. Adolescents (N=138) were randomized to the PAN or PA intervention or control condition (n=46 per group). Primary outcomes were change in PA accelerometer and 3-day dietary recording from baseline to 3-month follow-up. The PAN and PA interventions were efficacious in supporting boys' (p<.001) but not girls' (p=.663) PA relative to the control condition. Dietary change was minimal. Although the findings do not reveal a decrement to PA promotion when a nutrition intervention was added, neither do they reveal any additional benefit. More studies comparing single versus multibehavioral interventions are needed. ((c) 2004 APA, all rights reserved)

Characteristics of Innovators Adopting a National Personal Health Record in Portugal: Cross-Sectional Study

PubMed Central

Rodolfo, Inês; Pereira, Ana Marta; de Sá, Armando Brito

2017-01-01

Background Personal health records (PHRs) are increasingly being deployed worldwide, but their rates of adoption by patients vary widely across countries and health systems. Five main categories of adopters are usually considered when evaluating the diffusion of innovations: innovators, early adopters, early majority, late majority, and laggards. Objective We aimed to evaluate adoption of the Portuguese PHR 3 months after its release, as well as characterize the individuals who registered and used the system during that period (the innovators). Methods We conducted a cross-sectional study. Users and nonusers were defined based on their input, or not, of health-related information into the PHR. Users of the PHR were compared with nonusers regarding demographic and clinical variables. Users were further characterized according to their intensity of information input: single input (one single piece of health-related information recorded) and multiple inputs. Multivariate logistic regression was used to model the probability of being in the multiple inputs group. ArcGis (ESRI, Redlands, CA, USA) was used to create maps of the proportion of PHR registrations by region and district. Results The number of registered individuals was 109,619 (66,408/109,619, 60.58% women; mean age: 44.7 years, standard deviation [SD] 18.1 years). The highest proportion of registrations was observed for those aged between 30 and 39 years (25,810/109,619, 23.55%). Furthermore, 16.88% (18,504/109,619) of registered individuals were considered users and 83.12% (91,115/109,619) nonusers. Among PHR users, 32.18% (5955/18,504) engaged in single input and 67.82% (12,549/18,504) in multiple inputs. Younger individuals and male users had higher odds of engaging in multiple inputs (odds ratio for male individuals 1.32, CI 1.19-1.48). Geographic analysis revealed higher proportions of PHR adoption in urban centers when compared with rural noncoastal districts. Conclusions Approximately 1% of the country’s population registered during the first 3 months of the Portuguese PHR. Registered individuals were more frequently female aged between 30 and 39 years. There is evidence of a geographic gap in the adoption of the Portuguese PHR, with higher proportions of adopters in urban centers than in rural noncoastal districts. PMID:29021125

Ocean Color and Earth Science Data Records

NASA Astrophysics Data System (ADS)

Maritorena, S.

2014-12-01

The development of consistent, high quality time series of biogeochemical products from a single ocean color sensor is a difficult task that involves many aspects related to pre- and post-launch instrument calibration and characterization, stability monitoring and the removal of the contribution of the atmosphere which represents most of the signal measured at the sensor. It is even more challenging to build Climate Data Records (CDRs) or Earth Science Data Records (ESDRs) from multiple sensors as design, technology and methodologies (bands, spectral/spatial resolution, Cal/Val, algorithms) differ from sensor to sensor. NASA MEaSUREs, ESA Climate Change Initiative (CCI) and IOCCG Virtual Constellation are some of the underway efforts that investigate or produce ocean color CDRs or ESDRs from the recent and current global missions (SeaWiFS, MODIS, MERIS). These studies look at key aspects of the development of unified data records from multiple sensors, e.g. the concatenation of the "best" individual records vs. the merging of multiple records or band homogenization vs. spectral diversity. The pros and cons of the different approaches are closely dependent upon the overall science purpose of the data record and its temporal resolution. While monthly data are generally adequate for biogeochemical modeling or to assess decadal trends, higher temporal resolution data records are required to look into changes in phenology or the dynamics of phytoplankton blooms. Similarly, short temporal resolution (daily to weekly) time series may benefit more from being built through the merging of data from multiple sensors while a simple concatenation of data from individual sensors might be better suited for longer temporal resolution (e.g. monthly time series). Several Ocean Color ESDRs were developed as part of the NASA MEaSUREs project. Some of these time series are built by merging the reflectance data from SeaWiFS, MODIS-Aqua and Envisat-MERIS in a semi-analytical ocean color model that generates both merged reflectance and merged biogeochemical products. The benefits and limitations of this merging approach to develop ESDRs will be presented and discussed along with those of alternative approaches.

Recording multiple spatially-heterodyned direct to digital holograms in one digital image

DOEpatents

Hanson, Gregory R [Clinton, TN; Bingham, Philip R [Knoxville, TN

2008-03-25

Systems and methods are described for recording multiple spatially-heterodyned direct to digital holograms in one digital image. A method includes digitally recording, at a first reference beam-object beam angle, a first spatially-heterodyned hologram including spatial heterodyne fringes for Fourier analysis; Fourier analyzing the recorded first spatially-heterodyned hologram by shifting a first original origin of the recorded first spatially-heterodyned hologram to sit on top of a first spatial-heterodyne carrier frequency defined by the first reference beam-object beam angle; digitally recording, at a second reference beam-object beam angle, a second spatially-heterodyned hologram including spatial heterodyne fringes for Fourier analysis; Fourier analyzing the recorded second spatially-heterodyned hologram by shifting a second original origin of the recorded second spatially-heterodyned hologram to sit on top of a second spatial-heterodyne carrier frequency defined by the second reference beam-object beam angle; applying a first digital filter to cut off signals around the first original origin and define a first result; performing a first inverse Fourier transform on the first result; applying a second digital filter to cut off signals around the second original origin and define a second result; and performing a second inverse Fourier transform on the second result, wherein the first reference beam-object beam angle is not equal to the second reference beam-object beam angle and a single digital image includes both the first spatially-heterodyned hologram and the second spatially-heterodyned hologram.

Genotype Reconstruction of Paternity in European Lobsters (Homarus gammarus).

PubMed

Ellis, Charlie D; Hodgson, David J; André, Carl; Sørdalen, Tonje K; Knutsen, Halvor; Griffiths, Amber G F

2015-01-01

Decapod crustaceans exhibit considerable variation in fertilisation strategies, ranging from pervasive single paternity to the near-ubiquitous presence of multiple paternity, and such knowledge of mating systems and behaviour are required for the informed management of commercially-exploited marine fisheries. We used genetic markers to assess the paternity of individual broods in the European lobster, Homarus gammarus, a species for which paternity structure is unknown. Using 13 multiplexed microsatellite loci, three of which are newly described in this study, we genotyped 10 eggs from each of 34 females collected from an Atlantic peninsula in the south-western United Kingdom. Single reconstructed paternal genotypes explained all observed progeny genotypes in each of the 34 egg clutches, and each clutch was fertilised by a different male. Simulations indicated that the probability of detecting multiple paternity was in excess of 95% if secondary sires account for at least a quarter of the brood, and in excess of 99% where additional sire success was approximately equal. Our results show that multiple paternal fertilisations are either absent, unusual, or highly skewed in favour of a single male among H. gammarus in this area. Potential mechanisms upholding single paternal fertilisation are discussed, along with the prospective utility of parentage assignments in evaluations of hatchery stocking and other fishery conservation approaches in light of this finding.

Neuronal codes for the inhibitory control of impulsive actions in the rat infralimbic cortex.

PubMed

Tsutsui-Kimura, Iku; Ohmura, Yu; Izumi, Takeshi; Matsushima, Toshiya; Amita, Hidetoshi; Yamaguchi, Taku; Yoshida, Takayuki; Yoshioka, Mitsuhiro

2016-01-01

Poor impulse control is a debilitating condition observed in various psychiatric disorders and could be a risk factor for drug addiction, criminal involvement, and suicide. The rat infralimbic cortex (IL), located in the ventral portion of the medial prefrontal cortex, has been implicated in impulse control. To elucidate the neurophysiological basis of impulse control, we recorded single unit activity in the IL of a rat performing a 3-choiceserial reaction time task (3-CSRTT) and 2-choice task (2-CT), which are animal models for impulsivity. The inactivation of IL neuronal activity with an injection of muscimol (0.1 μg /side) disrupted impulse control in the 3-CSRTT. More than 60% (38/56) of isolated IL units were linked to impulse control, while approximately 30% of all units were linked to attentional function in the 3-CSRTT. To avoid confounding motor-related units with the impulse control-related units, we further conducted the 2-CT in which the animals' motor activities were restricted during recording window. More than 30% (14/44) of recorded IL units were linked to impulse control in the 2-CT. Several types of impulse control-related units were identified. Only 16% of all units were compatible with the results of the muscimol experiment, which showed a transient decline in the firing rate immediately before the release of behavioral inhibition. This is the first study to elucidate the neurophysiological basis of impulse control in the IL and to propose that IL neurons control impulsive actions in a more complex manner than previously considered. Copyright © 2015 Elsevier B.V. All rights reserved.

Event-recording devices with identification codes

NASA Technical Reports Server (NTRS)

Watters, David G. (Inventor); Huestis, David L. (Inventor); Bahr, Alfred J. (Inventor); Vidmar, Robert J. (Inventor)

2003-01-01

A recording device allows wireless interrogation to determine its identity and its state. The state indicates whether one or more physical or chemical events have taken place. In effect, the one or more physical or chemical events are recorded by the device. The identity of the device allows it to be distinguished from a number of similar devices. The recording device may be used in an array of devices that allows wireless probing by an interrogation unit. When probed, each device tells the interrogator who it is and what state it is in. The devices allow multiple use and the interrogator may use a logical reset to determine the state of each device. The interrogator can thus easily identify particular items in an array that have reached a particular condition. The device may record the status of each device in a database to maintain a history for each.

Large-scale, high-density (up to 512 channels) recording of local circuits in behaving animals

PubMed Central

Berényi, Antal; Somogyvári, Zoltán; Nagy, Anett J.; Roux, Lisa; Long, John D.; Fujisawa, Shigeyoshi; Stark, Eran; Leonardo, Anthony; Harris, Timothy D.

2013-01-01

Monitoring representative fractions of neurons from multiple brain circuits in behaving animals is necessary for understanding neuronal computation. Here, we describe a system that allows high-channel-count recordings from a small volume of neuronal tissue using a lightweight signal multiplexing headstage that permits free behavior of small rodents. The system integrates multishank, high-density recording silicon probes, ultraflexible interconnects, and a miniaturized microdrive. These improvements allowed for simultaneous recordings of local field potentials and unit activity from hundreds of sites without confining free movements of the animal. The advantages of large-scale recordings are illustrated by determining the electroanatomic boundaries of layers and regions in the hippocampus and neocortex and constructing a circuit diagram of functional connections among neurons in real anatomic space. These methods will allow the investigation of circuit operations and behavior-dependent interregional interactions for testing hypotheses of neural networks and brain function. PMID:24353300

Single neuronal recordings using surface micromachined polysilicon microelectrodes.

PubMed

Muthuswamy, Jit; Okandan, Murat; Jackson, Nathan

2005-03-15

Bulk micromachining techniques of silicon have been used successfully in the past several years to microfabricate microelectrodes for monitoring single neurons in acute and chronic experiments. In this study we report for the first time a novel surface micromachining technique to microfabricate a very thin polysilicon microelectrode that can be used for monitoring single-unit activity in the central nervous system. The microelectrodes are 3 mm long and 50 microm x 3.75 microm in cross-section. Excellent signal to noise ratios in the order of 25-35 dB were obtained while recording neuronal action potentials. The microelectrodes successfully penetrated the brains after a microincision of the dura mater. Chronic implantation of the microprobe for up to 33 days produced only minor gliosis. Since the polysilicon shank acts as a conductor, additional processing steps involved in laying conductor lines on silicon substrates are avoided. Further, surface micromachining allows for fabricating extremely thin microelectrodes which could result in decreased inflammatory responses. We conclude that the polysilicon microelectrode reported here could be a complementary approach to bulk-micromachined silicon microelectrodes for chronic monitoring of single neurons in the central nervous system.

Stereo multiplexed holographic particle image velocimeter

DOEpatents

Adrian, Ronald J.; Barnhart, Donald H.; Papen, George A.

1996-01-01

A holographic particle image velocimeter employs stereoscopic recording of particle images, taken from two different perspectives and at two distinct points in time for each perspective, on a single holographic film plate. The different perspectives are provided by two optical assemblies, each including a collecting lens, a prism and a focusing lens. Collimated laser energy is pulsed through a fluid stream, with elements carried in the stream scattering light, some of which is collected by each collecting lens. The respective focusing lenses are configured to form images of the scattered light near the holographic plate. The particle images stored on the plate are reconstructed using the same optical assemblies employed in recording, by transferring the film plate and optical assemblies as a single integral unit to a reconstruction site. At the reconstruction site, reconstruction beams, phase conjugates of the reference beams used in recording the image, are directed to the plate, then selectively through either one of the optical assemblies, to form an image reflecting the chosen perspective at the two points in time.

Stereo multiplexed holographic particle image velocimeter

DOEpatents

Adrian, R.J.; Barnhart, D.H.; Papen, G.A.

1996-08-20

A holographic particle image velocimeter employs stereoscopic recording of particle images, taken from two different perspectives and at two distinct points in time for each perspective, on a single holographic film plate. The different perspectives are provided by two optical assemblies, each including a collecting lens, a prism and a focusing lens. Collimated laser energy is pulsed through a fluid stream, with elements carried in the stream scattering light, some of which is collected by each collecting lens. The respective focusing lenses are configured to form images of the scattered light near the holographic plate. The particle images stored on the plate are reconstructed using the same optical assemblies employed in recording, by transferring the film plate and optical assemblies as a single integral unit to a reconstruction site. At the reconstruction site, reconstruction beams, phase conjugates of the reference beams used in recording the image, are directed to the plate, then selectively through either one of the optical assemblies, to form an image reflecting the chosen perspective at the two points in time. 13 figs.

Healthcare resource utilization among patients with relapsed multiple myeloma in the UK, France, and Italy.

PubMed

Gonzalez-McQuire, Sebastian; Yong, Kwee; Leleu, Henri; Mennini, Francesco S; Flinois, Alain; Gazzola, Carlotta; Schoen, Paul; Campioni, Marco; DeCosta, Lucy; Fink, Leah

2018-05-01

To assess the real-world healthcare resource utilization (HRU) and costs associated with different treatment regimens used in the management of patients with relapsed multiple myeloma in the UK, France, and Italy. Retrospective medical chart review of characteristics, time to progression, level of response, HRU during treatment, and adverse events (AEs). Data collection started on June 1, 2015 and was completed on July 15, 2015. In the 3 months before record abstraction, eligible patients had either disease progression after receiving one of their country's most commonly prescribed regimens or had received the best supportive care and died. Costs were calculated based on HRU and country-specific diagnosis-related group and/or unit reference costs, amongst other standard resources. Physicians provided data for 1,282 patients (387 in the UK, 502 in France, 393 in Italy) who met the inclusion criteria. Mean [median] total healthcare costs associated with a single line of treatment were €51,717 [35,951] in the UK, €37,009 [32,538] for France, and €34,496 [42,342] for Italy, driven largely by anti-myeloma medications costs (contributing 95.0%, 90.0%, and 94.2% of total cost, respectively). During active treatment, the highest costs were associated with lenalidomide- and pomalidomide-based regimens. Mean cost per month was lowest for patients achieving a very good partial response or better. Unscheduled events (i.e. not considered part of routine management, whether or not related to multiple myeloma, such as unscheduled hospitalization, AEs, fractures) accounted for 1-9% of total costs and were highest for bendamustine. The use of retrospective data means that clinical practice (e.g. use of medical procedures, evaluation of treatment response) is not standardized across participating countries/centers, and some data (e.g. low-grade AEs) may be incomplete or differently adjudicated/reported. The centers involved may not be fully representative of national practice. Drug costs are the main contributor to total HRU costs associated with multiple myeloma. The duration of active treatment may influence the average total costs, as well as response, associated with a single line of therapy. Improved treatment outcomes, and reductions in unscheduled events and concomitant medication use may, therefore, reduce the overall HRU and related costs of care in multiple myeloma.

Anomalous light output from lightning dart leaders

NASA Technical Reports Server (NTRS)

Guo, C.; Krider, E. P.

1985-01-01

About 5 percent of the multiple-stroke cloud-to-ground lightning discharges recorded at the NASA Kennedy Space Center during the summer of 1981 contained dart leaders that produced an unusually large light output. An analysis of these cases indicates that the average peak light output per unit length in the leader may be comparable to or even exceed that of the return stroke that follows.

Raman and infrared spectroscopic study of the anhydrous carbonate minerals shortite and barytocalcite.

PubMed

Frost, Ray L; Dickfos, Marilla J

2008-11-01

The Raman spectra of shortite and barytocalcite complimented with infrared spectra have been used to characterise the structure of these carbonate minerals. The Raman spectrum of barytocalcite shows a single band at 1086 cm(-1) attributed to the (CO3)(2-) symmetric stretching mode, in contrast to shortite where two bands are observed. The observation of two bands for shortite confirms the concept of more than one crystallographically distinct carbonate unit in the unit cell. Multiple bands are observed for the antisymmetric stretching and bending region for these minerals proving that the carbonate unit is distorted in the structure of both shortite and barytocalcite.

Slug Test Characterization Results for Multi-Test/Depth Intervals Conducted During the Drilling of CERCLA Operable Unit OU ZP-1 Wells 299-W10-33 and 299-W11-48

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

Newcomer, Darrell R.

2007-09-30

Slug-test results obtained from single and multiple, stress-level slug tests conducted during drilling and borehole advancement provide detailed hydraulic conductivity information at two Hanford Site Operable Unit (OU) ZP-1 test well locations. The individual test/depth intervals were generally sited to provide hydraulic-property information within the upper ~10 m of the unconfined aquifer (i.e., Ringold Formation, Unit 5). These characterization results complement previous and ongoing drill-and-test characterization programs at surrounding 200-West and -East Area locations (see Figure S.1).

Increasing Accuracy: A New Design and Algorithm for Automatically Measuring Weights, Travel Direction and Radio Frequency Identification (RFID) of Penguins.

PubMed

Afanasyev, Vsevolod; Buldyrev, Sergey V; Dunn, Michael J; Robst, Jeremy; Preston, Mark; Bremner, Steve F; Briggs, Dirk R; Brown, Ruth; Adlard, Stacey; Peat, Helen J

2015-01-01

A fully automated weighbridge using a new algorithm and mechanics integrated with a Radio Frequency Identification System is described. It is currently in use collecting data on Macaroni penguins (Eudyptes chrysolophus) at Bird Island, South Georgia. The technology allows researchers to collect very large, highly accurate datasets of both penguin weight and direction of their travel into or out of a breeding colony, providing important contributory information to help understand penguin breeding success, reproductive output and availability of prey. Reliable discrimination between single and multiple penguin crossings is demonstrated. Passive radio frequency tags implanted into penguins allow researchers to match weight and trip direction to individual birds. Low unit and operation costs, low maintenance needs, simple operator requirements and accurate time stamping of every record are all important features of this type of weighbridge, as is its proven ability to operate 24 hours a day throughout a breeding season, regardless of temperature or weather conditions. Users are able to define required levels of accuracy by adjusting filters and raw data are automatically recorded and stored allowing for a range of processing options. This paper presents the underlying principles, design specification and system description, provides evidence of the weighbridge's accurate performance and demonstrates how its design is a significant improvement on existing systems.

Composite Calderas: The Long and Short of it

NASA Astrophysics Data System (ADS)

Gravley, D. M.; Hasegawa, T.; Nakagawa, M.; Wilson, C. J.

2006-12-01

Calderas formed in supereruptions are normally linked to a single magma body. However, caldera formation, regional tectonics, and multiple magma bodies may interact to form composite structures with complex geometries. The term composite caldera is often used without reference as to whether the `composite' is in time or space. Three examples of composite caldera styles from New Zealand and Japan show field, geophysical, geochemical and isotopic evidence to suggest that current models for the size, shape and evolution of calderas may be too simplistic. In our examples, multiple separate magma bodies distributed in either space or time, or both, may play a significant role in composite caldera formation. Multiple, clustered collapse events incremental in time: Akan caldera in Hokkaido appears to be a single, rectangular shaped caldera. However, the identification of 17 eruptive units spanning >1 Myr suggests that the caldera evolved incrementally over time and space. New gravity data shows that the caldera is actually a daisy-chain of 3 distinct collapse structures that can be correlated, using lithic componentry, to 3 major geochemical groups in the eruptive products. Multiple, clustered collapse events in a single eruption sequence: Shikotsu caldera in Hokkaido was originally thought to have formed following the eruption of a single large zoned magma chamber. However, the caldera-related deposits are characterized by several geochemically distinct pumice types that can not have been accommodated in a single magma system. Our studies suggest that the variations in pumice compositions are consistent with multiple distinct magma bodies feeding coeval eruptions from several vent sources within an area that collapsed to form a single caldera. Paired calderas with linking eruption-related regional faulting: Rotorua and Ohakuri calderas in New Zealand are 30 km apart and formed in close succession during a complex but virtually continuous eruption sequence at ca. 240 ka. The distinct calderas are joined in dumb-bell fashion by an intervening zone of eruption-related and immediately post-eruptive faulting and collapse.

Characterizing episodic memory retrieval: electrophysiological evidence for diminished familiarity following unitization.

PubMed

Pilgrim, Lea K; Murray, Jamie G; Donaldson, David I

2012-08-01

Episodic memory relies on both recollection and familiarity; why these processes are differentially engaged during retrieval remains unclear. Traditionally, recollection has been considered necessary for tasks requiring associative retrieval, whereas familiarity supports recognition of items. Recently, however, familiarity has been shown to contribute to associative recognition if stimuli are "unitized" at encoding (a single representation is created from multiple elements)-the "benefit" of unitization. Here, we ask if there is also a "cost" of unitization; are the elements of unitized representations less accessible via familiarity? We manipulated unitization during encoding and used ERPs to index familiarity and recollection at retrieval. The data revealed a selective reduction in the neural correlate of familiarity for individual words originally encoded in unitized compared with nonunitized word pairs. This finding reveals a measurable cost of unitization, suggesting that the nature of to-be-remembered stimuli is critical in determining whether familiarity contributes to episodic memory.

Feasibility and performance evaluation of generating and recording visual evoked potentials using ambulatory Bluetooth based system.

PubMed

Ellingson, Roger M; Oken, Barry

2010-01-01

Report contains the design overview and key performance measurements demonstrating the feasibility of generating and recording ambulatory visual stimulus evoked potentials using the previously reported custom Complementary and Alternative Medicine physiologic data collection and monitoring system, CAMAS. The methods used to generate visual stimuli on a PDA device and the design of an optical coupling device to convert the display to an electrical waveform which is recorded by the CAMAS base unit are presented. The optical sensor signal, synchronized to the visual stimulus emulates the brain's synchronized EEG signal input to CAMAS normally reviewed for the evoked potential response. Most importantly, the PDA also sends a marker message over the wireless Bluetooth connection to the CAMAS base unit synchronized to the visual stimulus which is the critical averaging reference component to obtain VEP results. Results show the variance in the latency of the wireless marker messaging link is consistent enough to support the generation and recording of visual evoked potentials. The averaged sensor waveforms at multiple CPU speeds are presented and demonstrate suitability of the Bluetooth interface for portable ambulatory visual evoked potential implementation on our CAMAS platform.

Advances in indirect detector systems for ultra high-speed hard X-ray imaging with synchrotron light

NASA Astrophysics Data System (ADS)

Olbinado, M. P.; Grenzer, J.; Pradel, P.; De Resseguier, T.; Vagovic, P.; Zdora, M.-C.; Guzenko, V. A.; David, C.; Rack, A.

2018-04-01

We report on indirect X-ray detector systems for various full-field, ultra high-speed X-ray imaging methodologies, such as X-ray phase-contrast radiography, diffraction topography, grating interferometry and speckle-based imaging performed at the hard X-ray imaging beamline ID19 of the European Synchrotron—ESRF. Our work highlights the versatility of indirect X-ray detectors to multiple goals such as single synchrotron pulse isolation, multiple-frame recording up to millions frames per second, high efficiency, and high spatial resolution. Besides the technical advancements, potential applications are briefly introduced and discussed.

Comparison of Fucithalmic viscous eye drops and Chloramphenicol eye ointment as a single treatment in corneal abrasion.

PubMed

Boberg-Ans, G; Nissen, K R

1998-02-01

To compare the healing of the cornea and the incidence of infection after traumatic corneal epithelial defect after single treatment with double bandage combined with either Fucithalmic single unit dose eye drops or chloramphenicol eye ointment. This is a single-centre, randomised, single-blind, parallel-group study of 144 patients with accidental corneal abrasion or corpus alieni cornea who were referred to the Eye Department at Gentofte Hospital. The injured eye was examined with a photo slit-lamp before and 24 hours after treatment. The size of the abrasion was recorded and calculated on a PCX computerized video system and by slit-lamp photography. The Fucithalmic and chloramphenicol ointment treated groups showed no significant difference in corneal healing, local side effects, or signs of local infection.

Flight crew sleep during multiple layover polar flights

NASA Technical Reports Server (NTRS)

Sasaki, Mitsuo; Kurosaki, Yuko S.; Spinweber, Cheryl L.; Graeber, R. C.; Takahashi, Toshiharu

1993-01-01

This study investigated changes in sleep after multiple transmeridian flights. The subjects were 12 B747 airline pilots operating on the following polar flight: Tokyo (TYO)-Anchorage (ANC)-London (LON)-Anchorage-Tokyo. Sleep polysmonograms were recorded on two baseline nights (B1, B2), during layovers, and, after returning to Tokyo, two recovery nights were recorded (R1, R2). In ANC (outbound), total sleep time was reduced and, sleep efficiency was low (72.0 percent). In London, time in bed increased slightly, but sleep efficiency was still reduced. On return to ANC (inbound), there was considerable slow wave sleep rebound and multiple awakenings reduced sleep efficiency to 76.8 percent. Sleep efficiency on R2 was significantly lower than on B1 but not different from R1. To sum up, sleep of aircrews flying multiple transmeridian flights is disrupted during layovers and this effect persists during the two recovery nights. As a result, there is a marked cumulative sleep loss during multilegs polar route trip in comparison to single leg flights. These findings suggest that following such extensive transmeridian trips, crews should have at least three nights of recovery sleep in their home time zone before returning to duty.

Nonlinear Modeling of Causal Interrelationships in Neuronal Ensembles

PubMed Central

Zanos, Theodoros P.; Courellis, Spiros H.; Berger, Theodore W.; Hampson, Robert E.; Deadwyler, Sam A.; Marmarelis, Vasilis Z.

2009-01-01

The increasing availability of multiunit recordings gives new urgency to the need for effective analysis of “multidimensional” time-series data that are derived from the recorded activity of neuronal ensembles in the form of multiple sequences of action potentials—treated mathematically as point-processes and computationally as spike-trains. Whether in conditions of spontaneous activity or under conditions of external stimulation, the objective is the identification and quantification of possible causal links among the neurons generating the observed binary signals. A multiple-input/multiple-output (MIMO) modeling methodology is presented that can be used to quantify the neuronal dynamics of causal interrelationships in neuronal ensembles using spike-train data recorded from individual neurons. These causal interrelationships are modeled as transformations of spike-trains recorded from a set of neurons designated as the “inputs” into spike-trains recorded from another set of neurons designated as the “outputs.” The MIMO model is composed of a set of multiinput/single-output (MISO) modules, one for each output. Each module is the cascade of a MISO Volterra model and a threshold operator generating the output spikes. The Laguerre expansion approach is used to estimate the Volterra kernels of each MISO module from the respective input–output data using the least-squares method. The predictive performance of the model is evaluated with the use of the receiver operating characteristic (ROC) curve, from which the optimum threshold is also selected. The Mann–Whitney statistic is used to select the significant inputs for each output by examining the statistical significance of improvements in the predictive accuracy of the model when the respective inputs is included. Illustrative examples are presented for a simulated system and for an actual application using multiunit data recordings from the hippocampus of a behaving rat. PMID:18701382

Metal-Free Multiple Carbon-Carbon and Carbon-Hydrogen Bond Activations via Charge-Switching Mechanism in Unstrained Diindolylmethanes.

PubMed

Challa, Chandrasekhar; Varughese, Sunil; Suresh, Cherumuttathu H; Lankalapalli, Ravi S

2017-08-18

A transformation of the unstrained phenol substituted 3,3'-diindolylmethanes (DIPMs) to 2,3'-diindolylketones (DIKs) by double C-C single bond cleavage with associated rearrangements, triggered by phenyliodine(III) diacetate (PIDA), is reported. Density functional theory studies reveal a mechanism involving multiple "charge-switching" steps by synergistic involvement of the two indole units with overall low activation energy. The indole 'charge-switching' mechanism in DIPMs was further extended toward synthesis of a natural product motif cyclohepta[b]indole from biaryl appended DIBM.

Planning Physical Education Lessons as Teaching "Episodes"

ERIC Educational Resources Information Center

Chatoupis, Constantine

2016-01-01

An "episode" is a unit of time within which teachers and students are working on the same objective and are engaged in the same teaching/learning style. The duration of each episode, as well as the number of them in a single lesson, may vary. Additionally, the multiple episodes of a lesson may have similar objectives, offer similar…

Two Modalities of the Contextualized Courseware in Three Modalities of Classroom Use

ERIC Educational Resources Information Center

Akpinar, Yavuz; Sengül, Özlem

2018-01-01

This study investigated the effect of various combinations of contextualization and teacher support on achievement and critical thinking. Two specially-designed sets of courseware were used to teach a unit on logic, one based on a single context and one based on multiple contexts. The participants were 151 9th graders in two vocational high…

United States Census 2000 Population with Bridged Race Categories. Vital and Health Statistics. Data Evaluation and Methods Research.

ERIC Educational Resources Information Center

Ingram, Deborah D.; Parker, Jennifer D.; Schenker, Nathaniel; Weed, James A.; Hamilton, Brady; Arias, Elizabeth; Madans, Jennifer H.

This report documents the National Center for Health Statistics' (NCHS) methods for bridging the Census 2000 multiple-race resident population to single-race categories and describing bridged race resident population estimates. Data came from the pooled 1997-2000 National Health Interview Surveys. The bridging models included demographic and…

CLOSEUP VIEW OF THE FIRST STAGE OF THE SATURN I ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

CLOSE-UP VIEW OF THE FIRST STAGE OF THE SATURN I ROCKET, SHOWING A DETAIL VIEW OF THE ENGINE CLUSTER. THE SATURN I ROCKET WAS THE FIRST UNITED STATES ROCKET TO HAVE MULTIPLE ENGINES ON A SINGLE STAGE. - Marshall Space Flight Center, Saturn Propulsion & Structural Test Facility, East Test Area, Huntsville, Madison County, AL

Cooperating Teacher Perceptions of Music Student Teacher Preparedness for the Elementary Music Classroom

ERIC Educational Resources Information Center

Hester, Charlotte V.

2013-01-01

The present study investigated the strengths and areas of improvement for elementary music teacher preparation from the perspective of multiple members of a single body of music teachers. Subjects for the study were elementary music teachers from an urban school district in the southern United States. All elementary music teachers in the school…

Congenital malformations among newborns admitted in the neonatal unit of a tertiary hospital in Enugu, South-East Nigeria - a retrospective study

PubMed Central

2012-01-01

Background Congenital abnormalities are not uncommon among newborns and contribute to neonatal and infant morbidity and mortality. The prevalence and pattern of presentation vary from place to place. Many a time the exact etiology is unknown but genetic and environmental factors tend to be implicated. Methods The objective of this study was to determine the prevalence of congenital malformations among newborns admitted in a tertiary hospital in Enugu, the nature of these abnormalities and the outcome/prognosis. For purposes of this study, congenital abnormalities are defined as obvious abnormality of structure or form which is present at birth or noticed within a few days after birth. A cross-sectional retrospective study in which a review of the records of all babies admitted in the Newborn Special Care Unit (NBSCU) of the University of Nigeria Teaching Hospital (UNTH), Ituku/Ozalla, Enugu over a four year period (January 2007-April 2011) was undertaken. All babies admitted in the unit with the diagnosis of congenital abnormality were included in the study. Information extracted from the records included characteristics of the baby, maternal characteristics, nature/type of abnormalities and outcome. Data obtained was analyzed using SPSS 13. Rates and proportions were calculated with 95% confidence interval. The proportions were compared using students T-test. Level of significance was set at P < 0.05 Results Seventeen (17) out of a total of six hundred and seven newborn babies admitted in the newborn unit of UNTH over the study period (Jan 2007-March 2011) were found to have congenital abnormalities of various types, giving a prevalence of 2.8%. Common abnormalities seen in these babies were mainly surgical birth defects and included cleft lip/cleft palate, neural tube defects (occurring either singly or in combination with other abnormalities), limb abnormalities (often in combination with neural tube defects of various types), omphalocoele, umbilical herniae, ano-rectal malformations and dysmorphism associated with multiple congenital abnormalities. Conclusions The results of this study show that 2.8% of babies admitted to a Newborn Special Care Unit in a teaching hospital in Enugu had congenital abnormalities and that the commonest forms seen were mainly surgical birth defects and includes cleft lip/cleft palate and neural tube defects. PMID:22472067

Chemicals identified in human biological media: a data base. Third annual report, October 1981

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

Cone, M.V.; Baldauf, M.F.; Martin, F.M.

Data from almost 1600 of the 3800 body-burden documents collected to date have been entered in the data base as of October 1981. The emphasis on including recent literature and significant research documents has resulted in a chronological mix of articles from 1974 to the present. When body-burden articles are identified, data are extracted and entered in the data base by chemical and tissue/body fluid. Each data entry comprises a single record (or line entry) and is assigned a record number. If a particular document deals with more than one chemical and/or tissue, there will be multiple records for thatmore » document. For example, a study of 5 chemicals in each of 3 tissues has 15 different records (or 15 line entries) in the data base with 15 record numbers. Record numbers are assigned consecutively throughout the entire data base and appear in the upper left corner of the first column for each record.« less

Towards component-based validation of GATE: aspects of the coincidence processor.

PubMed

Moraes, Eder R; Poon, Jonathan K; Balakrishnan, Karthikayan; Wang, Wenli; Badawi, Ramsey D

2015-02-01

GATE is public domain software widely used for Monte Carlo simulation in emission tomography. Validations of GATE have primarily been performed on a whole-system basis, leaving the possibility that errors in one sub-system may be offset by errors in others. We assess the accuracy of the GATE PET coincidence generation sub-system in isolation, focusing on the options most closely modeling the majority of commercially available scanners. Independent coincidence generators were coded by teams at Toshiba Medical Research Unit (TMRU) and UC Davis. A model similar to the Siemens mCT scanner was created in GATE. Annihilation photons interacting with the detectors were recorded. Coincidences were generated using GATE, TMRU and UC Davis code and results compared to "ground truth" obtained from the history of the photon interactions. GATE was tested twice, once with every qualified single event opening a time window and initiating a coincidence check (the "multiple window method"), and once where a time window is opened and a coincidence check initiated only by the first single event to occur after the end of the prior time window (the "single window method"). True, scattered and random coincidences were compared. Noise equivalent count rates were also computed and compared. The TMRU and UC Davis coincidence generators agree well with ground truth. With GATE, reasonable accuracy can be obtained if the single window method option is chosen and random coincidences are estimated without use of the delayed coincidence option. However in this GATE version, other parameter combinations can result in significant errors. Copyright © 2014 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

Scalable, Lightweight, Integrated and Quick-to-Assemble (SLIQ) Hyperdrives for Functional Circuit Dissection.

PubMed

Liang, Li; Oline, Stefan N; Kirk, Justin C; Schmitt, Lukas Ian; Komorowski, Robert W; Remondes, Miguel; Halassa, Michael M

2017-01-01

Independently adjustable multielectrode arrays are routinely used to interrogate neuronal circuit function, enabling chronic in vivo monitoring of neuronal ensembles in freely behaving animals at a single-cell, single spike resolution. Despite the importance of this approach, its widespread use is limited by highly specialized design and fabrication methods. To address this, we have developed a Scalable, Lightweight, Integrated and Quick-to-assemble multielectrode array platform. This platform additionally integrates optical fibers with independently adjustable electrodes to allow simultaneous single unit recordings and circuit-specific optogenetic targeting and/or manipulation. In current designs, the fully assembled platforms are scalable from 2 to 32 microdrives, and yet range 1-3 g, light enough for small animals. Here, we describe the design process starting from intent in computer-aided design, parameter testing through finite element analysis and experimental means, and implementation of various applications across mice and rats. Combined, our methods may expand the utility of multielectrode recordings and their continued integration with other tools enabling functional dissection of intact neural circuits.

Magma evolution as seen through zircon geochemistry: an example from the Southern Adamello Batholith, N. Italy

NASA Astrophysics Data System (ADS)

Broderick, C.; Schaltegger, U.; Gerdes, A.; Frick, D.; Guenther, D.; Brack, P.

2012-04-01

Zircon is an ubiquitous accessory mineral often used for U-Pb geochronology but is also an important recorder of geochemical information. The trace element and isotopic characteristics of zircon yield potential for tracking changes in an evolving magma through time. With recent advances in U-Pb zircon geochronology, 10-100 ka to Ma timescales are observed for incremental pluton construction (Michel et al., 2008, Schaltegger et al., 2009). In observed 100 ka timescales of zircon crystallization, can zircon record the processes that produce trace element variations in a magma? This study focuses on the Val Fredda Complex (VFC) in the southern tip of the 43 to 33 Ma Adamello batholith, N. Italy. The VFC displays complex relationships among mafic melts that were injected into solidifying felsic magmas. Single zircon crystals were dated using CA-ID-TIMS. With permil uncertainties on 206Pb/238U zircon dates, zircons reveal complexities within single populations. The mafic units crystallized potential autocrystic zircons over a duration of 100 - 150ka, whereas the felsic units record up to 200ka of zircon crystallization. In order to understand these complex zircon populations, we analyzed Hf isotopes and trace elements, on the same volume of zircon used for U-Pb dating, following the TIMS-TEA method (Schoene et al., 2010). This detailed zircon study will allow us to look at how magmas are evolving with time. Hf isotopes of VFC mafic zircons reveal distinct ɛHf values between the three mafic units and their ɛHf values remain consistent through time, whereas the VFC felsic units record more complexity in their ɛHf values. We observe changes such as increasing and slight decreases in ɛHf with time which suggest different processes are occurring to produce the different felsic units. Trace element ratios in zircon reveal differences which allow us to make distinctions between felsic and mafic units (e.g. Th/U, (Lu/Gd)N, REEs). The VFC records 200 ka of zircon crystallization and our data suggests that zircons do in fact reflect changes in isotopic and in trace element signatures on 100 ka timescales. Although we observe changes in our trace elements, the TIMS-TEA method provides an average of trace element concentrations from a zircon volume, dominated by more marginal growth zones. Therefore we will compare our data with in situ methods to determine how our trace element data compares with trace elements across zircon profiles. We acknowledge funding of FNS in the frame of ProDoc Adamello 4-D. Michel et al., 2008, Geol. 36 : 459-462 ; Schaltegger et al., 2009, Earth Planet. Sci.Lett. 286: 208-218; Schoene et al., 2010, Geochim. Cosmochim. Acta 74, 7144-7159.

The molecular and crystal structure of dextrans: a combined electron and X-ray diffraction study. II. A low temperature, hydrated polymorph.

PubMed

Guizard, C; Chanzy, H; Sarko, A

1985-06-05

The crystal and molecular structure of a dextran hydrate has been determined through combined electron and X-ray diffraction analysis, aided by stereochemical model refinement. A total of 65 hk0 electron diffraction intensities were measured on frozen single crystals held at the temperature of liquid nitrogen, to a resolution limit of 1.6 A. The X-ray intensities were measured from powder patterns recorded from collections of the single crystals. The structure crystallizes in a monoclinic unit cell with parameters a = 25.71 A, b = 10.21 A, c (chain axis) = 7.76 A and beta = 91.3 degrees. The space group is P2(1) with b axis unique. The unit cell contains six chains and eight water molecules, with three chains of the same polarity and four water molecules constituting the asymmetric unit. Along the chain direction the asymmetric unit is a dimer residue; however, the individual glucopyranose residues are very nearly related by a molecular 2-fold screw axis. The conformation of the chain is very similar to that in the anhydrous structure, but the chain packing differs in the two structures in that the rotational positions of the chains about the helix axes (the chain setting angles) are considerably different. The chains still pack in the form of sheets that are separated by water molecules. The difference in the chain setting angles between the anhydrous and hydrate structures corresponds to the angle between like unit cell axes observed in the diffraction diagrams recorded from hybrid crystals containing both polymorphs. Despite some beam damage effects, the structure was determined to a satisfactory degree of agreement, with the residuals R''(electron diffraction) = 0.258 and R(X-ray) = 0.127.

Volumetric modulated arc therapy vs. IMRT for the treatment of distal esophageal cancer.

PubMed

Van Benthuysen, Liam; Hales, Lee; Podgorsak, Matthew B

2011-01-01

Several studies have demonstrated that volumetric modulated arc therapy (VMAT) has the ability to reduce monitor units and treatment time when compared with intensity-modulated radiation therapy (IMRT). This study aims to demonstrate that VMAT is able to provide adequate organs at risk (OAR) sparing and planning target volume (PTV) coverage for adenocarcinoma of the distal esophagus while reducing monitor units and treatment time. Fourteen patients having been treated previously for esophageal cancer were planned using both VMAT and IMRT techniques. Dosimetric quality was evaluated based on doses to several OARs, as well as coverage of the PTV. Treatment times were assessed by recording the number of monitor units required for dose delivery. Body V(5) was also recorded to evaluate the increased volume of healthy tissue irradiated to low doses. Dosimetric differences in OAR sparing between VMAT and IMRT were comparable. PTV coverage was similar for the 2 techniques but it was found that IMRT was capable of delivering a slightly more homogenous dose distribution. Of the 14 patients, 12 were treated with a single arc and 2 were treated with a double arc. Single-arc plans reduced monitor units by 42% when compared with the IMRT plans. Double-arc plans reduced monitor units by 67% when compared with IMRT. The V(5) for the body was found to be 18% greater for VMAT than for IMRT. VMAT has the capability to decrease treatment times over IMRT while still providing similar OAR sparing and PTV coverage. Although there will be a smaller risk of patient movement during VMAT treatments, this advantage comes at the cost of delivering small doses to a greater volume of the patient. Copyright © 2011 American Association of Medical Dosimetrists. Published by Elsevier Inc. All rights reserved.

Cortical modulation of the nucleus of the optic tract in the rabbit.

PubMed

Pettorossi, V E; Troiani, D

1983-09-01

We analyzed in rabbits the relationships between the temporooccipital nystagmogenic cortex (NGC)--the region sited at the border between cortical areas 17, 21, and 22--and the nucleus of the optic tract (NOT). Two experimental approaches were used: (a) eye movement analysis before and after electrolytic lesion of the NOT region provided an indication of the importance of the NOT for the interaction between the ocular nystagmus elicited by natural optokinetic stimulation (OKN) and the nystagmus evoked by electrical stimulation of the nystagmogenic area; (b) NOT direction-selective and velocity-sensitive units were tested with single shock or repetitive electrical stimulation of the nystagmogenic region. Single-shock stimulation evoked single or multiple spikes in 50% of NOT units analyzed and repetitive stimuli induced prolonged facilitation and inhibitory rebounds in 70% of the units tested. Comparison of orthodromic activation latencies of the NOT cells (3.2 and 6.1 ms) after cortical stimulation and of antidromic activation latencies of cortical nystagmogenic units (2.6 ms) after NOT shocks, suggested monosynaptic as well as polysynaptic connections between the temporooccipital cortex and the NOT. The existence of such cortical-NOT linkage indicates that the NOT is intercalated between the cortex and the oculomotor centers and represents the most probable site of interaction of the cortical nystagmus pathway with the optokinetic reflex arc.

Multiple-Angle Muon Radiography of a Dry Storage Cask

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

Durham, J. Matthew; Guardincerri, Elena; Morris, Christopher

A partially loaded dry storage cask was imaged using cosmic ray muons. Since the cask is large relative to the size of the muon tracking detectors, the instruments were placed at nine different positions around the cask to record data covering the entire fuel basket. We show that this technique can detect the removal of a single fuel assembly from the center of the cask.

Single-exposure color digital holography

NASA Astrophysics Data System (ADS)

Feng, Shaotong; Wang, Yanhui; Zhu, Zhuqing; Nie, Shouping

2010-11-01

In this paper, we report a method for color image reconstruction by recording only one single multi-wavelength hologram. In the recording process, three lasers of different wavelengths emitting in the red, green and blue regions are used for illuminating on the object and the object diffraction fields will arrive at the hologram plane simultaneously. Three reference beams with different spatial angles will interfere with the corresponding object diffraction fields on the hologram plane, respectively. Finally, a series of sub-holograms incoherently overlapped on the CCD to be recorded as a multi-wavelength hologram. Angular division multiplexing is employed to reference beams so that the spatial spectra of the multiple recordings will be separated in the Fourier plane. In the reconstruction process, the multi-wavelength hologram will be Fourier transformed into its Fourier plane, where the spatial spectra of different wavelengths are separated and can be easily extracted by employing frequency filtering. The extracted spectra are used to reconstruct the corresponding monochromatic complex amplitudes, which will be synthesized to reconstruct the color image. For singleexposure recording technique, it is convenient for applications on the real-time image processing fields. However, the quality of the reconstructed images is affected by speckle noise. How to improve the quality of the images needs for further research.

Photonic Doppler velocimetry lens array probe incorporating stereo imaging

DOEpatents

Malone, Robert M.; Kaufman, Morris I.

2015-09-01

A probe including a multiple lens array is disclosed to measure velocity distribution of a moving surface along many lines of sight. Laser light, directed to the moving surface is reflected back from the surface and is Doppler shifted, collected into the array, and then directed to detection equipment through optic fibers. The received light is mixed with reference laser light and using photonic Doppler velocimetry, a continuous time record of the surface movement is obtained. An array of single-mode optical fibers provides an optic signal to the multiple lens array. Numerous fibers in a fiber array project numerous rays to establish many measurement points at numerous different locations. One or more lens groups may be replaced with imaging lenses so a stereo image of the moving surface can be recorded. Imaging a portion of the surface during initial travel can determine whether the surface is breaking up.

A low-cost, multiplexed μECoG system for high-density recordings in freely moving rodents

NASA Astrophysics Data System (ADS)

Insanally, Michele; Trumpis, Michael; Wang, Charles; Chiang, Chia-Han; Woods, Virginia; Palopoli-Trojani, Kay; Bossi, Silvia; Froemke, Robert C.; Viventi, Jonathan

2016-04-01

Objective. Micro-electrocorticography (μECoG) offers a minimally invasive neural interface with high spatial resolution over large areas of cortex. However, electrode arrays with many contacts that are individually wired to external recording systems are cumbersome and make recordings in freely behaving rodents challenging. We report a novel high-density 60-electrode system for μECoG recording in freely moving rats. Approach. Multiplexed headstages overcome the problem of wiring complexity by combining signals from many electrodes to a smaller number of connections. We have developed a low-cost, multiplexed recording system with 60 contacts at 406 μm spacing. We characterized the quality of the electrode signals using multiple metrics that tracked spatial variation, evoked-response detectability, and decoding value. Performance of the system was validated both in anesthetized animals and freely moving awake animals. Main results. We recorded μECoG signals over the primary auditory cortex, measuring responses to acoustic stimuli across all channels. Single-trial responses had high signal-to-noise ratios (SNR) (up to 25 dB under anesthesia), and were used to rapidly measure network topography within ˜10 s by constructing all single-channel receptive fields in parallel. We characterized evoked potential amplitudes and spatial correlations across the array in the anesthetized and awake animals. Recording quality in awake animals was stable for at least 30 days. Finally, we used these responses to accurately decode auditory stimuli on single trials. Significance. This study introduces (1) a μECoG recording system based on practical hardware design and (2) a rigorous analytical method for characterizing the signal characteristics of μECoG electrode arrays. This methodology can be applied to evaluate the fidelity and lifetime of any μECoG electrode array. Our μECoG-based recording system is accessible and will be useful for studies of perception and decision-making in rodents, particularly over the entire time course of behavioral training and learning.

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

Buckley, L; Lambert, C; Nyiri, B

Purpose: To standardize the tube calibration for Elekta XVI cone beam CT (CBCT) systems in order to provide a meaningful estimate of the daily imaging dose and reduce the variation between units in a large centre with multiple treatment units. Methods: Initial measurements of the output from the CBCT systems were made using a Farmer chamber and standard CTDI phantom. The correlation between the measured CTDI and the tube current was confirmed using an Unfors Xi detector which was then used to perform a tube current calibration on each unit. Results: Initial measurements showed measured tube current variations of upmore » to 25% between units for scans with the same image settings. In order to reasonably estimate the imaging dose, a systematic approach to x-ray generator calibration was adopted to ensure that the imaging dose was consistent across all units at the centre and was adopted as part of the routine quality assurance program. Subsequent measurements show that the variation in measured dose across nine units is on the order of 5%. Conclusion: Increasingly, patients receiving radiation therapy have extended life expectancies and therefore the cumulative dose from daily imaging should not be ignored. In theory, an estimate of imaging dose can be made from the imaging parameters. However, measurements have shown that there are large differences in the x-ray generator calibration as installed at the clinic. Current protocols recommend routine checks of dose to ensure constancy. The present study suggests that in addition to constancy checks on a single machine, a tube current calibration should be performed on every unit to ensure agreement across multiple machines. This is crucial at a large centre with multiple units in order to provide physicians with a meaningful estimate of the daily imaging dose.« less

Dealing with time-varying recruitment and length in Hill-type muscle models.

PubMed

Hamouda, Ahmed; Kenney, Laurence; Howard, David

2016-10-03

Hill-type muscle models are often used in muscle simulation studies and also in the design and virtual prototyping of functional electrical stimulation systems. These models have to behave in a sufficiently realistic manner when recruitment level and contractile element (CE) length change continuously. For this reason, most previous models have used instantaneous CE length in the muscle׳s force vs. length (F-L) relationship, but thereby neglect the instability problem on the descending limb (i.e. region of negative slope) of the F-L relationship. Ideally CE length at initial recruitment should be used but this requires a multiple-motor-unit muscle model to properly account for different motor-units having different initial lengths when recruited. None of the multiple-motor-unit models reported in the literature have used initial CE length in the muscle׳s F-L relationship, thereby also neglecting the descending limb instability problem. To address the problem of muscle modelling for continuously varying recruitment and length, and hence different values of initial CE length for different motor-units, a new multiple-motor-unit muscle model is presented which considers the muscle to comprise 1000 individual Hill-type virtual motor-units, which determine the total isometric force. Other parts of the model (F-V relationship and passive elements) are not dependent on the initial CE length and, therefore, they are implemented for the muscle as a whole rather than for the individual motor-units. The results demonstrate the potential errors introduced by using a single-motor-unit model and also the instantaneous CE length in the F-L relationship, both of which are common in FES control studies. Copyright © 2016 Elsevier Ltd. All rights reserved.

Color-tuned neurons are spatially clustered according to color preference within alert macaque posterior inferior temporal cortex

PubMed Central

Conway, Bevil R.; Tsao, Doris Y.

2009-01-01

Large islands of extrastriate cortex that are enriched for color-tuned neurons have recently been described in alert macaque using a combination of functional magnetic resonance imaging (fMRI) and single-unit recording. These millimeter-sized islands, dubbed “globs,” are scattered throughout the posterior inferior temporal cortex (PIT), a swath of brain anterior to area V3, including areas V4, PITd, and posterior TEO. We investigated the micro-organization of neurons within the globs. We used fMRI to identify the globs and then used MRI-guided microelectrodes to test the color properties of single glob cells. We used color stimuli that sample the CIELUV perceptual color space at regular intervals to test the color tuning of single units, and make two observations. First, color-tuned neurons of various color preferences were found within single globs. Second, adjacent glob cells tended to have the same color tuning, demonstrating that glob cells are clustered by color preference and suggesting that they are arranged in color columns. Neurons separated by 50 μm, measured parallel to the cortical sheet, had more similar color tuning than neurons separated by 100 μm, suggesting that the scale of the color columns is <100 μm. These results show that color-tuned neurons in PIT are organized by color preference on a finer scale than the scale of single globs. Moreover, the color preferences of neurons recorded sequentially along a given electrode penetration shifted gradually in many penetrations, suggesting that the color columns are arranged according to a chromotopic map reflecting perceptual color space. PMID:19805195

Empress 2. First year clinical results.

PubMed

Culp, L

1999-03-01

As the search for perfect dental restorative materials continues, it seems we routinely return to ceramics as our standard. Current all-ceramic systems are state-of-the-art with regard to esthetics and function, but are limited in use to single unit restorations. Recently, an all-ceramic lithium disilicate-fluorapatite ceramic system was introduced (IPS Empress 2, Ivoclar North America, Amherst, NY), that allows multiple unit restorations to be fabricated and cemented using adhesive or traditional cementation techniques. This article will overview the technical procedures and advantages of this new ceramic system.

Gold-coated polydimethylsiloxane microwells for high-throughput electrochemiluminescence analysis of intracellular glucose at single cells.

PubMed

Xia, Juan; Zhou, Junyu; Zhang, Ronggui; Jiang, Dechen; Jiang, Depeng

2018-06-04

In this communication, a gold-coated polydimethylsiloxane (PDMS) chip with cell-sized microwells was prepared through a stamping and spraying process that was applied directly for high-throughput electrochemiluminescence (ECL) analysis of intracellular glucose at single cells. As compared with the previous multiple-step fabrication of photoresist-based microwells on the electrode, the preparation process is simple and offers fresh electrode surface for higher luminescence intensity. More luminescence intensity was recorded from cell-retained microwells than that at the planar region among the microwells that was correlated with the content of intracellular glucose. The successful monitoring of intracellular glucose at single cells using this PDMS chip will provide an alternative strategy for high-throughput single-cell analysis. Graphical abstract ᅟ.

Cretaceous-Tertiary findings, paradigms and problems

NASA Technical Reports Server (NTRS)

Officer, C. B.; Drake, C. L.

1988-01-01

The asteroid hypothesis has stimulated numerous studies of the paleontological record at Cretaceous/Tertiary time as well as of geological indicators of environmental crisis preserved in the rock record. Both extinctions and geological anomalies often occur at times that do not appear to be synchronous or instantaneous. The record includes paleontological indicators of dinosaurs, terrestrial flora, marine planktonic organisms, and shallow water marine macrofauna and geological phenomena include occurrences of iridium and other platinum metals, trace elements, clay mineralogy, shocked minerals, soot, microspherules, and isotopes of osmium, strontium and carbon. These findings are reviewed in the context of the alternate hypotheses of an exogenic cause, involving either a single asteroid impact or multiple commentary impacts, and an endogenic cause, involving intense global volcanism and major sea level regression.

Each cell counts: Hematopoiesis and immunity research in the era of single cell genomics.

PubMed

Jaitin, Diego Adhemar; Keren-Shaul, Hadas; Elefant, Naama; Amit, Ido

2015-02-01

Hematopoiesis and immunity are mediated through complex interactions between multiple cell types and states. This complexity is currently addressed following a reductionist approach of characterizing cell types by a small number of cell surface molecular features and gross functions. While the introduction of global transcriptional profiling technologies enabled a more comprehensive view, heterogeneity within sampled populations remained unaddressed, obscuring the true picture of hematopoiesis and immune system function. A critical mass of technological advances in molecular biology and genomics has enabled genome-wide measurements of single cells - the fundamental unit of immunity. These new advances are expected to boost detection of less frequent cell types and fuzzy intermediate cell states, greatly expanding the resolution of current available classifications. This new era of single-cell genomics in immunology research holds great promise for further understanding of the mechanisms and circuits regulating hematopoiesis and immunity in both health and disease. In the near future, the accuracy of single-cell genomics will ultimately enable precise diagnostics and treatment of multiple hematopoietic and immune related diseases. Copyright © 2015 Elsevier Ltd. All rights reserved.

Motor unit activity after eccentric exercise and muscle damage in humans.

PubMed

Semmler, J G

2014-04-01

It is well known that unaccustomed eccentric exercise leads to muscle damage and soreness, which can produce long-lasting effects on muscle function. How this muscle damage influences muscle activation is poorly understood. The purpose of this brief review is to highlight the effect of eccentric exercise on the activation of muscle by the nervous system, by examining the change in motor unit activity obtained from surface electromyography (EMG) and intramuscular recordings. Previous research shows that eccentric exercise produces unusual changes in the EMG–force relation that influences motor performance during isometric, shortening and lengthening muscle contractions and during fatiguing tasks. When examining the effect of eccentric exercise at the single motor unit level, there are substantial changes in recruitment thresholds, discharge rates, motor unit conduction velocities and synchronization, which can last for up to 1 week after eccentric exercise. Examining the time course of these changes suggests that the increased submaximal EMG after eccentric exercise most likely occurs through a decrease in motor unit conduction velocity and an increase in motor unit activity related to antagonist muscle coactivation and low-frequency fatigue. Furthermore, there is a commonly held view that eccentric exercise produces preferential damage to high-threshold motor units, but the evidence for this in humans is limited. Further research is needed to establish whether there is preferential damage to high-threshold motor units after eccentric exercise in humans, preferably by linking changes in motor unit activity with estimates of motor unit size using selective intramuscular recording techniques.

Association between Exposure of Young Children to Procedures Requiring General Anesthesia and Learning and Behavioral Outcomes in a Population-based Birth Cohort.

PubMed

Hu, Danqing; Flick, Randall P; Zaccariello, Michael J; Colligan, Robert C; Katusic, Slavica K; Schroeder, Darrell R; Hanson, Andrew C; Buenvenida, Shonie L; Gleich, Stephen J; Wilder, Robert T; Sprung, Juraj; Warner, David O

2017-08-01

Exposure of young animals to general anesthesia causes neurodegeneration and lasting behavioral abnormalities; whether these findings translate to children remains unclear. This study used a population-based birth cohort to test the hypothesis that multiple, but not single, exposures to procedures requiring general anesthesia before age 3 yr are associated with adverse neurodevelopmental outcomes. A retrospective study cohort was assembled from children born in Olmsted County, Minnesota, from 1996 to 2000 (inclusive). Propensity matching selected children exposed and not exposed to general anesthesia before age 3 yr. Outcomes ascertained via medical and school records included learning disabilities, attention-deficit/hyperactivity disorder, and group-administered ability and achievement tests. Analysis methods included proportional hazard regression models and mixed linear models. For the 116 multiply exposed, 457 singly exposed, and 463 unexposed children analyzed, multiple, but not single, exposures were associated with an increased frequency of both learning disabilities and attention-deficit/hyperactivity disorder (hazard ratio for learning disabilities = 2.17 [95% CI, 1.32 to 3.59], unexposed as reference). Multiple exposures were associated with decreases in both cognitive ability and academic achievement. Single exposures were associated with modest decreases in reading and language achievement but not cognitive ability. These findings in children anesthetized with modern techniques largely confirm those found in an older birth cohort and provide additional evidence that children with multiple exposures are more likely to develop adverse outcomes related to learning and attention. Although a robust association was observed, these data do not determine whether anesthesia per se is causal.

Storage characteristics of multiple-donor pooled red blood cells compared to single-donor red blood cell units.

PubMed

Mathur, Aabhas; Chowdhury, Raquibul; Hillyer, Christopher D; Mitchell, W Beau; Shaz, Beth H

2016-12-01

Each unit of blood donated is processed and stored individually resulting in variability in the amount of red blood cells (RBCs) collected, RBC properties, and the 24-hour posttransfusion RBC survivability. As a result, each unit differs in its ability to deliver oxygen and potentially its effects on the recipient. The goal of this study was to investigate the storage of pooled RBCs from multiple donors in comparison to control standard RBC units. Two units of irradiated, leukoreduced RBCs of same ABO, D, E, C, and K antigen phenotype were collected from each of five donors using apheresis. One unit from each donor was pooled in a 2-L bag and remaining units were used as controls. After being pooled, RBCs were separated in five bags and stored at 4°C along with the controls. Quality indexes were measured on Days 2, 14, and 28 for all the units. Adenosine triphosphate assays for both pooled and controls showed a slight decrease from Day 2 to Day 28 (pooled/control from 5.22/5.24 to 4.35/4.33 µmol/g hemoglobin [Hb]). 2,3-Diphosphoglycerate was successfully rejuvenated for all RBC units on Day 28 (pooled 11.46 µmol/g Hb; control 11.86 µmol/g Hb). The results showed a nonsignificant difference between pooled and control units, with a general trend of lower standard deviation for pooled units when compared to controls. Pooled units have reduced unit-to-unit variability. Future exploration of their immunogenicity is required before using pooled units for transfusion. © 2016 AABB.

Segmented ceramic liner for induction furnaces

DOEpatents

Gorin, Andrew H.; Holcombe, Cressie E.

1994-01-01

A non-fibrous ceramic liner for induction furnaces is provided by vertically stackable ring-shaped liner segments made of ceramic material in a light-weight cellular form. The liner segments can each be fabricated as a single unit or from a plurality of arcuate segments joined together by an interlocking mechanism. Also, the liner segments can be formed of a single ceramic material or can be constructed of multiple concentric layers with the layers being of different ceramic materials and/or cellular forms. Thermomechanically damaged liner segments are selectively replaceable in the furnace.

Segmented ceramic liner for induction furnaces

DOEpatents

Gorin, A.H.; Holcombe, C.E.

1994-07-26

A non-fibrous ceramic liner for induction furnaces is provided by vertically stackable ring-shaped liner segments made of ceramic material in a light-weight cellular form. The liner segments can each be fabricated as a single unit or from a plurality of arcuate segments joined together by an interlocking mechanism. Also, the liner segments can be formed of a single ceramic material or can be constructed of multiple concentric layers with the layers being of different ceramic materials and/or cellular forms. Thermomechanically damaged liner segments are selectively replaceable in the furnace. 5 figs.

AMS Radiocarbon Dating Individual Taxa and Individual Specimens: Implications for Small Mammal Paleoecology.

NASA Astrophysics Data System (ADS)

Graham, Russell; Stafford, Thomas, Jr.; Semken, Holmes, Jr.

2010-05-01

Advances in AMS physics and organic geochemistry have revolutionized our ability to establish absolute chronologies on vertebrate fossils. Highly purified collagen, which provides extremely accurate 14C ages, can be extracted from single bones and teeth as small as 50 mg. Combined with measurement precisions of ±15 to 25 years for ages of < 20,000 yr, the direct AMS 14C technique enables fossil deposits to be chronologically dissected at the level of single animals. Analysis of data from a variety of sites in the United States indicates that most excavation levels (analysis units) as small as 10 cm can be time averaged by several thousand years at a minimum, even with the greatest care in excavation and processing of sediments. Time averaging of this magnitude has important implications for fine-scale paleoecological analysis of faunas, especially when compared to high-resolution climate records like those derived from speleothems, ice cores, or marine cores. To this end, we propose saturation dating of indicative taxa and plotting dates of individual specimens against high-resolution climate records rather than analysis of complete faunas or faunules. This technique provides even higher resolution of paleoenvironments than pollen spectra.

Lateral Entorhinal Cortex Lesions Impair Local Spatial Frameworks

PubMed Central

Kuruvilla, Maneesh V.; Ainge, James A.

2017-01-01

A prominent theory in the neurobiology of memory processing is that episodic memory is supported by contextually gated spatial representations in the hippocampus formed by combining spatial information from medial entorhinal cortex (MEC) with non-spatial information from lateral entorhinal cortex (LEC). However, there is a growing body of evidence from lesion and single-unit recording studies in rodents suggesting that LEC might have a role in encoding space, particularly the current and previous locations of objects within the local environment. Landmarks, both local and global, have been shown to control the spatial representations hypothesized to underlie cognitive maps. Consequently, it has recently been suggested that information processing within this network might be organized with reference to spatial scale with LEC and MEC providing information about local and global spatial frameworks respectively. In the present study, we trained animals to search for food using either a local or global spatial framework. Animals were re-tested on both tasks after receiving excitotoxic lesions of either the MEC or LEC. LEC lesioned animals were impaired in their ability to learn a local spatial framework task. LEC lesioned animals were also impaired on an object recognition (OR) task involving multiple local features but unimpaired at recognizing a single familiar object. Together, this suggests that LEC is involved in associating features of the local environment. However, neither LEC nor MEC lesions impaired performance on the global spatial framework task. PMID:28567006

Highly parallel reconfigurable computer architecture for robotic computation having plural processor cells each having right and left ensembles of plural processors

NASA Technical Reports Server (NTRS)

Fijany, Amir (Inventor); Bejczy, Antal K. (Inventor)

1994-01-01

In a computer having a large number of single-instruction multiple data (SIMD) processors, each of the SIMD processors has two sets of three individual processor elements controlled by a master control unit and interconnected among a plurality of register file units where data is stored. The register files input and output data in synchronism with a minor cycle clock under control of two slave control units controlling the register file units connected to respective ones of the two sets of processor elements. Depending upon which ones of the register file units are enabled to store or transmit data during a particular minor clock cycle, the processor elements within an SIMD processor are connected in rings or in pipeline arrays, and may exchange data with the internal bus or with neighboring SIMD processors through interface units controlled by respective ones of the two slave control units.

Execution of a parallel edge-based Navier-Stokes solver on commodity graphics processor units

NASA Astrophysics Data System (ADS)

Corral, Roque; Gisbert, Fernando; Pueblas, Jesus

2017-02-01

The implementation of an edge-based three-dimensional Reynolds Average Navier-Stokes solver for unstructured grids able to run on multiple graphics processing units (GPUs) is presented. Loops over edges, which are the most time-consuming part of the solver, have been written to exploit the massively parallel capabilities of GPUs. Non-blocking communications between parallel processes and between the GPU and the central processor unit (CPU) have been used to enhance code scalability. The code is written using a mixture of C++ and OpenCL, to allow the execution of the source code on GPUs. The Message Passage Interface (MPI) library is used to allow the parallel execution of the solver on multiple GPUs. A comparative study of the solver parallel performance is carried out using a cluster of CPUs and another of GPUs. It is shown that a single GPU is up to 64 times faster than a single CPU core. The parallel scalability of the solver is mainly degraded due to the loss of computing efficiency of the GPU when the size of the case decreases. However, for large enough grid sizes, the scalability is strongly improved. A cluster featuring commodity GPUs and a high bandwidth network is ten times less costly and consumes 33% less energy than a CPU-based cluster with an equivalent computational power.

Search for supersymmetry in pp collisions at $$\\sqrt{s}$$=8 TeV in events with a single lepton, large jet multiplicity, and multiple b jets

DOE PAGES

Chatrchyan, Serguei

2014-04-18

Results are reported from a search for supersymmetry in pp collisions at a center-of-mass energy of 8 TeV, based on events with a single isolated lepton (electron or muon) and multiple jets, at least two of which are identified as b jets. The data sample corresponds to an integrated luminosity of 19.3 inverse femtobarns recorded by the CMS experiment at the LHC in 2012. The search is motivated by supersymmetric models that involve strong-production processes and cascade decays of new particles. The resulting final states contain multiple jets as well as missing transverse momentum from weakly interacting particles. The eventmore » yields, observed across several kinematic regions, are consistent with the expectations from standard model processes. Thus the results are interpreted in the context of simplified supersymmetric scenarios with pair production of gluinos, where each gluino decays to a top quark-antiquark pair and the lightest neutralino. For the case of decays via virtual top squarks, gluinos with a mass smaller than 1.26 TeV are excluded for low neutralino masses.« less

A Flexible High-Performance Photoimaging Device Based on Bioinspired Hierarchical Multiple-Patterned Plasmonic Nanostructures.

PubMed

Lee, Yoon Ho; Lee, Tae Kyung; Kim, Hongki; Song, Inho; Lee, Jiwon; Kang, Saewon; Ko, Hyunhyub; Kwak, Sang Kyu; Oh, Joon Hak

2018-03-01

In insect eyes, ommatidia with hierarchical structured cornea play a critical role in amplifying and transferring visual signals to the brain through optic nerves, enabling the perception of various visual signals. Here, inspired by the structure and functions of insect ommatidia, a flexible photoimaging device is reported that can simultaneously detect and record incoming photonic signals by vertically stacking an organic photodiode and resistive memory device. A single-layered, hierarchical multiple-patterned back reflector that can exhibit various plasmonic effects is incorporated into the organic photodiode. The multiple-patterned flexible organic photodiodes exhibit greatly enhanced photoresponsivity due to the increased light absorption in comparison with the flat systems. Moreover, the flexible photoimaging device shows a well-resolved spatiotemporal mapping of optical signals with excellent operational and mechanical stabilities at low driving voltages below half of the flat systems. Theoretical calculation and scanning near-field optical microscopy analyses clearly reveal that multiple-patterned electrodes have much stronger surface plasmon coupling than flat and single-patterned systems. The developed methodology provides a versatile and effective route for realizing high-performance optoelectronic and photonic systems. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Discharge properties of abductor hallucis before, during, and after an isometric fatigue task.

PubMed

Kelly, Luke A; Racinais, Sebastien; Cresswell, Andrew G

2013-08-01

Abductor hallucis is the largest muscle in the arch of the human foot and comprises few motor units relative to its physiological cross-sectional area. It has been described as a postural muscle, aiding in the stabilization of the longitudinal arch during stance and gait. The purpose of this study was to describe the discharge properties of abductor hallucis motor units during ramp and hold isometric contractions, as well as its discharge characteristics during fatigue. Intramuscular electromyographic recordings from abductor hallucis were made in 5 subjects; from those recordings, 42 single motor units were decomposed. Data were recorded during isometric ramp contractions at 60% maximum voluntary contraction (MVC), performed before and after a submaximal isometric contraction to failure (mean force 41.3 ± 15.3% MVC, mean duration 233 ± 116 s). Motor unit recruitment thresholds ranged from 10.3 to 54.2% MVC. No significant difference was observed between recruitment and derecruitment thresholds or their respective discharge rates for both the initial and postfatigue ramp contractions (all P > 0.25). Recruitment threshold was positively correlated with recruitment discharge rate (r = 0.47, P < 0.03). All motor units attained similar peak discharge rates (14.0 ± 0.25 pulses/s) and were not correlated with recruitment threshold. Thirteen motor units could be followed during the isometric fatigue task, with a decline in discharge rate and increase in discharge rate variability occurring in the final 25% of the task (both P < 0.05). We have shown that abductor hallucis motor units discharge relatively slowly and are considerably resistant to fatigue. These characteristics may be effective for generating and sustaining the substantial level of force that is required to stabilize the longitudinal arch during weight bearing.

Building an organic computing device with multiple interconnected brains

PubMed Central

Pais-Vieira, Miguel; Chiuffa, Gabriela; Lebedev, Mikhail; Yadav, Amol; Nicolelis, Miguel A. L.

2015-01-01

Recently, we proposed that Brainets, i.e. networks formed by multiple animal brains, cooperating and exchanging information in real time through direct brain-to-brain interfaces, could provide the core of a new type of computing device: an organic computer. Here, we describe the first experimental demonstration of such a Brainet, built by interconnecting four adult rat brains. Brainets worked by concurrently recording the extracellular electrical activity generated by populations of cortical neurons distributed across multiple rats chronically implanted with multi-electrode arrays. Cortical neuronal activity was recorded and analyzed in real time, and then delivered to the somatosensory cortices of other animals that participated in the Brainet using intracortical microstimulation (ICMS). Using this approach, different Brainet architectures solved a number of useful computational problems, such as discrete classification, image processing, storage and retrieval of tactile information, and even weather forecasting. Brainets consistently performed at the same or higher levels than single rats in these tasks. Based on these findings, we propose that Brainets could be used to investigate animal social behaviors as well as a test bed for exploring the properties and potential applications of organic computers. PMID:26158615

One pediatric burn unit's experience with sleepwear related injuries

PubMed Central

McLoughlin, E.; Clarke, N.; Stahl, K.; Crawford, J.

1998-01-01

Review of the records of 678 children with acute injuries referred during an eight year period to this burn unit indicated that flame burns from a single ignition source (50%) outranked scalds (27%) or house fires (12%) as causes of injury. There was no temporal trend in the rank pattern. The majority of these single-source flame injuries were severe and involved ignition of the child's clothing. From 1969 through 1973, sleepwear was the clothing involved in 32% of the instances. Since that time and coincident with promulgation of strict federal and state standards for flammability of children's night clothing, a dramatic decline in the number of children referred with injuries of this type has taken place. It is probable that the single factor most important to the decline, in our experience with these injuries, is lower fabric flammability but, because our data may not be representative, corroboration is needed before one can exclude factors such as altered garment design, fire safety related practices at home, or changing patterns of hospital referral. PMID:9887427

Multichannel ECG and Noise Modeling: Application to Maternal and Fetal ECG Signals

NASA Astrophysics Data System (ADS)

Sameni, Reza; Clifford, Gari D.; Jutten, Christian; Shamsollahi, Mohammad B.

2007-12-01

A three-dimensional dynamic model of the electrical activity of the heart is presented. The model is based on the single dipole model of the heart and is later related to the body surface potentials through a linear model which accounts for the temporal movements and rotations of the cardiac dipole, together with a realistic ECG noise model. The proposed model is also generalized to maternal and fetal ECG mixtures recorded from the abdomen of pregnant women in single and multiple pregnancies. The applicability of the model for the evaluation of signal processing algorithms is illustrated using independent component analysis. Considering the difficulties and limitations of recording long-term ECG data, especially from pregnant women, the model described in this paper may serve as an effective means of simulation and analysis of a wide range of ECGs, including adults and fetuses.

True Color Holography with Three Wavelengths

NASA Astrophysics Data System (ADS)

Swearingen, Jeremy R.

2006-12-01

Single wavelength holography provides a three-dimensional snapshot of an object?s size, shape, and position relative to the holographic medium. However, single wavelength holography is limited because it does not preserve the integrity of the original object?s color. When the hologram is played back, the object in the hologram will appear to be the color of the wavelength used to record the hologram. This can be remedied by employing multiple wavelengths, namely three: red, blue, and green as to create a ?pseudo white? laser beam. To achieve this pseudo white beam, the red, blue, and green lasers must be merged with the appropriate dichroic filters and passed through the same spatial filter to expose the hologram as if the light was all coming from the same source. I will discuss the setup used to record these ?true color? holograms and the difficulties in developing them.

Accuracy and Coverage of Diagnosis and Procedural Coding of Severely Injured Patients in the Finnish Hospital Discharge Register: Comparison to Patient Files and the Helsinki Trauma Registry.

PubMed

Heinänen, M; Brinck, T; Handolin, L; Mattila, V M; Söderlund, T

2017-09-01

The Finnish Hospital Discharge Register data are frequently used for research purposes. The Finnish Hospital Discharge Register has shown excellent validity in single injuries or disease groups, but no studies have assessed patients with multiple trauma diagnoses. We aimed to evaluate the accuracy and coverage of the Finnish Hospital Discharge Register but at the same time validate the data of the trauma registry of the Helsinki University Hospital's Trauma Unit. We assessed the accuracy and coverage of the Finnish Hospital Discharge Register data by comparing them to the original patient files and trauma registry files from the trauma registry of the Helsinki University Hospital's Trauma Unit. We identified a baseline cohort of patients with severe thorax injury from the trauma registry of the Helsinki University Hospital's Trauma Unit of 2013 (sample of 107 patients). We hypothesized that the Finnish Hospital Discharge Register would lack valuable information about these patients. Using patient files, we identified 965 trauma diagnoses in these 107 patients. From the Finnish Hospital Discharge Register, we identified 632 (65.5%) diagnoses and from the trauma registry of the Helsinki University Hospital's Trauma Unit, 924 (95.8%) diagnoses. A total of 170 (17.6%) trauma diagnoses were missing from the Finnish Hospital Discharge Register data and 41 (4.2%) from the trauma registry of the Helsinki University Hospital's Trauma Unit data. The coverage and accuracy of diagnoses in the Finnish Hospital Discharge Register were 65.5% (95% confidence interval: 62.5%-68.5%) and 73.8% (95% confidence interval: 70.4%-77.2%), respectively, and for the trauma registry of the Helsinki University Hospital's Trauma Unit, 95.8% (95% confidence interval: 94.5%-97.0%) and 97.6% (95% confidence interval: 96.7%-98.6%), respectively. According to patient records, these patients were subjects in 249 operations. We identified 40 (16.1%) missing operation codes from the Finnish Hospital Discharge Register and 19 (7.6%) from the trauma registry of the Helsinki University Hospital's Trauma Unit. The validity of the Finnish Hospital Discharge Register data is unsatisfactory in terms of the accuracy and coverage of diagnoses in patients with multiple trauma diagnoses. Procedural codes provide greater accuracy. We found the coverage and accuracy of the trauma registry of the Helsinki University Hospital's Trauma Unit to be excellent. Therefore, a special trauma registry, such as the trauma registry of the Helsinki University Hospital's Trauma Unit, provides much more accurate data and should be the preferred registry when extracting data for research or for administrative use, such as resource prioritizing.

Challenges with secondary use of multi-source water-quality data in the United States

USGS Publications Warehouse

Sprague, Lori A.; Oelsner, Gretchen P.; Argue, Denise M.

2017-01-01

Combining water-quality data from multiple sources can help counterbalance diminishing resources for stream monitoring in the United States and lead to important regional and national insights that would not otherwise be possible. Individual monitoring organizations understand their own data very well, but issues can arise when their data are combined with data from other organizations that have used different methods for reporting the same common metadata elements. Such use of multi-source data is termed “secondary use”—the use of data beyond the original intent determined by the organization that collected the data. In this study, we surveyed more than 25 million nutrient records collected by 488 organizations in the United States since 1899 to identify major inconsistencies in metadata elements that limit the secondary use of multi-source data. Nearly 14.5 million of these records had missing or ambiguous information for one or more key metadata elements, including (in decreasing order of records affected) sample fraction, chemical form, parameter name, units of measurement, precise numerical value, and remark codes. As a result, metadata harmonization to make secondary use of these multi-source data will be time consuming, expensive, and inexact. Different data users may make different assumptions about the same ambiguous data, potentially resulting in different conclusions about important environmental issues. The value of these ambiguous data is estimated at \\$US12 billion, a substantial collective investment by water-resource organizations in the United States. By comparison, the value of unambiguous data is estimated at \\$US8.2 billion. The ambiguous data could be preserved for uses beyond the original intent by developing and implementing standardized metadata practices for future and legacy water-quality data throughout the United States.

Heterodyne detection using spectral line pairing for spectral phase encoding optical code division multiple access and dynamic dispersion compensation.

PubMed

Yang, Yi; Foster, Mark; Khurgin, Jacob B; Cooper, A Brinton

2012-07-30

A novel coherent optical code-division multiple access (OCDMA) scheme is proposed that uses spectral line pairing to generate signals suitable for heterodyne decoding. Both signal and local reference are transmitted via a single optical fiber and a simple balanced receiver performs sourceless heterodyne detection, canceling speckle noise and multiple-access interference (MAI). To validate the idea, a 16 user fully loaded phase encoded system is simulated. Effects of fiber dispersion on system performance are studied as well. Both second and third order dispersion management is achieved by using a spectral phase encoder to adjust phase shifts of spectral components at the optical network unit (ONU).

Reconfigurable Solid-state Dye-doped Polymer Ring Resonator Lasers

NASA Astrophysics Data System (ADS)

Chandrahalim, Hengky; Fan, Xudong

2015-12-01

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

Reconfigurable Solid-state Dye-doped Polymer Ring Resonator Lasers

PubMed Central

Chandrahalim, Hengky; Fan, Xudong

2015-01-01

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

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

PubMed

Chandrahalim, Hengky; Fan, Xudong

2015-12-17

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

Integration of vestibular and head movement signals in the vestibular nuclei during whole-body rotation

NASA Technical Reports Server (NTRS)

Gdowski, G. T.; McCrea, R. A.; Peterson, B. W. (Principal Investigator)

1999-01-01

Single-unit recordings were obtained from 107 horizontal semicircular canal-related central vestibular neurons in three alert squirrel monkeys during passive sinusoidal whole-body rotation (WBR) while the head was free to move in the yaw plane (2.3 Hz, 20 degrees /s). Most of the units were identified as secondary vestibular neurons by electrical stimulation of the ipsilateral vestibular nerve (61/80 tested). Both non-eye-movement (n = 52) and eye-movement-related (n = 55) units were studied. Unit responses recorded when the head was free to move were compared with responses recorded when the head was restrained from moving. WBR in the absence of a visual target evoked a compensatory vestibulocollic reflex (VCR) that effectively reduced the head velocity in space by an average of 33 +/- 14%. In 73 units, the compensatory head movements were sufficiently large to permit the effect of the VCR on vestibular signal processing to be assessed quantitatively. The VCR affected the rotational responses of different vestibular neurons in different ways. Approximately one-half of the units (34/73, 47%) had responses that decreased as head velocity decreased. However, the responses of many other units (24/73) showed little change. These cells had signals that were better correlated with trunk velocity than with head velocity. The remaining units had responses that were significantly larger (15/73, 21%) when the VCR produced a decrease in head velocity. Eye-movement-related units tended to have rotational responses that were correlated with head velocity. On the other hand, non-eye-movement units tended to have rotational responses that were better correlated with trunk velocity. We conclude that sensory vestibular signals are transformed from head-in-space coordinates to trunk-in-space coordinates on many secondary vestibular neurons in the vestibular nuclei by the addition of inputs related to head rotation on the trunk. This coordinate transformation is presumably important for controlling postural reflexes and constructing a central percept of body orientation and movement in space.

Perceptions of Hazing and Bullying among U.S. Military Service Members

DTIC Science & Technology

2016-10-18

Institute (DEOMI) Organizational Climate Survey (DEOCS), perceptions of hazing and bullying among SMs of all branches of the U.S. Armed Forces (except...recorded survey responses. Reserve, Guard, Civilian, and Coast Guard respondents were excluded from the sample, thus resulting in 620,629 Active Duty...of respondents, some units may take the survey multiple times within a year due to commander turnover, mandatory regulatory requirements, or permanent

Clinical efficiency and safety analysis of transcatheter closure of multiple atrial septal defects in adults.

PubMed

Song, Zhi-Yuan; He, Guo-Xiang; Shu, Mao-Qin; Hu, Hou-Yuan; Tong, Shi-Fei; Ran, Bo-Li; Liu, Jian-Ping; Li, Yong-Hua; Jing, Tao

2009-03-01

Transcatheter closure of atrial septal defects (ASDs) is currently a reliable alternative to surgery, even though challenging in patients with multiple ASDs. The aim of this study was to evaluate the clinical efficiency and safety of transcatheter closure in multiple ASDs. Multiple ASDs were diagnosed by transthoracic echocardiography (TTE) or transesophageal echocardiography (TEE). The occlusive condition and distance between 2 adjacent ASDs were measured by TTE examination. Then, the number and size of the occluder(s) was determined. TTE examinations were performed after transcatheter closure as follow-up. The transcatheter procedure was successful in 15 patients with multiple ASDs, using a single occluder in 9 patients and 2 occluders in the remaining 6 patients. Overall, 21 ASD occluders were implanted. During a follow-up period of 6 mo to 5 y, a slight residual shunt was found in 1 patient without any symptoms; a moderate residual shunt was identified at the inferior vena cava and the occluder was removed by surgery 1 mo after procedure. Other complications, including endocarditis, arrhythmia, thromboembolism, and atrioventricular valve damage were not recorded in any of the 15 patients during the follow-up period. Transcatheter closure of multiple ASDs is safe and efficient. Two occluders are necessary for the distance of 2 ASDs more than 7 mm, and a single occluder is sufficient for those 7 mm or less. Copyright (c) 2009 Wiley Periodicals, Inc.

SU-G-BRC-14: Multi-Lesion, Multi-Rx, Brain Radiosurgery with Novel Single Isocenter Technique

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

Honig, N; Alani, S; Schlocker, A

Purpose: There is a strong trend to treat multiple brain metastases with radiosurgery rather than whole brain irradiation. This feasibility study investigates a novel planning technique for radio-surgical treatment of multiple brain lesions with differing dose prescriptions, a single isocenter, and dynamic conformal arcs. The novel technique will be compared to the well-established single-isocenter volumetric modulated arc therapy (VMAT) technique commonly used for treating brain lesions. Methods: Six patients with metastatic brain lesions were selected for a prospective treatment planning study to evaluate Interdigitating MLC Dynamic Conformal Arc (IMDCA) technique. Arcs were planned for simultaneous irradiation to maximize beam deliverymore » efficiency. To accommodate varying PTV dose prescriptions, selected arcs were re-irradiated in reverse. Beam weights were adjusted until all prescription constraints were met. The number of lesions ranged between 2 to 4 (mode = 3). For comparison, SRS VMAT plans were generated utilizing an established single-isocenter, 3 arc planning template. All plans were compared by means of Paddick conformity index (PCI), RTOG Conformity Index (RCI), gradient index (GI), and the normal brain volume receiving 10% (V10) of the highest prescription dose. The monitor units and delivery time were tabulated for each plan. Results: IMDCA achieved conformal plans (PCI = 0.72±0.03, RCI = 1.33±0.03) with steep dose fall-off (GI = 3.79±0.03) on average for all of the plans evaluated. The VMAT plans had slightly better conformity (PCI = 0.85 ± 0.03, RCI = 1.13 ± 0.03) than IMDCA, but overall worse GI (4.29 ± 0.06). IMDCA plans had lower V10% values, required 50% fewer MUs, and had 34% shorter beam delivery time on average compared to VMAT plans. Conclusion: IMDCA plans with varying dose prescriptions for multiple lesions, had comparable dosimetric coverage as VMAT plans, but were obtained with significantly lower integral dose, fewer monitor units, and quicker delivery time.« less

Multiple Differential-Amplifier MMICs Embedded in Waveguides

NASA Technical Reports Server (NTRS)

Kangaslahti, Pekka; Schlecht, Erich

2010-01-01

Compact amplifier assemblies of a type now being developed for operation at frequencies of hundreds of gigahertz comprise multiple amplifier units in parallel arrangements to increase power and/or cascade arrangements to increase gains. Each amplifier unit is a monolithic microwave integrated circuit (MMIC) implementation of a pair of amplifiers in differential (in contradistinction to single-ended) configuration. Heretofore, in cascading amplifiers to increase gain, it has been common practice to interconnect the amplifiers by use of wires and/or thin films on substrates. This practice has not yielded satisfactory results at frequencies greater than 200 Hz, in each case, for either or both of two reasons: Wire bonds introduce large discontinuities. Because the interconnections are typically tens of wavelengths long, any impedance mismatches give rise to ripples in the gain-vs.-frequency response, which degrade the performance of the cascade.

NeuroGrid: recording action potentials from the surface of the brain.

PubMed

Khodagholy, Dion; Gelinas, Jennifer N; Thesen, Thomas; Doyle, Werner; Devinsky, Orrin; Malliaras, George G; Buzsáki, György

2015-02-01

Recording from neural networks at the resolution of action potentials is critical for understanding how information is processed in the brain. Here, we address this challenge by developing an organic material-based, ultraconformable, biocompatible and scalable neural interface array (the 'NeuroGrid') that can record both local field potentials(LFPs) and action potentials from superficial cortical neurons without penetrating the brain surface. Spikes with features of interneurons and pyramidal cells were simultaneously acquired by multiple neighboring electrodes of the NeuroGrid, allowing for the isolation of putative single neurons in rats. Spiking activity demonstrated consistent phase modulation by ongoing brain oscillations and was stable in recordings exceeding 1 week's duration. We also recorded LFP-modulated spiking activity intraoperatively in patients undergoing epilepsy surgery. The NeuroGrid constitutes an effective method for large-scale, stable recording of neuronal spikes in concert with local population synaptic activity, enhancing comprehension of neural processes across spatiotemporal scales and potentially facilitating diagnosis and therapy for brain disorders.

Efficient generation of complete sequences of MDR-encoding plasmids by rapid assembly of MinION barcoding sequencing data.

PubMed

Li, Ruichao; Xie, Miaomiao; Dong, Ning; Lin, Dachuan; Yang, Xuemei; Wong, Marcus Ho Yin; Chan, Edward Wai-Chi; Chen, Sheng

2018-03-01

Multidrug resistance (MDR)-encoding plasmids are considered major molecular vehicles responsible for transmission of antibiotic resistance genes among bacteria of the same or different species. Delineating the complete sequences of such plasmids could provide valuable insight into the evolution and transmission mechanisms underlying bacterial antibiotic resistance development. However, due to the presence of multiple repeats of mobile elements, complete sequencing of MDR plasmids remains technically complicated, expensive, and time-consuming. Here, we demonstrate a rapid and efficient approach to obtaining multiple MDR plasmid sequences through the use of the MinION nanopore sequencing platform, which is incorporated in a portable device. By assembling the long sequencing reads generated by a single MinION run according to a rapid barcoding sequencing protocol, we obtained the complete sequences of 20 plasmids harbored by multiple bacterial strains. Importantly, single long reads covering a plasmid end-to-end were recorded, indicating that de novo assembly may be unnecessary if the single reads exhibit high accuracy. This workflow represents a convenient and cost-effective approach for systematic assessment of MDR plasmids responsible for treatment failure of bacterial infections, offering the opportunity to perform detailed molecular epidemiological studies to probe the evolutionary and transmission mechanisms of MDR-encoding elements.

Nature and Role of Traditional Forms of Counselling in Zambia: A Case of Lusaka Province

ERIC Educational Resources Information Center

Chiboola, Hector; Munsaka, Sody M.

2018-01-01

The aim of this study was to determine the nature and role of traditional forms of counselling and the scope of common problems presented to traditional counsellors in Lusaka province. It used a qualitative research methodology and deployed a holistic single-case study design with multiple embedded units of analysis. The sample consisted of 80…

Capable Reader Program: Language Arts. Volume II. Objectives for Units B2 through B4. Bulletin No. 335.

ERIC Educational Resources Information Center

Long, Sandra; And Others

Part of a curriculum series for academically gifted elementary students in the area of reading, the document presents objectives and activities for language arts instruction. There are three major objectives: (1) recognizing persuasive use of words, vague and imprecise words, multiple meanings conveyed by a single word, and propaganda techniques;…

"More Confident Going into College": Lessons Learned from Multiple Stakeholders in a New Blended Learning Initiative

ERIC Educational Resources Information Center

Whiteside, Aimee L.; Garrett Dikkers, Amy; Lewis, Somer

2016-01-01

This article examined a blended learning initiative in a large suburban high school in the Midwestern region of the United States. It employed a single-case exploratory design approach to learn about the experience of administrators, teachers, students, and parents. Using Zimmerman's Self-Regulated Learning (SRL) Theory as a guiding framework,…

Ecosante: Using Daily Prompts and Photo Capturing to Encourage Multiple Behavior Change in a Sustainable Lifestyle Intervention

ERIC Educational Resources Information Center

Kuo, Pei-Yi

2017-01-01

The United States has a weight problem. It's not just about food intake but also about energy consumption [97, 153]. This dissertation asks: "How can we encourage people to act in ways that are mutually beneficial for themselves and the environment?" To date, there is no single behavior intervention in the literature targets behavioral…

Parallel Execution of Functional Mock-up Units in Buildings Modeling

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

Ozmen, Ozgur; Nutaro, James J.; New, Joshua Ryan

2016-06-30

A Functional Mock-up Interface (FMI) defines a standardized interface to be used in computer simulations to develop complex cyber-physical systems. FMI implementation by a software modeling tool enables the creation of a simulation model that can be interconnected, or the creation of a software library called a Functional Mock-up Unit (FMU). This report describes an FMU wrapper implementation that imports FMUs into a C++ environment and uses an Euler solver that executes FMUs in parallel using Open Multi-Processing (OpenMP). The purpose of this report is to elucidate the runtime performance of the solver when a multi-component system is imported asmore » a single FMU (for the whole system) or as multiple FMUs (for different groups of components as sub-systems). This performance comparison is conducted using two test cases: (1) a simple, multi-tank problem; and (2) a more realistic use case based on the Modelica Buildings Library. In both test cases, the performance gains are promising when each FMU consists of a large number of states and state events that are wrapped in a single FMU. Load balancing is demonstrated to be a critical factor in speeding up parallel execution of multiple FMUs.« less

Estimating Single-Trial Responses in EEG

NASA Technical Reports Server (NTRS)

Shah, A. S.; Knuth, K. H.; Truccolo, W. A.; Mehta, A. D.; Fu, K. G.; Johnston, T. A.; Ding, M.; Bressler, S. L.; Schroeder, C. E.; Clancy, Daniel (Technical Monitor)

2002-01-01

Accurate characterization of single-trial field potential responses is critical from a number of perspectives. For example, it allows differentiation of an evoked response from ongoing EEG. We previously developed the multiple component Event Related Potential (mcERP) algorithm to improve resolution of the single-trial evoked response. The mcERP model states that multiple components, each specified by a stereotypic waveform varying in latency and amplitude from trial to trial, comprise the evoked response. Application of the mcERP algorithm to simulated data with three independent, synthetic components has shown that the model is capable of separating these components and estimating their variability. Application of the model to single trial, visual evoked potentials recorded simultaneously from all V1 laminae in an awake, fixating macaque yielded local and far-field components. Certain local components estimated by the model were distributed in both granular and supragranular laminae. This suggests a linear coupling between the responses of thalamo-recipient neuronal ensembles and subsequent responses of supragranular neuronal ensembles, as predicted by the feedforward anatomy of V1. Our results indicate that the mcERP algorithm provides a valid estimation of single-trial responses. This will enable analyses that depend on trial-to-trial variations and those that require separation of the evoked response from background EEG rhythms

Applying clinical guidelines in general practice: a qualitative study of potential complications.

PubMed

Austad, Bjarne; Hetlevik, Irene; Mjølstad, Bente Prytz; Helvik, Anne-Sofie

2016-07-22

Clinical guidelines for single diseases often pose problems in general practice work with multimorbid patients. However, little research focuses on how general practice is affected by the demand to follow multiple guidelines. This study explored Norwegian general practitioners' (GPs') experiences with and reflections upon the consequences for general practice of applying multiple guidelines. Qualitative focus group study carried out in Mid-Norway. The study involved a purposeful sample of 25 Norwegian GPs from four pre-existing groups. Interviews were audio-recorded, transcribed and analyzed using systematic text condensation, i.e. applying a phenomenological approach. The GPs' responses clustered around two major topics: 1) Complications for the GPs of applying multiple guidelines; and, 2) Complications for their patients when GPs apply multiple guidelines. For the GPs, applying multiple guidelines created a highly problematic situation as they felt obliged to implement guidelines that were not suited to their patients: too often, the map and the terrain did not match. They also experienced greater insecurity regarding their own practice which, they admitted, resulted in an increased tendency to practice 'defensive medicine'. For their patients, the GPs experienced that applying multiple guidelines increased the risk of polypharmacy, excessive non-pharmacological recommendations, a tendency toward medicalization and, for some, a reduction in quality of life. The GPs experienced negative consequences when obliged to apply a variety of single disease guidelines to multimorbid patients, including increased risk of polypharmacy and overtreatment. We believe patient-centered care and the GPs' courage to non-comply when necessary may aid in reducing these risks. Health care authorities and guideline developers need to be aware of the potential negative effects of applying a single disease focus in general practice, where multimorbidity is highly prevalent.

Symplectic multi-particle tracking on GPUs

NASA Astrophysics Data System (ADS)

Liu, Zhicong; Qiang, Ji

2018-05-01

A symplectic multi-particle tracking model is implemented on the Graphic Processing Units (GPUs) using the Compute Unified Device Architecture (CUDA) language. The symplectic tracking model can preserve phase space structure and reduce non-physical effects in long term simulation, which is important for beam property evaluation in particle accelerators. Though this model is computationally expensive, it is very suitable for parallelization and can be accelerated significantly by using GPUs. In this paper, we optimized the implementation of the symplectic tracking model on both single GPU and multiple GPUs. Using a single GPU processor, the code achieves a factor of 2-10 speedup for a range of problem sizes compared with the time on a single state-of-the-art Central Processing Unit (CPU) node with similar power consumption and semiconductor technology. It also shows good scalability on a multi-GPU cluster at Oak Ridge Leadership Computing Facility. In an application to beam dynamics simulation, the GPU implementation helps save more than a factor of two total computing time in comparison to the CPU implementation.

The impact of cross-border reproductive care or 'fertility tourism' on NHS maternity services.

PubMed

McKelvey, A; David, A L; Shenfield, F; Jauniaux, E R

2009-10-01

High order multiple pregnancies have substantial morbidity and mortality. Fertility treatment is commonly responsible for their conception and is available globally with variable regulation. We investigated cross-border fertility treatment in these pregnancies in a UK fetal medicine unit, recording mode of conception, country of fertility treatment, reason for non-UK treatment and fetal reduction. Over an 11-year period, 109 women had a high order multiple pregnancy. Ninety-four women (86%) conceived with fertility treatment of whom 24 (26%) had this performed overseas. Cross-border fertility treatment poses an increasing challenge to obstetricians. National data on its occurrence is urgently needed.

Aggregation of carbon dioxide sequestration storage assessment units

USGS Publications Warehouse

Blondes, Madalyn S.; Schuenemeyer, John H.; Olea, Ricardo A.; Drew, Lawrence J.

2013-01-01

The U.S. Geological Survey is currently conducting a national assessment of carbon dioxide (CO2) storage resources, mandated by the Energy Independence and Security Act of 2007. Pre-emission capture and storage of CO2 in subsurface saline formations is one potential method to reduce greenhouse gas emissions and the negative impact of global climate change. Like many large-scale resource assessments, the area under investigation is split into smaller, more manageable storage assessment units (SAUs), which must be aggregated with correctly propagated uncertainty to the basin, regional, and national scales. The aggregation methodology requires two types of data: marginal probability distributions of storage resource for each SAU, and a correlation matrix obtained by expert elicitation describing interdependencies between pairs of SAUs. Dependencies arise because geologic analogs, assessment methods, and assessors often overlap. The correlation matrix is used to induce rank correlation, using a Cholesky decomposition, among the empirical marginal distributions representing individually assessed SAUs. This manuscript presents a probabilistic aggregation method tailored to the correlations and dependencies inherent to a CO2 storage assessment. Aggregation results must be presented at the basin, regional, and national scales. A single stage approach, in which one large correlation matrix is defined and subsets are used for different scales, is compared to a multiple stage approach, in which new correlation matrices are created to aggregate intermediate results. Although the single-stage approach requires determination of significantly more correlation coefficients, it captures geologic dependencies among similar units in different basins and it is less sensitive to fluctuations in low correlation coefficients than the multiple stage approach. Thus, subsets of one single-stage correlation matrix are used to aggregate to basin, regional, and national scales.

Multiples of Median-Transformed, Normalized Reference Ranges of Steroid Profiling Data Independent of Age, Sex, and Units.

PubMed

Zalas, Dominika; Reinehr, Thomas; Niedziela, Marek; Borzikowsky, Christoph; Flader, Maciej; Simic-Schleicher, Gunter; Akkurt, Halit Ilker; Heger, Sabine; Hornig, Nadine; Holterhus, Paul-Martin; Kulle, Alexandra E

2018-01-01

The high complexity of pediatric reference ranges across age, sex, and units impairs clinical application and comparability of steroid hormone data, e.g., in congenital adrenal hyperplasia (CAH). We developed a multiples-of-median (MoM) normalization tool to overcome this major drawback in pediatric endocrinology. Liquid chromatography tandem mass spectrometry data comprising 10 steroid hormones representing 905 controls (555 males, 350 females, 0 to > 16 years) from 2 previous datasets were MoM transformed across age and sex. Twenty-three genetically proven CAH patients were included (21-hydroxylase deficiency [21OHD], n = 19; 11β-hydroxylase deficiency [11OHD], n = 4). MoM cutoffs for single steroids predicting 21OHD and 11OHD were computed and validated through new, independent patients (21OHD, n = 8; adrenal cortical carcinoma, n = 6; obesity, n = 40). 21OHD and 11OHD patients showed disease-typical, easily recognizable MoM patterns independent of age, sex, and concentration units. Two single-steroid cutoffs indicated 21OHD: 3.87 MoM for 17-hydroxyprogesterone (100% sensitivity and 98.83% specificity) and 12.28 MoM for 21-deoxycortisol (94.74% sensitivity and 100% specificity). A cutoff of 13.18 MoM for 11-deoxycortisol indicated 11OHD (100% sensitivity and 100% specificity). Age- and sex-independent MoMs are straightforward for a clinically relevant display of multi-steroid patterns. In addition, defined single-steroid MoMs can serve alone as predictors of 21OHD and 11OHD. Finally, MoM transformation offers substantial enhancement of routine and scientific steroid hormone data exchange due to improved comparability. © 2018 S. Karger AG, Basel.

Assessment of the Incidence of Posttreatment Endodontic Flare-ups in Patients undergoing Single-sitting Root Canal Therapies: A Clinical Study.

PubMed

Priyank, Harsh; Devi, T M Chaitra; Goel, Pallavi; Sahu, Nivedita; Nihalani, Shweta; Shandilya, Ashutosh

2016-10-01

Endodontic therapy is one of the commonly used procedures for treating the teeth affected by various pathologies. One of the major problems for endodontists despite the advancements in the root canal procedures is the posttreatment endodontic flare-ups. Much debate exists regarding the completion of endodontic therapy in a single sitting or multiple sittings. Hence, we assessed the incidence of endodontic flare-ups in patients undergoing single-sitting root canal therapies. The present study included 200 patients who underwent single-sitting endodontic therapy. Clinical details and conditions of each and every tooth of every patient were recorded before and after the completion of endodontic therapy. Irrigation during the root canal procedures was done by 2.5% NaOCl solution in most of the cases while others were irrigated with various combinations of ethylenediaminetetraacetic acid (EDTA) and cycloheximide (CHX) solutions. Follow-up records and readings of the patents were noted and were subjected to statistical analysis. Four groups were formed which divided the patients equally on the basis of their age. Out of 50 patients in the age group of 21 to 30 years, only 4 showed posttreatment endodontic flare-ups, while no endodontic flare-up was recorded in patients with age group of 31 to 50 years. Only two male and four females showed flare-ups postoperatively. A nonsignificant correlation was obtained when flare-up cases were compared on the basis of type of irrigation solution used during canal preparation. Single-sitting endodontic therapy appears to be a successful procedure with good prognosis and minimal posttreatment flare-up results, even in patients with periapical pathologies. Single-sitting root canal procedures can be successfully carried in patients with vital or nonvital pulp tissues and also in patients with periapical lesions.