A Volumetric and Functional Connectivity MRI Study of Brain Arginine-Vasopressin Pathways in Autistic Children.

PubMed

Shou, Xiao-Jing; Xu, Xin-Jie; Zeng, Xiang-Zhu; Liu, Ying; Yuan, Hui-Shu; Xing, Yan; Jia, Mei-Xiang; Wei, Qing-Yun; Han, Song-Ping; Zhang, Rong; Han, Ji-Sheng

2017-04-01

Dysfunction of brain-derived arginine-vasopressin (AVP) systems may be involved in the etiology of autism spectrum disorder (ASD). Certain regions such as the hypothalamus, amygdala, and hippocampus are known to contain either AVP neurons or terminals and may play an important role in regulating complex social behaviors. The present study was designed to investigate the concomitant changes in autistic behaviors, circulating AVP levels, and the structure and functional connectivity (FC) of specific brain regions in autistic children compared with typically developing children (TDC) aged from 3 to 5 years. The results showed: (1) children with ASD had a significantly increased volume in the left amygdala and left hippocampus, and a significantly decreased volume in the bilateral hypothalamus compared to TDC, and these were positively correlated with plasma AVP level. (2) Autistic children had a negative FC between the left amygdala and the bilateral supramarginal gyri compared to TDC. The degree of the negative FC between amygdala and supramarginal gyrus was associated with a higher score on the clinical autism behavior checklist. (3) The degree of negative FC between left amygdala and left supramarginal gyrus was associated with a lowering of the circulating AVP concentration in boys with ASD. (4) Autistic children showed a higher FC between left hippocampus and right subcortical area compared to TDC. (5) The circulating AVP was negatively correlated with the visual and listening response score of the childhood autism rating scale. These results strongly suggest that changes in structure and FC in brain regions containing AVP may be involved in the etiology of autism.

Stimulus modality and working memory performance in Greek children with reading disabilities: additional evidence for the pictorial superiority hypothesis.

PubMed

Constantinidou, Fofi; Evripidou, Christiana

2012-01-01

This study investigated the effects of stimulus presentation modality on working memory performance in children with reading disabilities (RD) and in typically developing children (TDC), all native speakers of Greek. It was hypothesized that the visual presentation of common objects would result in improved learning and recall performance as compared to the auditory presentation of stimuli. Twenty children, ages 10-12, diagnosed with RD were matched to 20 TDC age peers. The experimental tasks implemented a multitrial verbal learning paradigm incorporating three modalities: auditory, visual, and auditory plus visual. Significant group differences were noted on language, verbal and nonverbal memory, and measures of executive abilities. A mixed-model MANOVA indicated that children with RD had a slower learning curve and recalled fewer words than TDC across experimental modalities. Both groups of participants benefited from the visual presentation of objects; however, children with RD showed the greatest gains during this condition. In conclusion, working memory for common verbal items is impaired in children with RD; however, performance can be facilitated, and learning efficiency maximized, when information is presented visually. The results provide further evidence for the pictorial superiority hypothesis and the theory that pictorial presentation of verbal stimuli is adequate for dual coding.

Acquisition of Motor and Cognitive Skills through Repetition in Typically Developing Children

PubMed Central

Magallón, Sara; Narbona, Juan; Crespo-Eguílaz, Nerea

2016-01-01

Background Procedural memory allows acquisition, consolidation and use of motor skills and cognitive routines. Automation of procedures is achieved through repeated practice. In children, improvement in procedural skills is a consequence of natural neurobiological development and experience. Methods The aim of the present research was to make a preliminary evaluation and description of repetition-based improvement of procedures in typically developing children (TDC). Ninety TDC children aged 6–12 years were asked to perform two procedural learning tasks. In an assembly learning task, which requires predominantly motor skills, we measured the number of assembled pieces in 60 seconds. In a mirror drawing learning task, which requires more cognitive functions, we measured time spent and efficiency. Participants were tested four times for each task: three trials were consecutive and the fourth trial was performed after a 10-minute nonverbal interference task. The influence of repeated practice on performance was evaluated by means of the analysis of variance with repeated measures and the paired-sample test. Correlation coefficients and simple linear regression test were used to examine the relationship between age and performance. Results TDC achieved higher scores in both tasks through repetition. Older children fitted more pieces than younger ones in assembling learning and they were faster and more efficient at the mirror drawing learning task. Conclusions These findings indicate that three consecutive trials at a procedural task increased speed and efficiency, and that age affected basal performance in motor-cognitive procedures. PMID:27384671

Acquisition of Motor and Cognitive Skills through Repetition in Typically Developing Children.

PubMed

Magallón, Sara; Narbona, Juan; Crespo-Eguílaz, Nerea

2016-01-01

Procedural memory allows acquisition, consolidation and use of motor skills and cognitive routines. Automation of procedures is achieved through repeated practice. In children, improvement in procedural skills is a consequence of natural neurobiological development and experience. The aim of the present research was to make a preliminary evaluation and description of repetition-based improvement of procedures in typically developing children (TDC). Ninety TDC children aged 6-12 years were asked to perform two procedural learning tasks. In an assembly learning task, which requires predominantly motor skills, we measured the number of assembled pieces in 60 seconds. In a mirror drawing learning task, which requires more cognitive functions, we measured time spent and efficiency. Participants were tested four times for each task: three trials were consecutive and the fourth trial was performed after a 10-minute nonverbal interference task. The influence of repeated practice on performance was evaluated by means of the analysis of variance with repeated measures and the paired-sample test. Correlation coefficients and simple linear regression test were used to examine the relationship between age and performance. TDC achieved higher scores in both tasks through repetition. Older children fitted more pieces than younger ones in assembling learning and they were faster and more efficient at the mirror drawing learning task. These findings indicate that three consecutive trials at a procedural task increased speed and efficiency, and that age affected basal performance in motor-cognitive procedures.

EEG Dynamics of a Go/Nogo Task in Children with ADHD

PubMed Central

Baijot, Simon; Zarka, David; Leroy, Axelle; Slama, Hichem; Colin, Cecile; Deconinck, Nicolas; Dan, Bernard; Cheron, Guy

2017-01-01

Background: Studies investigating event-related potential (ERP) evoked in a Cue-Go/NoGo paradigm have shown lower frontal N1, N2 and central P3 in children with attention-deficit/hyperactivity disorder (ADHD) compared to typically developing children (TDC). However, the electroencephalographic (EEG) dynamics underlying these ERPs remain largely unexplored in ADHD. Methods: We investigate the event-related spectral perturbation and inter-trial coherence linked to the ERP triggered by visual Cue-Go/NoGo stimuli, in 14 children (7 ADHD and 7 TDC) aged 8 to 12 years. Results: Compared to TDC, the EEG dynamics of children with ADHD showed a lower theta-alpha ITC concomitant to lower occipito-parietal P1-N2 and frontal N1-P2 potentials in response to Cue, Go and Nogo stimuli; an upper alpha power preceding lower central Go-P3; a lower theta-alpha power and ITC were coupled to a lower frontal Nogo-N3; a lower low-gamma power overall scalp at 300 ms after Go and Nogo stimuli. Conclusion: These findings suggest impaired ability in children with ADHD to conserve the brain oscillations phase associated with stimulus processing. This physiological trait might serve as a target for therapeutic intervention or be used as monitoring of their effects. PMID:29261133

Broader autistic phenotype in parents of children with autism: Autism Spectrum Quotient-Turkish version.

PubMed

Kose, Sezen; Bora, Emre; Erermiş, Serpil; Özbaran, Burcu; Bildik, Tezan; Aydın, Cahide

2013-01-01

The Autism Spectrum Quotient (AQ) is a self-assessment screening instrument for measuring the degree to which an individual of normal intelligence shows autistic traits. Genetic factors could be responsible for the relatives of individuals with autism exhibiting higher than normal rates of autism-related impairments, referred to as the 'broader autism phenotype' (BAP). The aim of this study was to test whether there is a difference between the parents of autistic and those of typically developing children (TDC) on AQ scores in a Turkish sample. The AQ total and subscale scores of the 100 parents (47 fathers, 53 mothers) of children with autistic disorder (AD) were compared with the 100 parents (48 fathers, 52 mothers) of TDC. The parents of AD children scored significantly higher than the TDC parents on total AQ score, and two of five subscale scores; social skills, and communication. The other three subscales (attention to detail, attention switching, imagination) did not differentiate groups. There was no significant difference between mothers and fathers on any AQ scores, neither in the AD nor TDC group. The group × gender interaction was not significant on the total or the five subscale scores of AQ. Social skill and communication subscales differentiate AD parents more successfully, and are more sensitive, as reported in other studies. The present findings confirm that social skill and communication impairments in parents of children with autism spectrum disorders are indicators of BAP. © 2013 The Authors. Psychiatry and Clinical Neurosciences © 2013 Japanese Society of Psychiatry and Neurology.

Differences between the production of [s] and [ʃ] in the speech of adults, typically developing children, and children with speech sound disorders: An ultrasound study.

PubMed

Francisco, Danira Tavares; Wertzner, Haydée Fiszbein

2017-01-01

This study describes the criteria that are used in ultrasound to measure the differences between the tongue contours that produce [s] and [ʃ] sounds in the speech of adults, typically developing children (TDC), and children with speech sound disorder (SSD) with the phonological process of palatal fronting. Overlapping images of the tongue contours that resulted from 35 subjects producing the [s] and [ʃ] sounds were analysed to select 11 spokes on the radial grid that were spread over the tongue contour. The difference was calculated between the mean contour of the [s] and [ʃ] sounds for each spoke. A cluster analysis produced groups with some consistency in the pattern of articulation across subjects and differentiated adults and TDC to some extent and children with SSD with a high level of success. Children with SSD were less likely to show differentiation of the tongue contours between the articulation of [s] and [ʃ].

Postural Responses to a Suprapostural Visual Task among Children with and without Developmental Coordination Disorder

ERIC Educational Resources Information Center

Chen, F. C.; Tsai, C. L.; Stoffregen, T. A.; Wade, M. G.

2011-01-01

We sought to determine the effects of varying the perceptual demands of a suprapostural visual task on the postural activity of children with developmental coordination disorder (DCD), and typically developing children (TDC). Sixty-four (32 per group) children aged between 9 and 10 years participated. In a within-participants design, each child…

Motor Learning of a Bimanual Task in Children with Unilateral Cerebral Palsy

ERIC Educational Resources Information Center

Hung, Ya-Ching; Gordon, Andrew M.

2013-01-01

Children with unilateral cerebral palsy (CP) have been shown to improve their motor performance with sufficient practice. However, little is known about how they learn goal-oriented tasks. In the current study, 21 children with unilateral CP (age 4-10 years old) and 21 age-matched typically developed children (TDC) practiced a simple bimanual…

Inhibition and the Validity of the Stroop Task for Children with Autism

ERIC Educational Resources Information Center

Adams, Nena C.; Jarrold, Christopher

2009-01-01

Findings are mixed concerning inhibition in autism. Using the classic Stroop, children with autism (CWA) often outperform typically developing children (TDC). A classic Stroop and a chimeric animal Stroop were used to explore the validity of the Stroop task as a test of inhibition for CWA. During the classic Stroop, children ignored the word and…

Characterizing the Factor Structure of Parent Reported Executive Function in Autism Spectrum Disorders: The Impact of Cognitive Inflexibility

ERIC Educational Resources Information Center

Granader, Yael; Wallace, Gregory L.; Hardy, Kristina K.; Yerys, Benjamin E.; Lawson, Rachel A.; Rosenthal, Michael; Wills, Meagan C.; Dixon, Eunice; Pandey, Juhi; Penna, Rebecca; Schultz, Robert T.; Kenworthy, Lauren

2014-01-01

Parents of children with autism spectrum disorders (ASD) consistently report executive functioning (EF) deficits. This study investigates the factor structure of the Behavior Rating Inventory of Executive Function (BRIEF) as reported by parents of children with ASD and typically developing children (TDC). BRIEFs for 411 children with ASD and 467…

Motor demands impact speed of information processing in Autism Spectrum Disorders

PubMed Central

Kenworthy, Lauren; Yerys, Benjamin E.; Weinblatt, Rachel; Abrams, Danielle N.; Wallace, Gregory L.

2015-01-01

Objective The apparent contradiction between preserved or even enhanced perceptual processing speed on inspection time tasks in autism spectrum disorders (ASD) and impaired performance on complex processing speed tasks that require motor output (e.g. Wechsler Processing Speed Index) has not yet been systematically investigated. This study investigates whether adding motor output demands to an inspection time task impairs ASD performance compared to that of typically developing control (TDC) children. Method The performance of children with ASD (n=28; mean FSIQ=115) and TDC (n=25; mean FSIQ=122) children was compared on processing speed tasks with increasing motor demand. Correlations were run between ASD task performance and Autism Diagnostic Observation Schedule (ADOS) Communication scores. Results Performance by the ASD and TDC groups on a simple perceptual processing speed task with minimal motor demand was equivalent, though it diverged (ASD worse than TDC) on two tasks with the same stimuli, but increased motor output demands. ASD performance on the moderate but not the high speeded motor output demand task was negatively correlated with ADOS communication symptoms. Conclusions These data address the apparent contradiction between preserved inspection time in the context of slowed “processing speed” in ASD. They show that processing speed is preserved when motor demands are minimized, but that increased motor output demands interfere with the ability to act on perceptual processing of simple stimuli. Reducing motor demands (e.g. through the use of computers) may increase the capacity of people with ASD to demonstrate good perceptual processing in a variety of educational, vocational and social settings. PMID:23937483

Neurocognitive functioning in children with developmental dyslexia and attention-deficit/hyperactivity disorder: Multiple deficits and diagnostic accuracy.

PubMed

Moura, Octávio; Pereira, Marcelino; Alfaiate, Cláudia; Fernandes, Eva; Fernandes, Boavida; Nogueira, Susana; Moreno, Joana; Simões, Mário R

2017-04-01

This study aimed to investigate the neurocognitive functioning of children with developmental dyslexia (DD) and attention-deficit/hyperactivity disorder (ADHD). Four groups of children between the ages of 8 and 10 years participated in the study: typically developing children (TDC; N = 34), children with DD-only (N = 32), children with ADHD-only (N = 32), and children with DD+ADHD (N = 18). Children with DD and ADHD exhibited significant weaknesses on almost all neurocognitive measures compared with TDC. Large effect sizes were observed for naming speed and phonological awareness. The comorbid group showed deficits consistent with both DD and ADHD without additional impairments. Results from binary logistic regression and receiver-operating characteristic (ROC) curve analyses suggested that some neurocognitive measures revealed an adequate sensitivity for the clinical diagnosis of both neurodevelopmental disorders. Specifically, naming speed and phonological awareness were the strongest predictors to correctly discriminate both disorders. Taken together, the results lend support to the multiple cognitive deficit hypothesis showing a considerable overlap of neurocognitive deficits between both disorders.

Assessing psychosocial functioning following childhood acquired brain injury: The Sydney Psychosocial Reintegration Scale for Children.

PubMed

Soo, Cheryl; Tate, Robyn L; Anderson, Vicki; Beauchamp, Miriam H; Brookes, Naomi; Catroppa, Cathy; Galvin, Jane; Muscara, Frank

2016-12-01

The Sydney Psychosocial Reintegration Scale for Children (SPRS-C) assesses psychosocial functioning in children with acquired brain injury (ABI). This article aims to: (1) describe normative data for the parent-rated SPRS-C and, (2) evaluate the discriminant validity of the SPRS-C. For Aim 1, participants were parents of typically developing children (TDC) aged 5-14 years (N = 200). For Aim 2, participants with ABI were aged 5-14 years (n = 26). A matched group of TDC was sampled from the larger normative sample to serve as a control group (n = 26). For Aim 1, SPRS-C scores across the 10 age-bands were in the higher ranges. Correlation coefficients of SPRS-C total score with child's age and parent occupational skill level were not statistically significant. For Aim 2, SPRS-C scores for the ABI group were significantly lower than the control group. These data provide a guide for clinical interpretation of the SPRS-C for measuring psychosocial functioning in children with ABI.

Sensation-to-Cognition Cortical Streams in Attention-Deficit/Hyperactivity Disorder

PubMed Central

Carmona, Susana; Hoekzema, Elseline; Castellanos, Francisco X.; García-García, David; Lage-Castellanos, Agustín; Dijk, Koene R.A.Van; Navas-Sánchez, Francisco J.; Martínez, Kenia; Desco, Manuel; Sepulcre, Jorge

2015-01-01

We sought to determine whether functional connectivity streams that link sensory, attentional, and higher-order cognitive circuits are atypical in attention-deficit/hyperactivity disorder (ADHD). We applied a graph-theory method to the resting-state functional magnetic resonance imaging data of 120 children with ADHD and 120 age-matched typically developing children (TDC). Starting in unimodal primary cortex—visual, auditory, and somatosensory—we used stepwise functional connectivity to calculate functional connectivity paths at discrete numbers of relay stations (or link-step distances). First, we characterized the functional connectivity streams that link sensory, attentional, and higher-order cognitive circuits in TDC and found that systems do not reach the level of integration achieved by adults. Second, we searched for stepwise functional connectivity differences between children with ADHD and TDC. We found that, at the initial steps of sensory functional connectivity streams, patients display significant enhancements of connectivity degree within neighboring areas of primary cortex, while connectivity to attention-regulatory areas is reduced. Third, at subsequent link-step distances from primary sensory cortex, children with ADHD show decreased connectivity to executive processing areas and increased degree of connections to default mode regions. Fourth, in examining medication histories in children with ADHD, we found that children medicated with psychostimulants present functional connectivity streams with higher degree of connectivity to regions subserving attentional and executive processes compared to medication-naïve children. We conclude that predominance of local sensory processing and lesser influx of information to attentional and executive regions may reduce the ability to organize and control the balance between external and internal sources of information in ADHD. PMID:25821110

Magnetoencephalographic Imaging of Auditory and Somatosensory Cortical Responses in Children with Autism and Sensory Processing Dysfunction

PubMed Central

Demopoulos, Carly; Yu, Nina; Tripp, Jennifer; Mota, Nayara; Brandes-Aitken, Anne N.; Desai, Shivani S.; Hill, Susanna S.; Antovich, Ashley D.; Harris, Julia; Honma, Susanne; Mizuiri, Danielle; Nagarajan, Srikantan S.; Marco, Elysa J.

2017-01-01

This study compared magnetoencephalographic (MEG) imaging-derived indices of auditory and somatosensory cortical processing in children aged 8–12 years with autism spectrum disorder (ASD; N = 18), those with sensory processing dysfunction (SPD; N = 13) who do not meet ASD criteria, and typically developing control (TDC; N = 19) participants. The magnitude of responses to both auditory and tactile stimulation was comparable across all three groups; however, the M200 latency response from the left auditory cortex was significantly delayed in the ASD group relative to both the TDC and SPD groups, whereas the somatosensory response of the ASD group was only delayed relative to TDC participants. The SPD group did not significantly differ from either group in terms of somatosensory latency, suggesting that participants with SPD may have an intermediate phenotype between ASD and TDC with regard to somatosensory processing. For the ASD group, correlation analyses indicated that the left M200 latency delay was significantly associated with performance on the WISC-IV Verbal Comprehension Index as well as the DSTP Acoustic-Linguistic index. Further, these cortical auditory response delays were not associated with somatosensory cortical response delays or cognitive processing speed in the ASD group, suggesting that auditory delays in ASD are domain specific rather than associated with generalized processing delays. The specificity of these auditory delays to the ASD group, in addition to their correlation with verbal abilities, suggests that auditory sensory dysfunction may be implicated in communication symptoms in ASD, motivating further research aimed at understanding the impact of sensory dysfunction on the developing brain. PMID:28603492

Sensation-to-cognition cortical streams in attention-deficit/hyperactivity disorder.

PubMed

Carmona, Susana; Hoekzema, Elseline; Castellanos, Francisco X; García-García, David; Lage-Castellanos, Agustín; Van Dijk, Koene R A; Navas-Sánchez, Francisco J; Martínez, Kenia; Desco, Manuel; Sepulcre, Jorge

2015-07-01

We sought to determine whether functional connectivity streams that link sensory, attentional, and higher-order cognitive circuits are atypical in attention-deficit/hyperactivity disorder (ADHD). We applied a graph-theory method to the resting-state functional magnetic resonance imaging data of 120 children with ADHD and 120 age-matched typically developing children (TDC). Starting in unimodal primary cortex-visual, auditory, and somatosensory-we used stepwise functional connectivity to calculate functional connectivity paths at discrete numbers of relay stations (or link-step distances). First, we characterized the functional connectivity streams that link sensory, attentional, and higher-order cognitive circuits in TDC and found that systems do not reach the level of integration achieved by adults. Second, we searched for stepwise functional connectivity differences between children with ADHD and TDC. We found that, at the initial steps of sensory functional connectivity streams, patients display significant enhancements of connectivity degree within neighboring areas of primary cortex, while connectivity to attention-regulatory areas is reduced. Third, at subsequent link-step distances from primary sensory cortex, children with ADHD show decreased connectivity to executive processing areas and increased degree of connections to default mode regions. Fourth, in examining medication histories in children with ADHD, we found that children medicated with psychostimulants present functional connectivity streams with higher degree of connectivity to regions subserving attentional and executive processes compared to medication-naïve children. We conclude that predominance of local sensory processing and lesser influx of information to attentional and executive regions may reduce the ability to organize and control the balance between external and internal sources of information in ADHD. © 2015 Wiley Periodicals, Inc.

Exploratory analysis of diffusion tensor imaging in children with attention deficit hyperactivity disorder: evidence of abnormal white matter structure.

PubMed

Pastura, Giuseppe; Doering, Thomas; Gasparetto, Emerson Leandro; Mattos, Paulo; Araújo, Alexandra Prüfer

2016-06-01

Abnormalities in the white matter microstructure of the attentional system have been implicated in the aetiology of attention deficit hyperactivity disorder (ADHD). Diffusion tensor imaging (DTI) is a promising magnetic resonance imaging (MRI) technology that has increasingly been used in studies of white matter microstructure in the brain. The main objective of this work was to perform an exploratory analysis of white matter tracts in a sample of children with ADHD versus typically developing children (TDC). For this purpose, 13 drug-naive children with ADHD of both genders underwent MRI using DTI acquisition methodology and tract-based spatial statistics. The results were compared to those of a sample of 14 age- and gender-matched TDC. Lower fractional anisotropy was observed in the splenium of the corpus callosum, right superior longitudinal fasciculus, bilateral retrolenticular part of the internal capsule, bilateral inferior fronto-occipital fasciculus, left external capsule and posterior thalamic radiation (including right optic radiation). We conclude that white matter tracts in attentional and motor control systems exhibited signs of abnormal microstructure in this sample of drug-naive children with ADHD.

Alterations in regional shape on ipsilateral and contralateral cortex contrast in children with unilateral cerebral palsy and are predictive of multiple outcomes.

PubMed

Pagnozzi, Alex M; Dowson, Nicholas; Fiori, Simona; Doecke, James; Bradley, Andrew P; Boyd, Roslyn N; Rose, Stephen

2016-10-01

Congenital brain lesions result in a wide range of cerebral tissue alterations observed in children with cerebral palsy (CP) that are associated with a range of functional impairments. The relationship between injury severity and functional outcomes, however, remains poorly understood. This research investigates the differences in cortical shape between children with congenital brain lesions and typically developing children (TDC) and investigates the correlations between cortical shape and functional outcome in a large cohort of patients diagnosed with unilateral CP. Using 139 structural magnetic resonance images, including 95 patients with clinically diagnosed CP and 44 TDC, cortical segmentations were obtained using a modified expectation maximization algorithm. Three shape characteristics (cortical thickness, curvature, and sulcal depth) were computed within a number of cortical regions. Significant differences in these shape measures compared to the TDC were observed on both the injured hemisphere of children with CP (P < 0.004), as well as on the apparently uninjured hemisphere, illustrating potential compensatory mechanisms in these children. Furthermore, these shape measures were significantly correlated with several functional outcomes, including motor, cognition, vision, and communication (P < 0.012), with three out of these four models performing well on test set validation. This study highlights that cortical neuroplastic effects may be quantified using MR imaging, allowing morphological changes to be studied longitudinally, including any influence of treatment. Ultimately, such approaches could be used for the long term prediction of outcomes and the tailoring of treatment to individuals. Hum Brain Mapp 37:3588-3603, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Children at Risk for Developmental Coordination Disorder: Judgement of Changes in Action Capabilities

ERIC Educational Resources Information Center

Johnson, Daniel C.; Wade, Michael G.

2009-01-01

In three separate manipulations, a group of children at risk for developmental coordination disorder (DCD; five males, seven females; mean age 11y 6mo [SD 6.8mo] who were at or below the 15th percentile on the Movement ABC) and a group of typically developing children (TDC; seven males, five females; mean age 11y 3mo [SD 6.8mo]) judged the limit…

Emotional Face Identification in Youths with Primary Bipolar Disorder or Primary Attention-Deficit/Hyperactivity Disorder

ERIC Educational Resources Information Center

Seymour, Karen E.; Pescosolido, Matthew F.; Reidy, Brooke L.; Galvan, Thania; Kim, Kerri L.; Young, Matthew; Dickstein, Daniel P.

2013-01-01

Objective: Bipolar disorder (BD) and attention-deficit/hyperactivity disorder (ADHD) are often comorbid or confounded; therefore, we evaluated emotional face identification to better understand brain/behavior interactions in children and adolescents with either primary BD, primary ADHD, or typically developing controls (TDC). Method: Participants…

Perception and Lateralization of Spoken Emotion by Youths with High-Functioning Forms of Autism

ERIC Educational Resources Information Center

Baker, Kimberly F.; Montgomery, Allen A.; Abramson, Ruth

2010-01-01

The perception and the cerebral lateralization of spoken emotions were investigated in children and adolescents with high-functioning forms of autism (HFFA), and age-matched typically developing controls (TDC). A dichotic listening task using nonsense passages was used to investigate the recognition of four emotions: happiness, sadness, anger, and…

Response time variability under slow and fast-incentive conditions in children with ASD, ADHD and ASD+ADHD.

PubMed

Tye, Charlotte; Johnson, Katherine A; Kelly, Simon P; Asherson, Philip; Kuntsi, Jonna; Ashwood, Karen L; Azadi, Bahare; Bolton, Patrick; McLoughlin, Gráinne

2016-12-01

Attention deficit hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) show significant behavioural and genetic overlap. Both ADHD and ASD are characterised by poor performance on a range of cognitive tasks. In particular, increased response time variability (RTV) is a promising indicator of risk for both ADHD and ASD. However, it is not clear whether different indices of RTV and changes to RTV according to task conditions are able to discriminate between the two disorders. Children with ASD (n = 19), ADHD (n = 18), ASD + ADHD (n = 29) and typically developing controls (TDC; n = 26) performed a four-choice RT task with slow-baseline and fast-incentive conditions. Performance was characterised by mean RT (MRT), standard deviation of RT (SD-RT), coefficient of variation (CV) and ex-Gaussian distribution measures of Mu, Sigma and Tau. In the slow-baseline condition, categorical diagnoses and trait measures converged to indicate that children with ADHD-only and ASD + ADHD demonstrated increased MRT, SD-RT, CV and Tau compared to TDC and ASD-only. Importantly, greater improvement in MRT, SD-RT and Tau was demonstrated in ADHD and ASD + ADHD from slow-baseline to fast-incentive conditions compared to TDC and ASD-only. Slower and more variable RTs are markers of ADHD compared to ASD and typically developing controls during slow and less rewarding conditions. Energetic factors and rewards improve task performance to a greater extent in children with ADHD compared to children with ASD. These findings suggest that RTV can be distinguished in ASD, ADHD and ASD + ADHD based on the indices of variability used and the conditions in which they are elicited. Further work identifying neural processes underlying increased RTV is warranted, in order to elucidate disorder-specific and disorder-convergent aetiological pathways. © 2016 The Authors. Journal of Child Psychology and Psychiatry published by John Wiley & Sons Ltd on behalf of Association for Child and Adolescent Mental Health.

A Systematic Review of the Clinimetric Properties of Habitual Physical Activity Measures in Young Children with a Motor Disability

PubMed Central

Oftedal, Stina; Bell, Kristie L.; Mitchell, Louise E.; Davies, Peter S. W.; Ware, Robert S.; Boyd, Roslyn N.

2012-01-01

Aim. To identify and systematically review the clinimetric properties of habitual physical activity (HPA) measures in young children with a motor disability. Method. Five databases were searched for measures of HPA including: children aged <6.0 years with a neuromuscular disorder, physical activity defined as “bodily movement produced by skeletal muscles causing caloric expenditure”, reported HPA as duration, frequency, intensity, mode or energy expenditure, and evaluated clinimetric properties. The quality of papers was assessed using the COSMIN-checklist. A targeted search of identified measures found additional studies of typically developing young children (TDC). Results. Seven papers assessing four activity monitors met inclusion criteria. Four studies were of good methodological quality. The Minimod had good ability to measure continuous walking but the demonstrated poor ability to measure steps during free-living activities. The Intelligent Device for Energy Expenditure and Activity and Ambulatory Monitoring Pod showed poor ability to measure activity during both continuous walking and free-living activities. The StepWatch showed good ability to measure steps during continuous walking in TDC. Interpretation. Studies assessing the clinimetric properties of measures of HPA in this population are urgently needed to allow assessment of the relationship between HPA and health outcomes in this group. PMID:22927865

Abnormal Resting-State Quantitative Electroencephalogram in Children With Central Auditory Processing Disorder: A Pilot Study

PubMed Central

Milner, Rafał; Lewandowska, Monika; Ganc, Małgorzata; Włodarczyk, Elżbieta; Grudzień, Diana; Skarżyński, Henryk

2018-01-01

In this study, we showed an abnormal resting-state quantitative electroencephalogram (QEEG) pattern in children with central auditory processing disorder (CAPD). Twenty-seven children (16 male, 11 female; mean age = 10.7 years) with CAPD and no symptoms of other developmental disorders, as well as 23 age- and sex-matched, typically developing children (TDC, 11 male, 13 female; mean age = 11.8 years) underwent examination of central auditory processes (CAPs) and QEEG evaluation consisting of two randomly presented blocks of “Eyes Open” (EO) or “Eyes Closed” (EC) recordings. Significant correlations between individual frequency band powers and CAP tests performance were found. The QEEG studies revealed that in CAPD relative to TDC there was no effect of decreased delta absolute power (1.5–4 Hz) in EO compared to the EC condition. Furthermore, children with CAPD showed increased theta power (4–8 Hz) in the frontal area, a tendency toward elevated theta power in EO block, and reduced low-frequency beta power (12–15 Hz) in the bilateral occipital and the left temporo-occipital regions for both EO and EC conditions. Decreased middle-frequency beta power (15–18 Hz) in children with CAPD was observed only in the EC block. The findings of the present study suggest that QEEG could be an adequate tool to discriminate children with CAPD from normally developing children. Correlation analysis shows relationship between the individual EEG resting frequency bands and the CAPs. Increased power of slow waves and decreased power of fast rhythms could indicate abnormal functioning (hypoarousal of the cortex and/or an immaturity) of brain areas not specialized in auditory information processing.

Brief Report: Diminished Gaze Preference for Dynamic Social Interaction Scenes in Youth with Autism Spectrum Disorders

ERIC Educational Resources Information Center

Shaffer, Rebecca C.; Pedapati, Ernest V.; Shic, Frederick; Gaietto, Kristina; Bowers, Katherine; Wink, Logan K.; Erickson, Craig A.

2017-01-01

In this study, we present an eye-tracking paradigm, adapted from previous work with toddlers, for assessing social-interaction looking preferences in youth ages 5-17 with ASD and typically-developing controls (TDC). Videos of children playing together (Social Scenes, SS) were presented side-by-side with animated geometric shapes (GS). Participants…

Extended Operation of Stirling Convertors

NASA Technical Reports Server (NTRS)

Roth, Mary Ellen; Schreiber, Jeffery G.; Pepper, Stephen V.

2004-01-01

A high-efficiency 110 W Stirling Radioisotope Generator 110 (SRG110) is being developed for potential NASA exploration missions. The SRG system efficiency is greater than 20%, making it an attractive candidate power system for deep space missions and unmanned rovers. The Department of Energy SRG110 Project team consists of the System Integrator, Lockheed Martin (LM), Stirling Technology Company (STC), and NASA Glenn Research Center (GRC). One of the GRC roles is to provide Independent Verification and Validation of the Stirling TDC s. At the request of LM, a part of this effort includes the Extended Operation of the TDC s in the dynamically balanced dual-opposed configuration. Performance data of Stirling Convertors over time is required to demonstrate that an SRG110 can meet long-duration mission requirements. A test plan and test system were developed to evaluate TDC s #13 and #14 steady-state performance for a minimum of 5000 hours. Hardware, software and TDC preparation processes were developed to support this test and insure safe, round-the-clock operation of the TDC s. This paper will discuss the design and development, and status of the Extended Operation Test.

Implementation of a high precision multi-measurement time-to-digital convertor on a Kintex-7 FPGA

NASA Astrophysics Data System (ADS)

Kuang, Jie; Wang, Yonggang; Cao, Qiang; Liu, Chong

2018-05-01

Time-to-digital convertors (TDCs) based on field programmable gate array (FPGA) are becoming more and more popular. Multi-measurement is an effective method to improve TDC precision beyond the cell delay limitation. However, the implementation of TDC with multi-measurement on FPGAs manufactured with 28 nm and more advanced process is facing new challenges. Benefiting from the ones-counter encoding scheme, which was developed in our previous work, we implement a ring oscillator multi-measurement TDC on a Xilinx Kintex-7 FPGA. Using the two TDC channels to measure time-intervals in the range (0 ns-30 ns), the average RMS precision can be improved to 5.76 ps, meanwhile the logic resource usage remains the same with the one-measurement TDC, and the TDC dead time is only 22 ns. The investigation demonstrates that the multi-measurement methods are still available for current main-stream FPGAs. Furthermore, the new implementation in this paper could make the trade-off among the time precision, resource usage and TDC dead time better than ever before.

Stirling Technology Development at NASA GRC. Revised

NASA Technical Reports Server (NTRS)

Thieme, Lanny G.; Schreiber, Jeffrey G.; Mason, Lee S.

2002-01-01

The Department of Energy, Stirling Technology Company (STC), and NASA Glenn Research Center (NASA Glenn) are developing a free-piston Stirling convertor for a high-efficiency Stirling Radioisotope Generator (SRG) for NASA Space Science missions. The SRG is being developed for multimission use, including providing electric power for unmanned Mars rovers and deep space missions. NASA Glenn is conducting an in-house technology project to assist in developing the convertor for space qualification and mission implementation. Recent testing, of 55-We Technology Demonstration Convertors (TDC's) built by STC includes mapping, of a second pair of TDC's, single TDC testing, and TDC electromagnetic interference and electromagnetic compatibility characterization on a nonmagnetic test stand. Launch environment tests of a single TDC without its pressure vessel to better understand the convertor internal structural dynamics and of dual-opposed TDC's with several engineering mounting structures with different natural frequencies have recently been completed. A preliminary life assessment has been completed for the TDC heater head, and creep testing of the IN718 material to be used for the flight convertors is underway. Long-term magnet aging tests are continuing to characterize any potential aging in the strength or demagnetization resistance of the magnets used in the linear alternator (LA). Evaluations are now beginning on key organic materials used in the LA and piston/rod surface coatings. NASA Glenn is also conducting finite element analyses for the LA, in part to look at the demagnetization margin on the permanent magnets. The world's first known integrated test of a dynamic power system with electric propulsion was achieved at NASA Glenn when a Hall-effect thruster was successfully operated with a free-piston Stirling power source. Cleveland State University is developing a multidimensional Stirling computational fluid dynamics code to significantly improve Stirling loss predictions and assist in identifying convertor areas for further improvements. This paper will update the status and results for these efforts.

Stirling technology development at NASA GRC

NASA Astrophysics Data System (ADS)

Thieme, Lanny G.; Schreiber, Jeffrey G.; Mason, Lee S.

2002-01-01

The Department of Energy, Stirling Technology Company (STC), and NASA Glenn Research Center (GRC) are developing a free-piston Stirling convertor for a high-efficiency Stirling Radioisotope Generator (SRG) for NASA Space Science missions. The SRG is being developed for multimission use, including providing electric power for unmanned Mars rovers and deep space missions. NASA GRC is conducting an in-house technology project to assist in developing the convertor for space qualification and mission implementation. Recent testing of 55-We Technology Demonstration Convertors (TDC's) built by STC includes mapping of a second pair of TDC's, single TDC testing, and TDC electromagnetic interference and electromagnetic compatibility characterization on a non-magnetic test stand. Launch environment tests of a single TDC without its pressure vessel to better understand the convertor internal structural dynamics and of dual-opposed TDC's with several engineering mounting structures with different natural frequencies have recently been completed. A preliminary life assessment has been completed for the TDC heater head, and creep testing of the IN718 material to be used for the flight convertors is underway. Long-term magnet aging tests are continuing to characterize any potential aging in the strength or demagnetization resistance of the magnets used in the linear alternator (LA). Evaluations are now beginning on key organic materials used in the LA and piston/rod surface coatings. GRC is also conducting finite element analyses for the LA, in part to look at the demagnetization margin on the permanent magnets. The world's first known integrated test of a dynamic power system with electric propulsion was achieved at GRC when a Hall-effect thruster was successfully operated with a free-piston Stirling power source. Cleveland State University is developing a multi-dimensional Stirling computational fluid dynamics code to significantly improve Stirling loss predictions and assist in identifying convertor areas for further improvements. This paper will update the status and results for these efforts. .

A 7.4 ps FPGA-Based TDC with a 1024-Unit Measurement Matrix

PubMed Central

Zhang, Min; Wang, Hai; Liu, Yan

2017-01-01

In this paper, a high-resolution time-to-digital converter (TDC) based on a field programmable gate array (FPGA) device is proposed and tested. During the implementation, a new architecture of TDC is proposed which consists of a measurement matrix with 1024 units. The utilization of routing resources as the delay elements distinguishes the proposed design from other existing designs, which contributes most to the device insensitivity to variations of temperature and voltage. Experimental results suggest that the measurement resolution is 7.4 ps, and the INL (integral nonlinearity) and DNL (differential nonlinearity) are 11.6 ps and 5.5 ps, which indicates that the proposed TDC offers high performance among the available TDCs. Benefitting from the FPGA platform, the proposed TDC has superiorities in easy implementation, low cost, and short development time. PMID:28420121

A 7.4 ps FPGA-Based TDC with a 1024-Unit Measurement Matrix.

PubMed

Zhang, Min; Wang, Hai; Liu, Yan

2017-04-14

In this paper, a high-resolution time-to-digital converter (TDC) based on a field programmable gate array (FPGA) device is proposed and tested. During the implementation, a new architecture of TDC is proposed which consists of a measurement matrix with 1024 units. The utilization of routing resources as the delay elements distinguishes the proposed design from other existing designs, which contributes most to the device insensitivity to variations of temperature and voltage. Experimental results suggest that the measurement resolution is 7.4 ps, and the INL (integral nonlinearity) and DNL (differential nonlinearity) are 11.6 ps and 5.5 ps, which indicates that the proposed TDC offers high performance among the available TDCs. Benefitting from the FPGA platform, the proposed TDC has superiorities in easy implementation, low cost, and short development time.

A Field-Programmable Gate Array (FPGA) TDC for the Fermilab SeaQuest (E906) Experiment and Its Test with a Novel External Wave Union Launcher

NASA Astrophysics Data System (ADS)

Wang, Su-Yin; Wu, Jinyuan; Yao, Shi-Hong; Chang, Wen-Chen

2014-12-01

We developed a field-programmable gate array (FPGA) TDC module for the tracking detectors of the Fermilab SeaQuest (E906) experiment, including drift chambers, proportional tubes, and hodoscopes. This 64-channel TDC module had a 6U VMEbus form factor and was equipped with a low-power, radiation-hardened Microsemi ProASIC3 Flash-based FPGA. The design of the new FPGA firmware (Run2-TDC) aimed to reduce the data volume and data acquisition (DAQ) deadtime. The firmware digitized multiple input hits of both polarities while allowing users to turn on a multiple-hit elimination logic to remove after-pulses in the wire chambers and proportional tubes. A scaler was implemented in the firmware to allow for recording the number of hits in each channel. The TDC resolution was determined by an internal cell delay of 450 ps. A measurement precision of 200 ps was achieved. We used five kinds of tests to ensure the qualification of 93 TDCs in mass production. We utilized the external wave union launcher in our test to improve the TDC's measurement precision and also to illustrate how to construct the Wave Union TDC using an existing multi-hit TDC without modifying its firmware. Measurement precision was improved by a factor of about two (108 ps) based on the four-edge wave union. Better measurement precision (69 ps) was achieved by combining the approaches of Wave Union TDC and multiple-channel ganging.

Comparing Auditory Noise Treatment with Stimulant Medication on Cognitive Task Performance in Children with Attention Deficit Hyperactivity Disorder: Results from a Pilot Study.

PubMed

Söderlund, Göran B W; Björk, Christer; Gustafsson, Peik

2016-01-01

Recent research has shown that acoustic white noise (80 dB) can improve task performance in people with attention deficits and/or Attention Deficit Hyperactivity Disorder (ADHD). This is attributed to the phenomenon of stochastic resonance in which a certain amount of noise can improve performance in a brain that is not working at its optimum. We compare here the effect of noise exposure with the effect of stimulant medication on cognitive task performance in ADHD. The aim of the present study was to compare the effects of auditory noise exposure with stimulant medication for ADHD children on a cognitive test battery. A group of typically developed children (TDC) took the same tests as a comparison. Twenty children with ADHD of combined or inattentive subtypes and twenty TDC matched for age and gender performed three different tests (word recall, spanboard and n-back task) during exposure to white noise (80 dB) and in a silent condition. The ADHD children were tested with and without central stimulant medication. In the spanboard- and the word recall tasks, but not in the 2-back task, white noise exposure led to significant improvements for both non-medicated and medicated ADHD children. No significant effects of medication were found on any of the three tasks. This pilot study shows that exposure to white noise resulted in a task improvement that was larger than the one with stimulant medication thus opening up the possibility of using auditory noise as an alternative, non-pharmacological treatment of cognitive ADHD symptoms.

Neuropsychological and neurophysiological benefits from white noise in children with and without ADHD.

PubMed

Baijot, Simon; Slama, Hichem; Söderlund, Göran; Dan, Bernard; Deltenre, Paul; Colin, Cécile; Deconinck, Nicolas

2016-03-15

Optimal stimulation theory and moderate brain arousal (MBA) model hypothesize that extra-task stimulation (e.g. white noise) could improve cognitive functions of children with attention-deficit/hyperactivity disorder (ADHD). We investigate benefits of white noise on attention and inhibition in children with and without ADHD (7-12 years old), both at behavioral and at neurophysiological levels. Thirty children with and without ADHD performed a visual cued Go/Nogo task in two conditions (white noise or no-noise exposure), in which behavioral and P300 (mean amplitudes) data were analyzed. Spontaneous eye-blink rates were also recorded and participants went through neuropsychological assessment. Two separate analyses were conducted with each child separately assigned into two groups (1) ADHD or typically developing children (TDC), and (2) noise beneficiaries or non-beneficiaries according to the observed performance during the experiment. This latest categorization, based on a new index we called "Noise Benefits Index" (NBI), was proposed to determine a neuropsychological profile positively sensitive to noise. Noise exposure reduced omission rate in children with ADHD, who were no longer different from TDC. Eye-blink rate was higher in children with ADHD but was not modulated by white noise. NBI indicated a significant relationship between ADHD and noise benefit. Strong correlations were observed between noise benefit and neuropsychological weaknesses in vigilance and inhibition. Participants who benefited from noise had an increased Go P300 in the noise condition. The improvement of children with ADHD with white noise supports both optimal stimulation theory and MBA model. However, eye-blink rate results question the dopaminergic hypothesis in the latter. The NBI evidenced a profile positively sensitive to noise, related with ADHD, and associated with weaker cognitive control.

Vibration Testing of an Operating Stirling Convertor

NASA Technical Reports Server (NTRS)

Hughes, William O.; McNelis, Mark E.; Goodnight, Thomas W.

2000-01-01

The NASA John H. Glenn Research Center and the U.S. Department of Energy are currently developing a Stirling convertor for use as an advanced spacecraft power system for future NASA deep-space missions. As part of this development, a Stirling Technology Demonstrator Convertor (TDC) was recently tested to verify its survivability and capability of withstanding its expected launch random vibration environment. The TDC was fully operational (producing power) during the random vibration testing. The output power of the convertor was measured during the testing, and these results are discussed in this paper. Numerous accelerometers and force gauges were also present which provided information on the dynamic characteristics of the TDC and an indication of any possible damage due to vibration. These measurements will also be discussed in this paper. The vibration testing of the Stirling TDC was extremely successful. The TDC survived all its vibration testing with no structural damage or functional performance degradation. As a result of this testing, the Stirling convertor's capability to withstand vibration has been demonstrated, enabling its usage in future spacecraft power systems.

Customer Service in a Youth Development System.

ERIC Educational Resources Information Center

Tetro, Charles G.

The Training and Development Corporation (TDC) began the redesign of its youth development system with the belief that the center of effort would be local and success would ultimately turn on the capacity of individuals and organizations to transform themselves. TDC's first generation Career Advancement Center (CAC) prototype was in place by 1986.…

Chinese children with autism: A multiple chemical elements profile in erythrocytes.

PubMed

Wu, Jing; Liu, Duo-Jian; Shou, Xiao-Jing; Zhang, Ji-Shui; Meng, Fan-Chao; Liu, Ya-Qiong; Han, Song-Ping; Zhang, Rong; Jia, Jin-Zhu; Wang, Jing-Yu; Han, Ji-Sheng

2018-06-01

Several lines of evidence suggested that abnormal levels of certain chemical elements may contribute to the development of autism spectrum disorders (ASD). The present work aimed to investigate the multiple chemical elements profile in the erythrocytes of autistic versus typically developing children (TDC) of China. Analyses were carried out to explore the possible association between levels of elements and the risk as well as the severity of ASD. Erythrocyte levels of 11 elements (32%) among 34 detected elements in autistic group were significantly different from those in the TDC group. To our knowledge, this is the first study which compared the levels of rare earth elements in erythrocytes between children with or without ASD. Five elements including Pb, Na, Ca, Sb, and La are associated with the Childhood Autism Rating Scale (CARS) total score. Also, a series of tendencies were found in this research which was believed to affect auditory response, taste, smell, and touch, as well as fear or nervousness. It can be concluded that Chinese autistic children suffer from multi-chemical element imbalances which involves a complex combination of genetic and environmental factors. The results showed a significant correlation between abnormal levels of several chemical elements and the severity of the autistic syndrome. It is suggested that abnormal levels of some chemical elements may contribute to the development of autism spectrum disorders (ASD). In this work, the impact of element imbalances on the risk and severity of ASD was investigated, focusing on the analysis of abnormal levels of the multi-chemical elements profile in erythrocytes compared with typically developing children. Furthermore, the results showed a significant correlation between abnormal levels of several chemical elements and the severity of the autistic syndrome. Autism Res 2018, 11: 834-845. © 2018 International Society for Autism Research, Wiley Periodicals, Inc. © 2018 International Society for Autism Research, Wiley Periodicals, Inc.

Stirling Research Laboratory Providing Independent Performance Verification of Convertors for a Stirling Radioisotope Generator

NASA Technical Reports Server (NTRS)

Thieme, Lanny G.

2002-01-01

The Department of Energy (DOE), Germantown, Maryland, Stirling Technology Company (STC), Kennewick, Washington, and NASA Glenn Research Center are developing a free-piston Stirling convertor for a high-efficiency Stirling Radioisotope Generator for NASA Space Science missions. This generator is being developed for multimission use, including providing electric power for unmanned Mars rovers and for deep space missions. STC is developing the 55-W Technology Demonstration Convertor (TDC) under contract to DOE. Glenn is conducting an in-house technology project to assist in developing the convertor for readiness for space qualification and mission implementation. As part of this effort, a Stirling Research Laboratory was established to test the TDC's and related technologies. A key task is providing an independent verification and validation of the TDC performance. Four TDC's are now being tested at Glenn. Acceptance testing has been completed for all convertors, and in general, performance agreed well with that achieved by STC prior to the delivery of the convertors. Performance mapping has also been completed on two of the convertors over a range of hot-end temperatures (450 to 650 C), cold-end temperatures (80 to 120 C), and piston amplitudes (5.2 to 6.2 mm). These test data are available online at http://www.grc.nasa.gov/WWW/tmsb/. The TDC's can be tested in either a horizontal orientation with dual-opposed convertors or in a vertical orientation with a single convertor. Synchronized dual-opposed pairs are used for dynamically balanced operation that results in very low levels of vibration. The Stirling Research Laboratory also supports launch environment testing of the TDC's in Glenn's Structural Dynamics Laboratory and electromagnetic interference and electromagnetic compatibility characterization and reduction efforts. In addition, the TDC's will be used for long-term endurance testing, and preparations are underway for unattended operation.

A counting-weighted calibration method for a field-programmable-gate-array-based time-to-digital converter

NASA Astrophysics Data System (ADS)

Chen, Yuan-Ho

2017-05-01

In this work, we propose a counting-weighted calibration method for field-programmable-gate-array (FPGA)-based time-to-digital converter (TDC) to provide non-linearity calibration for use in positron emission tomography (PET) scanners. To deal with the non-linearity in FPGA, we developed a counting-weighted delay line (CWD) to count the delay time of the delay cells in the TDC in order to reduce the differential non-linearity (DNL) values based on code density counts. The performance of the proposed CWD-TDC with regard to linearity far exceeds that of TDC with a traditional tapped delay line (TDL) architecture, without the need for nonlinearity calibration. When implemented in a Xilinx Vertix-5 FPGA device, the proposed CWD-TDC achieved time resolution of 60 ps with integral non-linearity (INL) and DNL of [-0.54, 0.24] and [-0.66, 0.65] least-significant-bit (LSB), respectively. This is a clear indication of the suitability of the proposed FPGA-based CWD-TDC for use in PET scanners.

Extended Operation of Stirling Convertors

NASA Technical Reports Server (NTRS)

Roth, Mary Ellen; Schreiber, Jeffrey G.; Pepper, Stephen V.

2004-01-01

A high-efficiency 110 watt Stirling Radioisotope Generator 110 (SRG110) is being developed for potential NASA exploration missions. The SRG system efficiency is greater than 20%, making it an attractive candidate power system for deep space missions and unmanned rovers. The Department of Energy SRG110 Project team consists of the System Integrator, Lockheed Martin (LM), Stirling Technology Company (STC), and NASA Glenn Research Center (GRC). One of the GRC roles is to provide Independent Verification and Validation of the Stirling TDC's. At the request of LM, a part of this effort includes the extended operation of the TDC's in the dynamically balanced dual-opposed configuration. Performance data of the Stirling Converters over time is required to demonstrate that an SRG110 can meet long-duration mission requirements. A test plan and test system were developed to evaluate TDC's #13 and #14 steady-state performance for a minimum of 5000 hours and insure safe, round-the-clock operation of the TDC's. This paper will discuss the design and development, and status of the Extended Operation Test.

Different Visual Preference Patterns in Response to Simple and Complex Dynamic Social Stimuli in Preschool-Aged Children with Autism Spectrum Disorders

PubMed Central

Shi, Lijuan; Zhou, Yuanyue; Ou, Jianjun; Gong, Jingbo; Wang, Suhong; Cui, Xilong; Lyu, Hailong; Zhao, Jingping; Luo, Xuerong

2015-01-01

Eye-tracking studies in young children with autism spectrum disorder (ASD) have shown a visual attention preference for geometric patterns when viewing paired dynamic social images (DSIs) and dynamic geometric images (DGIs). In the present study, eye-tracking of two different paired presentations of DSIs and DGIs was monitored in a group of 13 children aged 4 to 6 years with ASD and 20 chronologically age-matched typically developing children (TDC). The results indicated that compared with the control group, children with ASD attended significantly less to DSIs showing two or more children playing than to similar DSIs showing a single child. Visual attention preference in 4- to 6-year-old children with ASDs, therefore, appears to be modulated by the type of visual stimuli. PMID:25781170

The index ‘Treatment Duration Control’ for enabling randomized controlled trials with variation in duration of treatment of chronic pain patients

PubMed Central

2013-01-01

Background Treatment duration varies with the type of therapy and a patient’s recovery speed. Including such a variation in randomized controlled trials (RCTs) enables comparison of the actual therapeutic potential of different therapies in clinical care. An index, Treatment Duration Control (TDC) of outcome scores was developed to help decide when to end treatment and also to determine treatment outcome by a blinded assessor. In contrast to traditional Routine Outcome Monitoring which considers raw score changes, TDC uses relative change. Methods Our theory shows that if a patient with the largest baseline scores in a sample requires a relative decrease by treatment factor T to reach a zone of low score values (functional status), any patient with smaller baselines will attain functional status with T. Furthermore, the end score values are proportional to the baseline. These characteristics concur with findings from the literature that a patient’s assessment of ‘much improved’ following treatment (related to attaining functional status) is associated with a particular relative decrease in pain intensity yielding a final pain intensity that is proportional to the baseline. Regarding the TDC-procedure: those patient’s scores that were related to pronounced signs and symptoms, were selected for adaptive testing (reference scores). A Contrast-value was determined for each reference score between its reference level and a subsequent level, and averaging all Contrast-values yielded TDC. A cut-off point related to factor T for attaining functional status, was the TDC-criterion to end a patient’s treatment as being successful. The use of TDC has been illustrated in RCT data from 118 chronic pain patients with myogenous Temporomandibular Disorders, and the TDC-criterion was validated. Results The TDC-criterion of successful/unsuccessful treatment approximated the cut-off separating two patient subgroups in a bimodal post-treatment distribution of TDC-values. Pain intensity decreased to residual levels and Health-Related Quality of Life (HRQoL) increased to normal levels, following successful treatment according to TDC. The post-treatment TDC-values were independent from the baseline values of pain intensity or HRQoL, and thus independent from the patient’s baseline severity of myogenous Temporomandibular Disorders. Conclusions TDC enables RCTs that have a variable therapy- and patient-specific duration. PMID:24112821

Vibration Modal Characterization of a Stirling Convertor via Base-Shake Excitation

NASA Technical Reports Server (NTRS)

Suarez, Vicente J.; Goodnight, Thomas W.; Hughes, William O.; Samorezov, Sergey

2003-01-01

The U.S. Department of Energy (DOE), Lockheed Martin (LM), Stirling Technology Company (STC), and NASA John H. Glenn Research Center (GRC) are currently developing a high-efficiency Stirling convertor for use in a Stirling Radioisotope Generator (SRG). NASA and DOE have identified the SRG for potential use as an advanced power system for future NASA Space Science missions, providing spacecraft onboard electric power for deep space missions and power for unmanned Mars rovers. Low-level, baseshake sine vibration tests were conducted on the Stirling Technology Demonstration Convertor (TDC), at NASA GRC's Structural Dynamics Laboratory, in February 2001, as part of the development of this Stirling technology. The purpose of these tests was to provide a better understanding of the TDC's internal dynamic response to external vibratory base excitations. The knowledge obtained can therein be used to help explain the success that the TDC enjoyed in its previous random vibration qualification tests (December 1999). This explanation focuses on the TDC s internal dynamic characteristics in the 50 to 250 Hz frequency range, which corresponds to the maximum input levels of its qualification random vibration test specification. The internal dynamic structural characteristics of the TDC have now been measured in two separate tests under different motoring and dynamic loading conditions: (1) with the convertor being electrically motored, under a vibratory base-shake excitation load, and (2) with the convertor turned off, and its alternator internals undergoing dynamic excitation via hammer impact loading. This paper addresses the test setup, procedure and results of the base-shake vibration testing conducted on the motored TDC, and will compare these results with those results obtained from the dynamic impact tests (May 2001) on the nonmotored TDC.

GSFC Technology Development Center Report

NASA Technical Reports Server (NTRS)

Himwich, Ed; Gipson, John

2013-01-01

This report summarizes the activities of the GSFC Technology Development Center (TDC) for 2012 and forecasts planned activities for 2013. The GSFC TDC develops station software including the Field System (FS), scheduling software (SKED), hardware including tools for station timing and meteorology, scheduling algorithms, and operational procedures. It provides a pool of individuals to assist with station implementation, check-out, upgrades, and training.

TOT measurement implemented in FPGA TDC

NASA Astrophysics Data System (ADS)

Fan, Huan-Huan; Cao, Ping; Liu, Shu-Bin; An, Qi

2015-11-01

Time measurement plays a crucial role for the purpose of particle identification in high energy physics experiments. With increasingly demanding physics goals and the development of electronics, modern time measurement systems need to meet the requirement of excellent resolution specification as well as high integrity. Based on Field Programmable Gate Arrays (FPGAs), FPGA time-to-digital converters (TDCs) have become one of the most mature and prominent time measurement methods in recent years. For correcting the time-walk effect caused by leading timing, a time-over-threshold (TOT) measurement should be added to the FPGA TDC. TOT can be obtained by measuring the interval between the signal leading and trailing edges. Unfortunately, a traditional TDC can recognize only one kind of signal edge, the leading or the trailing. Generally, to measure the interval, two TDC channels need to be used at the same time, one for leading, the other for trailing. However, this method unavoidably increases the amount of FPGA resources used and reduces the TDC's integrity. This paper presents one method of TOT measurement implemented in a Xilinx Virtex-5 FPGA. In this method, TOT measurement can be achieved using only one TDC input channel. The consumed resources and time resolution can both be guaranteed. Testing shows that this TDC can achieve resolution better than 15ps for leading edge measurement and 37 ps for TOT measurement. Furthermore, the TDC measurement dead time is about two clock cycles, which makes it good for applications with higher physics event rates. Supported by National Natural Science Foundation of China (11079003, 10979003)

Fine motor ability and psychiatric disorders in youth.

PubMed

Mendes, Lorenna Sena Teixeira; Manfro, Gisele Gus; Gadelha, Ary; Pan, Pedro Mario; Bressan, Rodrigo Affonseca; Rohde, Luis Augusto; Salum, Giovanni Abrahão

2018-05-01

Impaired fine motor ability has been linked to several domains of psychopathology. However, studies validating the specificity of this association among several categorical psychiatric disorders are still needed. The aim of this study was to assess differences in fine motor ability performance among four non-overlapping groups of psychiatric disorders and a group of typical developing comparisons (TDC). Our sample consisted of 2035 subjects aged 6-14-year-old. Diagnoses of psychiatric disorders were performed with the Development and Well-Being Assessment (DAWBA). Five non-overlapping groups without comorbidity were formed: phobic disorders (n = 101), distress disorders (n = 82), attention deficit hyperactivity disorder (ADHD) (n = 133), oppositional defiant disorder/conduct disorder (ODD/CD) (n = 52) and one group of typical developing comparisons (TDC) (n = 1667). Fine motor ability was evaluated by three tasks: sequential finger-thumb opposition, Oseretsky, and pronation/supination tests. Each task was assessed by total time to perform the movement and levels of accuracy, fluency, symmetry, precision, and coordination. We found that, when compared to TDC, the ADHD group performed more poorly in total fine motor ability (mean difference = - 0.28; p = 0.014), time to complete the task (mean difference = 0.36; p < 0.001), accuracy (mean difference = - 0.30; p = 0.005), fluency (mean difference = - 0.26; p = 0.03), symmetry (mean difference - 0.25; p = 0.04), precision (mean difference = - 0.26; p = 0.026), and coordination (mean difference = - 0.25; p = 0.042). The ADHD group also took more time to complete the task than the ODD/CD group (mean difference = 0.45; p = 0.037). No other significant between-group differences were found. Additional analyses showed those differences were statistically significant for all ADHD dimensions. Our results suggest that children with ADHD present impairments in all aspects of fine motor abilities compared to TDC, a difference not found in other psychiatric disorders.

Vibration Testing of Stirling Power Convertors

NASA Technical Reports Server (NTRS)

Hughes, Bill; Goodnight, Thomas; McNelis, Mark E.; Suarez, Vicente J.; Schreiber, Jeff; Samorezov, Sergey

2003-01-01

The NASA John H. Glenn Research Center (GRC) and the U.S. Department of Energy (DOE) are currently developing a high efficient, long life, free piston Stirling convertor for use as an advanced spacecraft power system for future NASA missions. As part of this development, a Stirling Technology Demonstrator Convertor (TDC), developed by Stirling Technology Company (STC) for DOE, was vibration tested at GRC s Structural Dynamics Laboratory (SDU7735) in November- December 1999. This testing demonstrated that the Stirling TDC is able to withstand the harsh random vibration (20 to 2000 Hertz) seen during a typical spacecraft launch and survive with no structural damage or functional power performance degradation, thereby enabling its usage in future spacecraft power systems. The Stirling Vibration Test Team at NASA GRC and STC personnel conducted tests on a single 55 electric watt TDC. The purpose was to characterize the TDC s structural response to vibration and determine if the TDC could survive the vibration criteria established by the Jet Propulsion Laboratory (JPL) for launch environments. The TDC was operated at full-stroke and full power conditions during the vibration testing. The TDC was tested in two orientations, with the direction of vibration parallel and perpendicular to the TDC s moving components (displacer and piston). The TDC successfully passed a series of sine and random vibration tests. The most severe test was a 12.3 Grms random vibration test (peak vibration level of 0.2 g2/Hz from 50 to 250 Hertz) with test durations of 3 minutes per axis. The random vibration test levels were chosen to simulate, with margin, the maximum anticipated launch vibration conditions. As a result of this very successful vibration testing and successful evaluations in other key technical readiness areas, the Stirling power system is now considered a viable technology for future application for NASA spacecraft missions. Possible usage of the Stirling power system would be to supply on- board electric spacecraft power for future NASA Deep-Space Missions, performing as an attractive alternative to Radioisotope Thermoelectric Generators (RTG). Usage of the Stirling technology is also being considered as the electric power source for future Mars rovers, whose mission profiles may exclude the use of photovoltaic power systems (such as exploring at high Martian latitudes or for missions of lengthy durations). GRC s Thermo-Mechanical Systems Branch (5490) provides Stirling technology expertise under a Space Act Agreement with the DOE. Additional vibration testing, by GRC s Structural Systems Dynamics Branch (7733, is planned to continue to demonstrate the Stirling power system s vibration capability as its technology and flight system designs progress.

Assessing localized skin-to-fat water in arms of women with breast cancer via tissue dielectric constant measurements in pre- and post-surgery patients.

PubMed

Mayrovitz, Harvey N; Weingrad, Daniel N; Lopez, Lidice

2015-05-01

Skin-to-fat tissue dielectric constant (TDC) values at 300 MHz largely depend on tissue water and provide a rapid way to assess skin water by touching skin with a probe for approximately 10 s. This method has been used to investigate lymphedema features accompanying breast cancer (BC), but relationships between TDC and nodes removed or symptoms is unclear. Our goals were: (1) to compare TDC values in BC patients prior to surgery (group A) and in patients who had BC-related surgery (group B) to determine if TDC of group B were related to nodes removed and reported symptoms and (2) to develop tentative lymphedema-detection thresholds. Arm volumes and TDC values of at-risk and contralateral forearms and biceps were determined in 103 women awaiting surgery for BC and 104 women who had BC-related surgery 26.3 ± 17.5 months prior to evaluation. Inter-arm ratios (at-risk/contralateral) were determined and patients answered questions about lymphedema-related symptoms. Inter-arm TDC ratios for group A forearm and biceps were respectively 1.003 ± 0.096 and 1.012 ± 0.143. Group B forearm ratios were significantly greater, and among group B patients who reported at least one symptom there was a significant correlation between TDC ratios and symptom burden and nodes removed. Inter-arm TDC ratios are significantly related to symptoms and nodes removed. Ratios increase with increasing symptom score and might be used to detect pre-clinical unilateral lymphedema using TDC ratio thresholds of 1.30 for forearm and 1.45 for biceps. Threshold confirmation awaits targeted prospective studies but can serve as guideposts to provide quantitative and easily done tracking assessments during follow-up visits.

Tissue dielectric constant (TDC) as an index of localized arm skin water: differences between measuring probes and genders.

PubMed

Mayrovitz, H N; Weingrad, D N; Brlit, F; Lopez, L B; Desfor, R

2015-03-01

An easily measured, non-invasive, quantitative estimate of local skin tissue water is useful to assess local lymphedema and its change. One method uses skin tissue dielectric constant (TDC) values that at 300 MHz TDC depend on free and bound water within the measurement volume. In practice such measurements have been done with a research-type multi-probe, but recently a hand-held compact-probe has become available that may be more clinically convenient. Because most available published data is based on multiprobe measurements it is important to characterize possible differences between devices that unless known might lead to ambiguous quantitative comparisons between TDC values. Thus, our purpose was to evaluate potential differences in measured TDC values between multi-probe and compact-probe devices with respect to probe effective sampling depth, anatomical site, and gender and also to compare compact-probe TDC values measured on women with and without breast cancer (BC). TDC was measured bilaterally on forearms and biceps of 32 male and 32 female volunteers and on 12 female patients awaiting surgery for breast cancer. Results show that 1) TDC values at 2.5 mm depth were significantly less than at 1.5 mm; 2) Female TDC values were significantly less than male values; 3) TDC values were not different between females with and without BC; and 4) dominant/non-dominant arm TDC ratios were not significantly different for any probe among genders or arm anatomical site. These findings indicate that probe type differences in absolute TDC values are present and should be taken into account when TDC values are compared. However, comparisons based on inter-arm TDC ratios are not statistically different among probes with respect to gender or anatomical location.

Decomposing Intra-Subject Variability in Children with Attention-Deficit/Hyperactivity Disorder

PubMed Central

Di Martino, Adriana; Ghaffari, Manely; Curchack, Jocelyn; Reiss, Philip; Hyde, Christopher; Vannucci, Marina; Petkova, Eva; Klein, Donald F.; Castellanos, F. Xavier

2009-01-01

Background Increased intra-subject response time standard deviations (RT-SD) discriminate children with Attention-Deficit/Hyperactivity Disorder (ADHD) from healthy controls. RT-SD is averaged over time, thus it does not provide information about the temporal structure of response time variability. We previously hypothesized that such increased variability may be related to slow spontaneous fluctuations in brain activity occurring with periods between 15s and 40s. Here, we investigated whether these slow response time fluctuations add unique differentiating information beyond the global increase in RT-SD. Methods We recorded RT at 3s intervals for 15 minutes during an Eriksen flanker task for 29 children with ADHD and 26 age-matched typically developing controls (TDC) (mean ages 12.5 ± 2.4 and 11.6 ± 2.5; 26 and 12 boys, respectively). The primary outcome was the magnitude of the spectral component in the frequency range between 0.027 and 0.073 Hz measured with continuous Morlet wavelet transform. Results The magnitude of the low frequency fluctuation was greater for children with ADHD compared to TDC (p=0.02, d= 0.69). After modeling ADHD diagnosis as a function of RT-SD, adding this specific frequency range significantly improved the model fit (p=0.03; odds ratio= 2.58). Conclusions Fluctuations in low frequency response time variability predict the diagnosis of ADHD beyond the effect associated with global differences in variability. Future studies will examine whether such spectrally specific fluctuations in behavioral responses are linked to intrinsic regional cerebral hemodynamic oscillations which occur at similar frequencies. PMID:18423424

In Vitro and In Vivo Demonstration of Human-Ovarian-Cancer Necrosis through a Water-Soluble and Near-Infrared-Absorbing Chlorin.

PubMed

Marydasan, Betsy; Madhuri, Bollapalli; Cherukommu, Shirisha; Jose, Jedy; Viji, Mambattakkara; Karunakaran, Suneesh C; Chandrashekar, Tavarekere K; Rao, Kunchala Sridhar; Rao, Ch Mohan; Ramaiah, Danaboyina

2018-06-14

With the objective of developing efficient sensitizers for therapeutic applications, we synthesized a water-soluble 5,10,15,20-tetrakis(3,4-dihydroxyphenyl)chlorin (TDC) and investigated its in vitro and in vivo biological efficacy, comparing it with the commercially available sensitizers. TDC showed high water solubility (6-fold) when compared with that of Foscan and exhibited excellent triplet-excited-state (84%) and singlet-oxygen (80%) yields. In vitro photobiological investigations in human-ovarian-cancer cell lines SKOV-3 showed high photocytotoxicity, negligible dark toxicity, rapid cellular uptake, and specific localization of TDC in neoplastic cells as assessed by flow-cytometric cell-cycle and propidium iodide staining analysis. The photodynamic effects of TDC include confirmed reactive-oxygen-species-induced mitochondrial damage leading to necrosis in SKOV-3 cell lines. The in vivo photodynamic activity in nude-mouse models demonstrated abrogation of tumor growth without any detectable pathology in the skin, liver, spleen, or kidney, thereby demonstrating TDC application as an efficient and safe photosensitizer.

Abnormal Cortical Plasticity in Youth with Autism Spectrum Disorder: A Transcranial Magnetic Stimulation Case-Control Pilot Study.

PubMed

Pedapati, Ernest V; Gilbert, Donald L; Erickson, Craig A; Horn, Paul S; Shaffer, Rebecca C; Wink, Logan K; Laue, Cameron S; Wu, Steve W

2016-09-01

This case-control study investigated the use of a low-intensity repetitive transcranial magnetic stimulation (rTMS) protocol to measure motor cortex (M1) plasticity in youth with autism spectrum disorder (ASD) compared with typically developing children (TDC). We hypothesized that impairments in long-term potentiation-like properties represent a neurophysiological biomarker of abnormal cortical function in ASD. We studied youth with ASD aged 11-18 years and matched controls (TDC). Intermittent theta burst stimulation (iTBS) was delivered to the dominant M1 at an intensity of 70% of resting motor threshold. Suprathreshold single-pulse TMS was performed to compare amplitudes of motor-evoked potentials (MEP) measured from surface electromyography electrodes on a target muscle before (20 pulses) and after (10 pulses/time point) iTBS at predefined timepoints (up to 30 minutes) to measure any potentiation effects. A linear mixed model was used to examine group differences in MEP amplitudes over time following iTBS. Nine youth with ASD (mean age 15.6; 7 males; 6 right-hand dominant) and 9 TDC (mean age 14.5; 5 males; 9 right-hand dominant) participated. All subjects tolerated the procedure well. Both groups had a mean increase in excitability after iTBS for 30 minutes; however, the time course of excitability changes differed (F9,144 = 2.05; p = 0.038). Post-hoc testing identified a significant decrease in amplitude of the ASD group at 20 minutes following iTBS compared with the TDC after correcting for multiple comparisons. In this study, we demonstrate early evidence for a potential physiological biomarker of cortical plasticity in youth with ASD using a rapid low-intensity rTMS protocol with a discriminate measure at 20 minutes following stimulation. The procedure was well tolerated by all 18 participants. Future work will include modification of the protocol to improve the ability to distinguish subtypes of ASD based on behavioral and cognitive testing.

A 128-channel Time-to-Digital Converter (TDC) inside a Virtex-5 FPGA on the GANDALF module

NASA Astrophysics Data System (ADS)

Büchele, M.; Fischer, H.; Gorzellik, M.; Herrmann, F.; Königsmann, K.; Schill, C.; Schopferer, S.

2012-03-01

The GANDALF 6U-VME64x/VXS module has been developed for the digitization and real time analysis of detector signals. To perform different applications such as analog-to-digital or time-to-digital conversions, coincidence matrix formation, fast pattern recognition and trigger generation, this module comes with exchangeable analog and digital mezzanine cards. Based on this platform, we present a 128-channel TDC which is implemented in a single Xilinx Virtex-5 FPGA using a shifted clock sampling method. In contrast to common TDC concepts, the input signal is sampled by 16 equidistant phase-shifted clocks. A particular challenge of the design is the minimum skew routing of the input signals to the sampling flip-flops. We present measurement results for the differential nonlinearity and the time resolution of the TDC readout system.

Arm, Leg, and Foot Skin Water in Persons With Diabetes Mellitus (DM) in Relation to HbA1c Assessed by Tissue Dielectric Constant (TDC) Technology Measured at 300 MHz.

PubMed

Mayrovitz, Harvey N; Volosko, Irina; Sarkar, Bansari; Pandya, Naushira

2017-05-01

DM is associated with structural skin changes. However, few studies have investigated changes in dermal water and specifically its relationship to glucose control as measured by HbA1c. Our goal was to test the hypothesis that skin water, assessed by its tissue dielectric constant (TDC), is inversely related to HbA1c. Water content of 3 skin sites (forearm, lower leg, and foot dorsum) of 50 persons with DM was estimated by measuring TDC at 300 MHz. TDC is the ratio of tissue dielectric constant to vacuum and depends on free and bound water in the measured volume. TDC was measured in triplicate to 4 depths, 0.5. 1.5, 2.5, and 5.0 mm to include different skin components. At each site increased measurement depth showed (1) a significant decrease in absolute TDC values and (2) a significant increase in foot-to-arm TDC ratios. TDC values at forearm were shown to be greater than at either leg or foot. However, testing of these 50 patients at 3 sites and 4 skin depths did not show any significant relationship between TDC and HbA1c or fasting glucose. The data indicate no relationship between TDC values, as indices for skin water, and HbA1c or fasting glucose. This implies that skin TDC values to assess skin property features and changes in persons with DM are not sensitive to recent glucose control. Furthermore, the results introduce a newly applied TDC technology useful to assess skin properties of persons with DM.

The integration of FPGA TDC inside White Rabbit node

NASA Astrophysics Data System (ADS)

Li, H.; Xue, T.; Gong, G.; Li, J.

2017-04-01

White Rabbit technology is capable of delivering sub-nanosecond accuracy and picosecond precision of synchronization and normal data packets over the fiber network. Carry chain structure in FPGA is a popular way to build TDC and tens of picosecond RMS resolution has been achieved. The integration of WR technology with FPGA TDC can enhance and simplify the TDC in many aspects that includes providing a low jitter clock for TDC, a synchronized absolute UTC/TAI timestamp for coarse counter, a fancy way to calibrate the carry chain DNL and an easy to use Ethernet link for data and control information transmit. This paper presents a FPGA TDC implemented inside a normal White Rabbit node with sub-nanosecond measurement precision. The measured standard deviation reaches 50ps between two distributed TDCs. Possible applications of this distributed TDC are also discussed.

Identification and characterization of polyclonal αβ T cells with dendritic cell properties

PubMed Central

Kuka, Mirela; Munitic, Ivana; Ashwell, Jonathan D.

2012-01-01

An efficient immune response requires coordination between innate and adaptive immunity, which act through cells different in origin and function. Here we report the identification of thymus-derived αβ TCR+ cells that express CD11c and MHC class II, and require FLT3L for development (TDC). TDC express genes heretofore found uniquely in T cells or DC, as well as a distinctive signature of cytotoxicity-related genes. Unlike other innate T cell subsets, TDC have a polyclonal TCR repertoire andrespond to cognate antigens. However, they differ from conventional T cells in that they do not require help from antigen-presenting cells, respond to TLR-mediated stimulation by producing IL-12 and process and present antigen. The physiologic relevance of TDC, found in mice and humans, is still under investigation, but the fact that they combine key features of T and DC cells suggests that they provide a bridge between the innate and adaptive immune systems. PMID:23187623

Multi-scale radiomic analysis of sub-cortical regions in MRI related to autism, gender and age

NASA Astrophysics Data System (ADS)

Chaddad, Ahmad; Desrosiers, Christian; Toews, Matthew

2017-03-01

We propose using multi-scale image textures to investigate links between neuroanatomical regions and clinical variables in MRI. Texture features are derived at multiple scales of resolution based on the Laplacian-of-Gaussian (LoG) filter. Three quantifier functions (Average, Standard Deviation and Entropy) are used to summarize texture statistics within standard, automatically segmented neuroanatomical regions. Significance tests are performed to identify regional texture differences between ASD vs. TDC and male vs. female groups, as well as correlations with age (corrected p < 0.05). The open-access brain imaging data exchange (ABIDE) brain MRI dataset is used to evaluate texture features derived from 31 brain regions from 1112 subjects including 573 typically developing control (TDC, 99 females, 474 males) and 539 Autism spectrum disorder (ASD, 65 female and 474 male) subjects. Statistically significant texture differences between ASD vs. TDC groups are identified asymmetrically in the right hippocampus, left choroid-plexus and corpus callosum (CC), and symmetrically in the cerebellar white matter. Sex-related texture differences in TDC subjects are found in primarily in the left amygdala, left cerebellar white matter, and brain stem. Correlations between age and texture in TDC subjects are found in the thalamus-proper, caudate and pallidum, most exhibiting bilateral symmetry.

Timing and Pulse Shape Discrimination Comparison Against Legacy TDC & QDC and the JLab F250 FADC

NASA Astrophysics Data System (ADS)

Milkeris-Zellar, Tyler; Sawatzky, Brad

2017-09-01

The F250 Flash Analog to Digital Convertor (FADC) is a relatively new module used in Data Acquisition Systems (DAQ) at Jefferson Lab. The FADC will replace or supplement older DAQ modules like Time to Digital Converters (TDCs) and Charge Analog to Digital Converters (QDCs). The TDC has a certain known timing resolution and the QDC can integrate a pulse's charge, a feature which can also be used for particle identification between photons and neutrons using pulse shape discrimination (PSD). The focus of this project is developing a test stand to study timing and PSD performance of legacy modules TDC and QDC, and the new F250 FADC. A cosmic telescope was used to extract timing resolution from the TDC and FADC. Through PSD with the QDC and FADC, using a liquid scintillator, we plan to identify photons and neutrons from an americium-beryllium (AmBe) source. Through PSD, we found that the FADC allows for flexible data analysis compared to the QDC. The results indicate that the TDC provides a more accurate measurement of timing resolution than the FADC. This improvement allows for a clear distinction of what module to use when wanting precision of measurement in a DAQ for a cosmic ray telescope. NSF.

Strong Lens Time Delay Challenge. I. Experimental Design

NASA Astrophysics Data System (ADS)

Dobler, Gregory; Fassnacht, Christopher D.; Treu, Tommaso; Marshall, Phil; Liao, Kai; Hojjati, Alireza; Linder, Eric; Rumbaugh, Nicholas

2015-02-01

The time delays between point-like images in gravitational lens systems can be used to measure cosmological parameters. The number of lenses with measured time delays is growing rapidly; the upcoming Large Synoptic Survey Telescope (LSST) will monitor ~103 strongly lensed quasars. In an effort to assess the present capabilities of the community, to accurately measure the time delays, and to provide input to dedicated monitoring campaigns and future LSST cosmology feasibility studies, we have invited the community to take part in a "Time Delay Challenge" (TDC). The challenge is organized as a set of "ladders," each containing a group of simulated data sets to be analyzed blindly by participating teams. Each rung on a ladder consists of a set of realistic mock observed lensed quasar light curves, with the rungs' data sets increasing in complexity and realism. The initial challenge described here has two ladders, TDC0 and TDC1. TDC0 has a small number of data sets, and is designed to be used as a practice set by the participating teams. The (non-mandatory) deadline for completion of TDC0 was the TDC1 launch date, 2013 December 1. The TDC1 deadline was 2014 July 1. Here we give an overview of the challenge, we introduce a set of metrics that will be used to quantify the goodness of fit, efficiency, precision, and accuracy of the algorithms, and we present the results of TDC0. Thirteen teams participated in TDC0 using 47 different methods. Seven of those teams qualified for TDC1, which is described in the companion paper.

Regional Alignment: Phase Zero Logistics Implications

DTIC Science & Technology

2014-05-01

Brigade TDC Theater Distribution Center TPFDL Time Phased Force Deployment List TSC Theater Sustainment Command v INTRODUCTION Not only are...Center ( TDC ) capability in response to the backlog of supplies and equipment required during major combat operation. The TDC was a contracted...organization, constructed to support units based on amount personnel and equipment. This TDC concept was a part of the logistics concept that supported

Experimental Evidence and In Silico Identification of Tryptophan Decarboxylase in Citrus Genus.

PubMed

De Masi, Luigi; Castaldo, Domenico; Pignone, Domenico; Servillo, Luigi; Facchiano, Angelo

2017-02-11

Plant tryptophan decarboxylase (TDC) converts tryptophan into tryptamine, precursor of indolealkylamine alkaloids. The recent finding of tryptamine metabolites in Citrus plants leads to hypothesize the existence of TDC activity in this genus. Here, we report for the first time that, in Citrus x limon seedlings, deuterium labeled tryptophan is decarboxylated into tryptamine, from which successively deuterated N , N , N -trimethyltryptamine is formed. These results give an evidence of the occurrence of the TDC activity and the successive methylation pathway of the tryptamine produced from the tryptophan decarboxylation. In addition, with the aim to identify the genetic basis for the presence of TDC, we carried out a sequence similarity search for TDC in the Citrus genomes using as a probe the TDC sequence reported for the plant Catharanthus roseus . We analyzed the genomes of both Citrus clementina and Citrus sinensis , available in public database, and identified putative protein sequences of aromatic l-amino acid decarboxylase. Similarly, 42 aromatic l-amino acid decarboxylase sequences from 23 plant species were extracted from public databases. Potential sequence signatures for functional TDC were then identified. With this research, we propose for the first time a putative protein sequence for TDC in the genus Citrus .

Structural diversity of alkaline-earth 2,5-thiophenedicarboxylates

NASA Astrophysics Data System (ADS)

Balendra; Ramanan, Arunachalam

2017-03-01

Exploration of the structural landscape of the system containing divalent alkaline-earth metal ion (Mg, Ca and Sr) with the rigid 2,5-thiophenedicarboxylic acid (TDC) under varying solvothermal condition (DMF, DMA and DEF) yielded five new crystals: [Mg(TDC) (DEF)2(H2O)1/2] (1), [Ca(TDC) (DMA)] (2), [Ca(TDC) (DMA) (H2O)] (3), [Sr(TDC) (DMA)] (4) and [Sr(TDC) (DMA) (H2O)] (5) and two known solids. Single crystal structures of all the solids are characteristic of extended coordination interaction between metal and carboxylate ions. While the smaller magnesium ion crystallized into a 2D coordination polymer, the larger calcium and strontium compounds resulted into the growth of 3D metal organic frameworks. All the solids show blue emission arising from intra ligand charge transfer.

Cell-specific expression of tryptophan decarboxylase and 10-hydroxygeraniol oxidoreductase, key genes involved in camptothecin biosynthesis in Camptotheca acuminata Decne (Nyssaceae)

PubMed Central

2010-01-01

Background Camptotheca acuminata is a major natural source of the terpenoid indole alkaloid camptothecin (CPT). At present, little is known about the cellular distribution of the biosynthesis of CPT, which would be useful knowledge for developing new strategies and technologies for improving alkaloid production. Results The pattern of CPT accumulation was compared with the expression pattern of some genes involved in CPT biosynthesis in C. acuminata [i.e., Ca-TDC1 and Ca-TDC2 (encoding for tryptophan decarboxylase) and Ca-HGO (encoding for 10-hydroxygeraniol oxidoreductase)]. Both CPT accumulation and gene expression were investigated in plants at different degrees of development and in plantlets subjected to drought-stress. In all organs, CPT accumulation was detected in epidermal idioblasts, in some glandular trichomes, and in groups of idioblast cells localized in parenchyma tissues. Drought-stress caused an increase in CPT accumulation and in the number of glandular trichomes containing CPT, whereas no increase in epidermal or parenchymatous idioblasts was observed. In the leaf, Ca-TDC1 expression was detected in some epidermal cells and in groups of mesophyll cells but not in glandular trichomes; in the stem, it was observed in parenchyma cells of the vascular tissue; in the root, no expression was detected. Ca-TDC2 expression was observed exclusively in leaves of plantlets subjected to drought-stress, in the same sites described for Ca-TDC1. In the leaf, Ca-HGO was detected in all chlorenchyma cells; in the stem, it was observed in the same sites described for Ca-TDC1; in the root, no expression was detected. Conclusions The finding that the sites of CPT accumulation are not consistently the same as those in which the studied genes are expressed demonstrates an organ-to-organ and cell-to-cell translocation of CPT or its precursors. PMID:20403175

Cell-specific expression of tryptophan decarboxylase and 10-hydroxygeraniol oxidoreductase, key genes involved in camptothecin biosynthesis in Camptotheca acuminata Decne (Nyssaceae).

PubMed

Valletta, Alessio; Trainotti, Livio; Santamaria, Anna Rita; Pasqua, Gabriella

2010-04-19

Camptotheca acuminata is a major natural source of the terpenoid indole alkaloid camptothecin (CPT). At present, little is known about the cellular distribution of the biosynthesis of CPT, which would be useful knowledge for developing new strategies and technologies for improving alkaloid production. The pattern of CPT accumulation was compared with the expression pattern of some genes involved in CPT biosynthesis in C. acuminata [i.e., Ca-TDC1 and Ca-TDC2 (encoding for tryptophan decarboxylase) and Ca-HGO (encoding for 10-hydroxygeraniol oxidoreductase)]. Both CPT accumulation and gene expression were investigated in plants at different degrees of development and in plantlets subjected to drought-stress. In all organs, CPT accumulation was detected in epidermal idioblasts, in some glandular trichomes, and in groups of idioblast cells localized in parenchyma tissues. Drought-stress caused an increase in CPT accumulation and in the number of glandular trichomes containing CPT, whereas no increase in epidermal or parenchymatous idioblasts was observed. In the leaf, Ca-TDC1 expression was detected in some epidermal cells and in groups of mesophyll cells but not in glandular trichomes; in the stem, it was observed in parenchyma cells of the vascular tissue; in the root, no expression was detected. Ca-TDC2 expression was observed exclusively in leaves of plantlets subjected to drought-stress, in the same sites described for Ca-TDC1. In the leaf, Ca-HGO was detected in all chlorenchyma cells; in the stem, it was observed in the same sites described for Ca-TDC1; in the root, no expression was detected. The finding that the sites of CPT accumulation are not consistently the same as those in which the studied genes are expressed demonstrates an organ-to-organ and cell-to-cell translocation of CPT or its precursors.

Mismatch Negativity and P3a in Adolescents and Young Adults with Autism Spectrum Disorders: Behavioral Correlates and Clinical Implications

ERIC Educational Resources Information Center

Chien, Yi-Ling; Hsieh, Ming Hsien; Gau, Susan Shur-Fen

2018-01-01

In a sample of 37 adolescents and young adults with autism spectrum disorder (ASD) and 35 typically-developing controls (TDC), we investigated sensory symptoms by clinical measures, and Mismatch Negativity and P3a component at Fz with the frequency and duration oddball paradigms of event-related potentials. Results showed that compared to TDC, ASD…

Tryptophan decarboxylase plays an important role in ajmalicine biosynthesis in Rauvolfia verticillata.

PubMed

Liu, Wanhong; Chen, Rong; Chen, Min; Zhang, Haoxing; Peng, Meifang; Yang, Chunxian; Ming, Xingjia; Lan, Xiaozhong; Liao, Zhihua

2012-07-01

Tryptophan decarboxylase (TDC) converts tryptophan into tryptamine that is the indole moiety of ajmalicine. The full-length cDNA of Rauvolfia verticillata (RvTDC) was 1,772 bps that contained a 1,500-bp ORF encoding a 499-amino-acid polypeptide. Recombinant 55.5 kDa RvTDC converted tryptophan into tryptamine. The K (m) of RvTDC for tryptophan was 2.89 mM, higher than those reported in other TIAs-producing plants. It demonstrated that RvTDC had lower affinity to tryptophan than other plant TDCs. The K (m) of RvTDC was also much higher than that of strictosidine synthase and strictosidine glucosidase in Rauvolfia. This suggested that TDC might be the committed-step enzyme involved in ajmalicine biosynthesis in R. verticillata. The expression of RvTDC was slightly upregulated by MeJA; the five MEP pathway genes and SGD showed no positive response to MeJA; and STR was sharply downregulated by MeJA. MeJA-treated hairy roots produced higher level of ajmalicine (0.270 mg g(-1) DW) than the EtOH control (0.183 mg g(-1) DW). Highest RvTDC expression level was detected in hairy root, about respectively 11, 19, 65, and 109-fold higher than in bark, young leaf, old leaf, and root. Highest ajmalicine content was also found in hairy root (0.249 mg g(-1) DW) followed by in bark (0.161 mg g(-1) DW) and young leaf (0.130 mg g(-1) DW), and least in root (0.014 mg g(-1) DW). Generally, the expression level of RvTDC was positively consistent with the accumulation of ajmalicine. Therefore, it could be deduced that TDC might be the key enzyme involved in ajmalicine biosynthesis in Rauvolfia.

STRONG LENS TIME DELAY CHALLENGE. I. EXPERIMENTAL DESIGN

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

Dobler, Gregory; Fassnacht, Christopher D.; Rumbaugh, Nicholas

2015-02-01

The time delays between point-like images in gravitational lens systems can be used to measure cosmological parameters. The number of lenses with measured time delays is growing rapidly; the upcoming Large Synoptic Survey Telescope (LSST) will monitor ∼10{sup 3} strongly lensed quasars. In an effort to assess the present capabilities of the community, to accurately measure the time delays, and to provide input to dedicated monitoring campaigns and future LSST cosmology feasibility studies, we have invited the community to take part in a ''Time Delay Challenge'' (TDC). The challenge is organized as a set of ''ladders'', each containing a groupmore » of simulated data sets to be analyzed blindly by participating teams. Each rung on a ladder consists of a set of realistic mock observed lensed quasar light curves, with the rungs' data sets increasing in complexity and realism. The initial challenge described here has two ladders, TDC0 and TDC1. TDC0 has a small number of data sets, and is designed to be used as a practice set by the participating teams. The (non-mandatory) deadline for completion of TDC0 was the TDC1 launch date, 2013 December 1. The TDC1 deadline was 2014 July 1. Here we give an overview of the challenge, we introduce a set of metrics that will be used to quantify the goodness of fit, efficiency, precision, and accuracy of the algorithms, and we present the results of TDC0. Thirteen teams participated in TDC0 using 47 different methods. Seven of those teams qualified for TDC1, which is described in the companion paper.« less

Abnormal Cortical Plasticity in Youth with Autism Spectrum Disorder: A Transcranial Magnetic Stimulation Case–Control Pilot Study

PubMed Central

Gilbert, Donald L.; Erickson, Craig A.; Horn, Paul S.; Shaffer, Rebecca C.; Wink, Logan K.; Laue, Cameron S.; Wu, Steve W.

2016-01-01

Abstract Objective: This case–control study investigated the use of a low-intensity repetitive transcranial magnetic stimulation (rTMS) protocol to measure motor cortex (M1) plasticity in youth with autism spectrum disorder (ASD) compared with typically developing children (TDC). We hypothesized that impairments in long-term potentiation-like properties represent a neurophysiological biomarker of abnormal cortical function in ASD. Methods: We studied youth with ASD aged 11–18 years and matched controls (TDC). Intermittent theta burst stimulation (iTBS) was delivered to the dominant M1 at an intensity of 70% of resting motor threshold. Suprathreshold single-pulse TMS was performed to compare amplitudes of motor-evoked potentials (MEP) measured from surface electromyography electrodes on a target muscle before (20 pulses) and after (10 pulses/time point) iTBS at predefined timepoints (up to 30 minutes) to measure any potentiation effects. A linear mixed model was used to examine group differences in MEP amplitudes over time following iTBS. Results: Nine youth with ASD (mean age 15.6; 7 males; 6 right-hand dominant) and 9 TDC (mean age 14.5; 5 males; 9 right-hand dominant) participated. All subjects tolerated the procedure well. Both groups had a mean increase in excitability after iTBS for 30 minutes; however, the time course of excitability changes differed (F9,144 = 2.05; p = 0.038). Post-hoc testing identified a significant decrease in amplitude of the ASD group at 20 minutes following iTBS compared with the TDC after correcting for multiple comparisons. Conclusion: In this study, we demonstrate early evidence for a potential physiological biomarker of cortical plasticity in youth with ASD using a rapid low-intensity rTMS protocol with a discriminate measure at 20 minutes following stimulation. The procedure was well tolerated by all 18 participants. Future work will include modification of the protocol to improve the ability to distinguish subtypes of ASD based on behavioral and cognitive testing. PMID:27007257

Novel subgroups of attention-deficit/hyperactivity disorder identified by topological data analysis and their functional network modular organizations

PubMed Central

Kyeong, Sunghyon; Kim, Jae-Jin; Kim, Eunjoo

2017-01-01

Attention-deficit/hyperactivity disorder (ADHD) is a clinically heterogeneous condition and identification of clinically meaningful subgroups would open up a new window for personalized medicine. Thus, we aimed to identify new clinical phenotypes in children and adolescents with ADHD and to investigate whether neuroimaging findings validate the identified phenotypes. Neuroimaging and clinical data from 67 children with ADHD and 62 typically developing controls (TDCs) from the ADHD-200 database were selected. Clinical measures of ADHD symptoms and intelligence quotient (IQ) were used as input features into a topological data analysis (TDA) to identify ADHD subgroups within our sample. As external validators, graph theoretical measures obtained from the functional connectome were compared to address the biological meaningfulness of the identified subtypes. The TDA identified two unique subgroups of ADHD, labelled as mild symptom ADHD (mADHD) and severe symptom ADHD (sADHD). The output topology shape was repeatedly observed in the independent validation dataset. The graph theoretical analysis showed a decrease in the degree centrality and PageRank in the bilateral posterior cingulate cortex in the sADHD group compared with the TDC group. The mADHD group showed similar patterns of intra- and inter-module connectivity to the sADHD group. Relative to the TDC group, the inter-module connectivity between the default mode network and executive control network were significantly increased in the sADHD group but not in the mADHD group. Taken together, our results show that the data-driven TDA is potentially useful in identifying objective and biologically relevant disease phenotypes in children and adolescents with ADHD. PMID:28829775

Twist-Drill or Burr Hole Craniostomy for Draining Chronic Subdural Hematomas: How to Choose It for Chronic Subdural Hematoma Drainage

PubMed Central

Lee, Seong-Jong; Im, Soo Bin

2016-01-01

Objective Although twist-drill craniostomy (TDC) has a number of procedural advantages and an equivalent outcome compared to burr hole craniostomy (BHC) for the treatment of chronic subdural hematomas (CSDHs), the latter technique remains the preferred method. We analyzed symptomatic CSDHs in whom TDC at the pre-coronal suture entry point (PCSEP) was the primary method for hematoma drainage and BHC on the parietal was the secondary option. Methods CSDHs in 86 consecutive patients were included. TDC at the PCSEP, which is 1 cm anterior to coronal suture at the level of the superior temporal line, was the primary operational technique when the hematoma thickness was suitable, and BHC was performed via the parietal when TDC was unreasonable or failed. The clinical feasibility and outcomes of these approaches were analyzed. Results Of the 86 patients, 68 (79.1%) were treated by TDC, and 18 (20.9%) by BHC. All patients showed improvements in their symptoms after hematoma drainage. Neither morbidity nor mortality was associated with either technique, and there were no differences in drainage days between the groups. Ten patients had bilateral hematomas and were treated using TDC. Two patients were not sufficiently treated by TDC and, as a result, BHC was applied. Only six hematomas (7% of 86 hematomas) exhibited insufficient thickness on the computed tomography to perform TDC. Conclusion When the hematoma was thick enough, a majority of the CSDHs were drained using TDC at the PCSEP as the first procedure, which was especially useful for bilateral hematomas and in elderly patients. PMID:27857917

Twist-Drill or Burr Hole Craniostomy for Draining Chronic Subdural Hematomas: How to Choose It for Chronic Subdural Hematoma Drainage.

PubMed

Lee, Seong-Jong; Hwang, Sun-Chul; Im, Soo Bin

2016-10-01

Although twist-drill craniostomy (TDC) has a number of procedural advantages and an equivalent outcome compared to burr hole craniostomy (BHC) for the treatment of chronic subdural hematomas (CSDHs), the latter technique remains the preferred method. We analyzed symptomatic CSDHs in whom TDC at the pre-coronal suture entry point (PCSEP) was the primary method for hematoma drainage and BHC on the parietal was the secondary option. CSDHs in 86 consecutive patients were included. TDC at the PCSEP, which is 1 cm anterior to coronal suture at the level of the superior temporal line, was the primary operational technique when the hematoma thickness was suitable, and BHC was performed via the parietal when TDC was unreasonable or failed. The clinical feasibility and outcomes of these approaches were analyzed. Of the 86 patients, 68 (79.1%) were treated by TDC, and 18 (20.9%) by BHC. All patients showed improvements in their symptoms after hematoma drainage. Neither morbidity nor mortality was associated with either technique, and there were no differences in drainage days between the groups. Ten patients had bilateral hematomas and were treated using TDC. Two patients were not sufficiently treated by TDC and, as a result, BHC was applied. Only six hematomas (7% of 86 hematomas) exhibited insufficient thickness on the computed tomography to perform TDC. When the hematoma was thick enough, a majority of the CSDHs were drained using TDC at the PCSEP as the first procedure, which was especially useful for bilateral hematomas and in elderly patients.

Validity and interobserver agreement of lower extremity local tissue water measurements in healthy women using tissue dielectric constant.

PubMed

Jensen, Mads R; Birkballe, Susanne; Nørregaard, Susan; Karlsmark, Tonny

2012-07-01

Tissue dielectric constant (TDC) measurement may become an important tool in the clinical evaluation of chronic lower extremity swelling in women; however, several factors are known to influence TDC measurements, and comparative data on healthy lower extremities are few. Thirty-four healthy women volunteered. Age, BMI, moisturizer use and hair removal were registered. Three blinded investigators performed TDC measurements in a randomized sequence on clearly marked locations on the foot, the ankle and the lower leg. The effective measuring depth was 2.5 mm. The mean TDC was 37.8 ± 5.5 (mean ± SD) on the foot, 29.0 ± 3.1 on the ankle and 30.5 ± 3.9 on the lower leg. TDC was highly dependent on measuring site (P<0.001) but did not vary significantly between investigators (P=0.127). Neither age, BMI, hair removal nor moisturizer use had any significant effect on the lower leg TDC. Intraclass correlation coefficients were 0.77 for the foot, 0.94 for the ankle and 0.94 for the lower leg. The TDC on the foot was significantly higher compared with ankle and lower leg values. Foot measurements should be interpreted cautiously because of questionable interobserver agreement. The interobserver agreement was high on lower leg and ankle measurements. Neither age, BMI, hair removal nor moisturizer use had any significant on effect on the lower leg TDC. TDC values of 35.2 for the ankle and 38.3 for the lower leg are suggested as upper normal reference limits in women. © 2012 The Authors Clinical Physiology and Functional Imaging © 2012 Scandinavian Society of Clinical Physiology and Nuclear Medicine.

Altered Cortico-Striatal–Thalamic Connectivity in Relation to Spatial Working Memory Capacity in Children with ADHD

PubMed Central

Mills, Kathryn L.; Bathula, Deepti; Dias, Taciana G. Costa; Iyer, Swathi P.; Fenesy, Michelle C.; Musser, Erica D.; Stevens, Corinne A.; Thurlow, Bria L.; Carpenter, Samuel D.; Nagel, Bonnie J.; Nigg, Joel T.; Fair, Damien A.

2012-01-01

Introduction: Attention deficit hyperactivity disorder (ADHD) captures a heterogeneous group of children, who are characterized by a range of cognitive and behavioral symptoms. Previous resting-state functional connectivity MRI (rs-fcMRI) studies have sought to understand the neural correlates of ADHD by comparing connectivity measurements between those with and without the disorder, focusing primarily on cortical–striatal circuits mediated by the thalamus. To integrate the multiple phenotypic features associated with ADHD and help resolve its heterogeneity, it is helpful to determine how specific circuits relate to unique cognitive domains of the ADHD syndrome. Spatial working memory has been proposed as a key mechanism in the pathophysiology of ADHD. Methods: We correlated the rs-fcMRI of five thalamic regions of interest (ROIs) with spatial span working memory scores in a sample of 67 children aged 7–11 years [ADHD and typically developing children (TDC)]. In an independent dataset, we then examined group differences in thalamo-striatal functional connectivity between 70 ADHD and 89 TDC (7–11 years) from the ADHD-200 dataset. Thalamic ROIs were created based on previous methods that utilize known thalamo-cortical loops and rs-fcMRI to identify functional boundaries in the thalamus. Results/Conclusion: Using these thalamic regions, we found atypical rs-fcMRI between specific thalamic groupings with the basal ganglia. To identify the thalamic connections that relate to spatial working memory in ADHD, only connections identified in both the correlational and comparative analyses were considered. Multiple connections between the thalamus and basal ganglia, particularly between medial and anterior dorsal thalamus and the putamen, were related to spatial working memory and also altered in ADHD. These thalamo-striatal disruptions may be one of multiple atypical neural and cognitive mechanisms that relate to the ADHD clinical phenotype. PMID:22291667

Melatonin biosynthesis enzymes recruit WRKY transcription factors to regulate melatonin accumulation and transcriptional activity on W-box in cassava.

PubMed

Wei, Yunxie; Liu, Guoyin; Chang, Yanli; Lin, Daozhe; Reiter, Russel J; He, Chaozu; Shi, Haitao

2018-03-12

Melatonin is widely involved in growth, development, and stress responses in plants. Although the melatonin synthesis enzymes have been identified in various plants, their interacting proteins remain unknown. Herein, overexpression of tryptophan decarboxylase 2 (MeTDC2)-interacting proteins, N-acetylserotonin O-methyltransferase 2 (MeASMT2) interacting proteins, and N-acetylserotonin O-methyltransferase 3 (MeASMT3) in cassava leaf protoplasts resulted in more melatonin than when other enzymes were overexpressed. Through yeast two-hybrid, 14 MeTDC2-interacting proteins, 24 MeASMT2 interacting proteins, and 9 MeASMT3-interacting proteins were identified. Notably, we highlighted MeWRKY20 and MeWRKY75 as common interacting proteins of the 3 enzymes, as evidenced by yeast two-hybrid, and in vivo bimolecular fluorescence complementation (BiFC). Moreover, co-overexpression of MeTDC2/MeASMT2/3 with MeWRKY20/75 in cassava leaf protoplasts did not only activated the transcriptional activities of MeWRKY20 and MeWRKY75 on W-box, but also induced the effects of MeTDC2, MeASMT2/3 on endogenous melatonin levels. Taken together, 3 melatonin synthesis enzymes (MeTDC2, MeASMT2/3) interact with MeWRKY20/75 to form a protein complex in cassava. This information significantly extends the knowledge of the complex modulation of plant melatonin signaling. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Tyramine and phenylethylamine biosynthesis by food bacteria.

PubMed

Marcobal, Angela; De las Rivas, Blanca; Landete, José María; Tabera, Laura; Muñoz, Rosario

2012-01-01

Tyramine poisoning is caused by the ingestion of food containing high levels of tyramine, a biogenic amine. Any foods containing free tyrosine are subject to tyramine formation if poor sanitation and low quality foods are used or if the food is subject to temperature abuse or extended storage time. Tyramine is generated by decarboxylation of the tyrosine through tyrosine decarboxylase (TDC) enzymes derived from the bacteria present in the food. Bacterial TDC have been only unequivocally identified and characterized in Gram-positive bacteria, especially in lactic acid bacteria. Pyridoxal phosphate (PLP)-dependent TDC encoding genes (tyrDC) appeared flanked by a similar genetic organization in several species of lactic acid bacteria, suggesting a common origin by a single mobile genetic element. Bacterial TDC are also able to decarboxylate phenylalanine to produce phenylethylamine (PEA), another biogenic amine. The molecular knowledge of the genes involved in tyramine production has led to the development of molecular methods for the detection of bacteria able to produce tyramine and PEA. These rapid and simple methods could be used for the analysis of the ability to form tyramine by bacteria in order to evaluate the potential risk of tyramine biosynthesis in food products.

The Strong Lensing Time Delay Challenge (2014)

NASA Astrophysics Data System (ADS)

Liao, Kai; Dobler, G.; Fassnacht, C. D.; Treu, T.; Marshall, P. J.; Rumbaugh, N.; Linder, E.; Hojjati, A.

2014-01-01

Time delays between multiple images in strong lensing systems are a powerful probe of cosmology. At the moment the application of this technique is limited by the number of lensed quasars with measured time delays. However, the number of such systems is expected to increase dramatically in the next few years. Hundred such systems are expected within this decade, while the Large Synoptic Survey Telescope (LSST) is expected to deliver of order 1000 time delays in the 2020 decade. In order to exploit this bounty of lenses we needed to make sure the time delay determination algorithms have sufficiently high precision and accuracy. As a first step to test current algorithms and identify potential areas for improvement we have started a "Time Delay Challenge" (TDC). An "evil" team has created realistic simulated light curves, to be analyzed blindly by "good" teams. The challenge is open to all interested parties. The initial challenge consists of two steps (TDC0 and TDC1). TDC0 consists of a small number of datasets to be used as a training template. The non-mandatory deadline is December 1 2013. The "good" teams that complete TDC0 will be given access to TDC1. TDC1 consists of thousands of lightcurves, a number sufficient to test precision and accuracy at the subpercent level, necessary for time-delay cosmography. The deadline for responding to TDC1 is July 1 2014. Submissions will be analyzed and compared in terms of predefined metrics to establish the goodness-of-fit, efficiency, precision and accuracy of current algorithms. This poster describes the challenge in detail and gives instructions for participation.

Lovastatin regulates brain spontaneous low-frequency brain activity in Neurofibromatosis type 1

PubMed Central

Chabernaud, Camille; Mennes, Maarten; Kardel, Peter G.; Gaillard, William D.; Kalbfleisch, M. Layne; VanMeter, John W.; Packer, Roger J.; Milham, Michael P.; Castellanos, Francisco X.; Acosta, Maria T.

2012-01-01

In the Neurofibromatosis type 1 (NF1) mouse model, lovastatin, used clinically for hypercholesterolemia, improves cognitive dysfunction. While such impairment has been studied in NF1, the neural substrates remain unclear. The aim of this imaging add-on to a phase-1 open-label trial was to examine the effect of lovastatin on Default Network (DN) resting state functional connectivity (RSFC). Seven children with NF1 (aged 11.9±2.2; 1 female) were treated with lovastatin once daily for 12 weeks. A 7-minute 3-Tesla echo-planar-imaging scan was collected one day before beginning treatment (off-drug) and the last day of treatment (on-drug) while performing a Flanker task. After regressing-out task-associated variance, we used the residual time series as “continuous resting-state data” for RSFC analyses using 11 DN regions of interest. For qualitative comparisons, we included a group of 19 typically developing children (TDC) collected elsewhere. In the on-drug condition, lovastatin increased long-range positive RSFC within DN core regions (i.e., anterior medial prefrontal cortex and posterior cingulate cortex, PCC). In addition, lovastatin produced less diffuse local RSFC in the dorsomedial prefrontal cortex and PCC. The pattern of RSFC observed in the NF1 participants when on-drug closely resembled the RSFC patterns exhibited by the TDC. Lovastatin administration in this open trial regulated anterior-posterior long-range and local RSFC within the DN. These preliminary results are consistent with a role for lovastatin in normalization of developmental processes and with apparent benefits in a mouse NF1 model. PMID:22433254

An 11-bit and 39 ps resolution time-to-digital converter for ADPLL in digital television

NASA Astrophysics Data System (ADS)

Liu, Wei; (Ruth) Li, Wei; Ren, P.; Lin, C. L.; Zhang, Shengdong; Wang, Yangyuan

2010-04-01

We propose and demonstrate an 11-bit time-to-digital converter (TDC) for all-digital phase-locked loops (ADPLLs) in digital television. The proposed TDC converts the width of the input pulse into digital output with the tap space of the outputs of a free-running ring oscillator (FRO) being the conversion resolution. The FRO is in a structure of coiled cell array and the TDC core is symmetrical in the input structure. This leads to equally spaced taps in the reference clocks and thereby a high TDC conversion linearity. The TDC is fabricated in 0.13 μm CMOS process and the chip area is 0.025 mm2. The measurement results show that the TDC has a conversion resolution of 39 ps at 1.2 V power supply and a 4.5 ns dead time in the 11-bits output case. Both the differential non-linearity (DNL) and integral non-linearity (INL) are below 0.5 LSB. The power consumption of the whole circuit is 4.2 mW.

Aversive odorant causing appetite decrease downregulates tyrosine decarboxylase gene expression in the olfactory receptor neuron of the blowfly, Phormia regina

NASA Astrophysics Data System (ADS)

Ishida, Yuko; Ozaki, Mamiko

2012-01-01

In the blowfly Phormia regina, exposure to d-limonene for 5 days during feeding inhibits proboscis extension reflex behavior due to decreasing tyramine (TA) titer in the brain. TA is synthesized by tyrosine decarboxylase (Tdc) and catalyzed into octopamine (OA) by TA ß-hydroxylase (Tbh). To address the mechanisms of TA titer regulation in the blowfly, we cloned Tdc and Tbh cDNAs from P. regina (PregTdc and PregTbh). The deduced amino acid sequences of both proteins showed high identity to those of the corresponding proteins from Drosophila melanogaster at the amino acid level. PregTdc was expressed in the antenna, labellum, and tarsus whereas PregTbh was expressed in the head, indicating that TA is mainly synthesized in the sensory organs whereas OA is primarily synthesized in the brain. d-Limonene exposure significantly decreased PregTdc expression in the antenna but not in the labellum and the tarsus, indicating that PregTdc expressed in the antenna is responsible for decreasing TA titer. PregTdc-like immunoreactive material was localized in the thin-walled sensillum. In contrast, the OA/TA receptor (PregOAR/TAR) was localized to the thick-walled sensillum. The results indicated that d-limonene inhibits PregTdc expression in the olfactory receptor neurons in the thin-walled sensilla, likely resulting in reduced TA levels in the receptor neurons in the antenna. TA may be transferred from the receptor neuron to the specific synaptic junction in the antennal lobe of the brain through the projection neurons and play a role in conveying the aversive odorant information to the projection and local neurons.

Development of an integrated four-channel fast avalanche-photodiode detector system with nanosecond time resolution

NASA Astrophysics Data System (ADS)

Li, Zhenjie; Li, Qiuju; Chang, Jinfan; Ma, Yichao; Liu, Peng; Wang, Zheng; Hu, Michael Y.; Zhao, Jiyong; Alp, E. E.; Xu, Wei; Tao, Ye; Wu, Chaoqun; Zhou, Yangfan

2017-10-01

A four-channel nanosecond time-resolved avalanche-photodiode (APD) detector system is developed at Beijing Synchrotron Radiation. It uses a single module for signal processing and readout. This integrated system provides better reliability and flexibility for custom improvement. The detector system consists of three parts: (i) four APD sensors, (ii) four fast preamplifiers and (iii) a time-digital-converter (TDC) readout electronics. The C30703FH silicon APD chips fabricated by Excelitas are used as the sensors of the detectors. It has an effective light-sensitive area of 10 × 10 mm2 and an absorption layer thickness of 110 μm. A fast preamplifier with a gain of 59 dB and bandwidth of 2 GHz is designed to readout of the weak signal from the C30703FH APD. The TDC is realized by a Spartan-6 field-programmable-gate-array (FPGA) with multiphase method in a resolution of 1ns. The arrival time of all scattering events between two start triggers can be recorded by the TDC. The detector has been used for nuclear resonant scattering study at both Advanced Photon Source and also at Beijing Synchrotron Radiation Facility. For the X-ray energy of 14.4 keV, the time resolution, the full width of half maximum (FWHM) of the detector (APD sensor + fast amplifier) is 0.86 ns, and the whole detector system (APD sensors + fast amplifiers + TDC readout electronics) achieves a time resolution of 1.4 ns.

A flexible 32-channel time-to-digital converter implemented in a Xilinx Zynq-7000 field programmable gate array

NASA Astrophysics Data System (ADS)

Wang, Yonggang; Kuang, Jie; Liu, Chong; Cao, Qiang; Li, Deng

2017-03-01

A high performance multi-channel time-to-digital converter (TDC) is implemented in a Xilinx Zynq-7000 field programmable gate array (FPGA). It can be flexibly configured as either 32 TDC channels with 9.9 ps time-interval RMS precision, 16 TDC channels with 6.9 ps RMS precision, or 8 TDC channels with 5.8 ps RMS precision. All TDCs have a 380 M Samples/second measurement throughput and a 2.63 ns measurement dead time. The performance consistency and temperature dependence of TDC channels are also evaluated. Because Zynq-7000 FPGA family integrates a feature-rich dual-core ARM based processing system and 28 nm Xilinx programmable logic in a single device, the realization of high performance TDCs on it will make the platform more widely used in time-measuring related applications.

A 256-channel, high throughput and precision time-to-digital converter with a decomposition encoding scheme in a Kintex-7 FPGA

NASA Astrophysics Data System (ADS)

Song, Z.; Wang, Y.; Kuang, J.

2018-05-01

Field Programmable Gate Arrays (FPGAs) made with 28 nm and more advanced process technology have great potentials for implementation of high precision time-to-digital convertors (TDC), because the delay cells in the tapped delay line (TDL) used for time interpolation are getting smaller and smaller. However, the bubble problems in the TDL status are becoming more complicated, which make it difficult to achieve TDCs on these chips with a high time precision. In this paper, we are proposing a novel decomposition encoding scheme, which not only can solve the bubble problem easily, but also has a high encoding efficiency. The potential of these chips to realize TDC can be fully released with the scheme. In a Xilinx Kintex-7 FPGA chip, we implemented a TDC system with 256 TDC channels, which doubles the number of TDC channels that our previous technique could achieve. Performances of all these TDC channels are evaluated. The average RMS time precision among them is 10.23 ps in the time-interval measurement range of (0–10 ns), and their measurement throughput reaches 277 M measures per second.

Distinct differences in striatal dysmorphology between attention deficit hyperactivity disorder boys with and without a comorbid reading disability.

PubMed

Goradia, Dhruman D; Vogel, Sherry; Mohl, Brianne; Khatib, Dalal; Zajac-Benitez, Caroline; Rajan, Usha; Robin, Arthur; Rosenberg, David R; Stanley, Jeffrey A

2016-12-30

There is evidence of greater cognitive deficits in attention deficit hyperactivity disorder with a comorbid reading disability (ADHD/+RD) compared to ADHD alone (ADHD/-RD). Additionally, the striatum has been consistently implicated in ADHD. However, the extent of morphological alterations in the striatum of ADHD/+RD is poorly understood, which is the main purpose of this study. Based on structural MRI images, the surface deformation of the caudate and putamen was assessed in 59 boys matching in age and IQ [19 ADHD/-RD, 15 ADHD/+RD and 25 typically developing controls (TDC)]. A vertex based analysis with multiple comparison correction was conducted to compare ADHD/-RD and ADHD/+RD to TDC. Compared to TDC, ADHD/+RD showed multiple bilateral significant clusters of surface compression. In contrast, ADHD/-RD showed fewer significant clusters of surface compression and restricted to the left side. Regarding the putamen, only ADHD/-RD showed significant clusters of surface compression. Results demonstrate for the first time a greater extent of morphological alterations in the caudate of ADHD/+RD than ADHD/-RD compared to TDC, which may suggest greater implicated cortical areas projecting to the caudate that are associated with the greater neuropsychological impairments observed in ADHD/+RD. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Endovascular image-guided treatment of in-vivo model aneurysms with asymmetric vascular stents (AVS): evaluation with time-density curve angiographic analysis and histology.

PubMed

Dohatcu, A; Ionita, C N; Paciorek, A; Bednarek, D R; Hoffmann, K R; Rudin, S

2008-01-01

In this study, we compare the results obtained from Time-Density Curve (TDC) analysis of angiographic imaging sequences with histological evaluation for a rabbit aneurysm model treated with standard stents and new asymmetric vascular stents (AVS) placed by image-guided endovascular deployment. AVSs are stents having a low-porosity patch region designed to cover the aneurysm neck and occlude blood flow inside. To evaluate the AVSs, rabbits with elastase-induced aneurysm models (n=20) were divided into three groups: the first (n=10) was treated with an AVS, the second (n=5) with a non-patch standard coronary stent, and third was untreated as a control (n=5). We used TDC analysis to measure how much contrast media entered the aneurysm before and after treatment. TDCs track contrast-media-density changes as a function of time over the region of interest in x-ray DSA cine-sequences. After 28 days, the animals were sacrificed and the explanted specimens were histologically evaluated. The first group showed an average reduction of contrast flow into the aneurysm of 95% after treatment with an AVS with fully developed thrombus at 28 days follow-up. The rabbits treated with standard stents showed an increase in TDC residency time after treatment and partial-thrombogenesis. The untreated control aneurysms displayed no reduction in flow and were still patent at follow-up. The quantitative TDC analysis findings were confirmed by histological evaluation suggesting that the new AVS has great potential as a definitive treatment for cerebro-vascular aneurysms and that angiographic TDC analysis can provide in-vivo verification.

Endovascular image-guided treatment of in-vivo model aneurysms with asymmetric vascular stents (AVS): evaluation with time-density curve angiographic analysis and histology

PubMed Central

Dohatcu, A.; Ionita, C. N.; Paciorek, A.; Bednarek, D. R.; Hoffmann, K. R.; Rudin, S.

2008-01-01

In this study, we compare the results obtained from Time-Density Curve (TDC) analysis of angiographic imaging sequences with histological evaluation for a rabbit aneurysm model treated with standard stents and new asymmetric vascular stents (AVS) placed by image-guided endovascular deployment. AVSs are stents having a low-porosity patch region designed to cover the aneurysm neck and occlude blood flow inside. To evaluate the AVSs, rabbits with elastase-induced aneurysm models (n=20) were divided into three groups: the first (n=10) was treated with an AVS, the second (n=5) with a non-patch standard coronary stent, and third was untreated as a control (n=5). We used TDC analysis to measure how much contrast media entered the aneurysm before and after treatment. TDCs track contrast-media-density changes as a function of time over the region of interest in x-ray DSA cine-sequences. After 28 days, the animals were sacrificed and the explanted specimens were histologically evaluated. The first group showed an average reduction of contrast flow into the aneurysm of 95% after treatment with an AVS with fully developed thrombus at 28 days follow-up. The rabbits treated with standard stents showed an increase in TDC residency time after treatment and partial-thrombogenesis. The untreated control aneurysms displayed no reduction in flow and were still patent at follow-up. The quantitative TDC analysis findings were confirmed by histological evaluation suggesting that the new AVS has great potential as a definitive treatment for cerebro-vascular aneurysms and that angiographic TDC analysis can provide in-vivo verification. PMID:18958295

Stirling Technology Development at NASA GRC

NASA Technical Reports Server (NTRS)

Thieme, Lanny G.; Schreiber, Jeffrey G.; Mason, Lee S.

2001-01-01

The Department of Energy, Stirling Technology Company (STC), and NASA Glenn Research Center (NASA Glenn) are developing a free-piston Stirling convertor for a high efficiency Stirling Radioisotope Generator (SRG) for NASA Space Science missions. The SRG is being developed for multimission use, including providing electric power for unmanned Mars rovers and deep space missions. NASA Glenn is conducting an in-house technology project to assist in developing the convertor for space qualification and mission implementation. Recent testing of 55-We Technology Demonstration Convertors (TDCs) built by STC includes mapping of a second pair of TDCs, single TDC testing, and TDC electromagnetic interference and electromagnetic compatibility characterization on a nonmagnetic test stand. Launch environment tests of a single TDC without its pressure vessel to better understand the convertor internal structural dynamics and of dual-opposed TDCs with several engineering mounting structures with different natural frequencies have recently been completed. A preliminary life assessment has been completed for the TDC heater head, and creep testing of the IN718 material to be used for the flight convertors is underway. Long-term magnet aging tests are continuing to characterize any potential aging in the strength or demagnetization resistance of the magnets used in the linear alternator (LA). Evaluations are now beginning on key organic materials used in the LA and piston/rod surface coatings. NASA Glenn is also conducting finite element analyses for the LA, in part to look at the demagnetization margin on the permanent magnets. The world's first known integrated test of a dynamic power system with electric propulsion was achieved at NASA Glenn when a Hall-effect thruster was successfully operated with a free-piston Stirling power source. Cleveland State University is developing a multidimensional Stirling computational fluid dynamics code to significantly improve Stirling loss predictions and assist in identifying convertor areas for further improvements. This paper will update the status and results for these efforts.

Evaluation of selective control information detection scheme in orthogonal frequency division multiplexing-based radio-over-fiber and visible light communication links

NASA Astrophysics Data System (ADS)

Dalarmelina, Carlos A.; Adegbite, Saheed A.; Pereira, Esequiel da V.; Nunes, Reginaldo B.; Rocha, Helder R. O.; Segatto, Marcelo E. V.; Silva, Jair A. L.

2017-05-01

Block-level detection is required to decode what may be classified as selective control information (SCI) such as control format indicator in 4G-long-term evolution systems. Using optical orthogonal frequency division multiplexing over radio-over-fiber (RoF) links, we report the experimental evaluation of an SCI detection scheme based on a time-domain correlation (TDC) technique in comparison with the conventional maximum likelihood (ML) approach. When compared with the ML method, it is shown that the TDC method improves detection performance over both 20 and 40 km of standard single mode fiber (SSMF) links. We also report a performance analysis of the TDC scheme in noisy visible light communication channel models after propagation through 40 km of SSMF. Experimental and simulation results confirm that the TDC method is attractive for practical orthogonal frequency division multiplexing-based RoF and fiber-wireless systems. Unlike the ML method, another key benefit of the TDC is that it requires no channel estimation.

Crystal structures of Salmonella typhimurium propionate kinase and its complex with Ap4A: evidence for a novel Ap4A synthetic activity.

PubMed

Simanshu, Dhirendra K; Savithri, H S; Murthy, M R N

2008-03-01

Propionate kinase catalyses the last step in the anaerobic breakdown of L-threonine to propionate in which propionyl phosphate and ADP are converted to propionate and ATP. Here we report the structures of propionate kinase (TdcD) in the native form as well as in complex with diadenosine 5',5'''-P1,P4-tetraphosphate (Ap4A) by X-ray crystallography. Structure of TdcD obtained after cocrystallization with ATP showed Ap4A bound to the active site pocket suggesting the presence of Ap4A synthetic activity in TdcD. Binding of Ap4A to the enzyme was confirmed by the structure determination of a TdcD-Ap4A complex obtained after cocrystallization of TdcD with commercially available Ap4A. Mass spectroscopic studies provided further evidence for the formation of Ap4A by propionate kinase in the presence of ATP. In the TdcD-Ap4A complex structure, Ap4A is present in an extended conformation with one adenosine moiety present in the nucleotide binding site and other in the proposed propionate binding site. These observations tend to support direct in-line transfer of phosphoryl group during the kinase reaction. 2007 Wiley-Liss, Inc.

Time-to-digital converter card for multichannel time-resolved single-photon counting applications

NASA Astrophysics Data System (ADS)

Tamborini, Davide; Portaluppi, Davide; Tisa, Simone; Tosi, Alberto

2015-03-01

We present a high performance Time-to-Digital Converter (TDC) card that provides 10 ps timing resolution and 20 ps (rms) timing precision with a programmable full-scale-range from 160 ns to 10 μs. Differential Non-Linearity (DNL) is better than 1.3% LSB (rms) and Integral Non-Linearity (INL) is 5 ps rms. Thanks to the low power consumption (400 mW) and the compact size (78 mm x 28 mm x 10 mm), this card is the building block for developing compact multichannel time-resolved instrumentation for Time-Correlated Single-Photon Counting (TCSPC). The TDC-card outputs the time measurement results together with the rates of START and STOP signals and the number of valid TDC conversions. These additional information are needed by many TCSPC-based applications, such as: Fluorescence Lifetime Imaging (FLIM), Time-of-Flight (TOF) ranging measurements, time-resolved Positron Emission Tomography (PET), single-molecule spectroscopy, Fluorescence Correlation Spectroscopy (FCS), Diffuse Optical Tomography (DOT), Optical Time-Domain Reflectometry (OTDR), quantum optics, etc.

A 41 ps ASIC time-to-digital converter for physics experiments

NASA Astrophysics Data System (ADS)

Russo, Stefano; Petra, Nicola; De Caro, Davide; Barbarino, Giancarlo; Strollo, Antonio G. M.

2011-12-01

We present a novel Time-to-Digital (TDC) converter for physics experiments. Proposed TDC is based on a synchronous counter and an asynchronous fine interpolator. The fine part of the measurement is obtained using NORA inverters that provide improved resolution. A prototype IC was fabricated in 180 nm CMOS technology. Experimental measurements show that proposed TDC features 41 ps resolution associated with 0.35LSB differential non-linearity, 0.77LSB integral non-linearity and a negligible single shot precision. The whole dynamic range is equal to 18 μs. The proposed TDC is designed using a flash architecture that reduces dead time. Data reported in the paper show that our design is well suited for present and future particle physics experiments.

Is head-shaft angle a valuable continuous risk factor for hip migration in cerebral palsy?

PubMed

Chougule, Sanjay; Dabis, John; Petrie, Aviva; Daly, Karen; Gelfer, Yael

2016-12-01

Reimer's migration percentage (MP) is the most established radiographic risk factor for hip migration in cerebral palsy (CP), and it assists surgical decision-making. The head-shaft angle (HSA) measures the valgus of the head and neck in relation to the shaft and may also be a useful predictor of hip migration at a young age. This study first defined normal values and investigated whether the head-shaft angle (HSA) is a continuous risk factor for hip migration in CP. Three hundred and fifty AP pelvic radiographs of 100 consecutive children comprising the hip surveillance programme in our region were analysed for MP and HSA. Inclusion criteria were children with spastic CP and Gross Motor Function Classification System (GMFCS) levels of III-V, along with a minimum follow-up of 5 years. The mean age was 8.8 (range 3-18) years and the mean follow-up time was 7.5 (range 5-10) years. Radiographs of 103 typically developing children (TDC) were selected for the control group. The reliability of the measurements was determined. A random effects analysis was used to assess the relationship between MP and HSA for all data and for MP > 40 %. The TDC cohort had a mean HSA of 157.7° whilst that for the CP cohort was 161.7°. The value declined with age in both groups but remained consistently higher in the CP group. A random effects analysis considering the longitudinal data showed that there was no significant effect of HSA on MP. Similarly, when excluding CP patients with MP < 40 %, there was no significant effect of HSA on MP. This study found no correlation between HSA and hip migration in children with CP in this age group. Using the HSA as a routine radiographic measure in the management pathway across childhood does not offer any added value. Early enrolment onto the hip surveillance programme could offer a better prediction of hip migration using the HSA at a very young age. II retrospective prognostic study.

Fractal Analyses of High-Resolution Cloud Droplet Measurements.

NASA Astrophysics Data System (ADS)

Malinowski, Szymon P.; Leclerc, Monique Y.; Baumgardner, Darrel G.

1994-02-01

Fractal analyses of individual cloud droplet distributions using aircraft measurements along one-dimensional horizontal cross sections through clouds are performed. Box counting and cluster analyses are used to determine spatial scales of inhomogeneity of cloud droplet spacing. These analyses reveal that droplet spatial distributions do not exhibit a fractal behavior. A high variability in local droplet concentration in cloud volumes undergoing mixing was found. In these regions, thin filaments of cloudy air with droplet concentration close to those observed in cloud cores were found. Results suggest that these filaments may be anisotropic. Additional box counting analyses performed for various classes of cloud droplet diameters indicate that large and small droplets are similarly distributed, except for the larger characteristic spacing of large droplets.A cloud-clear air interface defined by a certain threshold of total droplet count (TDC) was investigated. There are indications that this interface is a convoluted surface of a fractal nature, at least in actively developing cumuliform clouds. In contrast, TDC in the cloud interior does not have fractal or multifractal properties. Finally a random Cantor set (RCS) was introduced as a model of a fractal process with an ill-defined internal scale. A uniform measure associated with the RCS after several generations was introduced to simulate the TDC records. Comparison of the model with real TDC records indicates similar properties of both types of data series.

Tyramine and phenylethylamine production among lactic acid bacteria isolated from wine.

PubMed

Landete, José María; Pardo, Isabel; Ferrer, Sergi

2007-04-20

The ability of wine lactic acid bacteria to produce tyramine and phenylethylamine was investigated by biochemical and genetic methods. An easy and accurate plate medium was developed to detect tyramine-producer strains, and a specific PCR assay that detects the presence of tdc gene was employed. All strains possessing the tdc gene were shown to produce tyramine and phenylethylamine. Wines containing high quantities of tyramine and phenylethylamine were found to contain Lactobacillus brevis or Lactobacillus hilgardii. The main tyramine producer was L. brevis. The ability to produce tyramine was absent or infrequent in the rest of the analysed wine species.

Quantitative thickness prediction of tectonically deformed coal using Extreme Learning Machine and Principal Component Analysis: a case study

NASA Astrophysics Data System (ADS)

Wang, Xin; Li, Yan; Chen, Tongjun; Yan, Qiuyan; Ma, Li

2017-04-01

The thickness of tectonically deformed coal (TDC) has positive correlation associations with gas outbursts. In order to predict the TDC thickness of coal beds, we propose a new quantitative predicting method using an extreme learning machine (ELM) algorithm, a principal component analysis (PCA) algorithm, and seismic attributes. At first, we build an ELM prediction model using the PCA attributes of a synthetic seismic section. The results suggest that the ELM model can produce a reliable and accurate prediction of the TDC thickness for synthetic data, preferring Sigmoid activation function and 20 hidden nodes. Then, we analyze the applicability of the ELM model on the thickness prediction of the TDC with real application data. Through the cross validation of near-well traces, the results suggest that the ELM model can produce a reliable and accurate prediction of the TDC. After that, we use 250 near-well traces from 10 wells to build an ELM predicting model and use the model to forecast the TDC thickness of the No. 15 coal in the study area using the PCA attributes as the inputs. Comparing the predicted results, it is noted that the trained ELM model with two selected PCA attributes yields better predication results than those from the other combinations of the attributes. Finally, the trained ELM model with real seismic data have a different number of hidden nodes (10) than the trained ELM model with synthetic seismic data. In summary, it is feasible to use an ELM model to predict the TDC thickness using the calculated PCA attributes as the inputs. However, the input attributes, the activation function and the number of hidden nodes in the ELM model should be selected and tested carefully based on individual application.

The Relationship among Tyrosine Decarboxylase and Agmatine Deiminase Pathways in Enterococcus faecalis

PubMed Central

Perez, Marta; Ladero, Victor; del Rio, Beatriz; Redruello, Begoña; de Jong, Anne; Kuipers, Oscar; Kok, Jan; Martin, M. Cruz; Fernandez, Maria; Alvarez, Miguel A.

2017-01-01

Enterococci are considered mainly responsible for the undesirable accumulation of the biogenic amines tyramine and putrescine in cheeses. The biosynthesis of tyramine and putrescine has been described as a species trait in Enterococcus faecalis. Tyramine is formed by the decarboxylation of the amino acid tyrosine, by the tyrosine decarboxylase (TDC) route encoded in the tdc cluster. Putrescine is formed from agmatine by the agmatine deiminase (AGDI) pathway encoded in the agdi cluster. These biosynthesis routes have been independently studied, tyrosine and agmatine transcriptionally regulate the tdc and agdi clusters. The objective of the present work is to study the possible co-regulation among TDC and AGDI pathways in E. faecalis. In the presence of agmatine, a positive correlation between putrescine biosynthesis and the tyrosine concentration was found. Transcriptome studies showed that tyrosine induces the transcription of putrescine biosynthesis genes and up-regulates pathways involved in cell growth. The tyrosine modulation over AGDI route was not observed in the mutant Δtdc strain. Fluorescence analyses using gfp as reporter protein revealed PaguB (the promoter of agdi catabolic genes) was induced by tyrosine in the wild-type but not in the mutant strain, confirming that tdc cluster was involved in the tyrosine induction of putrescine biosynthesis. This study also suggests that AguR (the transcriptional regulator of agdi) was implicated in interaction among the two clusters. PMID:29163401

Changes in tissue water and indentation resistance of lymphedematous limbs accompanying low level laser therapy (LLLT) of fibrotic skin.

PubMed

Mayrovitz, H N; Davey, S

2011-12-01

Our goal was to determine effects of low-level-laser-therapy (LLLT) on skin water and tissue indentation resistance (TIR) in patients with arm (N = 38) or leg (N = 38) lymphedema. Skin water was determined from tissue dielectric constant (TDC) measurements and TIR determined from measurements of force resulting from tissue indentations of 3-4 mm. A limb-location with fibrosis was identified by palpation and treated with an LLLT device for one minute at each of five points within a 3 cm2 area. TDC and TIR at these sites and corresponding sites on the contralateral limb were measured prior to LLLT (pre-LLLT), immediately after LLLT (post-LLLT) and after a manual lymphatic drainage (MLD) session (post-MLD). Results, from arms and legs, showed that post-LLLT values of TIR and TDC were significantly less than pre-LLLT. TIR values remained significantly reduced at post-MLD whereas TDC values were not significantly different from pre-LLLT values. On follow-up visit, 17 previously LLLT treated legs were sham treated with an inactive LLLT unit and measurements replicated. A TIR and TDC change-pattern similar to that obtained with the active LLLT was obtained, but sham-related reductions in TIR and TDC immediately post sham-treatment were significantly less than achieved with the prior active LLLT treatment.

Technology Development Center at NICT

NASA Technical Reports Server (NTRS)

Takefuji, Kazuhiro; Ujihara, Hideki

2013-01-01

The National Institute of Information and Communications Technology (NICT) is developing and testing VLBI technologies and conducts observations with this new equipment. This report gives an overview of the Technology Development Center (TDC) at NICT and summarizes recent activities.

24 CFR 968.105 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-04-01

... not exceed 90 percent of the computed Total Development Cost (TDC) for a new development with the same structure type and number and size of units in the market area. Soft costs. The non-physical improvement...

Rates of abnormalities and infectious agents in cervical smears from female inmates in Texas: comparison with private and university clinic patients.

PubMed

Logrono, R; Wong, J Y

1999-09-01

Inmates are generally considered a high-risk population for gynecologic neoplasia and sexually transmitted diseases. Cervical smears from prisoners of the Texas Department of Corrections (TDC) were expected initially to have higher rates of cellular abnormalities and infectious agents than do smears from the general population. The cytologic findings from 25,522 TDC gynecologic smears were compared with those of 6883 cases from The University of Texas Medical Branch (UTMB) affiliated physician private clinics, and with 56,178 from the UTMB hospital clinics. The period of study was from September 1995 to February 1998. This study revealed a 5.23% higher rate of abnormalities for TDC gynecologic smears as compared with that for the private clinic smears. However, the TDC rate of abnormalities was unexpectedly 1.08% lower than that for the UTMB clinic smears. These unexpected findings were probably the result of a more selected high-risk population referred to the UTMB clinics. The TDC smears showed also the highest incidence of trichomoniasis.

Progressive calibration and averaging for tandem mass spectrometry statistical confidence estimation: Why settle for a single decoy?

PubMed Central

Keich, Uri; Noble, William Stafford

2017-01-01

Estimating the false discovery rate (FDR) among a list of tandem mass spectrum identifications is mostly done through target-decoy competition (TDC). Here we offer two new methods that can use an arbitrarily small number of additional randomly drawn decoy databases to improve TDC. Specifically, “Partial Calibration” utilizes a new meta-scoring scheme that allows us to gradually benefit from the increase in the number of identifications calibration yields and “Averaged TDC” (a-TDC) reduces the liberal bias of TDC for small FDR values and its variability throughout. Combining a-TDC with “Progressive Calibration” (PC), which attempts to find the “right” number of decoys required for calibration we see substantial impact in real datasets: when analyzing the Plasmodium falciparum data it typically yields almost the entire 17% increase in discoveries that “full calibration” yields (at FDR level 0.05) using 60 times fewer decoys. Our methods are further validated using a novel realistic simulation scheme and importantly, they apply more generally to the problem of controlling the FDR among discoveries from searching an incomplete database. PMID:29326989

Bone microarchitecture in adolescent boys with autism spectrum disorder.

PubMed

Neumeyer, Ann M; Cano Sokoloff, Natalia; McDonnell, Erin; Macklin, Eric A; McDougle, Christopher J; Misra, Madhusmita

2017-04-01

Boys with autism spectrum disorder (ASD) have lower areal bone mineral density (aBMD) than typically developing controls (TDC). Studies of volumetric BMD (vBMD) and bone microarchitecture provide information about fracture risk beyond that provided by aBMD but are currently lacking in ASD. To assess ultradistal radius and distal tibia vBMD, bone microarchitecture and strength estimates in adolescent boys with ASD compared to TDC. Cross-sectional study of 34 boys (16 ASD, 18 TDC) that assessed (i) aBMD at the whole body (WB), WB less head (WBLH), hip and spine using dual X-ray absorptiometry (DXA), (ii) vBMD and bone microarchitecture at the ultradistal radius and distal tibia using high-resolution peripheral quantitative CT (HRpQCT), and (iii) bone strength estimates (stiffness and failure load) using micro-finite element analysis (FEA). We controlled for age in all groupwise comparisons of HRpQCT and FEA measures. Activity questionnaires, food records, physical exam, and fasting levels of 25(OH) vitamin D and bone markers (C-terminal collagen crosslinks and N-terminal telopeptide (CTX and NTX) for bone resorption, N-terminal propeptide of Type 1 procollagen (P1NP) for bone formation) were obtained. ASD participants were slightly younger than TDC participants (13.6 vs. 14.2years, p=0.44). Tanner stage, height Z-scores and fasting serum bone marker levels did not differ between groups. ASD participants had higher BMI Z-scores, percent body fat, IGF-1 Z-scores, and lower lean mass and aBMD Z-scores than TDC at the WB, WBLH, and femoral neck (P<0.1). At the radius, ASD participants had lower trabecular thickness (0.063 vs. 0.070mm, p=0.004), compressive stiffness (56.7 vs. 69.7kN/mm, p=0.030) and failure load (3.0 vs. 3.7kN, p=0.031) than TDC. ASD participants also had 61% smaller cortical area (6.6 vs. 16.4mm 2 , p=0.051) and thickness (0.08 vs. 0.22mm, p=0.054) compared to TDC. At the tibia, ASD participants had lower compressive stiffness (183 vs. 210kN/mm, p=0.048) and failure load (9.4 vs. 10.8kN, p=0.043) and 23% smaller cortical area (60.3 vs. 81.5mm 2 , p=0.078) compared to TDC. A lower proportion of ASD participants were categorized as "very physically active" (20% vs. 72%, p=0.005). Differences in physical activity, calcium intake and IGF-1 responsiveness may contribute to group differences in stiffness and failure load. Bone microarchitectural parameters are impaired in ASD, with reductions in bone strength estimates (stiffness and failure load) at the ultradistal radius and distal tibia. This may result from lower physical activity and calcium intake, and decreased IGF-1 responsiveness. Copyright © 2017 Elsevier Inc. All rights reserved.

Impact Testing of a Stirling Converter's Linear Alternator

NASA Technical Reports Server (NTRS)

Suarez, Vicente J.; Goodnight, Thomas W.; Hughes, William O.; Samorezov, Sergey

2002-01-01

The U.S. Department of Energy (DOE), in conjunction with the NASA John H. Glenn Research Center and Stirling Technology Company, are currently developing a Stirling convertor for a Stirling Radioisotope Generator (SRG). NASA Headquarters and DOE have identified the SRG for potential use as an advanced spacecraft power system for future NASA deep-space and Mars surface missions. Low-level dynamic impact tests were conducted at NASA Glenn Research Center's Structural Dynamics Laboratory as part of the development of this technology. The purpose of this test was to identify dynamic structural characteristics of the Stirling Technology Demonstration Convertor (TDC). This paper addresses the test setup, procedure, and results of the impact testing conducted on the Stirling TDC in May 2001.

Impact testing of a Stirling convertor's linear alternator

NASA Astrophysics Data System (ADS)

Suárez, Vicente J.; Goodnight, Thomas W.; Hughes, William O.; Samorezov, Sergey

2002-01-01

The U.S. Department of Energy (DOE), in conjunction with NASA John H. Glenn Research Center and Stirling Technology Company, are currently developing a Stirling convertor for a Stirling Radioisotope Generator (SRG). NASA Headquarters and DOE have identified the SRG for potential use as an advanced spacecraft power system for future NASA deep-space and Mars surface missions. Low-level dynamic impact tests were conducted at NASA Glenn Research Center's Structural Dynamics Laboratory as part of the development of this technology. The purpose of this test was to identify dynamic structural characteristics of the Stirling Technology Demonstration Convertor (TDC). This paper addresses the test setup, procedure and results of the impact testing conducted on the Stirling TDC in May 2001. .

A New Approach to Investigate the Association between Brain Functional Connectivity and Disease Characteristics of Attention-Deficit/Hyperactivity Disorder: Topological Neuroimaging Data Analysis.

PubMed

Kyeong, Sunghyon; Park, Seonjeong; Cheon, Keun-Ah; Kim, Jae-Jin; Song, Dong-Ho; Kim, Eunjoo

2015-01-01

Attention-deficit/hyperactivity disorder (ADHD) is currently diagnosed by a diagnostic interview, mainly based on subjective reports from parents or teachers. It is necessary to develop methods that rely on objectively measureable neurobiological data to assess brain-behavior relationship in patients with ADHD. We investigated the application of a topological data analysis tool, Mapper, to analyze the brain functional connectivity data from ADHD patients. To quantify the disease severity using the neuroimaging data, the decomposition of individual functional networks into normal and disease components by the healthy state model (HSM) was performed, and the magnitude of the disease component (MDC) was computed. Topological data analysis using Mapper was performed to distinguish children with ADHD (n = 196) from typically developing controls (TDC) (n = 214). In the topological data analysis, the partial clustering results of patients with ADHD and normal subjects were shown in a chain-like graph. In the correlation analysis, the MDC showed a significant increase with lower intelligence scores in TDC. We also found that the rates of comorbidity in ADHD significantly increased when the deviation of the functional connectivity from HSM was large. In addition, a significant correlation between ADHD symptom severity and MDC was found in part of the dataset. The application of HSM and topological data analysis methods in assessing the brain functional connectivity seem to be promising tools to quantify ADHD symptom severity and to reveal the hidden relationship between clinical phenotypic variables and brain connectivity.

An 18-ps TDC using timing adjustment and bin realignment methods in a Cyclone-IV FPGA

NASA Astrophysics Data System (ADS)

Cao, Guiping; Xia, Haojie; Dong, Ning

2018-05-01

The method commonly used to produce a field-programmable gate array (FPGA)-based time-to-digital converter (TDC) creates a tapped delay line (TDL) for time interpolation to yield high time precision. We conduct timing adjustment and bin realignment to implement a TDC in the Altera Cyclone-IV FPGA. The former tunes the carry look-up table (LUT) cell delay by changing the LUT's function through low-level primitives according to timing analysis results, while the latter realigns bins according to the timing result obtained by timing adjustment so as to create a uniform TDL with bins of equivalent width. The differential nonlinearity and time resolution can be improved by realigning the bins. After calibration, the TDC has a 18 ps root-mean-square timing resolution and a 45 ps least-significant bit resolution.

23Na and 35/37Cl as NMR probes of growth and shape of sodium taurodeoxycholate micellar aggregates in the presence of NaCl.

PubMed

Asaro, Fioretta; Feruglio, Luigi; Galantini, Luciano; Nardelli, Alessia

2013-02-15

The growth of the aggregates of the dihydroxylated bile salt sodium taurodeoxycholate (NaTDC) upon NaCl addition and the involvement of the counterion were investigated by NMR spectroscopy of monoatomic ionic species. (23)Na T(1) values from 0.015, 0.100, and 0.200 mol kg(-1) NaTDC solutions in D(2)O, at variable NaCl content, proved to be sensitive to the transition from primary to secondary aggregates, which occurs in the former sample, and to intermicellar interaction. Some (79)Br NMR measurements were performed on a 0.100 mol kg(-1) NaTDC sample added by NaBr in place of NaCl for comparison purposes. The (23)Na, (35)Cl, and (37)Cl double quantum filtered (DQF) patterns, from the 0.100 mol kg(-1) NaTDC sample, and (23)Na ones also from the 0.200 mol kg(-1) NaTDC one, in the presence of 0.750 mol kg(-1) NaCl, are a clear manifestation of motional anisotropy. Moreover, the DQF spectra of (23)Na and (37)Cl, which possess close quadrupole moments, display a striking similarity. The DQF lineshapes were simulated exploiting the Scilab environment to obtain an estimate of the residual quadrupole splitting magnitude. These results support the description of NaTDC micelles as cylindrical aggregates, strongly interacting at high ionic strengths, and capable of association with added electrolytes. Copyright © 2012 Elsevier Inc. All rights reserved.

A 3.9 ps Time-Interval RMS Precision Time-to-Digital Converter Using a Dual-Sampling Method in an UltraScale FPGA

NASA Astrophysics Data System (ADS)

Wang, Yonggang; Liu, Chong

2016-10-01

Field programmable gate arrays (FPGAs) manufactured with more advanced processing technology have faster carry chains and smaller delay elements, which are favorable for the design of tapped delay line (TDL)-style time-to-digital converters (TDCs) in FPGA. However, new challenges are posed in using them to implement TDCs with a high time precision. In this paper, we propose a bin realignment method and a dual-sampling method for TDC implementation in a Xilinx UltraScale FPGA. The former realigns the disordered time delay taps so that the TDC precision can approach the limit of its delay granularity, while the latter doubles the number of taps in the delay line so that the TDC precision beyond the cell delay limitation can be expected. Two TDC channels were implemented in a Kintex UltraScale FPGA, and the effectiveness of the new methods was evaluated. For fixed time intervals in the range from 0 to 440 ns, the average RMS precision measured by the two TDC channels reaches 5.8 ps using the bin realignment, and it further improves to 3.9 ps by using the dual-sampling method. The time precision has a 5.6% variation in the measured temperature range. Every part of the TDC, including dual-sampling, encoding, and on-line calibration, could run at a 500 MHz clock frequency. The system measurement dead time is only 4 ns.

Time of flight system on a chip

NASA Technical Reports Server (NTRS)

Paschalidis, Nicholas P. (Inventor)

2006-01-01

A CMOS time-of-flight TOF system-on-a-chip SoC for precise time interval measurement with low power consumption and high counting rate has been developed. The analog and digital TOF chip may include two Constant Fraction Discriminators CFDs and a Time-to-Digital Converter TDC. The CFDs can interface to start and stop anodes through two preamplifiers and perform signal processing for time walk compensation (110). The TDC digitizes the time difference with reference to an off-chip precise external clock (114). One TOF output is an 11-bit digital word and a valid event trigger output indicating a valid event on the 11-bit output bus (116).

High resolution distributed time-to-digital converter (TDC) in a White Rabbit network

NASA Astrophysics Data System (ADS)

Pan, Weibin; Gong, Guanghua; Du, Qiang; Li, Hongming; Li, Jianmin

2014-02-01

The Large High Altitude Air Shower Observatory (LHAASO) project consists of a complex detector array with over 6000 detector nodes spreading over 1.2 km2 areas. The arrival times of shower particles are captured by time-to-digital converters (TDCs) in the detectors' frontend electronics, the arrival direction of the high energy cosmic ray are then to be reconstructed from the space-time information of all detector nodes. To guarantee the angular resolution of 0.5°, a time synchronization of 500 ps (RMS) accuracy and 100 ps precision must be achieved among all TDC nodes. A technology enhancing Gigabit Ethernet, called the White Rabbit (WR), has shown the capability of delivering sub-nanosecond accuracy and picoseconds precision of synchronization over the standard data packet transfer. In this paper we demonstrate a distributed TDC prototype system combining the FPGA based TDC and the WR technology. With the time synchronization and data transfer services from a compact WR node, separate FPGA-TDC nodes can be combined to provide uniform time measurement information for correlated events. The design detail and test performance will be described in the paper.

Hippocampal Functioning and Verbal Associative Memory in Adolescents with Congenital Hypothyroidism

PubMed Central

Wheeler, Sarah M.; McLelland, Victoria C.; Sheard, Erin; McAndrews, Mary Pat; Rovet, Joanne F.

2015-01-01

Thyroid hormone (TH) is essential for normal development of the hippocampus, which is critical for memory and particularly for learning and recalling associations between visual and verbal stimuli. Adolescents with congenital hypothyroidism (CH), who lack TH in late gestation and early life, demonstrate weak verbal recall abilities, reduced hippocampal volumes, and abnormal hippocampal functioning for visually associated material. However, it is not known if their hippocampus functions abnormally when remembering verbal associations. Our objective was to assess hippocampal functioning in CH using functional magnetic resonance imaging (fMRI). Fourteen adolescents with CH and 14 typically developing controls (TDC) were studied. Participants studied pairs of words and then, during fMRI acquisition, made two types of recognition decisions: in one they judged whether the pairs were the same as when seen originally and in the other, whether individual words were seen before regardless of pairing. Hippocampal activation was greater for pairs than items in both groups, but this difference was only significant in TDC. When we directly compared the groups, the right anterior hippocampus was the primary region in which the TDC and CH groups differed for this pair memory effect. Results signify that adolescents with CH show abnormal hippocampal functioning during verbal memory processing. PMID:26539162

Tunnelled haemodialysis catheter and haemodialysis outcomes: a retrospective cohort study in Zagreb, Croatia.

PubMed

Pašara, Vedran; Maksimović, Bojana; Gunjača, Mihaela; Mihovilović, Karlo; Lončar, Andrea; Kudumija, Boris; Žabić, Igor; Knotek, Mladen

2016-05-17

Studies have reported that the tunnelled dialysis catheter (TDC) is associated with inferior haemodialysis (HD) patient survival, in comparison with arteriovenous fistula (AVF). Since many cofactors may also affect survival of HD patients, it is unclear whether the greater risk for survival arises from TDC per se, or from associated conditions. Therefore, the aim of this study was to determine, in a multivariate analysis, the long-term outcome of HD patients, with respect to vascular access (VA). Retrospective cohort study. This retrospective cohort study included all 156 patients with a TDC admitted at University Hospital Merkur, from 2010 to 2012. The control group consisted of 97 patients dialysed via AVF. The groups were matched according to dialysis unit and time of VA placement. The site of choice for the placement of the TDC was the right jugular vein. Kaplan-Meier analysis with log-rank test was used to assess patient survival. Multivariate Cox regression analysis was used to determine independent variables associated with patient survival. Patient survival with respect to VA. The cumulative 1-year survival of patients who were dialysed exclusively via TDC was 86.4% and of those who were dialysed exclusively via AVF, survival was 97.1% (p=0.002). In multivariate Cox regression analysis, male sex and older age were independently negatively associated with the survival of HD patients, while shorter HD vintage before the creation of the observed VA, hypertensive renal disease and glomerulonephritis were positively associated with survival. TDC was an independent risk factor for survival of HD patients (HR 23.0, 95% CI 6.2 to 85.3). TDC may be an independent negative risk factor for HD patient survival. 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/

Crustal structure of Tolfa domes complex (northern Latium - Italy) inferred from receiver functions analysis: an interplay between tectonics and magmatism

NASA Astrophysics Data System (ADS)

Buttinelli, M.; Bianchi, I.; Anselmi, M.; Chiarabba, C.; de Rita, D.; Quattrocchi, F.

2010-12-01

The Tolfa-Cerite volcanic district developed along the Tyrrhenian passive margin of central Italy, as part of magmatic processes started during the middle Pliocene. In this area the uncertainties on the deep crustal structures and the definition of the intrusive bodies geometry are focal issues that still need to be addressed. After the onset of the spreading of the Tyrrhenian sea during the Late Miocene, the emplacement of the intrusive bodies of the Tolfa complex (TDC), in a general back-arc geodynamical regime, generally occurred in a low stretching rate, in correspondence of the junctions between major lithospheric discontinuities. Normal faults, located at the edge of Mio-Pliocene basins, were used as preferential pathways for the rising of magmatic masses from the mantle to the surface. We used teleseismic recordings at the TOLF and MAON broad band station of the INGV seismic network (located between the Argentario promontory and Tolfa-Ceriti dome complexes -TDC-) to image the principal seismic velocity discontinuities by receiver function analysis (RF's). Together with RF’s velocity models of the area computed using the teleseismic events recorded by a temporary network of eight stations deployed around the TDC, we achieve a general crustal model of this area. The geometry of the seismic network has been defined to focus on the crustal structure beneath the TDC, trying to define the main velocity changes attributable to the intrusive bodies, the calcareous basal complex, the deep metamorphic basement, the lower crust and the Moho. The analysis of these data show the Moho at a depth of 23 km in the TDC area and 20 km in the Argentario area. Crustal models also show an unexpected velocity decrease between 12 and 18 km, consistent with a slight dropdown of the Vp/Vs ratio, imputable to a regional mid-crustal shear zone inherited from the previous alpine orogenesis, re-activated in extensional tectonic by the early opening phases of the Tyrrhenian sea. Above this low Vs layer, we find some interesting features corresponding to: - a low Vs shallow and 2 km thick layer of Liguride and Plio-Pleistocene units (z = 0-2 km of depth) - a high Vs 4-5 km thick anisotropic layer of limestones (z = 2-7 km of depth) - a very high Vs (3.8 km/s) 4 km thick layer probably corresponding to the metamorphic basement. The analysis of the geometry of the velocity changes between these layers (from the surface to the bottom of metamorphic basement), also yield evidence of crustal block tilting, due to the development of the eastern continental passive margin of the Tyrrhenian sea. The general crustal setting observed between the TDC and the Argentario areas is also consistent with the simple shear models suggested for back-arc basins opening. Comparison of RF’s TDC models with MAON station data also led to important considerations confirming the initial evolutive phase of the Tyrrhenian sea opening, in association with the first occurrences of intrusive magmatism in these areas.

A high-resolution time-to-digital converter using a three-level resolution

NASA Astrophysics Data System (ADS)

Dehghani, Asma; Saneei, Mohsen; Mahani, Ali

2016-08-01

In this article, a three-level resolution Vernier delay line time-to-digital converter (TDC) was proposed. The proposed TDC core was based on the pseudo-differential digital architecture that made it insensitive to nMOS and pMOS transistor mismatches. It also employed a Vernier delay line (VDL) in conjunction with an asynchronous read-out circuitry. The time interval resolution was equal to the difference of delay between buffers of upper and lower chains. Then, via the extra chain included in the lower delay line, resolution was controlled and power consumption was reduced. This method led to high resolution and low power consumption. The measurement results of TDC showed a resolution of 4.5 ps, 12-bit output dynamic range, and integral nonlinearity of 1.5 least significant bits. This TDC achieved the consumption of 68.43 µW from 1.1-V supply.

SURVEY OF DENTAL STUDENTS' ATTITUDE REGARDING ORIENTAL MEDICINE/COMPLEMENTARY AND ALTERNATIVE MEDICINE: COMPARISON BETWEEN TWO JAPANESE DENTAL SCHOOLS.

PubMed

Kameyama, Atsushi; Toda, Kazuo

2017-01-01

The present study aimed to examine the impact of "curricula for undergraduate education in oriental medicine (OM)/complementary and alternative medicine (CAM)" on student awareness of OM. A questionnaire survey was conducted involving the Nagasaki University School of Dentistry (NUSD), a university that implements education in OM as part of its undergraduate curriculum, and Tokyo Dental College (TDC), which does not teach OM. The third- and fifth-year students of both NUSD and TDC underwent the anonymous questionnaire survey, which included questions regarding their knowledge of OM and CAM, interests in these subjects, and their opinions on the necessity of teaching OM in the undergraduate dental education, and the results were collected for analysis. Whereas 33% of 5 th year NUSD students had knowledge of OM/CAM was 33%, only 10% of 5 th year TDC students reported knowledge on the subject. 69% of 5 th year NUSD students interested in OM/CAM, while 5 th year TDC students who interest them were only 45%. Although 77% of 5 th year NUSD students were in favor of OM education implemented in the Faculty of Dentistry, the percentages of TDC students of that were smaller (46% in 3 rd year and 48% in 5 th year). Whereas 26% of 5 th year TDC students did not recognize the necessity of oriental medicine education, only one 5 th year NUSD student (2%) did not so. Introduction of education in OM in the undergraduate dental education program helps students to increase their interests in dental clinical applications.

Closure of patent foramen ovale for cryptogenic stroke patients: an updated systematic review and meta-analysis of randomized trials.

PubMed

Niu, Xuan; Ou-Yang, Guang; Yan, Peng-Fei; Huang, Shu-Lan; Zhang, Zhen-Tao; Zhang, Zhao-Hui

2018-06-01

This systematic review and meta-analysis was performed to investigate the efficacy and safety of transcatheter device closure (TDC) plus anti-thrombotic drugs over medical management alone for patients with cryptogenic stroke and patent foramen oval. PubMed, Embase and Cochrane Library database were searched for randomized controlled clinical trials (RCTs). The primary endpoint is the composite of stroke and transient ischemic attack. The secondary endpoints are all-cause mortality, total serious adverse events, atrial fibrillation and bleeding. Five RCTs with a total of 3440 participants were included. TDC significantly decreased the risk of primary endpoint when compared to medical therapy alone (RR 0.54, 95% CI 0.43-0.69). Further subgroup analyses showed that patients with male gender and with substantial shunt size of foramen ovale significantly benefited from TDC as compared to those with female gender and with no substantial shunt size of foramen oval separately. Moreover, TDC was superior to medical therapy with anti-platelet drug alone (not with anti-coagulation). On the other hand, the incidence of atrial fibrillation was higher in TDC group (RR 4.49, 95% CI 2.02-9.97), with the risk of other adverse events equivalent between the two groups. TDC plus anti-thrombotic drugs is superior than medical therapy alone for secondary prevention of stroke, especially for those with male gender and with substantial shunt size of foramen ovale. Though it may increase the risk of postoperative atrial fibrillation, it would not bring higher risk of all-cause mortality, total adverse events and bleeding.

A 4.2 ps Time-Interval RMS Resolution Time-to-Digital Converter Using a Bin Decimation Method in an UltraScale FPGA

NASA Astrophysics Data System (ADS)

Wang, Yonggang; Liu, Chong

2016-10-01

The common solution for a field programmable gate array (FPGA)-based time-to-digital converter (TDC) is constructing a tapped delay line (TDL) for time interpolation to yield a sub-clock time resolution. The granularity and uniformity of the delay elements of TDL determine the TDC time resolution. In this paper, we propose a dual-sampling TDL architecture and a bin decimation method that could make the delay elements as small and uniform as possible, so that the implemented TDCs can achieve a high time resolution beyond the intrinsic cell delay. Two identical full hardware-based TDCs were implemented in a Xilinx UltraScale FPGA for performance evaluation. For fixed time intervals in the range from 0 to 440 ns, the average time-interval RMS resolution is measured by the two TDCs with 4.2 ps, thus the timestamp resolution of single TDC is derived as 2.97 ps. The maximum hit rate of the TDC is as high as half the system clock rate of FPGA, namely 250 MHz in our demo prototype. Because the conventional online bin-by-bin calibration is not needed, the implementation of the proposed TDC is straightforward and relatively resource-saving.

Stirling convertor performance mapping test results

NASA Astrophysics Data System (ADS)

Qiu, Songgang; Peterson, Allen A.; White, Maurice A.; Faultersack, Franklyn; Redinger, Darin L.; Petersen, Stephen L.

2002-01-01

The Department of Energy (DOE) has selected Free-Piston Stirling Convertors as a technology for future advanced radioisotope space power systems. In August 2000, DOE awarded competitive Phase I, Stirling Radioisotope Generator (SRG) power system integration contracts to three major aerospace contractors, resulting in SRG conceptual designs in February 2001. All three contractors based their designs on the Technology Demonstration Convertor (TDC) developed by Stirling Technology Company (STC) for DOE. The contract award to a single system integration contractor for Phases II and III of the SRG program is anticipated in late 2001. The first potential SRG mission is targeted for a Mars rover. Recent TDC performance data are provided in this paper, together with predictions from Stirling simulation models. .

Assessing progress and outcome of early intensive behavioral intervention for toddlers with autism.

PubMed

MacDonald, Rebecca; Parry-Cruwys, Diana; Dupere, Sally; Ahearn, William

2014-12-01

Intensive behavioral intervention for young children diagnosed with autism can produce large gains in social, cognitive, and language development. Although several studies have identified behaviors that are possible indicators of best outcome, changes in performance are typically measured using norm-referenced standardized scores referencing overall functioning level rather than via repeated observational measures of autism-specific deficits (i.e., social behavior). In the current study, 83 children with autism (CWA), aged 1, 2 and 3 years, and 58 same-aged typically developing children (TDC) were directly observed in the areas of cognitive skills, joint attention (JA), play, and stereotypic behavior using a measure called the Early Skills Assessment Tool (ESAT; MacDonald et al., 2006). CWA were assessed at entry into an EIBI program and again after 1 year of treatment. Changes in performance were compared pre- and post-treatment as well as to the normative data by age. Results indicate significant gains on the ESAT across all age groups with the greatest gains seen in the children who entered treatment prior to their second birthday. Increases were seen on direct measures of JA, play, imitation and language while decreases were seen in stereotypy regardless of level of performance at entry into EIBI. The ESAT, a direct measurement tool, served as a sensitive tool to measure changes in autism symptomatology following EIBI treatment. Copyright © 2014 Elsevier Ltd. All rights reserved.

High-performance electronics for time-of-flight PET systems

NASA Astrophysics Data System (ADS)

Choong, W.-S.; Peng, Q.; Vu, C. Q.; Turko, B. T.; Moses, W. W.

2013-01-01

We have designed and built a high-performance readout electronics system for time-of-flight positron emission tomography (TOF PET) cameras. The electronics architecture is based on the electronics for a commercial whole-body PET camera (Siemens/CPS Cardinal electronics), modified to improve the timing performance. The fundamental contributions in the electronics that can limit the timing resolution include the constant fraction discriminator (CFD), which converts the analog electrical signal from the photo-detector to a digital signal whose leading edge is time-correlated with the input signal, and the time-to-digital converter (TDC), which provides a time stamp for the CFD output. Coincident events are identified by digitally comparing the values of the time stamps. In the Cardinal electronics, the front-end processing electronics are performed by an Analog subsection board, which has two application-specific integrated circuits (ASICs), each servicing a PET block detector module. The ASIC has a built-in CFD and TDC. We found that a significant degradation in the timing resolution comes from the ASIC's CFD and TDC. Therefore, we have designed and built an improved Analog subsection board that replaces the ASIC's CFD and TDC with a high-performance CFD (made with discrete components) and TDC (using the CERN high-performance TDC ASIC). The improved Analog subsection board is used in a custom single-ring LSO-based TOF PET camera. The electronics system achieves a timing resolution of 60 ps FWHM. Prototype TOF detector modules are read out with the electronics system and give coincidence timing resolutions of 259 ps FWHM and 156 ps FWHM for detector modules coupled to LSO and LaBr3 crystals respectively.

Cruise ship environmental hygiene and the risk of norovirus infection outbreaks: an objective assessment of 56 vessels over 3 years.

PubMed

Carling, Philip C; Bruno-Murtha, Lou Ann; Griffiths, Jeffrey K

2009-11-01

Norovirus infection outbreaks (NoVOs) occur frequently in closed populations, such as cruise ship passengers. Environmental contamination is believed to play an important role in NoVO propagation. Trained health care professionals covertly evaluated the thoroughness of disinfection cleaning (TDC) of 6 standardized objects (toilet seat, flush handle or button, toilet stall inner handhold, stall inner door handle, restroom inner door handle, and baby changing table surfaces) with high potential for fecal contamination in cruise ship public restrooms, by means of a previously validated novel targeting method. Fifty-six cruise ships (approximately 30% of 180 vessels operated by 9 large cruise lines) were evaluated from July 2005 through August 2008. Overall, 37% (range, 4%-100%; 95% confidence interval, 29.2%-45.4%) of 8344 objects in 273 randomly selected public restrooms were cleaned daily. The TDC did not differ by cruise line and did not correlate with the Centers for Disease Control and Prevention (CDC) Vessel Sanitation Program inspection scores (r(2), .002; P = .75). More than half the vessels had overall TDC scores <30%, although several of these low-scoring ships had near-perfect CDC sanitation scores. The mean TDC of the 3 ships evaluated within 4 months before a NoVO (10.3%) was substantially less than the mean TDC of the 40 ships that did not experience NoVOs (40.4%) (P < .004). An objective evaluation of public restroom environmental hygiene on 56 cruise ships found that only 37% of selected toilet area objects were cleaned on a daily basis. Low TDC scores may predict subsequent NoVO-prone vessels. Enhanced public restroom cleaning may prevent or moderate NoVOs on cruise ships.

Senescence-Induced Serotonin Biosynthesis and Its Role in Delaying Senescence in Rice Leaves1[C][W][OA

PubMed Central

Kang, Kiyoon; Kim, Young-Soon; Park, Sangkyu; Back, Kyoungwhan

2009-01-01

Serotonin, which is well known as a pineal hormone in mammals, plays a key role in conditions such as mood, eating disorders, and alcoholism. In plants, although serotonin has been suggested to be involved in several physiological roles, including flowering, morphogenesis, and adaptation to environmental changes, its regulation and functional roles are as yet not characterized at the molecular level. In this study, we found that serotonin is greatly accumulated in rice (Oryza sativa) leaves undergoing senescence induced by either nutrient deprivation or detachment, and its synthesis is closely coupled with transcriptional and enzymatic induction of the tryptophan biosynthetic genes as well as tryptophan decarboxylase (TDC). Transgenic rice plants that overexpressed TDC accumulated higher levels of serotonin than the wild type and showed delayed senescence of rice leaves. However, transgenic rice plants, in which expression of TDC was suppressed through an RNA interference (RNAi) system, produced less serotonin and senesced faster than the wild type, suggesting that serotonin is involved in attenuating leaf senescence. The senescence-retarding activity of serotonin is associated with its high antioxidant activity compared to either tryptophan or chlorogenic acid. Results of TDC overexpression and TDC RNAi plants suggest that TDC plays a rate-limiting role for serotonin accumulation, but the synthesis of serotonin depends on an absolute amount of tryptophan accumulation by the coordinate induction of the tryptophan biosynthetic genes. In addition, immunolocalization analysis revealed that serotonin was abundant in the vascular parenchyma cells, including companion cells and xylem-parenchyma cells, suggestive of its involvement in maintaining the cellular integrity of these cells for facilitating efficient nutrient recycling from senescing leaves to sink tissues during senescence. PMID:19439571

High-performance electronics for time-of-flight PET systems.

PubMed

Choong, W-S; Peng, Q; Vu, C Q; Turko, B T; Moses, W W

2013-01-01

We have designed and built a high-performance readout electronics system for time-of-flight positron emission tomography (TOF PET) cameras. The electronics architecture is based on the electronics for a commercial whole-body PET camera (Siemens/CPS Cardinal electronics), modified to improve the timing performance. The fundamental contributions in the electronics that can limit the timing resolution include the constant fraction discriminator (CFD), which converts the analog electrical signal from the photo-detector to a digital signal whose leading edge is time-correlated with the input signal, and the time-to-digital converter (TDC), which provides a time stamp for the CFD output. Coincident events are identified by digitally comparing the values of the time stamps. In the Cardinal electronics, the front-end processing electronics are performed by an Analog subsection board, which has two application-specific integrated circuits (ASICs), each servicing a PET block detector module. The ASIC has a built-in CFD and TDC. We found that a significant degradation in the timing resolution comes from the ASIC's CFD and TDC. Therefore, we have designed and built an improved Analog subsection board that replaces the ASIC's CFD and TDC with a high-performance CFD (made with discrete components) and TDC (using the CERN high-performance TDC ASIC). The improved Analog subsection board is used in a custom single-ring LSO-based TOF PET camera. The electronics system achieves a timing resolution of 60 ps FWHM. Prototype TOF detector modules are read out with the electronics system and give coincidence timing resolutions of 259 ps FWHM and 156 ps FWHM for detector modules coupled to LSO and LaBr 3 crystals respectively.

Corrosion and Fatigue Behavior of High-Strength Steel Treated with a Zn-Alloy Thermo-diffusion Coating

NASA Astrophysics Data System (ADS)

Mulligan, C. P.; Vigilante, G. N.; Cannon, J. J.

2017-11-01

High and low cycle fatigue tests were conducted on high-strength steel using four-point bending. The materials tested were ASTM A723 steel in the as-machined condition, grit-blasted condition, MIL-DTL-16232 heavy manganese phosphate-coated condition, and ASTM A1059 Zn-alloy thermo-diffusion coated (Zn-TDC). The ASTM A723 steel base material exhibits a yield strength of 1000 MPa. The effects of the surface treatments versus uncoated steel were examined. The fatigue life of the Zn-TDC specimens was generally reduced on as-coated specimens versus uncoated or phosphate-coated specimens. Several mechanisms are examined including the role of compressive residual stress relief with the Zn-TDC process as well as fatigue crack initiation from the hardened Zn-Fe alloy surface layer produced in the gas-metal reaction. Additionally, the effects of corrosion pitting on the fatigue life of coated specimens are explored as the Zn-TDC specimens exhibit significantly improved corrosion resistance over phosphate-coated and oiled specimens.

Development of a Stiffness-Based Chemistry Load Balancing Scheme, and Optimization of Input/Output and Communication, to Enable Massively Parallel High-Fidelity Internal Combustion Engine Simulations

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

Kodavasal, Janardhan; Harms, Kevin; Srivastava, Priyesh

A closed-cycle gasoline compression ignition engine simulation near top dead center (TDC) was used to profile the performance of a parallel commercial engine computational fluid dynamics code, as it was scaled on up to 4096 cores of an IBM Blue Gene/Q supercomputer. The test case has 9 million cells near TDC, with a fixed mesh size of 0.15 mm, and was run on configurations ranging from 128 to 4096 cores. Profiling was done for a small duration of 0.11 crank angle degrees near TDC during ignition. Optimization of input/output performance resulted in a significant speedup in reading restart files, andmore » in an over 100-times speedup in writing restart files and files for post-processing. Improvements to communication resulted in a 1400-times speedup in the mesh load balancing operation during initialization, on 4096 cores. An improved, “stiffness-based” algorithm for load balancing chemical kinetics calculations was developed, which results in an over 3-times faster run-time near ignition on 4096 cores relative to the original load balancing scheme. With this improvement to load balancing, the code achieves over 78% scaling efficiency on 2048 cores, and over 65% scaling efficiency on 4096 cores, relative to 256 cores.« less

Implementation of high-resolution time-to-digital converter in 8-bit microcontrollers.

PubMed

Bengtsson, Lars E

2012-04-01

This paper will demonstrate how a time-to-digital converter (TDC) with sub-nanosecond resolution can be implemented into an 8-bit microcontroller using so called "direct" methods. This means that a TDC is created using only five bidirectional digital input-output-pins of a microcontroller and a few passive components (two resistors, a capacitor, and a diode). We will demonstrate how a TDC for the range 1-10 μs is implemented with 0.17 ns resolution. This work will also show how to linearize the output by combining look-up tables and interpolation. © 2012 American Institute of Physics

The perception and identification of facial emotions in individuals with autism spectrum disorders using the Let's Face It! Emotion Skills Battery.

PubMed

Tanaka, James W; Wolf, Julie M; Klaiman, Cheryl; Koenig, Kathleen; Cockburn, Jeffrey; Herlihy, Lauren; Brown, Carla; Stahl, Sherin S; South, Mikle; McPartland, James C; Kaiser, Martha D; Schultz, Robert T

2012-12-01

Although impaired social-emotional ability is a hallmark of autism spectrum disorder (ASD), the perceptual skills and mediating strategies contributing to the social deficits of autism are not well understood. A perceptual skill that is fundamental to effective social communication is the ability to accurately perceive and interpret facial emotions. To evaluate the expression processing of participants with ASD, we designed the Let's Face It! Emotion Skills Battery (LFI! Battery), a computer-based assessment composed of three subscales measuring verbal and perceptual skills implicated in the recognition of facial emotions. We administered the LFI! Battery to groups of participants with ASD and typically developing control (TDC) participants that were matched for age and IQ. On the Name Game labeling task, participants with ASD (N = 68) performed on par with TDC individuals (N = 66) in their ability to name the facial emotions of happy, sad, disgust and surprise and were only impaired in their ability to identify the angry expression. On the Matchmaker Expression task that measures the recognition of facial emotions across different facial identities, the ASD participants (N = 66) performed reliably worse than TDC participants (N = 67) on the emotions of happy, sad, disgust, frighten and angry. In the Parts-Wholes test of perceptual strategies of expression, the TDC participants (N = 67) displayed more holistic encoding for the eyes than the mouths in expressive faces whereas ASD participants (N = 66) exhibited the reverse pattern of holistic recognition for the mouth and analytic recognition of the eyes. In summary, findings from the LFI! Battery show that participants with ASD were able to label the basic facial emotions (with the exception of angry expression) on par with age- and IQ-matched TDC participants. However, participants with ASD were impaired in their ability to generalize facial emotions across different identities and showed a tendency to recognize the mouth feature holistically and the eyes as isolated parts. © 2012 The Authors. Journal of Child Psychology and Psychiatry © 2012 Association for Child and Adolescent Mental Health.

24 CFR 941.306 - Maximum project cost.

Code of Federal Regulations, 2011 CFR

2011-04-01

...) project costs that are subject to the TDC limit (i.e., Housing Construction Costs and Community Renewal... project, the actual project cost is determined based upon the amount of public housing capital assistance... Community Renewal Costs in excess of the TDC limit, as determined under paragraph (b)(2) of this section...

24 CFR 941.306 - Maximum project cost.

Code of Federal Regulations, 2010 CFR

2010-04-01

...) project costs that are subject to the TDC limit (i.e., Housing Construction Costs and Community Renewal... project, the actual project cost is determined based upon the amount of public housing capital assistance... Community Renewal Costs in excess of the TDC limit, as determined under paragraph (b)(2) of this section...

Technology Assessment of Doe's 55-we Stirling Technology Demonstrator Convector (TDC)

NASA Technical Reports Server (NTRS)

Furlong, Richard; Shaltens, Richard

2000-01-01

The Department of Energy (DOE), Germantown, Maryland and the NASA Glenn Research Center (GRC), Cleveland, Ohio are developing a Stirling Convertor for an advanced radioisotope power system as a potential power source for spacecraft on-board electric power for NASA deep space science missions. The Stirling Convertor is being evaluated as an alternative high efficiency power source to replace Radioisotope Thermoelectric Generators (RTGs). Stirling Technology Company (STC), Kennewick, Washington, is developing the highly efficient, long life 55-We free-piston Stirling Convertor known as the Technology Demonstrator Convertor (TDC) under contract to DOE. GRC provides Stirling technology expertise under a Space Act Agreement with the DOE. Lockheed Martin Astronautics (LMA), Valley Forge, Pennsylvania is the current power system integrator for the Advanced Radioisotope Power System (ARPS) Project for the DOE. JPL is responsible for the Outer Planets/Solar Probe Project for NASA.

Whole brain white matter connectivity analysis using machine learning: An application to autism.

PubMed

Zhang, Fan; Savadjiev, Peter; Cai, Weidong; Song, Yang; Rathi, Yogesh; Tunç, Birkan; Parker, Drew; Kapur, Tina; Schultz, Robert T; Makris, Nikos; Verma, Ragini; O'Donnell, Lauren J

2018-05-15

In this paper, we propose an automated white matter connectivity analysis method for machine learning classification and characterization of white matter abnormality via identification of discriminative fiber tracts. The proposed method uses diffusion MRI tractography and a data-driven approach to find fiber clusters corresponding to subdivisions of the white matter anatomy. Features extracted from each fiber cluster describe its diffusion properties and are used for machine learning. The method is demonstrated by application to a pediatric neuroimaging dataset from 149 individuals, including 70 children with autism spectrum disorder (ASD) and 79 typically developing controls (TDC). A classification accuracy of 78.33% is achieved in this cross-validation study. We investigate the discriminative diffusion features based on a two-tensor fiber tracking model. We observe that the mean fractional anisotropy from the second tensor (associated with crossing fibers) is most affected in ASD. We also find that local along-tract (central cores and endpoint regions) differences between ASD and TDC are helpful in differentiating the two groups. These altered diffusion properties in ASD are associated with multiple robustly discriminative fiber clusters, which belong to several major white matter tracts including the corpus callosum, arcuate fasciculus, uncinate fasciculus and aslant tract; and the white matter structures related to the cerebellum, brain stem, and ventral diencephalon. These discriminative fiber clusters, a small part of the whole brain tractography, represent the white matter connections that could be most affected in ASD. Our results indicate the potential of a machine learning pipeline based on white matter fiber clustering. Copyright © 2017 Elsevier Inc. All rights reserved.

A SPAD-based 3D imager with in-pixel TDC for 145ps-accuracy ToF measurement

NASA Astrophysics Data System (ADS)

Vornicu, I.; Carmona-Galán, R.; Rodríguez-Vázquez, Á.

2015-03-01

The design and measurements of a CMOS 64 × 64 Single-Photon Avalanche-Diode (SPAD) array with in-pixel Time-to-Digital Converter (TDC) are presented. This paper thoroughly describes the imager at architectural and circuit level with particular emphasis on the characterization of the SPAD-detector ensemble. It is aimed to 2D imaging and 3D image reconstruction in low light environments. It has been fabricated in a standard 0.18μm CMOS process, i. e. without high voltage or low noise features. In these circumstances, we are facing a high number of dark counts and low photon detection efficiency. Several techniques have been applied to ensure proper functionality, namely: i) time-gated SPAD front-end with fast active-quenching/recharge circuit featuring tunable dead-time, ii) reverse start-stop scheme, iii) programmable time resolution of the TDC based on a novel pseudo-differential voltage controlled ring oscillator with fast start-up, iv) a global calibration scheme against temperature and process variation. Measurements results of individual SPAD-TDC ensemble jitter, array uniformity and time resolution programmability are also provided.

Neural responses to affective and cognitive theory of mind in children and adolescents with autism spectrum disorder.

PubMed

Kim, Eunjoo; Kyeong, Sunghyon; Cheon, Keun-Ah; Park, Bumhee; Oh, Maeng-Keun; Chun, Ji Won; Park, Hae-Jeong; Kim, Jae-Jin; Song, Dong-Ho

2016-05-16

Children and adolescents with Autism Spectrum Disorder (ASD) are characterized by an impaired Theory of Mind (ToM). Recent evidence suggested that two aspects of ToM (cognitive ToM versus affective ToM) are differentially impaired in individuals with ASD. In this study, we examined the neural correlates of cognitive and affective ToM in children and adolescents with ASD compared to typically developing children (TDCs). Twelve children and adolescents with ASD and 12 age, IQ matched TDCs participated in this functional MRI study. The ToM task involved the attribution of cognitive and affective mental states to a cartoon character based on verbal and eye-gaze cues. In cognitive ToM tasks, ASD participants recruited the medial prefrontal cortex (mPFC), anterior cingulate cortex (ACC), and superior temporal gyrus (STG) to a greater extent than did TDCs. In affective ToM tasks, both ASD and TDC participants showed more activation in the insula and other subcortical regions than in cognitive ToM tasks. Correlational analysis revealed that greater activation of the mPFC/ACC regions was associated with less symptom severity in ASD patients. In sum, our study suggests that the recruitment of additional prefrontal resources can compensate for the successful behavioral performance in the ToM task in ASD participants. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

The characterization and application of a low resource FPGA-based time to digital converter

NASA Astrophysics Data System (ADS)

Balla, Alessandro; Mario Beretta, Matteo; Ciambrone, Paolo; Gatta, Maurizio; Gonnella, Francesco; Iafolla, Lorenzo; Mascolo, Matteo; Messi, Roberto; Moricciani, Dario; Riondino, Domenico

2014-03-01

Time to Digital Converters (TDCs) are very common devices in particles physics experiments. A lot of "off-the-shelf" TDCs can be employed but the necessity of a custom DAta acQuisition (DAQ) system makes the TDCs implemented on the Field-Programmable Gate Arrays (FPGAs) desirable. Most of the architectures developed so far are based on the tapped delay lines with precision down to 10 ps, obtained with high FPGA resources usage and non-linearity issues to be managed. Often such precision is not necessary; in this case TDC architectures with low resources occupancy are preferable allowing the implementation of data processing systems and of other utilities on the same device. In order to reconstruct γγ physics events tagged with High Energy Tagger (HET) in the KLOE-2 (K LOng Experiment 2), we need to measure the Time Of Flight (TOF) of the electrons and positrons from the KLOE-2 Interaction Point (IP) to our tagging stations (11 m apart). The required resolution must be better than the bunch spacing (2.7 ns). We have developed and implemented on a Xilinx Virtex-5 FPGA a 32 channel TDC with a precision of 255 ps and low non-linearity effects along with an embedded data acquisition system and the interface to the online FARM of KLOE-2. The TDC is based on a low resources occupancy technique: the 4×Oversampling technique which, in this work, is pushed to its best resolution and its performances were exhaustively measured.

High linearity SPAD and TDC array for TCSPC and 3D ranging applications

NASA Astrophysics Data System (ADS)

Villa, Federica; Lussana, Rudi; Bronzi, Danilo; Dalla Mora, Alberto; Contini, Davide; Tisa, Simone; Tosi, Alberto; Zappa, Franco

2015-01-01

An array of 32x32 Single-Photon Avalanche-Diodes (SPADs) and Time-to-Digital Converters (TDCs) has been fabricated in a 0.35 μm automotive-certified CMOS technology. The overall dimension of the chip is 9x9 mm2. Each pixel is able to detect photons in the 300 nm - 900 nm wavelength range with a fill-factor of 3.14% and either to count them or to time stamp their arrival time. In photon-counting mode an in-pixel 6-bit counter provides photon-numberresolved intensity movies at 100 kfps, whereas in photon-timing mode the 10-bit in-pixel TDC provides time-resolved maps (Time-Correlated Single-Photon Counting measurements) or 3D depth-resolved (through direct time-of-flight technique) images and movies, with 312 ps resolution. The photodetector is a 30 μm diameter SPAD with low Dark Count Rate (120 cps at room temperature, 3% hot-pixels) and 55% peak Photon Detection Efficiency (PDE) at 450 nm. The TDC has a 6-bit counter and a 4-bit fine interpolator, based on a Delay Locked Loop (DLL) line, which makes the TDC insensitive to process, voltage, and temperature drifts. The implemented sliding-scale technique improves linearity, giving 2% LSB DNL and 10% LSB INL. The single-shot precision is 260 ps rms, comprising SPAD, TDC and driving board jitter. Both optical and electrical crosstalk among SPADs and TDCs are negligible. 2D fast movies and 3D reconstructions with centimeter resolution are reported.

75 FR 25829 - Notice of Acceptance of Proposals for the Section 538 Multi-Family Housing Guaranteed Rural...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-10

..., Senior, or Mixed) 6. Project's Total Units 7. Project's Total Development Cost (TDC) 8. Amount of 538...) prohibits discrimination in all its programs and activities on the basis of race, color, national origin...

Toward the establishment of standardized in vitro tests for lipid-based formulations. 2. The effect of bile salt concentration and drug loading on the performance of type I, II, IIIA, IIIB, and IV formulations during in vitro digestion.

PubMed

Williams, Hywel D; Anby, Mette U; Sassene, Philip; Kleberg, Karen; Bakala-N'Goma, Jean-Claude; Calderone, Marilyn; Jannin, Vincent; Igonin, Annabel; Partheil, Anette; Marchaud, Delphine; Jule, Eduardo; Vertommen, Jan; Maio, Mario; Blundell, Ross; Benameur, Hassan; Carrière, Frédéric; Müllertz, Anette; Pouton, Colin W; Porter, Christopher J H

2012-11-05

The LFCS Consortium was established to develop standardized in vitro tests for lipid-based formulations (LBFs) and to examine the utility of these tests to probe the fundamental mechanisms that underlie LBF performance. In this publication, the impact of bile salt (sodium taurodeoxycholate, NaTDC) concentration and drug loading on the ability of a range of representative LBFs to generate and sustain drug solubilization and supersaturation during in vitro digestion testing has been explored and a common driver of the potential for drug precipitation identified. Danazol was used as a model poorly water-soluble drug throughout. In general, increasing NaTDC concentrations increased the digestion of the most lipophilic LBFs and promoted lipid (and drug) trafficking from poorly dispersed oil phases to the aqueous colloidal phase (AP(DIGEST)). High NaTDC concentrations showed some capacity to reduce drug precipitation, although, at NaTDC concentrations ≥3 mM, NaTDC effects on either digestion or drug solubilization were modest. In contrast, increasing drug load had a marked impact on drug solubilization. For LBFs containing long-chain lipids, drug precipitation was limited even at drug loads approaching saturation in the formulation and concentrations of solubilized drug in AP(DIGEST) increased with increased drug load. For LBFs containing medium-chain lipids, however, significant precipitation was evident, especially at higher drug loads. Across all formulations a remarkably consistent trend emerged such that the likelihood of precipitation was almost entirely dependent on the maximum supersaturation ratio (SR(M)) attained on initiation of digestion. SR(M) defines the supersaturation "pressure" in the system and is calculated from the maximum attainable concentration in the AP(DIGEST) (assuming zero precipitation), divided by the solubility of the drug in the colloidal phases formed post digestion. For LBFs where phase separation of oil phases did not occur, a threshold value for SR(M) was evident, regardless of formulation composition and drug solubilization reduced markedly above SR(M) > 2.5. The threshold SR(M) may prove to be an effective tool in discriminating between LBFs based on performance.

The GANDALF 128-Channel Time-to-Digital Converter

NASA Astrophysics Data System (ADS)

Büchele, M.; Fischer, H.; Herrmann, F.; Königsmann, K.; Schill, C.; Schopferer, S.

The GANDALF 6U-VME64x/VXS module has been designed to cope with a variety of readout tasks in high energy and nuclear physics experiments, in particular the COMPASS experiment at CERN. The exchangeable mezzanine cards allow for an employment of the system in very different applications such as analog-to-digital or time-to-digital conversions, coincidence matrix formation, fast pattern recognition or fast trigger generation. Based on this platform, we present a 128-channel TDC which is implemented in a single Xilinx Virtex-5 FPGA using a shifted clock sampling method. In this concept each input signal is continuously sampled by 16 flip-flops using equidistant phase-shifted clocks. Compared to previous FPGA designs, usually based on delay lines and comprising few TDC channels with resolutions in the order of 10 ps, our design permits the implementation of a large number of TDC channels with a resolution of 64 ps in a single FPGA. Predictable placement of logic components and uniform routing inside the FPGA fabric is a particular challenge of this design. We present measurement results for the time resolution and the nonlinearity of the TDC readout system.

A 3D metal-organic framework with a pcu net constructed from lead(II) and thiophene-2, 5-dicarboxylic acid: Synthesis, structure and ferroelectric property

NASA Astrophysics Data System (ADS)

Lin, Jian-Di; Rong, Cheng; Lv, Ri-Xin; Wang, Zu-Jian; Long, Xi-Fa; Guo, Guo-Cong; Pan, Chun-Yang

2018-01-01

Self-assembly reaction of Pb(NO3)2 with thiophene-2, 5-dicarboxylic acid (H2TDC) led to an acentric three-dimensional (3D) metal-organic framework under solvothermal conditions, namely, Pb(TDC) (1). The 3D framework of 1 is a pillared-layer structure with the I2O1 type which is composed of a 2D inorganic Pb-O-Pb substructural layer and two independent μ6-TDC2- anions pillars. This 3D framework shows a six-connected pcu topological net according to the topological analysis. Compound 1 crystallizes in an acentric space group and displays potential ferroelectric property which could be due to the swing of the thiophene rings. The remnant polarization (Pr), coercive field (Ec) and saturation spontaneous polarization (Ps) of 1 are ca. 0.034 μC cm-2, 15.7 kV cm-1 and 0.0997 μC cm-2, respectively. Among the H2TDC-based MOFs, the present compound is the first example which shows ferroelectric property. In addition, 1 also exhibits photoluminescent property which can be attributed to ligand-to-metal charge transfer.

Closure versus medical therapy for preventing recurrent stroke in patients with patent foramen ovale and a history of cryptogenic stroke or transient ischemic attack.

PubMed

Li, Jie; Liu, Junfeng; Liu, Ming; Zhang, Shihong; Hao, Zilong; Zhang, Jing; Zhang, Canfei

2015-09-08

The optimal therapy for preventing recurrent stroke in people with cryptogenic stroke and patent foramen ovale (PFO) has not been defined. The choice between medical therapy (antithrombotic treatment with antiplatelet agents or anticoagulants) and transcatheter device closure has been the subject of intense debate over the past several years. Despite the lack of scientific evidence, a substantial number of people undergo transcatheter device closure (TDC) for secondary stroke prevention. To: 1) compare the safety and efficacy of TDC with best medical therapy alone for preventing recurrent stroke (fatal or non-fatal) or transient ischemic attacks (TIAs) in people with PFO and a history of cryptogenic stroke or TIA; 2) identify specific subgroups of people most likely to benefit from closure for secondary prevention; and 3) assess the cost-effectiveness of this strategy, if possible. We searched the Cochrane Stroke Group Trials Register (July 2014), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 2, 2014), MEDLINE (1950 to July 2014) and EMBASE (1980 to July 2014). In an effort to identify unpublished and ongoing trials we searched seven trials registers and checked reference lists. We included randomized controlled trials (RCTs), irrespective of blinding, publication status, and language, comparing the safety and efficacy of device closure with medical therapy for preventing recurrent stroke or TIA in people with PFO and a history of cryptogenic stroke or TIA. Two review authors independently selected trials for inclusion, assessed quality and risk of bias, and extracted data. The primary outcome measures of this analysis were the composite endpoint of ischemic stroke or TIA events as well as recurrent fatal or non-fatal ischemic stroke. Secondary endpoints included all-cause mortality, serious adverse events (atrial fibrillation, myocardial infarction, bleeding) and procedural success and effective closure. We used the Mantel-Haenszel method to obtain pooled risk ratios (RRs) using the random-effects model regardless of the level of heterogeneity. We pooled data for the primary outcome measure with the generic inverse variance method using the random-effects model, yielding risk estimates as pooled hazard ratio (HR), which accounts for time-to-event outcomes. We included three RCTs involving a total of 2303 participants: 1150 participants were randomized to receive TDC and 1153 participants were randomized to receive medical therapy. Overall, the risk of bias was regarded as high. The mean follow-up period of all three included trials was less than five years. Baseline characteristics (age, sex, and vascular risk factors) were similar across trials. Intention-to-treat analyses did not show a statistically significant risk reduction in the composite endpoint of recurrent stroke or TIA in the TDC group when compared with medical therapy (RR 0.73, 95% CI 0.45 to 1.17). A time-to-event analysis combining the results of two RCTs also failed to show a significant risk reduction with TDC (HR 0.69, 95% CI 0.43 to 1.13). When assessing stroke prevention alone, TDC still did not show a statistically significant benefit (RR 0.61, 95% CI 0.29 to 1.27) (HR 0.55, 95% CI 0.26 to 1.18). In a sensitivity analysis including the two studies using the Amplatzer PFO occluder, TDC showed a possible protective effect on recurrent stroke compared with medical therapy (HR 0.38, 95% CI 0.14 to 1.02); however, it did not reach statistical significance. Safety analysis found that the overall risks for all-cause mortality and adverse events were similar in both the TDC and medical therapy groups. However, TDC increased the risk of new-onset atrial fibrillation (RR 3.50, 95% CI 1.47 to 8.35) and may be associated with the type of device used. The combined data from recent RCTs have shown no statistically significant differences between TDC and medical therapy in the prevention of recurrent ischemic stroke. TDC closure was associated with an increased risk of atrial fibrillation but not with serious adverse events.

Hardware Assessment in Support of the Dynamic Power Convertor Development Effort

NASA Technical Reports Server (NTRS)

Wilson, Scott D.; Oriti, Sal M.; Schifer, Nicholas A.

2017-01-01

Stirling Radioisotope Power Systems (RPS) are being developed by NASA's RPS Program in collaboration with the U.S. Department of Energy (DOE). Efforts ranging from 2001 to 2015 enabled development of the Technology Demonstration Convertor (TDC) for use in the 110-watt Stirling Radioisotope Generator (SRG-110) and the Advanced Stirling Convertor (ASC) for use in the Advanced Stirling Radioisotope Generator (ASRG). The DOE selected Lockheed Martin Space Systems Company (LMSSC) as the system integration contractor for both flight development efforts. The SRG-110 housed two TDCs fabricated by Infinia and resulted in the production of 16x demonstration units and 2x engineering units. The project was redirected in 2006 to make use of a more efficient and lower mass ASCs under development by Sunpower Inc. The DOE managed the flight contract with LMSSC and subcontractor Sunpower Inc. from 2007 to 2013 to build the ASRG, with support from NASA Glenn Research Center (GRC). Sunpower Inc. held two parallel contracts to produce ASCs, one with Lockheed Martin to produce ASC-F flight units and one with GRC for the production of ASC-E3 engineering unit pathfinders that were used to refine the flight design and production processes. The DOE initiated termination of the ASRG contract in late 2013. After ASRG had ended, GRC completed characterization testing of the ASRG Engineering Unit #2 (EU2) and the GRC contract with Sunpower was also completed. The NASA RPS Program Office has recently initiated a new Dynamic Power Conversion development effort which includes the potential maturation of Stirling, Brayton, and Rankine power convertors for the next generation of RPS. The effort started with the request for proposal and review of submits. Contracts are anticipated for release in 2017 and will initially focus on a design phase prior to fabrication and testing. This new effort will focus on robustness in addition to high efficiency, specific power, and reliability. Also, some requirements introduced during the ASRG contract have also been included in the new effort, such as constant lateral loading. Due to the focus on robustness and new requirements relative to the older TDC design, the Stirling Cycle Development Project has initiated an assessment of government owned hardware to help inform requirements evolution and evaluation of future designs. While lessons learned from the ASRG flight development project have been taken into consideration, the evaluation of the TDC design had not been completed for some existing environments or relatively new requirements. To further assess the TDC design, a series of tasks were initiated to evaluate degradation for units that have operated unattended for over 105,000 hours, demonstrate robustness to a random vibration environment, characterize and evaluate performance for varying lateral load profiles. The status for each task are described.

Development of analytical methods of predicting the pressure distribution about a nacelle at transonic speeds: Exact solution

NASA Technical Reports Server (NTRS)

Grossman, B.; Moretti, G.

1973-01-01

A computer program to predict the inviscid, transonic flow field about isolated nacelles was developed. The problem was to be formulated to solve Euler's equations without any approximation (such as small disturbances) and hence the terminology exact solution. The flow field was complicated by the presence of imbedded shock waves, an engine-inlet interface, and exhaust plumes. Furthermore, the transonic nacelles of interest had a very slender but blunt cowl lip. This created two distinct length scales, the length of the nacelle and the cowl lip radius that can differ by several orders of magnitude. These aspects of the flow field presented many numerical difficulties. The approach to the problem was to calculate the nacelle flow field using the method of time-dependent computations (TDC). Although at the time of the issuance of this contract, other approaches to transonic flow calculations existed, it was felt that TDC offered the most effective means of meeting the goals of the contract.

Developing a Free-Piston Stirling Convertor for advanced radioisotope space power systems

NASA Astrophysics Data System (ADS)

Qiu, Songgang; Augenblick, John E.; White, Maurice A.; Peterson, Allen A.; Redinger, Darin L.; Petersen, Stephen L.

2002-01-01

The Department of Energy (DOE) has selected Free-Piston Stirling Convertors as a technology for future advanced radioisotope space power systems. In August 2000, DOE awarded competitive Phase I, Stirling Radioisotope Generator (SRG) power system integration contracts to three major aerospace contractors, resulting in SRG conceptual designs in February 2001. All three contractors based their designs on the Technology Demonstration Convertor (TDC) developed by Stirling Technology Company (STC) for DOE. The contract award to a single system integration contractor for Phases II and III of the SRG program is anticipated in late 2001. The first potential SRG mission is targeted for a Mars rover. This paper provides a description of the Flight Prototype (FP) Stirling convertor design as compared to the previous TDC design. The initial flight prototype units are already undergoing performance tuning at STC. The new design will be hermetically scaled and will provide a weight reduction from approximately 4.8 kg to approximately 3.9 kg. .

Status update of a free-piston Stirling convertor for radioisotope space power systems

NASA Astrophysics Data System (ADS)

White, Maurice; Qiu, Songgang; Augenblick, Jack; Peterson, Allen; Faultersack, Frank

2001-02-01

Free-piston Stirling engines offer a relatively mature technology that is well-suited for advanced, high-efficiency radioisotope space power systems. This paper updates results from a combination of DOE and NASA contracts with Stirling Technology Company (STC). These contracts have demonstrated STC's Stirling convertor technology in a configuration and power level representative of a space power system. Based on demonstrated performance, long-life maintenance-free technology heritage, and success with aggressively imposed vibration testing. DOE has awarded system integration contracts to Boeing, Lockheed Martin and Teledyne Energy Systems. The objectives of these competitive Phase I contracts are to develop complete spacecraft power system conceptual designs based on the STC Stirling convertor, and to plan subsequent phases for two launches. Performance results for the DOE 55-W(e) Technology Demonstration Convertors (TDC's) have met original projections. Although the TDC's were intended only for technology demonstration, they have achieved very aggressive efficiency goals, demonstrated convertor-induced vibration levels below the Jet Propulsion Laboratory (JPL) specifications, passed a simulated launch load vibration test at 0.2 g2/Hz (12.3 g rms), and met EMI/EMC goals for most contemplated missions. No consideration for EMI reduction was included in the TDC design. Minor changes are underway to reduce EMI levels, with a goal of meeting specifications for missions such as Solar Probe with highly sensitive instrumentation. The long-term objective for DOE is to develop a power system with a system efficiency exceeding 20% that can function with a high degree of reliability for 10 years and longer on deep space missions. .

Marine magnetotellurics imaged no distinct plume beneath the Tristan da Cunha hotspot in the southern Atlantic Ocean

NASA Astrophysics Data System (ADS)

Baba, Kiyoshi; Chen, Jin; Sommer, Malte; Utada, Hisashi; Geissler, Wolfram H.; Jokat, Wilfried; Jegen, Marion

2017-10-01

The Tristan da Cunha (TDC) is a volcanic island located above a prominent hotspot in the Atlantic Ocean. Many geological and geochemical evidences support a deep origin of the mantle material feeding the hotspot. However, the existence of a plume has not been confirmed as an anomalous structure in the mantle resolved by geophysical data because of lack of the observations in the area. Marine magnetotelluric and seismological observations were conducted in 2012-2013 to examine the upper mantle structure adjacent to TDC. The electrical conductivity structure of the upper mantle beneath the area was investigated in this study. Three-dimensional inversion analysis depicted a high conductive layer at 120 km depth but no distinct plume-like vertical structure. The conductive layer is mostly flat independently on seafloor age and bulges upward beneath the lithospheric segment where the TDC islands are located compared to younger segment south of the TDC Fracture Zone, while the bathymetry is rather deeper than prediction for the northern segment. The apparent inconsistency between the absence of vertical structure in this study and geochemical evidences on deep origin materials suggests that either the upwelling is too small and/or weak to be resolved by the current data set or that the upwelling takes place elsewhere outside of the study area. Other observations suggest that 1) the conductivity of the upper mantle can be explained by the fact that the mantle above the high conductivity layer is depleted in volatiles as the result of partial melting beneath the spreading ridge, 2) the potential temperature of the segments north of the TDC Fracture Zone is lower than that of the southern segment at least during the past 30 Myr.

Developing Telecommunication Linkages for Microcomputer-Aided Instruction. TDC Research Report No. 1.

ERIC Educational Resources Information Center

Blinn, Charles R.; And Others

A project undertaken at the University of Minnesota evaluated two microcomputer teletraining systems (audiographic conferencing) to determine the effectiveness of this technology for point-to-point and multipoint distance education. System design requirements included broadcast keystrokes, error checking, master-slave linkages, simultaneous voice…

DEVELOPMENT OF A SMALL CHAMBER METHOD FOR SVOC SINK EFFECT STUDY

EPA Science Inventory

This paper describes the details of the improved chamber system and reports the sink effect study for organophosphorus flame retardants (OP-FRs), including tris(2-chloroethyl) phosphate(TCEP), tris(1-chlor-2-propyl) phosphate (TCPP) and tris(1,3-dichloro-2-propyl) phosphate (TDC...

Webis at TREC 2014: Web, Session, and Contextual Suggestion Tracks

DTIC Science & Technology

2014-11-01

8] Yes TFC2 [8] Yes TFC3 [9] Yes TDC [8] Yes Document length LNC1 [8] Yes LNC2 [8] Yes TF-LNC [8] Yes Lower bound LB1 [19] Yes LB2 [19] No Semantic...axioms TFC1, TDC , LNC2, LB1, PROX2 and PROX3. 2.4 Brief Discussion The results of our different runs indicate that the syn- and max-combinations can

Effect of Cultivar, Temperature, and Environmental Conditions on the Dynamic Change of Melatonin in Mulberry Fruit Development and Wine Fermentation.

PubMed

Wang, Cheng; Yin, Li-Yuan; Shi, Xue-Ying; Xiao, Hua; Kang, Kun; Liu, Xing-Yan; Zhan, Ji-Cheng; Huang, Wei-Dong

2016-04-01

High levels of melatonin have been reported in various foods but not in mulberry or its wine. This study investigated the dynamic changes of melatonin levels during mulberry fruit development and ethanol fermentation of 2 different colored mulberry cultivars ("Hongguo2ˮ Morus nigra, black and "Baiyuwangˮ Morus alba, white) at 2 fermentation temperatures (16 and 25 °C). Our results showed that the melatonin level increased in the beginning of mulberry development but decreased in the end. The MnTDC gene expression level correlated with melatonin production, which implied that TDC may be the rate-limiting enzyme of the melatonin biosynthetic process in mulberries. During mulberry fermentation, the melatonin concentration increased rapidly in the beginning and then decreased gradually. Low temperature delayed the melatonin production during fermentation. A relatively high level of melatonin was found in "Hongguo2ˮ compared with "Baiyuwangˮ during fruit development and fermentation. The variation of melatonin correlated with the ethanol production rate, suggesting that melatonin may participate in physiological regulation of Saccharomyces cerevisiae during the fermentation stage. © 2016 Institute of Food Technologists®

Photon-Limited Information in High Resolution Laser Ranging

DTIC Science & Technology

2014-05-28

entangled photons generated by spontaneous parametric down-conversion of a chirped source to perform ranging measurements. Summary of the Most... Matlab program to collect the photon counts from the time to digital converter (TDC). This entailed setting up Matlab to talk to the TDC to get the...SECURITY CLASSIFICATION OF: This project is an effort under the Information in a Photon (InPho) program at DARPA\\DSO. Its purpose is to investigate

Two double and triple interpenetrated Cd(II) and Zn(II) coordination polymers based on mixed O- and N-donor ligands: Syntheses, crystal structures and luminescent properties

NASA Astrophysics Data System (ADS)

Zhang, Li; Li, Xiaohui; Zhang, Yan

2016-01-01

Two interpenetrated 3D coordination polymers, namely [Cd2(tdc)2(bpp) (DMA)]n (1) and [Zn2(tdc)2(bib)2]n·2n(DMA) (2) (H2tdc = 2,5-thiophenedicarboxylic acid, bpp = 1,3-di(4-pyridyl)propane, bib = 1, 4-bis(imidazolyl)butane, DMA = N,N-dimethylacetamide), have been solvothermally synthesized by the self-assembly of flexible N-donor and dicarboxylate ligands. Single crystal X-ray diffraction analyses revealed that compound 1 features a 2-fold interpenetrated 3D framework based on dinuclear [Cd2(COO)3] subunits and can be simplified into a 6-connected pcu topology, and compound 2 features a 3-fold interpenetrated 3D framework with 4-connected dia topology. Moreover, the thermal stabilities and luminescent properties of these two compounds were also investigated.

A 780 × 800 μm2 Multichannel Digital Silicon Photomultiplier With Column-Parallel Time-to-Digital Converter and Basic Characterization

NASA Astrophysics Data System (ADS)

Mandai, Shingo; Jain, Vishwas; Charbon, Edoardo

2014-02-01

This paper presents a digital silicon photomultiplier (SiPM) partitioned in columns, whereas each column is connected to a column-parallel time-to-digital converter (TDC), in order to improve the timing resolution of single-photon detection. By reducing the number of pixels per TDC using a sharing scheme with three TDCs per column, the pixel-to-pixel skew is reduced. We report the basic characterization of the SiPM, comprising 416 single-photon avalanche diodes (SPADs); the characterization includes photon detection probability, dark count rate, afterpulsing, and crosstalk. We achieved 264-ps full-width at half maximum timing resolution of single-photon detection using a 48-fold column-parallel TDC with a temporal resolution of 51.8 ps (least significant bit), fully integrated in standard complementary metal-oxide semiconductor technology.

Patients started on hemodialysis with tunneled dialysis catheter have similar survival after arteriovenous fistula and arteriovenous graft creation.

PubMed

Yuo, Theodore H; Chaer, Rabih A; Dillavou, Ellen D; Leers, Steven A; Makaroun, Michel S

2015-12-01

Current guidelines suggest that arteriovenous fistula (AVF) is associated with survival advantage over arteriovenous graft (AVG). However, AVFs often require months to become functional, increasing tunneled dialysis catheter (TDC) use, which can erode the benefit of an AVF. We sought to compare survival in patients with end-stage renal disease after creation of an AVF or AVG in patients starting hemodialysis (HD) with a TDC and to identify patient populations that may benefit from preferential use of AVG over AVF. Using U.S. Renal Data System databases, we identified incident HD patients in 2005 through 2008 and observed them through 2008. Initial access type and clinical variables including albumin levels were assessed using U.S. Renal Data System data collection forms. Attempts at AVF and AVG creation in patients who started HD through a TDC were identified by Current Procedural Terminology codes. We accounted for the effect of changes in access type by truncating follow-up when an additional AVF or AVG was performed. Survival curves were then constructed, and log-rank tests were used for pairwise survival comparisons, stratified by age. Multivariate analysis was performed with Cox proportional hazards regressions; variables were chosen using stepwise elimination. An interaction of access type and albumin level was detected, and Cox models using differing thresholds for albumin level were constructed. The primary outcome was survival. Among the 138,245 patients who started with a TDC and had complete records amenable for analysis, 22.8% underwent AVF creation (mean age ± standard deviation, 68.9 ± 12.5 years; 27.8% mortality at 1 year) and 7.6% underwent AVG placement (70.2 ± 12.0 years; 28.2% mortality) within 3 months of HD initiation; 69.6% remained with a TDC (63.2 ± 15.4 years; 33.8% mortality). In adjusted Cox proportional hazards regression, AVF creation is equivalent to AVG placement in terms of survival (hazard ratio [HR], 0.98; 95% confidence interval [CI], 0.93-1.02; P = .349). AVG placement is superior to continued TDC use (HR, 1.54; 95% CI, 1.48-1.61; P < .001). In patients older than 80 years with albumin levels >4.0 g/dL, AVF creation is associated with higher mortality hazard compared with AVG creation (HR, 1.22; 95% CI, 1.04-1.43; P = .013). For patients who start HD through a TDC, placement of an AVF and AVG is associated with similar mortality hazard. Further study is necessary to determine the ideal access for patients in whom the survival advantage of an AVF over an AVG is uncertain. Copyright © 2015 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

Digitization of Analog Signals using a Field Programmable Gate Array (FPGA)

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

Aguilera, Daniel; Rusu, Vadim

The idea of this research is consolidating the electrical components used for capturing data in the Mu2e Tracker. Ideally, an FPGA will serve as the Time-Division Converters (TDC) and Analog-to-Digital Converters (ADC). The TDC is already being carried out by the FPGA, but we are still using off the shelf ADCs. This poster proposes using Low Voltage Differential Signaling as the basis for analog-to-digital conversion using and FPGA.

The Iowa Disinfection Cleaning Project: Opportunities, Successes, and Challenges of a Structured Intervention Program in 56 Hospitals.

PubMed

Carling, Philip; Herwaldt, Loreen A

2017-08-01

OBJECTIVE A diverse group of hospitals in Iowa implemented a program to objectively evaluate and improve the thoroughness of disinfection cleaning of near-patient surfaces. Administrative benefits of, challenges of, and impediments to the program were also evaluated. METHODS We conducted a prospective, quasi-experimental pre-/postintervention trial to improve the thoroughness of terminal room disinfection cleaning. Infection preventionists utilized an objective cleaning performance monitoring system (DAZO) to evaluate the thoroughness of disinfection cleaning (TDC) expressed as a proportion of objects confirmed to have been cleaned (numerator) to objects to be cleaned per hospital policy (denominator)×100. Data analysis, educational interventions, and objective performance feedback were modeled on previously published studies using the same monitoring tool. Programmatic analysis utilized unstructured and structured information from participants irrespective of whether they participated in the process improvement aspects to the program. RESULTS Initially, the overall TDC was 61% in 56 hospitals. Hospitals completing 1 or 2 feedback cycles improved their TDC percentages significantly (P90% for at least 38 months. A survey of infection preventionists found that lack of time and staff turnover were the most common reasons for terminating the study early. CONCLUSION The study confirmed that hospitals using this program can improve their TDC percentages significantly. Hospitals must invest resources to improve cleaning and to sustain their gains. Infect Control Hosp Epidemiol 2017;38:960-965.

Desktop Publishing: Organizational Considerations for Adoption and Implementation. TDC Research Report No. 6.

ERIC Educational Resources Information Center

Lee, Paul

This report explores the implementation of desktop publishing in the Minnesota Extension Service (MES) and provides a framework for its implementation in other organizations. The document begins with historical background on the development of desktop publishing. Criteria for deciding whether to purchase a desktop publishing system, advantages and…

The within-match patterns of locomotor efficiency during professional soccer match play: Implications for injury risk?

PubMed

Barrett, Steve; Midgley, Adrian; Reeves, Matt; Joel, Tom; Franklin, Ed; Heyworth, Rob; Garrett, Andrew; Lovell, Ric

2016-10-01

The principle aim of the current study was to examine within-match patterns of locomotor efficiency in professional soccer, determined as the ratio between tri-axial accelerometer data (PlayerLoad™) and locomotor activities. Between match variability and determinants of PlayerLoad™ during match play were also assessed. A single cohort, observational study. Tri-axial accelerometer data (PlayerLoad™) was recorded during 86 competitive soccer matches in 63 English championship players (574 match observations). Accelerometer data accumulated (PlayerLoad Vector Magnitude [PLVM]) from the individual-component planes of PlayerLoad™ (anterior-posterior PlayerLoad™ [PLAP], medial-lateral PlayerLoad™ [PLML] and vertical PlayerLoad™ [PLV]), together with locomotor activity (Total Distance Covered [TDC]) were determined in 15-min segments. Locomotor efficiency was calculated using the ratio of PLVM and TDC (PlayerLoad™ per metre). The proportion of variance explaining the within-match trends in PLVM, PLAP, APML, APv, and TDC was determined owing to matches, individual players, and positional role. PLVM, PLAP, APML, APv and TDC reduced after the initial 15-min match period (p=0.001; η(2)=0.22-0.43, large effects). PL:TDC increased in the last 15min of each half (p=0.001; η(2)=0.25, large effect). The variance in PLVM during soccer match-play was explained by individual players (63.9%; p=0.001) and between-match variation (21.6%; p=0.001), but not positional role (14.1%; p=0.364). Locomotor efficiency is lower during the latter stages of each half of competitive soccer match-play, a trend synonymous with observations of increased injury incidence and fatigue in these periods. Locomotor efficiency may be a valuable metric to identify fatigue and heightened injury risk during soccer training and match-play. Copyright © 2015 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

On heat transfer in squish gaps

NASA Astrophysics Data System (ADS)

Spurk, J. H.

1986-06-01

Attention is given to the heat transfer characteristics of a squish gap in an internal combustion engine cylinder, when the piston is nearing top dead center (TDC) on the compression stroke. If the lateral extent of the gap is much larger than its height, the inviscid flow is similar to the stagnation point flow. Surface temperature and pressure histories during compression and expansion are studied. Surface temperature has a maximum near TDC, then drops and rises again during expansion; higher values are actually achieved during expansion than during compression.

Environmentally Assisted Cracking of High Strength Beta Titanium Alloys

DTIC Science & Technology

1993-11-01

financially supported by the Virginia Center for Innovative Technology TDC on Electrochemical Science and Engineering (Grant CIT- TDC -88-01) and by the Office...Material Behayir, N.R. Moody and A.W. Thompson, eds., TMS -AIME, Warrendale, PA, p. 891(1990). 18. 0. Vosikovsky, J.Tt. EyaL, Vol. 6, p. 175 (1978). 19...acknowledged. 3 23 REFERENCES 1. Beta Titanium Alloys in the 80’s R.R. Boyer and H.W. Rosenberg, eds., TMS -AIME,3 Warrendale, PA. pp. 209-229, 1983. 2

First evidence of a membrane-bound, tyramine and beta-phenylethylamine producing, tyrosine decarboxylase in Enterococcus faecalis: a two-dimensional electrophoresis proteomic study.

PubMed

Pessione, Enrica; Pessione, Alessandro; Lamberti, Cristina; Coïsson, Daniel Jean; Riedel, Kathrin; Mazzoli, Roberto; Bonetta, Silvia; Eberl, Leo; Giunta, Carlo

2009-05-01

The soluble and membrane proteome of a tyramine producing Enterococcus faecalis, isolated from an Italian goat cheese, was investigated. A detailed analysis revealed that this strain also produces small amounts of beta-phenylethylamine. Kinetics of tyramine and beta-phenylethylamine accumulation, evaluated in tyrosine plus phenylalanine-enriched cultures (stimulated condition), suggest that the same enzyme, the tyrosine decarboxylase (TDC), catalyzes both tyrosine and phenylalanine decarboxylation: tyrosine was recognized as the first substrate and completely converted into tyramine (100% yield) while phenylalanine was decarboxylated to beta-phenylethylamine (10% yield) only when tyrosine was completely depleted. The presence of an aspecific aromatic amino acid decarboxylase is a common feature in eukaryotes, but in bacteria only indirect evidences of a phenylalanine decarboxylating TDC have been presented so far. Comparative proteomic investigations, performed by 2-DE and MALDI-TOF/TOF MS, on bacteria grown in conditions stimulating tyramine and beta-phenylethylamine biosynthesis and in control conditions revealed 49 differentially expressed proteins. Except for aromatic amino acid biosynthetic enzymes, no significant down-regulation of the central metabolic pathways was observed in stimulated conditions, suggesting that tyrosine decarboxylation does not compete with the other energy-supplying routes. The most interesting finding is a membrane-bound TDC highly over-expressed during amine production. This is the first evidence of a true membrane-bound TDC, longly suspected in bacteria on the basis of the gene sequence.

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

Wu, Jinyuan

A digitization scheme of sub-microampere current using a commercial comparator with adjustable hysteresis and FPGA-based Wave Union TDC has been tested. The comparator plus a few passive components forms a current controlled oscillator and the input current is sent into the hysteresis control pin. The input current is converted into the transition times of the oscillations, which are digitized with a Wave Union TDC in FPGA and the variation of the transition times reflects the variation of the input current. Preliminary tests show that input charges < 25 fC can be measured at > 50 M samples/s without a preamplifier.

TRACALS Evaluation Report. Initial Evaluation Report (AN/GPN-24) Nellis AFB, Nevada, 10 December 1979-6 Mar 1980.

DTIC Science & Technology

1980-05-16

Scott AFB, IL 62225 1 1842 EEG /EEIT, Scott AFB, IL 62225 1 1843 EES/EIELT, H-ickam AFB, H-I 96853 1 1844 EES/EIELT, Griffiss AFB, NY 13441 I HQ AFCC/DAPL...Time Control TDC Target Data Computer TO Technical Order TRACALS Traffic Cortrol and Landing Systems TSDA Transfer Switch Drawer Assembly TWT Traveling...the designated targets. The error detector outputs are fed to the TDC to update the beam position data during the next track interval. (b) Processor

Cortical Signatures of Dyslexia and Remediation: An Intrinsic Functional Connectivity Approach

PubMed Central

Koyama, Maki S.; Di Martino, Adriana; Kelly, Clare; Jutagir, Devika R.; Sunshine, Jessica; Schwartz, Susan J.; Castellanos, Francisco X.; Milham, Michael P.

2013-01-01

This observational, cross-sectional study investigates cortical signatures of developmental dyslexia, particularly from the perspective of behavioral remediation. We employed resting-state fMRI, and compared intrinsic functional connectivity (iFC) patterns of known reading regions (seeds) among three dyslexia groups characterized by (a) no remediation (current reading and spelling deficits), (b) partial remediation (only reading deficit remediated), and (c) full remediation (both reading and spelling deficits remediated), and a group of age- and IQ-matched typically developing children (TDC) (total N = 44, age range = 7–15 years). We observed significant group differences in iFC of two seeds located in the left posterior reading network – left intraparietal sulcus (L.IPS) and left fusiform gyrus (L.FFG). Specifically, iFC between L.IPS and left middle frontal gyrus was significantly weaker in all dyslexia groups, irrespective of remediation status/literacy competence, suggesting that persistent dysfunction in the fronto-parietal attention network characterizes dyslexia. Additionally, relative to both TDC and the no remediation group, the remediation groups exhibited stronger iFC between L.FFG and right middle occipital gyrus (R.MOG). The full remediation group also exhibited stronger negative iFC between the same L.FFG seed and right medial prefrontal cortex (R.MPFC), a core region of the default network These results suggest that behavioral remediation may be associated with compensatory changes anchored in L.FFG, which reflect atypically stronger coupling between posterior visual regions (L.FFG-R.MOG) and greater functional segregation between task-positive and task-negative regions (L.FFG-R.MPFC). These findings were bolstered by significant relationships between the strength of the identified functional connections and literacy scores. We conclude that examining iFC can reveal cortical signatures of dyslexia with particular promise for monitoring neural changes associated with behavioral remediation. PMID:23408984

Organization and Technology Issues Related to Distance Education. TDC Research Report No. 3.

ERIC Educational Resources Information Center

Kovel-Jarboe, Patricia

This report focuses on the first of three phases in a project at the Institute of Agriculture, Forestry, and Home Economics (IAFHE) at the University of Minnesota. This project has been charged with developing a plan for delivering credit and on-credit educational offerings at multiple locations in the state. Background information on the project…

A flexible FPGA based QDC and TDC for the HADES and the CBM calorimeters

NASA Astrophysics Data System (ADS)

Rost, A.; Galatyuk, T.; Koenig, W.; Michel, J.; Pietraszko, J.; Skott, P.; Traxler, M.

2017-02-01

A Charge-to-Digital-Converter (QDC) and Time-to-Digital-Converter (TDC) based on a commercial FPGA (Field Programmable Gate Array) was developed to read out PMT signals of the planned HADES electromagnetic calorimeter (ECAL) at GSI Helmholtzzentrum für Schwerionenforschung GmbH (Darmstadt, Germany). The main idea is to convert the charge measurement of a detector signal into a time measurement, where the charge is encoded in the width of a digital pulse, while the arrival time information is encoded in the leading edge time of the pulse. The PaDiWa-AMPS prototype front-end board for the TRB3 (General Purpose Trigger and Readout Board—version 3) which implements this conversion method was developed and qualified. The already well established TRB3 platform provides the needed precise time measurements and serves as a data acquisition system. We present the read-out concept and the performance of the prototype boards in laboratory and also under beam conditions. First steps have been completed in order to adapt this concept to SiPM signals of the hadron calorimeter in the CBM experiment at the planned FAIR facility (Darmstadt).

Developmental trajectories for attention and working memory in healthy Japanese school-aged children.

PubMed

Egami, Chiyomi; Yamashita, Yushiro; Tada, Yasuhiro; Anai, Chiduru; Mukasa, Akiko; Yuge, Kotaro; Nagamitsu, Shinichiro; Matsuishi, Toyojiro

2015-10-01

The aim of this study was to investigate the developmental trajectories of attention, short-term memory, and working memory in school-aged children using a 10 min test battery of cognitive function. Participants comprised 144 typically developing children (TDC) aged 7-12 years and 24 healthy adults, divided according to age into seven groups (12 males and 12 females for each age group). Participants were assessed using CogHealth, which is a computer-based measure composed of five tasks. We measured attention, short-term memory, and working memory (WM) with visual stimulation. Each task was analyzed for age-related differences in reaction time and accuracy rate. Attention tasks were faster in stages from the age of 7-10 years. Accuracy rate of short-term memory gradually increased from 12 years of age and suddenly increased and continued to increase at 22 years of age. Accuracy rate of working memory increased until 12 years of age. Correlations were found between the ages and reaction time, and between ages and accuracy rate of the tasks. These results indicate that there were rapid improvements in attention, short-term memory, and WM performance between 7 and 10 years of age followed by gradual improvement until 12 years of age. Increase in short-term memory continued until 22 years of age. In our experience CogHealth was an easy and useful measure for the evaluation of cognitive function in school-age children. Copyright © 2015 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

Crash testing difference-smoothing algorithm on a large sample of simulated light curves from TDC1

NASA Astrophysics Data System (ADS)

Rathna Kumar, S.

2017-09-01

In this work, we propose refinements to the difference-smoothing algorithm for the measurement of time delay from the light curves of the images of a gravitationally lensed quasar. The refinements mainly consist of a more pragmatic approach to choose the smoothing time-scale free parameter, generation of more realistic synthetic light curves for the estimation of time delay uncertainty and using a plot of normalized χ2 computed over a wide range of trial time delay values to assess the reliability of a measured time delay and also for identifying instances of catastrophic failure. We rigorously tested the difference-smoothing algorithm on a large sample of more than thousand pairs of simulated light curves having known true time delays between them from the two most difficult 'rungs' - rung3 and rung4 - of the first edition of Strong Lens Time Delay Challenge (TDC1) and found an inherent tendency of the algorithm to measure the magnitude of time delay to be higher than the true value of time delay. However, we find that this systematic bias is eliminated by applying a correction to each measured time delay according to the magnitude and sign of the systematic error inferred by applying the time delay estimator on synthetic light curves simulating the measured time delay. Following these refinements, the TDC performance metrics for the difference-smoothing algorithm are found to be competitive with those of the best performing submissions of TDC1 for both the tested 'rungs'. The MATLAB codes used in this work and the detailed results are made publicly available.

A Nonlinearity Minimization-Oriented Resource-Saving Time-to-Digital Converter Implemented in a 28 nm Xilinx FPGA

NASA Astrophysics Data System (ADS)

Wang, Yonggang; Liu, Chong

2015-10-01

Because large nonlinearity errors exist in the current tapped-delay line (TDL) style field programmable gate array (FPGA)-based time-to-digital converters (TDC), bin-by-bin calibration techniques have to be resorted for gaining a high measurement resolution. If the TDL in selected FPGAs is significantly affected by changes in ambient temperature, the bin-by-bin calibration table has to be updated as frequently as possible. The on-line calibration and calibration table updating increase the TDC design complexity and limit the system performance to some extent. This paper proposes a method to minimize the nonlinearity errors of TDC bins, so that the bin-by-bin calibration may not be needed while maintaining a reasonably high time resolution. The method is a two pass approach: By a bin realignment, the large number of wasted zero-width bins in the original TDL is reused and the granularity of the bins is improved; by a bin decimation, the bin size and its uniformity is traded-off, and the time interpolation by the delay line turns more precise so that the bin-by-bin calibration is not necessary. Using Xilinx 28 nm FPGAs, in which the TDL property is not very sensitive to ambient temperature, the proposed TDC achieves approximately 15 ps root-mean-square (RMS) time resolution by dual-channel measurements of time-intervals over the range of operating temperature. Because of removing the calibration and less logic resources required for the data post-processing, the method has bigger multi-channel capability.

Clock and trigger distribution for CBM-TOF quality evaluation of RPC super module detector assemblies

NASA Astrophysics Data System (ADS)

Li, C.; Huang, X.; Cao, P.; Wang, J.; An, Q.

2018-03-01

RPC Super module (SM) detector assemblies are used for charged hadron identification in the Time-of-Flight (TOF) spectrometer at the Compressed Baryonic Matter (CBM) experiment. Each SM contains several multi-gap Resistive Plate Chambers (MRPCs) and provides up to 320 electronic channels in total for high-precision time measurements. Time resolution of the Time-to-Digital Converter (TDC) is required to be better than 20 ps. During mass production, the quality of each SM needs to be evaluated. In order to meet the requirements, the system clock signal as well as the trigger signal should be distributed precisely and synchronously to all electronics modules within the evaluation readout system. In this paper, a hierarchical clock and trigger distribution method is proposed for the quality evaluation of CBM-TOF SM detectors. In a first stage, the master clock and trigger module (CTM) allocated in a 6U PXI chassis distributes the clock and trigger signals to the slave CTM in the same chassis. In a second stage, the slave CTM transmits the clock and trigger signals to the TDC readout module (TRM) through one optical link. In a third stage, the TRM distributes the clock and trigger signals synchronously to 10 individual TDC boards. Laboratory test results show that the clock jitter at the third stage is less than 4 ps (RMS) and the trigger transmission latency from the master CTM to the TDC is about 272 ns with 11 ps (RMS) jitter. The overall performance complies well with the required specifications.

Self-injurious implicit attitudes among adolescent suicide attempters versus those engaged in nonsuicidal self-injury.

PubMed

Dickstein, Daniel P; Puzia, Megan E; Cushman, Grace K; Weissman, Alexandra B; Wegbreit, Ezra; Kim, Kerri L; Nock, Matthew K; Spirito, Anthony

2015-10-01

Suicide is among the most important mental health issues affecting adolescents today despite much research on its detection and prevention. Beyond suicide attempts (SAs), clinicians are increasingly confronted with another, potentially related problem: non-suicidal self-injury (NSSI)-defined as the deliberate destruction of body tissue without intent to die. NSSI may increase risk for making an SA by sevenfold, but many studies examining this link have involved youths engaging in both NSSI and SAs. Thus, there is a need to compare homogeneous groups of adolescents engaged in NSSI-only or SA-only, but not both, to advance what is known about each form of self-harm. The self-injurious implicit association task (SI-IAT) is a particularly important computerized behavioral task to study such adolescents because the SI-IAT provides objective behavioral data about problems for which people may lack insight or be motivated to conceal, such as SAs and NSSI. We evaluated implicit associations with cutting and death/suicide using the computerized SI-IAT in three mutually exclusive groups: (1) adolescents who made an SA but had never engaged in NSSI (n = 47); (2) adolescents who engaged in NSSI but had never made an SA (n = 46); and (3) typically developing control (TDC) adolescents without history of psychiatric problems (n = 43). Nonsuicidal self-injury participants had stronger identification with cutting versus no cutting than either SA or TDC participants. Contrary to our hypothesis, NSSI participants had stronger identification with suicide/death versus life than either SA or TDC participants. Strong implicit attitudes towards suicide/death among adolescents with NSSI without a prior SA suggest that clinicians should not dismiss NSSI as not serious. Further work is required to elucidate the mechanism by which youths engaged in NSSI acquire these stronger identifications and make a first-time SA to develop novel treatment and prevention strategies blocking this transformation, ultimately reducing youth suicide. © 2015 Association for Child and Adolescent Mental Health.

Estimation of Cyclic Shift with Delayed Correlation and Matched Filtering in Time Domain Cyclic-SLM for PAPR Reduction

PubMed Central

2016-01-01

Time domain cyclic-selective mapping (TDC-SLM) reduces the peak-to-average power ratio (PAPR) in OFDM systems while the amounts of cyclic shifts are required to recover the transmitted signal in a receiver. One of the critical issues of the SLM scheme is sending the side information (SI) which reduces the throughputs in wireless OFDM systems. The proposed scheme implements delayed correlation and matched filtering (DC-MF) to estimate the amounts of the cyclic shifts in the receiver. In the proposed scheme, the DC-MF is placed after the frequency domain equalization (FDE) to improve the accuracy of cyclic shift estimation. The accuracy rate of the propose scheme reaches 100% at E b/N 0 = 5 dB and the bit error rate (BER) improves by 0.2 dB as compared with the conventional TDC-SLM. The BER performance of the proposed scheme is also better than that of the conventional TDC-SLM even though a nonlinear high power amplifier is assumed. PMID:27752539

[Family Health Program and children palliative care: listening the relatives of technology dependent children].

PubMed

Rabello, Cláudia Azevedo Ferreira Guimarães; Rodrigues, Paulo Henrique de Almeida

2010-03-01

This study discusses the creation of a new children palliative care program based on the Family Health Program, considering the level of care at home and yielding to family requests. The study focused on eighteen members of nine families of technology dependent children (TDC) who were hospital patients at Instituto Fernandes Figueira (IFF): four who are being assisted by its palliative care program Programa de Assistência Domiciliar Interdisciplinar (PADI); three who were inpatients waiting for inclusion in the Program, and finally two inpatients already included in PADI. PADI was chosen because it is the only child palliative care program in Brazil. The results are positive in regards to the connection established between the families and the health care team, the reception of the children, the explanation to the family concerning the disease, and the functional dynamics between the PADI and IFF. As negative points, difficulties arose as a result of the implementation of the program, from its continuity to the worsening or illness of the entire family. In conclusion, although the PADI is the IFF's way of discharging patients, the domiciliary cares taken by the Family Health Program, well articulated with the healthcare system, would be ideal for being the adequate assistance for such.

Thyroglossal duct cyst cancer most likely arises from a thyroid gland remnant.

PubMed

Rossi, Esther D; Martini, Maurizio; Straccia, Patrizia; Cocomazzi, Alessandra; Pennacchia, Ilaria; Revelli, Luca; Rossi, Armando; Lombardi, Celestino Pio; Larocca, Luigi M; Fadda, Guido

2014-07-01

Thyroglossal duct cancer is a rare entity, occurring in 1.5 % of all thyroglossal duct cysts (TDC). A definitive consensus about its neoplastic origin has not been established as two contrasting theories exist, one proposing an origin in extra-thyroid remnants and the other a metastatic localization of a primary thyroid cancer. We compare morphological and molecular characteristics of both thyroglossal and thyroid carcinomas in a case series from our institute. We evaluated histology of 80 TDC. In 12 cases, prior cytological evaluation had been performed by liquid-based cytology (LBC). The BRAF gene was examined for mutations, and the histology of both thyroglossal duct and synchronous thyroid carcinoma was reevaluated. In 9 out of 80 (11 %) TDC cases, a papillary thyroid cancer (PTC) was diagnosed. In five out of nine (56 %) thyroglossal carcinomas, a synchronous thyroid cancer was diagnosed: 3 PTC and 2 follicular variant PTC (FVPC). In five thyroglossal carcinomas, mutated BRAF (V600E) was found, three in PTC and in thyroglossal as well as in the synchronous tumor in the thyroid. All the patients are in a disease-free status and still alive. Our results suggest that the majority of thyroglossal carcinomas most likely develop as a primary malignancy from a thyroid remnant. Neither the presence of V600E BRAF mutations nor that of a well-differentiated thyroid carcinoma changed the outcome or disease-free survival. We suggest that a diagnosis of thyroglossal carcinoma should be followed by a detailed evaluation of the thyroid gland. In the absence of clinical and radiological thyroid alterations, follow-up as for thyroid cancer is the correct management.

Emotional face recognition in adolescent suicide attempters and adolescents engaging in non-suicidal self-injury.

PubMed

Seymour, Karen E; Jones, Richard N; Cushman, Grace K; Galvan, Thania; Puzia, Megan E; Kim, Kerri L; Spirito, Anthony; Dickstein, Daniel P

2016-03-01

Little is known about the bio-behavioral mechanisms underlying and differentiating suicide attempts from non-suicidal self-injury (NSSI) in adolescents. Adolescents who attempt suicide or engage in NSSI often report significant interpersonal and social difficulties. Emotional face recognition ability is a fundamental skill required for successful social interactions, and deficits in this ability may provide insight into the unique brain-behavior interactions underlying suicide attempts versus NSSI in adolescents. Therefore, we examined emotional face recognition ability among three mutually exclusive groups: (1) inpatient adolescents who attempted suicide (SA, n = 30); (2) inpatient adolescents engaged in NSSI (NSSI, n = 30); and (3) typically developing controls (TDC, n = 30) without psychiatric illness. Participants included adolescents aged 13-17 years, matched on age, gender and full-scale IQ. Emotional face recognition was evaluated using the diagnostic assessment of nonverbal accuracy (DANVA-2). Compared to TDC youth, adolescents with NSSI made more errors on child fearful and adult sad face recognition while controlling for psychopathology and medication status (ps < 0.05). No differences were found on emotional face recognition between NSSI and SA groups. Secondary analyses showed that compared to inpatients without major depression, those with major depression made fewer errors on adult sad face recognition even when controlling for group status (p < 0.05). Further, compared to inpatients without generalized anxiety, those with generalized anxiety made fewer recognition errors on adult happy faces even when controlling for group status (p < 0.05). Adolescent inpatients engaged in NSSI showed greater deficits in emotional face recognition than TDC, but not inpatient adolescents who attempted suicide. Further results suggest the importance of psychopathology in emotional face recognition. Replication of these preliminary results and examination of the role of context-dependent emotional processing are needed moving forward.

Advanced X-ray Imaging Crystal Spectrometer for Magnetic Fusion Tokamak Devices

NASA Astrophysics Data System (ADS)

Lee, S. G.; Bak, J. G.; Bog, M. G.; Nam, U. W.; Moon, M. K.; Cheon, J. K.

2008-03-01

An advanced X-ray imaging crystal spectrometer is currently under development using a segmented position sensitive detector and time-to-digital converter (TDC) based delay-line readout electronics for burning plasma diagnostics. The proposed advanced XICS utilizes an eight-segmented position sensitive multi-wire proportional counter and supporting electronics to increase the spectrometer performance includes the photon count-rate capability and spatial resolution.

Single-mode 140 nm swept light source realized by using SSG-DBR lasers

NASA Astrophysics Data System (ADS)

Fujiwara, N.; Yoshimura, R.; Kato, K.; Ishii, H.; Kano, F.; Kawaguchi, Y.; Kondo, Y.; Ohbayashi, K.; Oohashi, H.

2008-02-01

We demonstrate a single-mode and fast wavelength swept light source by using Superestrucuture grating distributed Bragg reflector (SSG-DBR) lasers for use in optical frequency-domain reflectometry optical coherence tomography. The SSG-DBR lasers provide single-mode operation resulting in high coherency. Response of the wavelength tuning is very fast; several nanoseconds, but there was an unintentional wavelength drift resulting from a thermal drift due to injecting tuning current. The dri1ft unfortunately requires long time to converge; more than a few milliseconds. For suppressing the wavelength drift, we introduced Thermal Drift Compensation mesa (TDC) parallel to the laser mesa with the spacing of 20 μm. By controlling TDC current to satisfy the total electric power injected into both the laser mesa and the TDC mesa, the thermal drift can be suppressed. In the present work, we fabricated 4 wavelength's kinds of SSG-DBR laser, which covers respective wavelength band; S-band (1496-1529 nm), C-band (1529-1564 nm), L --band (1564-1601 nm), and L +-band (1601-1639). We set the frequency channel of each laser with the spacing 6.25 GHz and 700 channels. The total frequency channel number is 2800 channels (700 ch × 4 lasers). We simultaneously operated the 4 lasers with a time interval of 500 ns/channel. A wavelength tuning range of more than 140 nm was achieved within 350 μs. The output power was controlled to be 10 mW for all channels. A single-mode, accurate, wide, and fast wavelength sweep was demonstrated with the SSG-DBR lasers having TDC mesa structure for the first time.

3D CT cerebral angiography technique using a 320-detector machine with a time-density curve and low contrast medium volume: comparison with fixed time delay technique.

PubMed

Das, K; Biswas, S; Roughley, S; Bhojak, M; Niven, S

2014-03-01

To describe a cerebral computed tomography angiography (CTA) technique using a 320-detector CT machine and a small contrast medium volume (35 ml, 15 ml for test bolus). Also, to compare the quality of these images with that of the images acquired using a larger contrast medium volume (90 or 120 ml) and a fixed time delay (FTD) of 18 s using a 16-detector CT machine. Cerebral CTA images were acquired using a 320-detector machine by synchronizing the scanning time with the time of peak enhancement as determined from the time-density curve (TDC) using a test bolus dose. The quality of CTA images acquired using this technique was compared with that obtained using a FTD of 18 s (by 16-detector CT), retrospectively. Average densities in four different intracranial arteries, overall opacification of arteries, and the degree of venous contamination were graded and compared. Thirty-eight patients were scanned using the TDC technique and 40 patients using the FTD technique. The arterial densities achieved by the TDC technique were higher (significant for supraclinoid and basilar arteries, p < 0.05). The proportion of images deemed as having "good" arterial opacification was 95% for TDC and 90% for FTD. The degree of venous contamination was significantly higher in images produced by the FTD technique (p < 0.001%). Good diagnostic quality CTA images with significant reduction of venous contamination can be achieved with a low contrast medium dose using a 320-detector machine by coupling the time of data acquisition with the time of peak enhancement. Copyright © 2013 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

Age and Hydration dependence of jowl and forearm skin firmness in young and mature women.

PubMed

Mayrovitz, Harvey N; Wong, Jennifer; Fasen, Madeline

2017-12-27

Quantitative assessment of possible linkages between skin's firmness and water content is useful for cosmetic and clinical purposes and to better understand features of advancing age. Our goals were to characterize age-related differential features in skin firmness in women and determine the relationship between skin firmness and indices of skin water. Skin firmness was quantified using handheld devices that measure the force to indent skin 0.3 and 1.3 mm (F0.3 and F1.3). Skin hydration was quantified using handheld devices that measured tissue dielectric constant (TDC) at 300 MHz to skin depths of 0.5 and 2.0-2.5 mm. All parameters were measured bilaterally in the jowl area and volar forearm of 60 women grouped by age <45 years (YOUNG) and ≥45 years old (MATURE). All measured parameters were bilaterally symmetrical at jowl and forearm. Forearm and jowl indentation forces were greater in YOUNG with statistically significant declines with advancing age with regression relations most evident at shallower indentation depths (P < .001). Quantitative relations for arm and jowl were F 0.3 = 0.256 × AGE + 32.7 mN and F 0.3 = -0.07 × AGE + 17.7 mN. Firmness was related to TDC values only when indentation force and TDC were assessed on the arm at the shallowest skin depths, as weakly related to firmness and was observed to change with age only when measured to a depth of 0.5 mm represented by TDC5 = 0.096 × AGE + 32.7. Experimental finding show clear differences in skin firmness between age-groups with skin hydration playing a minor role. Possible explanations and suggestions for further studies are provided. © 2017 Wiley Periodicals, Inc.

STRONG LENS TIME DELAY CHALLENGE. II. RESULTS OF TDC1

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

Liao, Kai; Treu, Tommaso; Marshall, Phil

2015-02-10

We present the results of the first strong lens time delay challenge. The motivation, experimental design, and entry level challenge are described in a companion paper. This paper presents the main challenge, TDC1, which consisted of analyzing thousands of simulated light curves blindly. The observational properties of the light curves cover the range in quality obtained for current targeted efforts (e.g., COSMOGRAIL) and expected from future synoptic surveys (e.g., LSST), and include simulated systematic errors. Seven teams participated in TDC1, submitting results from 78 different method variants. After describing each method, we compute and analyze basic statistics measuring accuracy (ormore » bias) A, goodness of fit χ{sup 2}, precision P, and success rate f. For some methods we identify outliers as an important issue. Other methods show that outliers can be controlled via visual inspection or conservative quality control. Several methods are competitive, i.e., give |A| < 0.03, P < 0.03, and χ{sup 2} < 1.5, with some of the methods already reaching sub-percent accuracy. The fraction of light curves yielding a time delay measurement is typically in the range f = 20%-40%. It depends strongly on the quality of the data: COSMOGRAIL-quality cadence and light curve lengths yield significantly higher f than does sparser sampling. Taking the results of TDC1 at face value, we estimate that LSST should provide around 400 robust time-delay measurements, each with P < 0.03 and |A| < 0.01, comparable to current lens modeling uncertainties. In terms of observing strategies, we find that A and f depend mostly on season length, while P depends mostly on cadence and campaign duration.« less

Multichannel FPGA based MVT system for high precision time (20 ps RMS) and charge measurement

NASA Astrophysics Data System (ADS)

Pałka, M.; Strzempek, P.; Korcyl, G.; Bednarski, T.; Niedźwiecki, Sz.; Białas, P.; Czerwiński, E.; Dulski, K.; Gajos, A.; Głowacz, B.; Gorgol, M.; Jasińska, B.; Kamińska, D.; Kajetanowicz, M.; Kowalski, P.; Kozik, T.; Krzemień, W.; Kubicz, E.; Mohhamed, M.; Raczyński, L.; Rudy, Z.; Rundel, O.; Salabura, P.; Sharma, N. G.; Silarski, M.; Smyrski, J.; Strzelecki, A.; Wieczorek, A.; Wiślicki, W.; Zieliński, M.; Zgardzińska, B.; Moskal, P.

2017-08-01

In this article it is presented an FPGA based Multi-Voltage Threshold (MVT) system which allows of sampling fast signals (1-2 ns rising and falling edge) in both voltage and time domain. It is possible to achieve a precision of time measurement of 20 ps RMS and reconstruct charge of signals, using a simple approach, with deviation from real value smaller than 10%. Utilization of the differential inputs of an FPGA chip as comparators together with an implementation of a TDC inside an FPGA allowed us to achieve a compact multi-channel system characterized by low power consumption and low production costs. This paper describes realization and functioning of the system comprising 192-channel TDC board and a four mezzanine cards which split incoming signals and discriminate them. The boards have been used to validate a newly developed Time-of-Flight Positron Emission Tomography system based on plastic scintillators. The achieved full system time resolution of σ(TOF) ≈ 68 ps is by factor of two better with respect to the current TOF-PET systems.

Comparison of algorithms to generate event times conditional on time-dependent covariates.

PubMed

Sylvestre, Marie-Pierre; Abrahamowicz, Michal

2008-06-30

The Cox proportional hazards model with time-dependent covariates (TDC) is now a part of the standard statistical analysis toolbox in medical research. As new methods involving more complex modeling of time-dependent variables are developed, simulations could often be used to systematically assess the performance of these models. Yet, generating event times conditional on TDC requires well-designed and efficient algorithms. We compare two classes of such algorithms: permutational algorithms (PAs) and algorithms based on a binomial model. We also propose a modification of the PA to incorporate a rejection sampler. We performed a simulation study to assess the accuracy, stability, and speed of these algorithms in several scenarios. Both classes of algorithms generated data sets that, once analyzed, provided virtually unbiased estimates with comparable variances. In terms of computational efficiency, the PA with the rejection sampler reduced the time necessary to generate data by more than 50 per cent relative to alternative methods. The PAs also allowed more flexibility in the specification of the marginal distributions of event times and required less calibration.

Ion-ion coincidence imaging at high event rate using an in-vacuum pixel detector.

PubMed

Long, Jingming; Furch, Federico J; Durá, Judith; Tremsin, Anton S; Vallerga, John; Schulz, Claus Peter; Rouzée, Arnaud; Vrakking, Marc J J

2017-07-07

A new ion-ion coincidence imaging spectrometer based on a pixelated complementary metal-oxide-semiconductor detector has been developed for the investigation of molecular ionization and fragmentation processes in strong laser fields. Used as a part of a velocity map imaging spectrometer, the detection system is comprised of a set of microchannel plates and a Timepix detector. A fast time-to-digital converter (TDC) is used to enhance the ion time-of-flight resolution by correlating timestamps registered separately by the Timepix detector and the TDC. In addition, sub-pixel spatial resolution (<6 μm) is achieved by the use of a center-of-mass centroiding algorithm. This performance is achieved while retaining a high event rate (10 4 per s). The spectrometer was characterized and used in a proof-of-principle experiment on strong field dissociative double ionization of carbon dioxide molecules (CO 2 ), using a 400 kHz repetition rate laser system. The experimental results demonstrate that the spectrometer can detect multiple ions in coincidence, making it a valuable tool for studying the fragmentation dynamics of molecules in strong laser fields.

Ion-ion coincidence imaging at high event rate using an in-vacuum pixel detector

NASA Astrophysics Data System (ADS)

Long, Jingming; Furch, Federico J.; Durá, Judith; Tremsin, Anton S.; Vallerga, John; Schulz, Claus Peter; Rouzée, Arnaud; Vrakking, Marc J. J.

2017-07-01

A new ion-ion coincidence imaging spectrometer based on a pixelated complementary metal-oxide-semiconductor detector has been developed for the investigation of molecular ionization and fragmentation processes in strong laser fields. Used as a part of a velocity map imaging spectrometer, the detection system is comprised of a set of microchannel plates and a Timepix detector. A fast time-to-digital converter (TDC) is used to enhance the ion time-of-flight resolution by correlating timestamps registered separately by the Timepix detector and the TDC. In addition, sub-pixel spatial resolution (<6 μm) is achieved by the use of a center-of-mass centroiding algorithm. This performance is achieved while retaining a high event rate (104 per s). The spectrometer was characterized and used in a proof-of-principle experiment on strong field dissociative double ionization of carbon dioxide molecules (CO2), using a 400 kHz repetition rate laser system. The experimental results demonstrate that the spectrometer can detect multiple ions in coincidence, making it a valuable tool for studying the fragmentation dynamics of molecules in strong laser fields.

Mesial Temporal Lobe and Memory Function in Autism Spectrum Disorder: An Exploration of Volumetric Findings

PubMed Central

Trontel, Haley G.; Duffield, Tyler C.; Bigler, Erin D.; Abildskov, Tracy J.; Froehlich, Alyson; Prigge, Molly B.D.; Travers, Brittany G.; Anderson, Jeffrey S.; Zielinski, Brandon A.; Alexander, Andrew; Lange, Nicholas; Lainhart, Janet E.

2015-01-01

Studies have shown that individuals with autism spectrum disorder (ASD) tend to perform significantly below typical developing individuals on standardized measures of memory, even when not significantly different on measures of IQ. The current study sought to examine within ASD whether anatomical correlates of memory performance differed between those with average-to-above-average IQ (AIQ Group) compared to those with low average to borderline ability (LIQ group) as well as in relations to typically-developing comparisons (TDC). Using automated volumetric analyses, we examined regional volume of classic memory areas including the hippocampus, parahippocampal gyrus, entorhinal cortex, and amygdala in an all-male sample AIQ (n = 38) and LIQ (n = 18) individuals with ASD along with 30 typically-developing comparisons (TDC). Memory performance was assessed using the Test of Memory and Learning (TOMAL) compared among the groups and then correlated with regional brain volumes. Analyses revealed group differences on almost all facets of memory and learning as assessed by the various subtests of the TOMAL. The three groups did not differ on any ROI memory-related brain volumes. However, significant size-memory function interactions were observed. Negative correlations were found between the volume of the amygdala and composite, verbal, and delayed memory indices for the LIQ ASD group indicating larger volume related to poorer performance. Implications for general memory functioning and dysfunctional neural connectivity in ASD are discussed. PMID:25749302

Auditory attention in autism spectrum disorder: An exploration of volumetric magnetic resonance imaging findings.

PubMed

Lalani, Sanam J; Duffield, Tyler C; Trontel, Haley G; Bigler, Erin D; Abildskov, Tracy J; Froehlich, Alyson; Prigge, Molly B D; Travers, Brittany G; Anderson, Jeffrey S; Zielinski, Brandon A; Alexander, Andrew; Lange, Nicholas; Lainhart, Janet E

2018-06-01

Studies have shown that individuals with autism spectrum disorder (ASD) tend to perform significantly below typically developing individuals on standardized measures of attention, even when controlling for IQ. The current study sought to examine within ASD whether anatomical correlates of attention performance differed between those with average to above-average IQ (AIQ group) and those with low-average to borderline ability (LIQ group) as well as in comparison to typically developing controls (TDC). Using automated volumetric analyses, we examined regional volume of classic attention areas including the superior frontal gyrus, anterior cingulate cortex, and precuneus in ASD AIQ (n = 38) and LIQ (n = 18) individuals along with 30 TDC. Auditory attention performance was assessed using subtests of the Test of Memory and Learning (TOMAL) compared among the groups and then correlated with regional brain volumes. Analyses revealed group differences in attention. The three groups did not differ significantly on any auditory attention-related brain volumes; however, trends toward significant size-attention function interactions were observed. Negative correlations were found between the volume of the precuneus and auditory attention performance for the AIQ ASD group, indicating larger volume related to poorer performance. Implications for general attention functioning and dysfunctional neural connectivity in ASD are discussed.

Subnanosecond time-to-digital converter implemented in a Kintex-7 FPGA

NASA Astrophysics Data System (ADS)

Sano, Y.; Horii, Y.; Ikeno, M.; Sasaki, O.; Tomoto, M.; Uchida, T.

2017-12-01

Time-to-digital converters (TDCs) are used in various fields, including high-energy physics. One advantage of implementing TDCs in field-programmable gate arrays (FPGAs) is the flexibility on the modification of the logics, which is useful to cope with the changes in the experimental conditions. Recent FPGAs make it possible to implement TDCs with a time resolution less than 10 ps. On the other hand, various drift chambers require a time resolution of O(0.1) ns, and a simple and easy-to-implement TDC is useful for a robust operation. Herein an eight-channel TDC with a variable bin size down to 0.28 ns is implemented in a Xilinx Kintex-7 FPGA and tested. The TDC is based on a multisampling scheme with quad phase clocks synchronised with an external reference clock. Calibration of the bin size is unnecessary if a stable reference clock is available, which is common in high-energy physics experiments. Depending on the channel, the standard deviation of the differential nonlinearity for a 0.28 ns bin size is 0.13-0.31. The performance has a negligible dependence on the temperature. The power consumption and the potential to extend the number of channels are also discussed.

A High-Linearity, Ring-Oscillator-Based, Vernier Time-to-Digital Converter Utilizing Carry Chains in FPGAs

NASA Astrophysics Data System (ADS)

Cui, Ke; Ren, Zhongjie; Li, Xiangyu; Liu, Zongkai; Zhu, Rihong

2017-01-01

Time-to-digital converters (TDCs) using dedicated carry chains of field programmable gate arrays (FPGAs) are usually organized in tapped-delay-line type which are intensively researched in recent years. However this method incurs poor differential nonlinearity (DNL) which arises from the inherent uneven bin granularity. This paper proposes a TDC architecture which utilizes the carry chains in a quite different manner in order to alleviate this long-standing problem. Two independent carry chains working as the delay lines for the fine time interpolation are organized in a ring-oscillator-based Vernier style and the time difference between them is finely adjusted by assigning different number of basic delay cells. A specific design flow is described to obtain the desired delay difference. The TDC was implemented on a Stratix III FPGA. Test results show that the obtained resolution is 31 ps and the DNL\\INL is in the range of (-0.080 LSB, 0.073 LSB)(-0.087 LSB, 0.091 LSB). This demonstrates that the proposed architecture greatly improves linearity compared to previous techniques. Additionally the resource cost is rather low which uses only 319 LUTs and 104 registers per TDC channel.

Orders of Magnitude Extension of the Effective Dynamic Range of TDC-Based TOFMS Data Through Maximum Likelihood Estimation

NASA Astrophysics Data System (ADS)

Ipsen, Andreas; Ebbels, Timothy M. D.

2014-10-01

In a recent article, we derived a probability distribution that was shown to closely approximate that of the data produced by liquid chromatography time-of-flight mass spectrometry (LC/TOFMS) instruments employing time-to-digital converters (TDCs) as part of their detection system. The approach of formulating detailed and highly accurate mathematical models of LC/MS data via probability distributions that are parameterized by quantities of analytical interest does not appear to have been fully explored before. However, we believe it could lead to a statistically rigorous framework for addressing many of the data analytical problems that arise in LC/MS studies. In this article, we present new procedures for correcting for TDC saturation using such an approach and demonstrate that there is potential for significant improvements in the effective dynamic range of TDC-based mass spectrometers, which could make them much more competitive with the alternative analog-to-digital converters (ADCs). The degree of improvement depends on our ability to generate mass and chromatographic peaks that conform to known mathematical functions and our ability to accurately describe the state of the detector dead time—tasks that may be best addressed through engineering efforts.

Towards an optimal therapy strategy for myogenous TMD, physiotherapy compared with occlusal splint therapy in an RCT with therapy-and-patient-specific treatment durations.

PubMed

van Grootel, Robert J; Buchner, Rob; Wismeijer, Daniël; van der Glas, Hilbert W

2017-02-10

Temporomandibular Disorders (TMD) may be characterized by pain and restricted jaw movements. In the absence of somatic factors in the temporomandibular joint, mainly myogenous, psychobiological, and psychosocial factors may be involved in the aetiology of myogenous TMD. An occlusal appliance (splint) is commonly used as a basic therapy of the dental practice. Alternatively, a type of physiotherapy which includes, apart from massage of sore muscles, aspects of cognitive-behavioural therapy might be a basic therapy for myogenous TMD. Treatment outcome of physiotherapy (Ph-Tx) was evaluated in comparison to that of splint therapy (Sp-Tx), using the index Treatment Duration Control (TDC) that enabled a randomized controlled trial with, comparable to clinical care, therapy-and-patient-specific treatment durations. Seventy-two patients were randomly assigned to either Ph-Tx or Sp-Tx, with an intended treatment duration between 10 and 21 or 12 and 30 weeks respectively. Using TDC, the clinician controlled treatment duration and the number of visits needed. A blinded assessor recorded anamnestic and clinical data to determine TDC-values following treatment and a 1-year follow-up, yielding success rate (SR) and effectiveness (mean TDC) as treatment outcomes. Cohen's d, was determined for pain intensity. Overall SR for stepped-care was assessed in a theoretical model, i.e. a second of the two studied therapies was applied if the first treatment was unsuccessful, and the effect of therapy sequence and difference in success rates was examined. SR and effectiveness were similar for Ph-Tx and Sp-Tx (long-term SR: 51-60%; TDC: -0.512- -0.575). Cohen's d was 0.86 (Ph-Tx) and 1.39 (Sp-Tx). Treatment duration was shorter for Ph-Tx (on average 10.4 weeks less; p < 0.001). Sp-Tx needed 7.1 less visits (p < 0.001). Physiotherapy may be preferred as initial therapy over occlusal splint therapy in stepped-care of myogenous TMD. With a similar SR and effectiveness, physiotherapy has a shorter duration. Thus patients whose initial physiotherapy is unsuccessful can continue earlier with subsequent treatment. The stepped-care model reinforces the conclusion on therapy preference as the overall SR hardly depends on therapy sequence. isrctn.com/ISRCTN17469828 . Retrospectively registered: 11/11/2016.

Three-Dimensional Magnetic Analysis Technique Developed for Evaluating Stirling Convertor Linear Alternators

NASA Technical Reports Server (NTRS)

Geng, Steven M.

2003-01-01

The Department of Energy, the Stirling Technology Company (STC), and the NASA Glenn Research Center are developing Stirling convertors for Stirling radioisotope generators to provide electrical power for future NASA deep space missions. STC is developing the 55-We technology demonstration convertor (TDC) under contract to the Department of Energy. The Department of Energy recently named Lockheed Martin as the system integration contractor for the Stirling radioisotope generator development project. Lockheed Martin will develop the Stirling radioisotope generator engineering unit and has contract options to develop the qualification unit and the first flight unit. Glenn s role includes an in-house project to provide convertor, component, and materials testing and evaluation in support of the overall power system development. As a part of this work, Glenn has established an in-house Stirling research laboratory for testing, analyzing, and evaluating Stirling machines. STC has built four 55-We convertors for NASA, and these are being tested at Glenn. A cross-sectional view of the 55-We TDC is shown in the figure. Of critical importance to the successful development of the Stirling convertor for space power applications is the development of a lightweight and highly efficient linear alternator. In support, Glenn has been developing finite element analysis and finite element method tools for performing various linear alternator thermal and electromagnetic analyses and evaluating design configurations. A three-dimensional magnetostatic finite element model of STC's 55-We TDC linear alternator was developed to evaluate the demagnetization fields affecting the alternator magnets. Since the actual linear alternator hardware is symmetric to the quarter section about the axis of motion, only a quarter section of the alternator was modeled. The components modeled included the mover laminations, the neodymium-iron-boron magnets, the stator laminations, and the copper coils. The three-dimensional magnetostatic model was then coupled with a circuit simulator model of the alternator load and convertor controller. The coupled model was then used to generate alternator terminal voltage and current predictions. The predicted voltage and current waveforms agreed well with the experimental data, which tended to validate the accuracy of the coupled model. The model was then used to generate predictions of the demagnetization fields acting on the alternator magnets for the alternator under load. The preliminary model predictions indicate that the highest potential for demagnetization is along the inside surface of the uncovered magnets. The demagnetization field for the uncovered magnets when the mover is positioned at the end of a stroke is higher than it is when the mover is at the position of maximum induced voltage or maximum alternator current. Assuming normal load conditions, the model predicted that the onset of demagnetization is most likely to occur for magnet temperatures above 101 C.

A Dynamic Range Enhanced Readout Technique with a Two-Step TDC for High Speed Linear CMOS Image Sensors.

PubMed

Gao, Zhiyuan; Yang, Congjie; Xu, Jiangtao; Nie, Kaiming

2015-11-06

This paper presents a dynamic range (DR) enhanced readout technique with a two-step time-to-digital converter (TDC) for high speed linear CMOS image sensors. A multi-capacitor and self-regulated capacitive trans-impedance amplifier (CTIA) structure is employed to extend the dynamic range. The gain of the CTIA is auto adjusted by switching different capacitors to the integration node asynchronously according to the output voltage. A column-parallel ADC based on a two-step TDC is utilized to improve the conversion rate. The conversion is divided into coarse phase and fine phase. An error calibration scheme is also proposed to correct quantization errors caused by propagation delay skew within -T(clk)~+T(clk). A linear CMOS image sensor pixel array is designed in the 0.13 μm CMOS process to verify this DR-enhanced high speed readout technique. The post simulation results indicate that the dynamic range of readout circuit is 99.02 dB and the ADC achieves 60.22 dB SNDR and 9.71 bit ENOB at a conversion rate of 2 MS/s after calibration, with 14.04 dB and 2.4 bit improvement, compared with SNDR and ENOB of that without calibration.

Pre-training Catechin gavage prevents memory impairment induced by intracerebroventricular streptozotocin in rats.

PubMed

Zamani, Marzieh; Rohampour, Kambiz; Zeraati, Maryam; Hosseinmardi, Narges; Kazemian, Mostafa M

2015-07-01

To evaluate the effects of Catechin (CAT) on memory acquisition and retrieval in the animal model of sporadic alzheimer`s disease (sAD) induced by intracerebroventricular (icv) injection of streptozotocin (STZ) in passive avoidance memory test. Thirty adult rats were divided into 5 experimental groups (n=6). Animals were treated by icv saline/STZ (3 mg/kg) injection at day one and 3 after cannulation. The STZ+CAT group received 40 mg/kg CAT by daily gavages for 10 days, after icv STZ treatment and before training. The step-through latency (STL) and time spent in the dark compartment (TDC) were evaluated to examine the memory acquisition and retrieval. All tests were performed in Qom University of Medical Sciences, Qom, Iran, from April to December 2013. The STZ treatment significantly decreased STL and increased the number of entries to the dark compartment on the training day. It also increased TDC, on day one and 7 after training. Pre-training gavage of CAT reversed the STL significantly (p=0.027). The CAT treatment also decreased the TDC in both early and late retrieval, in respect to STZ group. This data suggests that CAT as an antioxidant could improve both memory acquisition and retrieval in the animal model of sAD.

The Gigatracker: An ultra-fast and low-mass silicon pixel detector for the NA62 experiment

NASA Astrophysics Data System (ADS)

Fiorini, M.; Carassiti, V.; Ceccucci, A.; Cortina, E.; Cotta Ramusino, A.; Dellacasa, G.; Garbolino, S.; Jarron, P.; Kaplon, J.; Kluge, A.; Mapelli, A.; Marchetto, F.; Martin, E.; Martoiu, S.; Mazza, G.; Morel, M.; Noy, M.; Nuessle, G.; Petrucci, F.; Riedler, P.; Aglieri Rinella, G.; Rivetti, A.; Tiuraniemi, S.

2011-02-01

The Gigatracker is a hybrid silicon pixel detector developed to track the highly intense NA62 hadron beam with a time resolution of 150 ps (rms). The beam spectrometer of the experiment is composed of three Gigatracker stations installed in vacuum in order to precisely measure momentum, time and direction of every traversing particle. Precise tracking demands a very low mass of the detector assembly ( <0.5% X0 per station) in order to limit multiple scattering and beam hadronic interactions. The high rate and especially the high timing precision requirements are very demanding: two R&D options are ongoing and the corresponding prototype read-out chips have been recently designed and produced in 0.13 μm CMOS technology. One solution makes use of a constant fraction discriminator and on-pixel analogue-based time-to-digital-converter (TDC); the other comprises a delay-locked loop based TDC placed at the end of each pixel column and a time-over-threshold discriminator with time-walk correction technique. The current status of the R&D program is overviewed and results from the prototype read-out chips test are presented.

An improved electronic twist-drill craniostomy procedure with post-operative urokinase instillation in treating chronic subdural hematoma.

PubMed

Lu, Jing; Shen, Dongwei; Hu, Fangjin; Zhou, Jianjun; Lan, Folin; Guo, Dongbing; Liu, Tianqing

2015-09-01

Twist-drill craniostomy (TDC) with closed-system drainage is a less invasive surgical technique for the treatment of chronic subdural hematoma (CSDH), but results in a higher disease recurrence rate. Therefore, we aimed to modify the TDC procedure in order to reduce the recurrence rate and further decrease complications. We retrospectively reviewed 230 cases of standard CSDH in 202 patients treated in our hospital between January 2006 and December 2013. We employed a new TDC device called micro-steel-needle-tube-bit for puncture and drainage. We chose an entry point 0.5cm anterior to the coronal suture at the superior temporal line and maintained post-operative drainage with urokinase instillation into the hematoma cavity. Clinical performance was assessed and compared by the Markwalder Grading Scale (MGS) score during the pre-operative period and at discharge. Recurrence of CSDH and complications were also recorded. Mean operation time was only 8.9 (6-13) min. Mean catheter indwelling duration and hospital stay were 1.18 (271/230, 1-3) and 2.27 (458/202, 2-9) days, respectively. The average frequency of urokinase instillation was 1.14 (262/230, 1-3) times. Intracerebral and sub-arachnoid hemorrhages were found in one patient, but were not in the puncture pathway. No perioperative deaths occurred. Recurrence was observed in only one patient at 28 days post-operation. Among 202 patients, 193 (95.54%) showed improved clinical symptoms and neurological function, and significantly lower MGS scores at discharge than pre-operation (0.13±0.45 vs. 1.37±0.55, P<0.01). In conclusion, electric TDC with micro-steel-needle-tube-bit at the pre-coronal suture entry point might be a safer, simpler, and faster mini-invasive surgical procedure for CSDH treatment. Post-operative drainage with instillation of urokinase could dramatically shorten drainage time and decrease recurrence rate. Copyright © 2015 Elsevier B.V. All rights reserved.

IMOTEPAD: A mixed-signal 64-channel front-end ASIC for small-animal PET imaging

NASA Astrophysics Data System (ADS)

Fang, Xiaochao; Ollivier-Henry, Nicolas; Gao, Wu; Hu-Guo, Christine; Colledani, Claude; Humbert, Bernard; Brasse, David; Hu, Yann

2011-04-01

This paper presents the design and characteristics of a mixed-signal 64-channel front-end readout ASIC called IMOTEPAD dedicated to multi-channel plate (MCP) photodetector coupled to LYSO scintillating crystals for small-animal PET imaging. In our configuration, the crystals are oriented in the axial direction readout on both sides by individual photodetector channels allowing the spatial resolution and the detection efficiency to be independent of each other. As a result, both energy signals and timing triggers from the photodetectors are required to be read out by the front-end ASIC. This dedicated ASIC IMOTEPAD comprises two parts: the analog part IMOTEPA and the digital part IMOTEPD. The IMOTEPA is dedicated to energy measurement. And the timing information is digitized by the IMOTEPD in which the key principal element is a time-to-digital converter (TDC) based on a delay-locked loop (DLL) with 32 delay cells. The chip is designed and fabricated in 0.35 μm CMOS process. The measurements show that for the analog part IMOTEPA, the energy gain is 13.1 mV/pC while the peak time of a CR-RC pulse shaper is 280 ns. The SNR is 39 dB and the RMS noise is 300 μV. The nonlinearity is less than 3%. The crosstalk is less than 0.2%. For the IMOTEPD, the bin size of the TDC is 625 ps with a reference clock of 50 MHz. The RMS jitter of the DLL is less than 42 ps. The DNL of the TDC is equal to about 0.17 LSB and the INL is equal to 0.31 LSB. The power dissipation of each channel is less than 16.8 mW. The design of the ASIC, especially for TDC and the measurement results of the IMOTEPAD will be presented and discussed in this paper.

Design and prototype results of the FAST detector

NASA Astrophysics Data System (ADS)

Mozzanica, A.; Basset, M.; Caccia, M.; Corradini, M.; Leali, M.; Lodi Rizzini, E.; Prest, M.; Venturelli, L.; Vallazza, E.; Zurlo, N.

2006-11-01

A new fiber tracker is being developed for the ASACUSA experiment at the Antiproton Decelerator at CERN. The detector is based on 1 mm diameter scintillating fibers readout by HAMAMATSU 64 channel multianode photomultipliers (MA-PMTs) connected to a dedicated electronic chain. The paper gives a description of the testing procedures for time resolution, spatial resolution and efficiency measurements performed with standard NIM electronics and a commercial TDC and reports the results for different prototype detectors.

CYD-TDV dengue vaccine: systematic review and meta-analysis of efficacy, immunogenicity and safety.

PubMed

Godói, Isabella Piassi; Lemos, Livia Lovato Pires; de Araújo, Vânia Eloisa; Bonoto, Braúlio Cesar; Godman, Brian; Guerra Júnior, Augusto Afonso

2017-03-01

Dengue virus (DENV) is a serious global health problem. CYD-TDC (Dengvaxia ® ) was the first vaccine to gain regulatory approval to try and address this problem. Summarize all available evidence on the immunogenicity, efficacy and safety of the CYD-TDV dengue vaccine. Meta-analysis and systematic review. The best and worst immunogenicity results were for DENV4 and DENV1, respectively. Vaccine efficacy of 60% was derived from studies with participants aged 2-16 years old, with DENV4 and DENV2 presenting the best and worst results, respectively. Erythema and swelling were more frequent with CYD-TDV. No differences were detected for systemic adverse events. CYD-TDV showed moderate efficacy in children and adolescents. From the immunogenicity results in adults, we can expect satisfactory efficacy from vaccination in this population.

Structure, photoluminescent properties and photocatalytic activities of a new Cd(II) metal-organic framework.

PubMed

Zhang, Cheng Yan; Ma, Wei Xing; Wang, Ming Yan; Yang, Xu Jie; Xu, Xing You

2014-01-24

A new metal-organic framework, [Cd(TDC)(bix)(H2O)]n (H2TDC = thiophene-2,5-dicarboxylic acid; bix = 1,4-bis(imidazol-1-ylmethyl)benzene), has been synthesized under hydrothermal conditions and structurally characterized by elemental analysis, infrared spectroscopy, thermogravimetric analysis, UV-vis and single X-ray diffraction. Cd-MOF is a 2D infinite layer framework, which is further interconnected by hydrogen-bond interactions leading to a 3D supramolecular architecture. The photoluminescent properties of the Cd-MOF were investigated and this compound shows intense fluorescent emissions in the solid state. In addition, it exhibits good photocatalytic activities for the degradation of methyl organic under UV light irradiation. Copyright © 2013 Elsevier B.V. All rights reserved.

Cognitive flexibility and performance in children and adolescents with threshold and sub-threshold bipolar disorder.

PubMed

Dickstein, Daniel P; Axelson, David; Weissman, Alexandra B; Yen, Shirley; Hunt, Jeffrey I; Goldstein, Benjamin I; Goldstein, Tina R; Liao, Fangzi; Gill, Mary Kay; Hower, Heather; Frazier, Thomas W; Diler, Rasim S; Youngstrom, Eric A; Fristad, Mary A; Arnold, L Eugene; Findling, Robert L; Horwitz, Sarah M; Kowatch, Robert A; Ryan, Neal D; Strober, Michael; Birmaher, Boris; Keller, Martin B

2016-06-01

Greater understanding of cognitive function in children and adolescents with bipolar disorder (BD) is of critical importance to improve our ability to design targeted treatments to help with real-world impairment, including academic performance. We sought to evaluate cognitive performance among children with either BD type I, II, or "not otherwise specified" (NOS) participating in multi-site Course and Outcome of Bipolar Youth study compared to typically developing controls (TDC) without psychopathology. In particular, we sought to test the hypothesis that BD-I and BD-II youths with full threshold episodes of mania or hypomania would have cognitive deficits, including in reversal learning, vs. those BD-NOS participants with sub-threshold episodes and TDCs. N = 175 participants (BD-I = 81, BD-II = 11, BD-NOS = 28, TDC = 55) completed Cambridge Neuropsychological Automated Testing Battery (CANTAB) tasks. A priori analyses of the simple reversal stage of the CANTAB intra-/extra-dimensional shift task showed that aggregated BD-I/II participants required significantly more trials to complete the task than either BD-NOS participants with sub-syndromal manic/hypomanic symptoms or than TDCs. BD participants across sub-types had impairments in sustained attention and information processing for emotionally valenced words. Our results align with prior findings showing that BD-I/II youths with distinct episodes have specific alterations in reversal learning. More broadly, our study suggests that further work is necessary to see the interaction between neurocognitive performance and longitudinal illness course. Additional work is required to identify the neural underpinnings of these differences as targets for potential novel treatments, such as cognitive remediation.

[Family health and infant palliative care: listening the relatives of technology dependent children].

PubMed

Rabello, Claudia Azevedo Ferreira Guimarães; Rodrigues, Paulo Henrique de Almeida

2010-10-01

This study discusses the creation of a new child palliative care program based on the Family Health Program, considering the level of care at home and yielding to family requests. Eighteen members of nine families of technology dependent children (TDC) who were hospital patients in the Instituto Fernandes Figueira (IFF) participated on the study. From those four were being assisted by its palliative care program Programa de Assistência Domiciliar Interdisciplinar (PADI); three were inpatients waiting for inclusion in the program, and finally two inpatients already included in PADI. PADI was chosen because it is the only child palliative care program in Brazil. The results are positive in regards to the connection established between the families and the health care team, the reception of the children, the explanation to the family concerning the disease, and the functional dynamics between the PADI and the IFF. As negative points, difficulties arose as a result of the implementation of the program, from its continuity to the worsening or illness of the entire family. In conclusion, although the PADI is the IFF's way of discharging patients, the domiciliary care provided by the Family Health Program, well articulated with the healthcare system, would be ideal for being the adequate assistance for it.

Melatonin mediates selenium-induced tolerance to cadmium stress in tomato plants.

PubMed

Li, Meng-Qi; Hasan, Md Kamrul; Li, Cai-Xia; Ahammed, Golam Jalal; Xia, Xiao-Jian; Shi, Kai; Zhou, Yan-Hong; Reiter, Russel J; Yu, Jing-Quan; Xu, Ming-Xing; Zhou, Jie

2016-10-01

Both selenium (Se) and melatonin reduce cadmium (Cd) uptake and mitigate Cd toxicity in plants. However, the relationship between Se and melatonin in Cd detoxification remains unclear. In this study, we investigated the influence of three forms of Se (selenocysteine, sodium selenite, and sodium selenate) on the biosynthesis of melatonin and the tolerance against Cd in tomato plants. Pretreatment with different forms of Se significantly induced the biosynthesis of melatonin and its precursors (tryptophan, tryptamine, and serotonin); selenocysteine had the most marked effect on melatonin biosynthesis. Furthermore, Se and melatonin supplements significantly increased plant Cd tolerance as evidenced by decreased growth inhibition, photoinhibition, and electrolyte leakage (EL). Se-induced Cd tolerance was compromised in melatonin-deficient plants following tryptophan decarboxylase (TDC) gene silencing. Se treatment increased the levels of glutathione (GSH) and phytochelatins (PCs), as well as the expression of GSH and PC biosynthetic genes in nonsilenced plants, but the effects of Se were compromised in TDC-silenced plants under Cd stress. In addition, Se and melatonin supplements reduced Cd content in leaves of nonsilenced plants, but Se-induced reduction in Cd content was compromised in leaves of TDC-silenced plants. Taken together, our results indicate that melatonin is involved in Se-induced Cd tolerance via the regulation of Cd detoxification. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Parallel characterization of anaerobic toluene- and ethylbenzene-degrading microbial consortia by PCR-denaturing gradient gel electrophoresis, RNA-DNA membrane hybridization, and DNA microarray technology

NASA Technical Reports Server (NTRS)

Koizumi, Yoshikazu; Kelly, John J.; Nakagawa, Tatsunori; Urakawa, Hidetoshi; El-Fantroussi, Said; Al-Muzaini, Saleh; Fukui, Manabu; Urushigawa, Yoshikuni; Stahl, David A.

2002-01-01

A mesophilic toluene-degrading consortium (TDC) and an ethylbenzene-degrading consortium (EDC) were established under sulfate-reducing conditions. These consortia were first characterized by denaturing gradient gel electrophoresis (DGGE) fingerprinting of PCR-amplified 16S rRNA gene fragments, followed by sequencing. The sequences of the major bands (T-1 and E-2) belonging to TDC and EDC, respectively, were affiliated with the family Desulfobacteriaceae. Another major band from EDC (E-1) was related to an uncultured non-sulfate-reducing soil bacterium. Oligonucleotide probes specific for the 16S rRNAs of target organisms corresponding to T-1, E-1, and E-2 were designed, and hybridization conditions were optimized for two analytical formats, membrane and DNA microarray hybridization. Both formats were used to characterize the TDC and EDC, and the results of both were consistent with DGGE analysis. In order to assess the utility of the microarray format for analysis of environmental samples, oil-contaminated sediments from the coast of Kuwait were analyzed. The DNA microarray successfully detected bacterial nucleic acids from these samples, but probes targeting specific groups of sulfate-reducing bacteria did not give positive signals. The results of this study demonstrate the limitations and the potential utility of DNA microarrays for microbial community analysis.

Parallel Characterization of Anaerobic Toluene- and Ethylbenzene-Degrading Microbial Consortia by PCR-Denaturing Gradient Gel Electrophoresis, RNA-DNA Membrane Hybridization, and DNA Microarray Technology

PubMed Central

Koizumi, Yoshikazu; Kelly, John J.; Nakagawa, Tatsunori; Urakawa, Hidetoshi; El-Fantroussi, Saïd; Al-Muzaini, Saleh; Fukui, Manabu; Urushigawa, Yoshikuni; Stahl, David A.

2002-01-01

A mesophilic toluene-degrading consortium (TDC) and an ethylbenzene-degrading consortium (EDC) were established under sulfate-reducing conditions. These consortia were first characterized by denaturing gradient gel electrophoresis (DGGE) fingerprinting of PCR-amplified 16S rRNA gene fragments, followed by sequencing. The sequences of the major bands (T-1 and E-2) belonging to TDC and EDC, respectively, were affiliated with the family Desulfobacteriaceae. Another major band from EDC (E-1) was related to an uncultured non-sulfate-reducing soil bacterium. Oligonucleotide probes specific for the 16S rRNAs of target organisms corresponding to T-1, E-1, and E-2 were designed, and hybridization conditions were optimized for two analytical formats, membrane and DNA microarray hybridization. Both formats were used to characterize the TDC and EDC, and the results of both were consistent with DGGE analysis. In order to assess the utility of the microarray format for analysis of environmental samples, oil-contaminated sediments from the coast of Kuwait were analyzed. The DNA microarray successfully detected bacterial nucleic acids from these samples, but probes targeting specific groups of sulfate-reducing bacteria did not give positive signals. The results of this study demonstrate the limitations and the potential utility of DNA microarrays for microbial community analysis. PMID:12088997

Safety, beneficial and technological properties of Enterococcus faecium isolated from Brazilian cheeses

PubMed Central

dos Santos, Karina Maria Olbrich; Vieira, Antônio Diogo Silva; Salles, Hévila Oliveira; Oliveira, Jacqueline da Silva; Rocha, Cíntia Renata Costa; Borges, Maria de Fátima; Bruno, Laura Maria; Franco, Bernadette Dora Gombossy de Melo; Todorov, Svetoslav Dimitrov

2015-01-01

This study aimed to characterize the safety and technological properties of Enterococcus faecium strains isolated from Brazilian Coalho cheeses. High levels of co-aggregation were observed between Enterococcus faecium strains EM485 and EM925 and both Escherichia coli and Clostridium perfringens . Both strains presented low levels of hydrophobicity. E. faecium EM485 and EM925 were both able to grow in the presence of 0.5% of the sodium salts of taurocholic acid (TC), taurodeoxycholic acid (TDC), glycocholic acid (GC), and glycodeoxycholic acid (GDC), although they showed the ability to deconjugate only GDC and TDC. Both strains showed good survival when exposed to conditions simulating the gastro intestinal tract (GIT). When tested for the presence of virulence genes, only tyrosine decarboxylase and vancomycin B generated positive PCR results. PMID:26221113

Safety, beneficial and technological properties of Enterococcus faecium isolated from Brazilian cheeses.

PubMed

Dos Santos, Karina Maria Olbrich; Vieira, Antônio Diogo Silva; Salles, Hévila Oliveira; Oliveira, Jacqueline da Silva; Rocha, Cíntia Renata Costa; Borges, Maria de Fátima; Bruno, Laura Maria; Franco, Bernadette Dora Gombossy de Melo; Todorov, Svetoslav Dimitrov

2015-03-01

This study aimed to characterize the safety and technological properties of Enterococcus faecium strains isolated from Brazilian Coalho cheeses. High levels of co-aggregation were observed between Enterococcus faecium strains EM485 and EM925 and both Escherichia coli and Clostridium perfringens . Both strains presented low levels of hydrophobicity. E. faecium EM485 and EM925 were both able to grow in the presence of 0.5% of the sodium salts of taurocholic acid (TC), taurodeoxycholic acid (TDC), glycocholic acid (GC), and glycodeoxycholic acid (GDC), although they showed the ability to deconjugate only GDC and TDC. Both strains showed good survival when exposed to conditions simulating the gastro intestinal tract (GIT). When tested for the presence of virulence genes, only tyrosine decarboxylase and vancomycin B generated positive PCR results.

Multichannel low power time-to-digital converter card with 21 ps precision and full scale range up to 10 μs

NASA Astrophysics Data System (ADS)

Tamborini, D.; Portaluppi, D.; Villa, F.; Tisa, S.; Tosi, A.

2014-11-01

We present a Time-to-Digital Converter (TDC) card with a compact form factor, suitable for multichannel timing instruments or for integration into more complex systems. The TDC Card provides 10 ps timing resolution over the whole measurement range, which is selectable from 160 ns up to 10 μs, reaching 21 ps rms precision, 1.25% LSB rms differential nonlinearity, up to 3 Mconversion/s with 400 mW power consumption. The I/O edge card connector provides timing data readout through either a parallel bus or a 100 MHz serial interface and further measurement information like input signal rate and valid conversion rate (typically useful for time-correlated single-photon counting application) through an independent serial link.

Multichannel low power time-to-digital converter card with 21 ps precision and full scale range up to 10 μs.

PubMed

Tamborini, D; Portaluppi, D; Villa, F; Tisa, S; Tosi, A

2014-11-01

We present a Time-to-Digital Converter (TDC) card with a compact form factor, suitable for multichannel timing instruments or for integration into more complex systems. The TDC Card provides 10 ps timing resolution over the whole measurement range, which is selectable from 160 ns up to 10 μs, reaching 21 ps rms precision, 1.25% LSB rms differential nonlinearity, up to 3 Mconversion/s with 400 mW power consumption. The I/O edge card connector provides timing data readout through either a parallel bus or a 100 MHz serial interface and further measurement information like input signal rate and valid conversion rate (typically useful for time-correlated single-photon counting application) through an independent serial link.

Tracking reliability for space cabin-borne equipment in development by Crow model.

PubMed

Chen, J D; Jiao, S J; Sun, H L

2001-12-01

Objective. To study and track the reliability growth of manned spaceflight cabin-borne equipment in the course of its development. Method. A new technique of reliability growth estimation and prediction, which is composed of the Crow model and test data conversion (TDC) method was used. Result. The estimation and prediction value of the reliability growth conformed to its expectations. Conclusion. The method could dynamically estimate and predict the reliability of the equipment by making full use of various test information in the course of its development. It offered not only a possibility of tracking the equipment reliability growth, but also the reference for quality control in manned spaceflight cabin-borne equipment design and development process.

Summary of Stirling Convertor Testing at NASA Glenn Research Center

NASA Technical Reports Server (NTRS)

Schreiber, Jeffrey G.

2006-01-01

The NASA Glenn Research Center (GRC) has been testing free-piston Stirling convertors for potential use in radioisotope power systems. These convertors tend to be in the 35 to 80 W electric power output range. Tests at GRC have accumulated over 80,000 hr of operation. Test articles have been received from Infinia Corporation of Kennewick, Washington and from Sunpower of Athens, Ohio. Infinia designed and built the developmental Stirling Technology Demonstration Convertors (TDC) in addition to the more advanced Test Bed and Engineering Unit convertors. GRC has eight of the TDC's under test including two that operate in a thermal vacuum environment. Sunpower designed and developed the EE-35 and the Advanced Stirling Convertor (ASC). GRC has six of the EE- 35 s and is preparing for testing multiple ASC s. Free-piston Stirling convertors for radioisotope power systems make use of non-contacting operation that eliminates wear and is suited for long-term operation. Space missions with radioisotope power systems are often considered that extend from three to 14 years. One of the key capabilities of the GRC test facility is the ability to support continuous, unattended operation. Hardware, software, and procedures for preparing the test articles were developed to support these tests. These included the processing of the convertors for minimizing the contaminants in the working fluid, developing a helium charging system for filling and for gas sample analysis, and the development of new control software and a high-speed protection circuit to insure safe, round-the-clock operation. Performance data of Stirling convertors over time is required to demonstrate that a radioisotope power system is capable of providing reliable power for multi-year missions. This paper will discuss the status of Stirling convertor testing at GRC.

Summary of Stirling Convertor Testing at GRC

NASA Technical Reports Server (NTRS)

Schreiber, Jeffrey G.

2006-01-01

The NASA Glenn Research Center (GRC) has been testing free-piston Stirling convertors for potential use in radioisotope power systems. These convertors tend to be in the 35 to 80 watt electric power output range. Tests at GRC have accumulated over 80,000 hours of operation. Test articles have been received from Infinia Corporation of Kennewick, WA and from Sunpower of Athens, OH. Infinia designed and built the developmental Stirling Technology Demonstration Convertors (TDC) in addition to the more advanced Test Bed and Engineering Unit convertors. GRC has eight of the TDC's under test including two that operate in a thermal vacuum environment. Sunpower designed and developed the EE- 35 and the Advanced Stirling Convertor (ASC). GRC has six of the EE-35's and is preparing for testing multiple ASC's. Free-piston Stirling convertors for radioisotope power systems make use of non-contacting operation that eliminates wear and is suited for longterm operation. Space missions with radioisotope power systems are often considered that extend from three to 14 years. One of the key capabilities of the GRC test facility is the ability to support continuous, unattended operation. Hardware, software, and procedures for preparing the test articles were developed to support these tests. These included the processing of the convertors for minimizing the contaminants in the working fluid, developing a helium charging system for filling and for gas sample analysis, and the development of new control software and a high-speed protection circuit to insure safe, round-the-clock operation. Performance data of Stirling convertors over time is required to demonstrate that a radioisotope power system is capable of providing reliable power for multi-year missions. This paper will discuss the status of Stirling convertor testing at GRC.

Design of a delay-locked-loop-based time-to-digital converter

NASA Astrophysics Data System (ADS)

Zhaoxin, Ma; Xuefei, Bai; Lu, Huang

2013-09-01

A time-to-digital converter (TDC) based on a reset-free and anti-harmonic delay-locked loop (DLL) circuit for wireless positioning systems is discussed and described. The DLL that generates 32-phase clocks and a cycle period detector is employed to avoid “false locking". Driven by multiphase clocks, an encoder detects pulses and outputs the phase of the clock when the pulse arrives. The proposed TDC was implemented in SMIC 0.18 μm CMOS technology, and its core area occupies 0.7 × 0.55 mm2. The reference frequency ranges from 20 to 150 MHz. An LSB resolution of 521 ps can be achieved by using a reference clock of 60 MHz and the DNL is less than ±0.75 LSB. It dissipates 31.5 mW at 1.8 V supply voltage.

Multichannel low power time-to-digital converter card with 21 ps precision and full scale range up to 10 μs

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

Tamborini, D., E-mail: davide.tamborini@polimi.it; Portaluppi, D.; Villa, F.

We present a Time-to-Digital Converter (TDC) card with a compact form factor, suitable for multichannel timing instruments or for integration into more complex systems. The TDC Card provides 10 ps timing resolution over the whole measurement range, which is selectable from 160 ns up to 10 μs, reaching 21 ps rms precision, 1.25% LSB rms differential nonlinearity, up to 3 Mconversion/s with 400 mW power consumption. The I/O edge card connector provides timing data readout through either a parallel bus or a 100 MHz serial interface and further measurement information like input signal rate and valid conversion rate (typically usefulmore » for time-correlated single-photon counting application) through an independent serial link.« less

How to create successful Open Hardware projects — About White Rabbits and open fields

NASA Astrophysics Data System (ADS)

van der Bij, E.; Arruat, M.; Cattin, M.; Daniluk, G.; Gonzalez Cobas, J. D.; Gousiou, E.; Lewis, J.; Lipinski, M. M.; Serrano, J.; Stana, T.; Voumard, N.; Wlostowski, T.

2013-12-01

CERN's accelerator control group has embraced ''Open Hardware'' (OH) to facilitate peer review, avoid vendor lock-in and make support tasks scalable. A web-based tool for easing collaborative work was set up and the CERN OH Licence was created. New ADC, TDC, fine delay and carrier cards based on VITA and PCI-SIG standards were designed and drivers for Linux were written. Often industry was paid for developments, while quality and documentation was controlled by CERN. An innovative timing network was also developed with the OH paradigm. Industry now sells and supports these designs that find their way into new fields.

Temporal Changes in Technical and Physical Performances During a Small-Sided Game in Elite Youth Soccer Players

PubMed Central

Moreira, Alexandre; Saldanha Aoki, Marcelo; Carling, Chris; Alan Rodrigues Lopes, Rafael; Felipe Schultz de Arruda, Ademir; Lima, Marcelo; Cesar Correa, Umberto; Bradley, Paul S

2016-01-01

Background There have been claims that small-sided games (SSG) may generate an appropriate environment to develop youth players’ technical performance associated to game-related problem solving. However, the temporal change in technical performance parameters of youth players during SSG is still unknown. Objectives The aim of this study was to examine temporal changes in technical and physical performances during a small-sided game (SSG) in elite soccer players. Methods Sixty elite youth players (age 14.8 ± 0.2 yr; stature 177 ± 5 cm; body mass 66.2 ± 4.7 kg) completed a 5 v 5 SSG using two repetitions of 8 minutes interspersed by 3 minutes of passive recovery. To evaluate temporal changes in performance, the data were analysed across 4 minutes quarters. Physical performance parameters included the total distance covered (TDC), the frequency of sprints (>18 km•h-1), accelerations and decelerations (> 2.0 m•s-2 and - 2.0 m•s-2), metabolic power (W•kg-1), training impulse (TRIMP), TDC: TRIMP, number of impacts, and body load. Technical performance parameters included goal attempts, total number of tackles, tackles and interceptions, total number of passes, and passes effectiveness. Results All physical performance parameters decreased from the first to the last quarter with notable declines in TDC, metabolic power and the frequency of sprints, accelerations and decelerations (P < 0.05; moderate to very large ES: 1.08 - 3.30). However, technical performance parameters did not vary across quarters (P > 0.05; trivial ES for 1st v 4th quarters: 0.15 - 0.33). Conclusions The data demonstrate that technical performance is maintained despite substantial declines in physical performance during a SSG in elite youth players. This finding may have implications for designing SSG’s for elite youth players to ensure physical, technical and tactical capabilities are optimized. Modifications in player number, pitch dimensions, rules, coach encouragement, for instance, should be included taking into account the main aim of a given session and then focused on overloading physical or technical elements. PMID:28144411

Temporal Changes in Technical and Physical Performances During a Small-Sided Game in Elite Youth Soccer Players.

PubMed

Moreira, Alexandre; Saldanha Aoki, Marcelo; Carling, Chris; Alan Rodrigues Lopes, Rafael; Felipe Schultz de Arruda, Ademir; Lima, Marcelo; Cesar Correa, Umberto; Bradley, Paul S

2016-12-01

There have been claims that small-sided games (SSG) may generate an appropriate environment to develop youth players' technical performance associated to game-related problem solving. However, the temporal change in technical performance parameters of youth players during SSG is still unknown. The aim of this study was to examine temporal changes in technical and physical performances during a small-sided game (SSG) in elite soccer players. Sixty elite youth players (age 14.8 ± 0.2 yr; stature 177 ± 5 cm; body mass 66.2 ± 4.7 kg) completed a 5 v 5 SSG using two repetitions of 8 minutes interspersed by 3 minutes of passive recovery. To evaluate temporal changes in performance, the data were analysed across 4 minutes quarters. Physical performance parameters included the total distance covered (TDC), the frequency of sprints (>18 km•h -1 ), accelerations and decelerations (> 2.0 m•s -2 and - 2.0 m•s -2 ), metabolic power (W•kg -1 ), training impulse (TRIMP), TDC: TRIMP, number of impacts, and body load. Technical performance parameters included goal attempts, total number of tackles, tackles and interceptions, total number of passes, and passes effectiveness. All physical performance parameters decreased from the first to the last quarter with notable declines in TDC, metabolic power and the frequency of sprints, accelerations and decelerations (P < 0.05; moderate to very large ES: 1.08 - 3.30). However, technical performance parameters did not vary across quarters (P > 0.05; trivial ES for 1st v 4th quarters: 0.15 - 0.33). The data demonstrate that technical performance is maintained despite substantial declines in physical performance during a SSG in elite youth players. This finding may have implications for designing SSG's for elite youth players to ensure physical, technical and tactical capabilities are optimized. Modifications in player number, pitch dimensions, rules, coach encouragement, for instance, should be included taking into account the main aim of a given session and then focused on overloading physical or technical elements.

Intact mirror mechanisms for automatic facial emotions in children and adolescents with autism spectrum disorder.

PubMed

Schulte-Rüther, Martin; Otte, Ellen; Adigüzel, Kübra; Firk, Christine; Herpertz-Dahlmann, Beate; Koch, Iring; Konrad, Kerstin

2017-02-01

It has been suggested that an early deficit in the human mirror neuron system (MNS) is an important feature of autism. Recent findings related to simple hand and finger movements do not support a general dysfunction of the MNS in autism. Studies investigating facial actions (e.g., emotional expressions) have been more consistent, however, mostly relied on passive observation tasks. We used a new variant of a compatibility task for the assessment of automatic facial mimicry responses that allowed for simultaneous control of attention to facial stimuli. We used facial electromyography in 18 children and adolescents with Autism spectrum disorder (ASD) and 18 typically developing controls (TDCs). We observed a robust compatibility effect in ASD, that is, the execution of a facial expression was facilitated if a congruent facial expression was observed. Time course analysis of RT distributions and comparison to a classic compatibility task (symbolic Simon task) revealed that the facial compatibility effect appeared early and increased with time, suggesting fast and sustained activation of motor codes during observation of facial expressions. We observed a negative correlation of the compatibility effect with age across participants and in ASD, and a positive correlation between self-rated empathy and congruency for smiling faces in TDC but not in ASD. This pattern of results suggests that basic motor mimicry is intact in ASD, but is not associated with complex social cognitive abilities such as emotion understanding and empathy. Autism Res 2017, 10: 298-310. © 2016 International Society for Autism Research, Wiley Periodicals, Inc. © 2016 International Society for Autism Research, Wiley Periodicals, Inc.

Overview of NASA GRC Stirling Technology Development

NASA Technical Reports Server (NTRS)

Schreiber, Jeffrey G.; Thieme, Lanny G.

2004-01-01

The Stirling Radioisotope Generator (SRG) is currently being developed by Lockheed Martin Astronautics (LMA) under contract to the Department of Energy (DOE). The generator will be a high efficiency electric power source for NASA Space Science missions with the ability to operate in vacuum or in an atmosphere such as on Mars. High efficiency is obtained through the use of free-piston Stirling power conversion. Power output will be greater than 100 watts at the beginning of life with the decline in power largely due to the decay of the plutonium heat source. In support of the DOE SRG project, the NASA Glenn Research Center (GRC) has established a technology effort to provide data to ensure a successful transition to flight for what will be the first dynamic power system in space. Initially, a limited number of areas were selected for the effort, however this is now being expanded to more thoroughly cover key technical issues. There is also an advanced technology effort that is complementary to the near-term technology effort. Many of the tests use the 55-We Technology Demonstration Convertor (TDC). There have been multiple controller tests to support the LMA flight controller design effort. Preparation is continuing for a thermal/vacuum system demonstration. A pair of flight prototype TDC s have been placed on continuous operation. Heater head life assessment continues, with the material data being refined and the analysis moving toward the system perspective. Magnet aging tests continue to characterize any possible aging in the strength or demagnetization resistance of the magnets in the linear alternator. A reliability effort has been initiated to help guide the development activities with focus on the key components and subsystems. This paper will provide an overview of some of the GRC technical efforts, including the status, and a description of future efforts.

Phenotypic and genetic evaluations of biogenic amine production by lactic acid bacteria isolated from fish and fish products.

PubMed

Muñoz-Atienza, Estefanía; Landeta, Gerardo; de las Rivas, Blanca; Gómez-Sala, Beatriz; Muñoz, Rosario; Hernández, Pablo E; Cintas, Luis M; Herranz, Carmen

2011-03-30

In this work, biogenic amine production (histamine, tyramine and putrescine) by a collection of 74 lactic acid bacteria of aquatic origin has been investigated by means of amino acid decarboxylation by growth on decarboxylase differential medium, biogenic amine detection by thin-layer chromatography (TLC) and decarboxylase gene detection by PCR. None of the evaluated strains showed neither production of histamine and putrescine, nor presence of the genetic determinants encoding the corresponding decarboxylase activities. However, the tyrosine decarboxylase gene (tdc) was present in all the enterococcal strains, and tyramine production was detected by TLC in all of them but Enterococcus faecium BCS59 and MV5. Analysis of the tyrosine decarboxylase operon of these strains revealed the presence of an insertion sequence upstream tdc that could be responsible for their lack of tyrosine decarboxylase activity. Copyright © 2011 Elsevier B.V. All rights reserved.

Timing in a FLASH

NASA Astrophysics Data System (ADS)

Hoek, M.; Cardinali, M.; Corell, O.; Dickescheid, M.; Ferretti B., M. I.; Lauth, W.; Schlimme, B. S.; Sfienti, C.; Thiel, M.

2017-12-01

A prototype detector, called FLASH (Fast Light Acquiring Start Hodoscope), was built to provide precise Time-of-Flight (TOF) measurements and reference timestamps for detector setups at external beam lines. Radiator bars, made of synthetic fused silica, were coupled to a fast MCP-PMT with 64 channels and read out with custom electronics using Time-over-Threshold (TOT) for signal characterization. The TRB3 system, a high-precision TDC implemented in an FPGA, was used as data acquisition system. The performance of a system consisting of two FLASH units was investigated at a dedicated test experiment at the Mainz Microtron (MAMI) accelerator using its 855 MeV electron beam. The TOT measurement enabled time walk corrections and an overall TOF resolution of ∼70 ps could be achieved which translates into a resolution of ∼50 ps per FLASH unit. The intrinsic resolution of the frontend electronics including the TDC was measured to be less than 25 ps.

Multiclass Classification for the Differential Diagnosis on the ADHD Subtypes Using Recursive Feature Elimination and Hierarchical Extreme Learning Machine: Structural MRI Study

PubMed Central

Qureshi, Muhammad Naveed Iqbal; Min, Beomjun; Jo, Hang Joon; Lee, Boreom

2016-01-01

The classification of neuroimaging data for the diagnosis of certain brain diseases is one of the main research goals of the neuroscience and clinical communities. In this study, we performed multiclass classification using a hierarchical extreme learning machine (H-ELM) classifier. We compared the performance of this classifier with that of a support vector machine (SVM) and basic extreme learning machine (ELM) for cortical MRI data from attention deficit/hyperactivity disorder (ADHD) patients. We used 159 structural MRI images of children from the publicly available ADHD-200 MRI dataset. The data consisted of three types, namely, typically developing (TDC), ADHD-inattentive (ADHD-I), and ADHD-combined (ADHD-C). We carried out feature selection by using standard SVM-based recursive feature elimination (RFE-SVM) that enabled us to achieve good classification accuracy (60.78%). In this study, we found the RFE-SVM feature selection approach in combination with H-ELM to effectively enable the acquisition of high multiclass classification accuracy rates for structural neuroimaging data. In addition, we found that the most important features for classification were the surface area of the superior frontal lobe, and the cortical thickness, volume, and mean surface area of the whole cortex. PMID:27500640

Multiclass Classification for the Differential Diagnosis on the ADHD Subtypes Using Recursive Feature Elimination and Hierarchical Extreme Learning Machine: Structural MRI Study.

PubMed

Qureshi, Muhammad Naveed Iqbal; Min, Beomjun; Jo, Hang Joon; Lee, Boreom

2016-01-01

The classification of neuroimaging data for the diagnosis of certain brain diseases is one of the main research goals of the neuroscience and clinical communities. In this study, we performed multiclass classification using a hierarchical extreme learning machine (H-ELM) classifier. We compared the performance of this classifier with that of a support vector machine (SVM) and basic extreme learning machine (ELM) for cortical MRI data from attention deficit/hyperactivity disorder (ADHD) patients. We used 159 structural MRI images of children from the publicly available ADHD-200 MRI dataset. The data consisted of three types, namely, typically developing (TDC), ADHD-inattentive (ADHD-I), and ADHD-combined (ADHD-C). We carried out feature selection by using standard SVM-based recursive feature elimination (RFE-SVM) that enabled us to achieve good classification accuracy (60.78%). In this study, we found the RFE-SVM feature selection approach in combination with H-ELM to effectively enable the acquisition of high multiclass classification accuracy rates for structural neuroimaging data. In addition, we found that the most important features for classification were the surface area of the superior frontal lobe, and the cortical thickness, volume, and mean surface area of the whole cortex.

A finite state machine read-out chip for integrated surface acoustic wave sensors

NASA Astrophysics Data System (ADS)

Rakshit, Sambarta; Iliadis, Agis A.

2015-01-01

A finite state machine based integrated sensor circuit suitable for the read-out module of a monolithically integrated SAW sensor on Si is reported. The primary sensor closed loop consists of a voltage controlled oscillator (VCO), a peak detecting comparator, a finite state machine (FSM), and a monolithically integrated SAW sensor device. The output of the system oscillates within a narrow voltage range that correlates with the SAW pass-band response. The period of oscillation is of the order of the SAW phase delay. We use timing information from the FSM to convert SAW phase delay to an on-chip 10 bit digital output operating on the principle of time to digital conversion (TDC). The control inputs of this digital conversion block are generated by a second finite state machine operating under a divided system clock. The average output varies with changes in SAW center frequency, thus tracking mass sensing events in real time. Based on measured VCO gain of 16 MHz/V our system will convert a 10 kHz SAW frequency shift to a corresponding mean voltage shift of 0.7 mV. A corresponding shift in phase delay is converted to a one or two bit shift in the TDC output code. The system can handle alternate SAW center frequencies and group delays simply by adjusting the VCO control and TDC delay control inputs. Because of frequency to voltage and phase to digital conversion, this topology does not require external frequency counter setups and is uniquely suitable for full monolithic integration of autonomous sensor systems and tags.

A Selected Interactive Videodisc Bibliography. TDC Research Report No. 2.

ERIC Educational Resources Information Center

Montgomery, Rae; Sayre, Scott

This bibliography lists 360 monographs, journal articles, research reports, and conference proceedings on interactive videodisc and educational applications of this technology. Materials through December 1988 are included. A sidebar provides background on interactive video technology. (MES)

Understanding of the Dynamics of the Stirling Convertor Advanced by Structural Testing

NASA Technical Reports Server (NTRS)

Hughes, William O.

2003-01-01

The NASA Glenn Research Center, the U.S. Department of Energy, and the Stirling Technology Company (STC) are developing a highly efficient, long-life, free-piston Stirling convertor for use as an advanced spacecraft power system for future NASA missions, including deep-space and Mars surface applications. As part of this development, four structural dynamic test programs were recently performed on Stirling Technology Demonstration Convertors (TDC's) that were designed and built by STC under contract to the Department of Energy. This testing was performed in Glenn's Structural Dynamics Laboratory and Microgravity Emissions Laboratory. The first test program, in November and December 1999, demonstrated that the Stirling TDC could withstand the harsh random vibration experienced during a typical spacecraft launch and survive with no structural damage or functional power performance degradation. This was a critical step in enabling the use of Stirling convertors for future spacecraft power systems. The most severe test was a 12.3grms random vibration test, with test durations of 3 min per axis. The random vibration test levels were chosen to simulate, with margin, the maximum anticipated launch vibration conditions. The Microgravity Emissions Laboratory is typically used to measure the dynamics produced by operating space experiments and the resulting impact to the International Space Station's microgravity environment. For the second Stirling dynamic test program, performed in January 2001, the Microgravity Emissions Laboratory was used to characterize the structure-borne disturbances produced by the normal operation of a pair of Stirling convertors. The forces and moments produced by the normal operation of a Stirling system must be recognized and controlled, if necessary, so that other nearby spacecraft components, such as cameras, are not adversely affected. The Stirling convertor pair emitted relatively benign tonal forces at its operational frequency and associated harmonics. Therefore, Stirling power systems will not disturb spacecraft science experiments if minimal appropriate mounting efforts are made. The third test program, performed in February and May 2001, resulted in a modal characterization of a Stirling convertor. Since the deflection of the TDC piston rod, under vibration excitation, was of particular interest, the outer pressure shell was removed to allow access to the rod. Through this testing, the Stirling TDC's natural frequencies and modes were identified. This knowledge advanced our understanding of the successful 1999 vibration test and may be utilized to optimize the output power of future Stirling designs. The fourth test program, in April 2001, was conducted to characterize the structural response of a pair of Stirling convertors, as a function of their mounting interface stiffness. The test results provide guidance for the Stirling power package interface design. Properly designed, the interface may lead to increased structural capability and power performance beyond what was demonstrated in the successful 1999 vibration test. Dynamic testing performed to date at Glenn has shown that the Stirling convertors can withstand liftoff random vibration environments and meet "good neighbor" vibratory emission requirements. Furthermore, the future utilization of the information obtained during the tests will allow the corporation selected to be the Stirling system integrator to optimize their convertor and system interfaces designs. Glenn's Thermo-Mechanical Systems Branch provides Stirling technology expertise under a Space Act Agreement with the Department of Energy. Additional vibration testing by Glenn's Structural Systems Dynamics Branch is planned to continue to demonstrate the Stirling power system's vibration capability as its technology and flight system designs progress.

Characterization and optimization of an optical and electronic architecture for photon counting

NASA Astrophysics Data System (ADS)

Correa, M. del M.; Pérez, F. R.

2018-04-01

This work shows a time-domain method for the discrimination and digitization of pulses coming from optical detectors, considering the presence of electronic noise and afterpulsing. The developed signal processing scheme is based on a time-to-digital converter (TDC) and a voltage discriminator. After setting appropriate parameters for taking spectra, acquisition data was corrected by wavelength, intensity response function, and noise suppression. The performance of this scheme is discussed by its characterization as well as the comparison of its spectra to those obtained by an Ocean Optics HR4000 commercial reference.

A 64ch readout module for PPD/MPPC/SiPM using EASIROC ASIC

NASA Astrophysics Data System (ADS)

Nakamura, Isamu; Ishijima, N.; Hanagaki, K.; Yoshimura, K.; Nakai, Y.; Ueno, K.

2015-07-01

A readout module for PPD/MPPC/GAPD/SiPM is developed using EASIROC ASIC. The module can handle 64 PPDs and has on-board bias power supply, ADC for energy measurement, 1 ns TDC on FPGA as well as 64ch Logic output for external trigger. Controls and data transfer are through SiTCP technology implemented in FPGA. The module has NIM format for convenience, but can be operated without crate with 5 V AC/DC converter. Basic performance of production module was tested and the results are presented in the poster.

Environmental Technology Verification: Baghouse Filtration Products--TDC Filter Manufacturing, Inc., SB025 Filtration Media

EPA Science Inventory

The U.S. Environmental Protection Agency (EPA) has created the Environmental Technology Verification (ETV) Program to facilitate the deployment of innovative or improved environmental technologies through performance verification and dissemination of information. ETV seeks to ach...

Compensation of PVT Variations in ToF Imagers with In-Pixel TDC

PubMed Central

Vornicu, Ion; Carmona-Galán, Ricardo; Rodríguez-Vázquez, Ángel

2017-01-01

The design of a direct time-of-flight complementary metal-oxide-semiconductor (CMOS) image sensor (dToF-CIS) based on a single-photon avalanche-diode (SPAD) array with an in-pixel time-to-digital converter (TDC) must contemplate system-level aspects that affect its overall performance. This paper provides a detailed analysis of the impact of process parameters, voltage supply, and temperature (PVT) variations on the time bin of the TDC array. Moreover, the design and characterization of a global compensation loop is presented. It is based on a phase locked loop (PLL) that is integrated on-chip. The main building block of the PLL is a voltage-controlled ring-oscillator (VCRO) that is identical to the ones employed for the in-pixel TDCs. The reference voltage that drives the master VCRO is distributed to the voltage control inputs of the slave VCROs such that their multiphase outputs become invariant to PVT changes. These outputs act as time interpolators for the TDCs. Therefore the compensation scheme prevents the time bin of the TDCs from drifting over time due to the aforementioned factors. Moreover, the same scheme is used to program different time resolutions of the direct time-of-flight (ToF) imager aimed at 3D ranging or depth map imaging. Experimental results that validate the analysis are provided as well. The compensation loop proves to be remarkably effective. The spreading of the TDCs time bin is lowered from: (i) 20% down to 2.4% while the temperature ranges from 0 °C to 100 °C; (ii) 27% down to 0.27%, when the voltage supply changes within ±10% of the nominal value; (iii) 5.2 ps to 2 ps standard deviation over 30 sample chips, due to process parameters’ variation. PMID:28486405

Compensation of PVT Variations in ToF Imagers with In-Pixel TDC.

PubMed

Vornicu, Ion; Carmona-Galán, Ricardo; Rodríguez-Vázquez, Ángel

2017-05-09

The design of a direct time-of-flight complementary metal-oxide-semiconductor (CMOS) image sensor (dToF-CIS) based on a single-photon avalanche-diode (SPAD) array with an in-pixel time-to-digital converter (TDC) must contemplate system-level aspects that affect its overall performance. This paper provides a detailed analysis of the impact of process parameters, voltage supply, and temperature (PVT) variations on the time bin of the TDC array. Moreover, the design and characterization of a global compensation loop is presented. It is based on a phase locked loop (PLL) that is integrated on-chip. The main building block of the PLL is a voltage-controlled ring-oscillator (VCRO) that is identical to the ones employed for the in-pixel TDCs. The reference voltage that drives the master VCRO is distributed to the voltage control inputs of the slave VCROs such that their multiphase outputs become invariant to PVT changes. These outputs act as time interpolators for the TDCs. Therefore the compensation scheme prevents the time bin of the TDCs from drifting over time due to the aforementioned factors. Moreover, the same scheme is used to program different time resolutions of the direct time-of-flight (ToF) imager aimed at 3D ranging or depth map imaging. Experimental results that validate the analysis are provided as well. The compensation loop proves to be remarkably effective. The spreading of the TDCs time bin is lowered from: (i) 20% down to 2.4% while the temperature ranges from 0 °C to 100 °C; (ii) 27% down to 0.27%, when the voltage supply changes within ±10% of the nominal value; (iii) 5.2 ps to 2 ps standard deviation over 30 sample chips, due to process parameters' variation.

Delay grid multiplexing: simple time-based multiplexing and readout method for silicon photomultipliers

NASA Astrophysics Data System (ADS)

Won, Jun Yeon; Ko, Guen Bae; Lee, Jae Sung

2016-10-01

In this paper, we propose a fully time-based multiplexing and readout method that uses the principle of the global positioning system. Time-based multiplexing allows simplifying the multiplexing circuits where the only innate traces that connect the signal pins of the silicon photomultiplier (SiPM) channels to the readout channels are used as the multiplexing circuit. Every SiPM channel is connected to the delay grid that consists of the traces on a printed circuit board, and the inherent transit times from each SiPM channel to the readout channels encode the position information uniquely. Thus, the position of each SiPM can be identified using the time difference of arrival (TDOA) measurements. The proposed multiplexing can also allow simplification of the readout circuit using the time-to-digital converter (TDC) implemented in a field-programmable gate array (FPGA), where the time-over-threshold (ToT) is used to extract the energy information after multiplexing. In order to verify the proposed multiplexing method, we built a positron emission tomography (PET) detector that consisted of an array of 4  ×  4 LGSO crystals, each with a dimension of 3  ×  3  ×  20 mm3, and one- to-one coupled SiPM channels. We first employed the waveform sampler as an initial study, and then replaced the waveform sampler with an FPGA-TDC to further simplify the readout circuits. The 16 crystals were clearly resolved using only the time information obtained from the four readout channels. The coincidence resolving times (CRTs) were 382 and 406 ps FWHM when using the waveform sampler and the FPGA-TDC, respectively. The proposed simple multiplexing and readout methods can be useful for time-of-flight (TOF) PET scanners.

IR spectroscopy analysis of pancreatic lipase-related protein 2 interaction with phospholipids: 1. Discriminative recognition of mixed micelles versus liposomes.

PubMed

Mateos-Diaz, Eduardo; Bakala N'Goma, Jean-Claude; Byrne, Deborah; Robert, Sylvie; Carrière, Frédéric; Gaussier, Hélène

2018-03-01

Guinea pig pancreatic lipase-related protein 2 (GPLRP2) is an interesting model enzyme that can hydrolyze a large set of acylglycerols in vitro but displays however some selectivity depending on the supramolecular structure of substrate and the presence of surfactants like bile salts. We showed that GPLRP2 hydrolyzes 1,2-dipalmitoyl phosphatidylcholine (DPPC) present in mixed micelles with sodium taurodeoxycholate (NaTDC) but not in multilamellar (MLV) and large unilamellar (LUV) vesicles of DPPC. After characterization of these lipid aggregates by dynamic light scattering (DLS), the discriminative recognition of DPPC in DPPC/NaTDC micelles versus MLV and LUV by an inactive variant (S152G) of GPLRP2 to avoid the effect of substrate hydrolysis was investigated using Fourier transform infrared spectroscopy (FTIR). IR spectra were recorded after hydrogen/deuterium exchange, at pD 6 and various temperatures to study phase transitions. We analyzed the methylene asymmetric stretching (ν(CH2) as ), the carbonyl stretching (ν(CO)) and the composite polar head-group vibration bands, first to characterized differences in DPPC micelles and vesicles, and second to estimate the degree of interaction of GPLRP2 S152G with phospholipid. Our results indicate that a significant interaction between GPLRP2 S152G and DPPC is only observed when NaTDC is added to the system to form micelles and this can be explained by the different organization of DPPC in mixed micelles compared to lamellar vesicles (higher hydration of polar head, higher mobility of alkyl chains) that favors GPLRP2 penetration into the phospholipid layer. Copyright © 2017 Elsevier B.V. All rights reserved.

The occurrence of lysogenic bacteria and microbial aggregates in the lakes of the McMurdo Dry Valleys, Antarctica

USGS Publications Warehouse

Lisle, J.T.; Priscu, J.C.

2004-01-01

The McMurdo Dry Valleys of Antarctica form the coldest and driest ecosystem on Earth. Within this region there are a number of perennially ice-covered (3-6 m thick) lakes that support active microbial assemblages and have a paucity of metazoans. These lakes receive limited allochthonous input of carbon and nutrients, and primary productivity is limited to only 6 months per year owing to an absence of sunlight during the austral winters. In an effort to establish the role that bacteria and their associated viruses play in carbon and nutrient cycling in these lakes, indigenous bacteria, free bacteriophage, and lysogen abundances were determined. Total bacterial abundances (TDC) ranged from 3.80 ?? 104 to 2.58 ?? 107 cells mL-1 and virus-like particle (VLP) abundances ranged from 2.26 ?? 105 to 5.56 ?? 107 VLP mL-1. VLP abundances were significantly correlated (P < 0.05) with TDC, bacterial productivity (TdR), chlorophyll a (Chl a), and soluble reactive phosphorus (SRP). Lysogenic bacteria, determined by induction with mitomycin C, made up between 2.0% and 62.5% of the total population of bacteria when using significant decreases and increases in TDC and VLP abundances, respectively, and 89.5% when using increases in VLP abundances as the sole criterion for a successful induction event. The contribution of viruses released from induced lysogens contributed <0.015% to the total viral production rate. Carbohydrate and protein based organic aggregates were abundant within the water column of the lakes and were heavily colonized by bacteria and VLPs. Alkaline phosphatase activity was detected within the matrix of the aggregates, implying phosphorus deficiency and consortial nutrient exchanges among microorganisms.

Preparation for Life after Incarceration.

ERIC Educational Resources Information Center

Alston, Jerry G.

After presenting a rationale for educational programs within correctional institutions, this paper describes the comprehensive educational program offered since 1965 by Lee College, Texas, to eligible inmates within units of the Texas Department of Corrections (TDC). The paper first discusses the importance of education to felon rehabilitation in…

Confined Water in Layered Silicates: The Origin of Anomalous Thermal Expansion Behavior in Calcium-Silicate-Hydrates

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

Krishnan, N. M. Anoop; Wang, Bu; Falzone, Gabriel

Water, under conditions of nanoscale confinement, exhibits anomalous dynamics, and enhanced thermal deformations, which may be further enhanced when such water is in contact with hydrophilic surfaces. Such heightened thermal deformations of water could control the volume stability of hydrated materials containing nanoconfined structural water. Understanding and predicting the thermal deformation coefficient (TDC, often referred to as the CTE, coefficient of thermal expansion), which represents volume changes induced in materials under conditions of changing temperature, is of critical importance for hydrated solids including: hydrogels, biological tissues, and calcium silicate hydrates, as changes in their volume can result in stress development,more » and cracking. By pioneering atomistic simulations, we examine the physical origin of thermal expansion in calcium-silicate-hydrates (C–S–H), the binding agent in concrete that is formed by the reaction of cement with water. We report that the TDC of C–S–H shows a sudden increase when the CaO/SiO 2 (molar ratio; abbreviated as Ca/Si) exceeds 1.5. This anomalous behavior arises from a notable increase in the confinement of water contained in the C–S–H’s nanostructure. We identify that confinement is dictated by the topology of the C–S–H’s atomic network. Altogether, the results suggest that thermal deformations of hydrated silicates can be altered by inducing compositional changes, which in turn alter the atomic topology and the resultant volume stability of the solids.« less

Hemodialysis Reliable Outflow (HeRO) device in end-stage dialysis access: a decision analysis model.

PubMed

Dageforde, Leigh Anne; Bream, Peter R; Moore, Derek E

2012-09-01

The Hemodialysis Reliable Outflow (HeRO) dialysis access device is a permanent tunneled dialysis graft connected to a central venous catheter and is used in patients with end-stage dialysis access (ESDA) issues secondary to central venous stenosis. The safety and effectiveness of the HeRO device has previously been proven, but no study thus far has compared the cost of its use with tunneled dialysis catheters (TDCs) and thigh grafts in patients with ESDA. A decision analytic model was developed to simulate outcomes for patients with ESDA undergoing placement of a HeRO dialysis access device, TDC, or thigh graft. Outcomes of interest were infection, thrombosis, and ischemic events. Baseline values, ranges, and costs were determined from a systematic review of the literature. Total costs were based on 1 year of post-procedure outcomes. Sensitivity analyses were conducted to test model strength. The HeRO dialysis access device is the least costly dialysis access with an average 1-year cost of $6521. The 1-year cost for a TDC was $8477. A thigh graft accounted for $9567 in a 1-year time period. The HeRO dialysis access device is the least costly method of ESDA. The primary determinants of cost in this model are infection in TDCs and leg ischemia necessitating amputation in thigh grafts. Further study is necessary to incorporate patient preference and quality of life into the model. Copyright © 2012 Elsevier Inc. All rights reserved.

Confined Water in Layered Silicates: The Origin of Anomalous Thermal Expansion Behavior in Calcium-Silicate-Hydrates.

PubMed

Krishnan, N M Anoop; Wang, Bu; Falzone, Gabriel; Le Pape, Yann; Neithalath, Narayanan; Pilon, Laurent; Bauchy, Mathieu; Sant, Gaurav

2016-12-28

Water, under conditions of nanoscale confinement, exhibits anomalous dynamics, and enhanced thermal deformations, which may be further enhanced when such water is in contact with hydrophilic surfaces. Such heightened thermal deformations of water could control the volume stability of hydrated materials containing nanoconfined structural water. Understanding and predicting the thermal deformation coefficient (TDC, often referred to as the CTE, coefficient of thermal expansion), which represents volume changes induced in materials under conditions of changing temperature, is of critical importance for hydrated solids including: hydrogels, biological tissues, and calcium silicate hydrates, as changes in their volume can result in stress development, and cracking. By pioneering atomistic simulations, we examine the physical origin of thermal expansion in calcium-silicate-hydrates (C-S-H), the binding agent in concrete that is formed by the reaction of cement with water. We report that the TDC of C-S-H shows a sudden increase when the CaO/SiO 2 (molar ratio; abbreviated as Ca/Si) exceeds 1.5. This anomalous behavior arises from a notable increase in the confinement of water contained in the C-S-H's nanostructure. We identify that confinement is dictated by the topology of the C-S-H's atomic network. Taken together, the results suggest that thermal deformations of hydrated silicates can be altered by inducing compositional changes, which in turn alter the atomic topology and the resultant volume stability of the solids.

Confined Water in Layered Silicates: The Origin of Anomalous Thermal Expansion Behavior in Calcium-Silicate-Hydrates

DOE PAGES

Krishnan, N. M. Anoop; Wang, Bu; Falzone, Gabriel; ...

2016-12-06

Water, under conditions of nanoscale confinement, exhibits anomalous dynamics, and enhanced thermal deformations, which may be further enhanced when such water is in contact with hydrophilic surfaces. Such heightened thermal deformations of water could control the volume stability of hydrated materials containing nanoconfined structural water. Understanding and predicting the thermal deformation coefficient (TDC, often referred to as the CTE, coefficient of thermal expansion), which represents volume changes induced in materials under conditions of changing temperature, is of critical importance for hydrated solids including: hydrogels, biological tissues, and calcium silicate hydrates, as changes in their volume can result in stress development,more » and cracking. By pioneering atomistic simulations, we examine the physical origin of thermal expansion in calcium-silicate-hydrates (C–S–H), the binding agent in concrete that is formed by the reaction of cement with water. We report that the TDC of C–S–H shows a sudden increase when the CaO/SiO 2 (molar ratio; abbreviated as Ca/Si) exceeds 1.5. This anomalous behavior arises from a notable increase in the confinement of water contained in the C–S–H’s nanostructure. We identify that confinement is dictated by the topology of the C–S–H’s atomic network. Altogether, the results suggest that thermal deformations of hydrated silicates can be altered by inducing compositional changes, which in turn alter the atomic topology and the resultant volume stability of the solids.« less

Readout architecture for sub-nanosecond resolution TDC

NASA Astrophysics Data System (ADS)

Marteau, J.; Carlus, B.; Gardien, S.; Girerd, C.; Ianigro, J.-C.; Montorio, J.-L.; Gibert, D.; Nicollin, F.

2012-04-01

The DIAPHANE project is pluri-disciplinary collaboration between particle physicists and geophysicists to perform the tomography of large geological structure mainly devoted to the study of active volcanoes. The detector used for this tomography, hereafter referred to as telescope, uses a standard, robust, cost-effective and well-known technology based on solid plastic scintillator readout by photomultiplier(s) (either multichannel pixelized PM or silicon PM). The electronics system is built on the concept of autonomous, triggerless, smart sensor directly connected on a standard fast Ethernet network. First radiographies have been performed on the Mont-Terri underground laboratory (St-Ursanne, Switzerland) and on the active volcano of La Soufrière (Guadeloupe, Lesser Antilles, France). We present an upgrade of the readout architecture allowing to embed a sub-nanosecond resolution TDC within the existing programmable logic to help in the background rejection (rear flux, random coincidences) and to improve the detection purity and the radiography quality. First results obtained are also presented and briefly discussed.

FPGA-based Trigger System for the Fermilab SeaQuest Experimentz

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

Shiu, Shiuan-Hal; Wu, Jinyuan; McClellan, Randall Evan

The SeaQuest experiment (Fermilab E906) detects pairs of energetic μ + and μ -produced in 120 GeV/c proton–nucleon interactions in a high rate environment. The trigger system we used consists of several arrays of scintillator hodoscopes and a set of field-programmable gate array (FPGA) based VMEbus modules. Signals from up to 96 channels of hodoscope are digitized by each FPGA with a 1-ns resolution using the time-to-digital convertor (TDC) firmware. The delay of the TDC output can be adjusted channel-by-channel in 1-ns step and then re-aligned with the beam RF clock. The hit pattern on the hodoscope planes is thenmore » examined against pre-determined trigger matrices to identify candidate muon tracks. Finally, information on the candidate tracks is sent to the 2nd-level FPGA-based track correlator to find candidate di-muon events. The design and implementation of the FPGA-based trigger system for SeaQuest experiment are presented.« less

FPGA-based trigger system for the Fermilab SeaQuest experimentz

NASA Astrophysics Data System (ADS)

Shiu, Shiuan-Hal; Wu, Jinyuan; McClellan, Randall Evan; Chang, Ting-Hua; Chang, Wen-Chen; Chen, Yen-Chu; Gilman, Ron; Nakano, Kenichi; Peng, Jen-Chieh; Wang, Su-Yin

2015-12-01

The SeaQuest experiment (Fermilab E906) detects pairs of energetic μ+ and μ- produced in 120 GeV/c proton-nucleon interactions in a high rate environment. The trigger system consists of several arrays of scintillator hodoscopes and a set of field-programmable gate array (FPGA) based VMEbus modules. Signals from up to 96 channels of hodoscope are digitized by each FPGA with a 1-ns resolution using the time-to-digital convertor (TDC) firmware. The delay of the TDC output can be adjusted channel-by-channel in 1-ns step and then re-aligned with the beam RF clock. The hit pattern on the hodoscope planes is then examined against pre-determined trigger matrices to identify candidate muon tracks. Information on the candidate tracks is sent to the 2nd-level FPGA-based track correlator to find candidate di-muon events. The design and implementation of the FPGA-based trigger system for SeaQuest experiment are presented.

FPGA-based Trigger System for the Fermilab SeaQuest Experimentz

DOE PAGES

Shiu, Shiuan-Hal; Wu, Jinyuan; McClellan, Randall Evan; ...

2015-09-10

The SeaQuest experiment (Fermilab E906) detects pairs of energetic μ + and μ -produced in 120 GeV/c proton–nucleon interactions in a high rate environment. The trigger system we used consists of several arrays of scintillator hodoscopes and a set of field-programmable gate array (FPGA) based VMEbus modules. Signals from up to 96 channels of hodoscope are digitized by each FPGA with a 1-ns resolution using the time-to-digital convertor (TDC) firmware. The delay of the TDC output can be adjusted channel-by-channel in 1-ns step and then re-aligned with the beam RF clock. The hit pattern on the hodoscope planes is thenmore » examined against pre-determined trigger matrices to identify candidate muon tracks. Finally, information on the candidate tracks is sent to the 2nd-level FPGA-based track correlator to find candidate di-muon events. The design and implementation of the FPGA-based trigger system for SeaQuest experiment are presented.« less

Construction of Escherichia coli strains producing L-serine from glucose.

PubMed

Li, Yu; Chen, Gu-Kui; Tong, Xin-Wei; Zhang, Hui-Tu; Liu, Xiao-Guang; Liu, Yi-Han; Lu, Fu-Ping

2012-08-01

L-Serine is usually produced from glycine. We have genetically engineered Escherichia coli to produce L-serine from glucose intracellularly. D-3-Phosphoglycerate dehydrogenase (PGDH, EC 1.1.1.95) in E. coli catalyzes the first committed step in L-serine formation but is inhibited by L-serine. To overcome this feedback inhibition, both the His(344) and Asn(346) residues of PGDH were converted to alanine and the mutated PGDH (PGDH(dr)) became insensitive to L-serine. However, overexpression of PGDH(dr) gave no significant increase of L-serine accumulation but, when L-serine deaminase genes (sdaA, sdaB and tdcG) were deleted, serine accumulated: (1) deletion of sdaA gave up to 0.03 mmol L-serine/g; (2) deletion of both sdaA and sdaB accumulated L-serine up to 0.09 mmol/g; and (3) deletion of sdaA, sdaB and tdcG gave up to 0.13 mmol L-serine/g cell dry wt.

Time-resolved optical spectrometer based on a monolithic array of high-precision TDCs and SPADs

NASA Astrophysics Data System (ADS)

Tamborini, Davide; Markovic, Bojan; Di Sieno, Laura; Contini, Davide; Bassi, Andrea; Tisa, Simone; Tosi, Alberto; Zappa, Franco

2013-12-01

We present a compact time-resolved spectrometer suitable for optical spectroscopy from 400 nm to 1 μm wavelengths. The detector consists of a monolithic array of 16 high-precision Time-to-Digital Converters (TDC) and Single-Photon Avalanche Diodes (SPAD). The instrument has 10 ps resolution and reaches 70 ps (FWHM) timing precision over a 160 ns full-scale range with a Differential Non-Linearity (DNL) better than 1.5 % LSB. The core of the spectrometer is the application-specific integrated chip composed of 16 pixels with 250 μm pitch, containing a 20 μm diameter SPAD and an independent TDC each, fabricated in a 0.35 μm CMOS technology. In front of this array a monochromator is used to focus different wavelengths into different pixels. The spectrometer has been used for fluorescence lifetime spectroscopy: 5 nm spectral resolution over an 80 nm bandwidth is achieved. Lifetime spectroscopy of Nile blue is demonstrated.

A Qualitative Comparison of Porcine and Rodent Thyroperoxidase -Effects of Environmental Chemicals.

EPA Science Inventory

A wide variety of environmental chemicals alter the function of the thyroid system in many animal species. Thyroperoxidase (TPO), the enzyme that synthesizes thyroid hormone, is one of the known biochemical targets for thyroid disrupting chemicals (TDC). The majority of the in vi...

Does homologous reinfection drive multiple-wave influenza outbreaks? Accounting for immunodynamics in epidemiological models.

PubMed

Camacho, A; Cazelles, B

2013-12-01

Epidemiological models of influenza transmission usually assume that recovered individuals instantly develop a fully protective immunity against the infecting strain. However, recent studies have highlighted host heterogeneity in the development of this immune response, characterized by delay and even absence of protection, that could lead to homologous reinfection (HR). Here, we investigate how these immunological mechanisms at the individual level shape the epidemiological dynamics at the population level. In particular, because HR was observed during the successive waves of past pandemics, we assess its role in driving multiple-wave influenza outbreaks. We develop a novel mechanistic model accounting for host heterogeneity in the immune response. Immunological parameters are inferred by fitting our dynamical model to a two-wave influenza epidemic that occurred on the remote island of Tristan da Cunha (TdC) in 1971, and during which HR occurred in 92 of 284 islanders. We then explore the dynamics predicted by our model for various population settings. We find that our model can explain HR over both short (e.g. week) and long (e.g. month) time-scales, as reported during past pandemics. In particular, our results reveal that the HR wave on TdC was a natural consequence of the exceptional contact configuration and high susceptibility of this small and isolated community. By contrast, in larger, less mixed and partially protected populations, HR alone cannot generate multiple-wave outbreaks. However, in the latter case, we find that a significant proportion of infected hosts would remain unprotected at the end of the pandemic season and should therefore benefit from vaccination. Crucially, we show that failing to account for these unprotected individuals can lead to large underestimation of the magnitude of the first post-pandemic season. These results are relevant in the context of the 2009 A/H1N1 influenza post-pandemic era. Copyright © 2013 The Authors. Published by Elsevier B.V. All rights reserved.

Cross-species analysis of thyroperoxidase inhibition by xenobiotics demonstrates conservation of response between pig and rat

EPA Science Inventory

Thyroperoxidase (TPO), the enzyme that catalyzes the synthesis of thyroid hormone (TH), is a known target for thyroid-disrupting chemicals (TDC). In vivo toxicological evidence supporting TPO-inhibition as one molecular-initiating event that leads to thyroid disruption is derive...

Issues in Interaction Language Specification and Representation.

DTIC Science & Technology

1983-11-01

of Dialogues for Human-Computer Interfaces," to be submitted for publication (1983). IHEINL75] Heindel, L. and J. Roberto . "LANG-PAK: An Interactive...22043 Bolling Air Force Base Washington, D.C. 20332 Dr. Paul E. Lehner PAR Technology Corp. AFHRL/LRS TDC P.O. Box 2005 Attn: Susan Ewing Reston, VA 22090

Audiotex Information Systems: Answering Consumer Queries Electronically. TDC Research Report No. 5.

ERIC Educational Resources Information Center

Conlan, Sharon; And Others

A 14-month pilot of INFO-U, a fully automated telephone information service, assessed the feasibility of the technology in Minnesota Extension Service (MES) county offices to respond to consumer telephone queries. The project was designed to: (1) explore the potential of regional Extension cooperation and resource sharing; (2) increase recognition…

Evaluation of flow with dynamic x-ray imaging for aneurysms

NASA Astrophysics Data System (ADS)

Dohatcu, Andreea Cristina

The main goal of this thesis is to evaluate blood flow inside cerebrovascular aneurysms using dynamic x-ray imaging. X-ray contrast substance (dye) was auto injected in elastomer aneurysm models placed in a flow loop (for in-vitro studies) to trace flow passing through aneurysms. More specifically, an improved Time-Density Curves (TDC) Roentgen-videodensitometric tracking technique, that included looking to designated regions (R) within an aneurysm rather than focusing on the entire aneurysm, was employed to get information about blood flow using cine-angiographic sequences. It is the first time R-TDC technique has been used. In complex real-time interventions on patients, 2D/3D angiographic analysis of contrast media flow is the only reliable and rapid source of information that we have in order to assess the seriousness of the disease, suggest the treatment, and verify the result of the treatment. The present study focused on finding a "correlation metric" to quantitatively describe the flow behavior within the aneurysms and examine the hemodynamic implications of several treatments using flow modulating devices applied to saccular and bifurcation geometries aneurysms. The main idea in treatment of an aneurysm is rapid reduction of the risk of rupture. This is usually done endovascularly now by totally occluding the aneurysm by packing it with mechanical or chemical agents. Our research, however, involves a new method of blocking the neck using various types of asymmetric vascular stents (AVS). We proposed and analyzed, using R-TDCs, the feasibility of a new modified endovascular method of treatment based on alteration of blood flow through the aneurysm by partial occlusion only. In-vitro studies using aneurysm phantoms with patient-specific aneurysm models were performed. Also, for the first time the new methods were used in in-vivo studies as well, on rabbit-model experimental data, in an attempt to correlate thrombogenic response of a living organism to flow characteristics as a result of interaction with an AVS. A comparison with optical-dye-dilution data and 3D Computational Fluid Dynamics virtual angiography (CFD) data in similar conditions was also performed. Task oriented optimization of x-ray system parameters with regard to the needs of obtaining TDCs so as to obtain more accurate information of contrast media flow into aneurysms from angiographic images, were done. This includes a comparison between a commercial x-ray Flat Panel Detector (FPD) and an in-house new x-ray micro detector prototype, the Micro-Angiographic Fluoroscope (MAF). X-ray dose levels given in clinical procedures similar in length and complexity to aneurysm treatments, were studied on a statistical representative batch. It was concluded that there is a need for reduction of radiation-induced skin injuries to patients following interventional procedures. Hence, we developed and assessed a method to evaluate the variation of image quality (which impacts the success of TDC analysis) and dose with the acquisition mode operation logic and the automatic-brightness-control (ABC); this method was applied to two clinical interventional fluoroscopic imaging systems: one with an Image Intensifier (II) and the other with a Flat Panel Detector (FPD). The resultant ABC tracking curves obtained for the various imaging modes available on a given system can then be used for proper selection of technique to achieve the needed contrast signal to noise ratio to acquire adequate data for TDC evaluation, while controlling the patient dose.

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

Zelenyuk, Alla; Reitz, Paul; Stewart, Mark L.

Gasoline Compression Ignition (GCI) engines have the potential to achieve high fuel efficiency and to significantly reduce both NOx and particulate matter (PM) emissions by operating under dilute partially-premixed conditions. This low temperature combustion strategy is dependent upon direct-injection of gasoline during the compression stroke and potentially near top dead center (TDC). The timing and duration of the in-cylinder injections can be tailored based on speed and load to create optimized conditions that result in a stable combustion. We present the results of advanced aerosol analysis methods that have been used for detailed real-time characterization of PM emitted from amore » single-cylinder GCI engine operated at different speed, load, timing, and number and duration of near-TDC fuel injections. PM characterization included 28 measurements of size and composition of individual particles sampled directly from the exhaust and after mass and/or mobility classification. We use these data to calculate particle effective density, fractal dimension, dynamic shape factors in free-molecular and transition flow regimes, average diameter of primary spherules, number of spherules, and void fraction of soot agglomerates.« less

Hybrid Ion-Detector/Data-Acquisition System for a TOF-MS

NASA Technical Reports Server (NTRS)

Burton, William D., Jr.; Schultz, J. Albert; Vaughn, Valentine; McCully, Michael; Ulrich, Steven; Egan, Thomas F.

2006-01-01

A modified ion-detector/data-acquisition system has been devised to increase the dynamic range of a time-of-flight mass spectrometer (TOF-MS) that, previously, included a microchannel-plate detector and a data-acquisition system based on counting pulses and time-tagging them by use of a time-to-digital converter (TDC). The dynamic range of the TOF-MS was limited by saturation of the microchannel plate detector, which can handle no more than a few million counts per second. The modified system includes (1) a combined microchannel plate/discrete ion multiplier and (2) a hybrid data-acquisition system that simultaneously performs analog current or voltage measurements and multianode single-ion-pulse-counting time-of-flight measurements to extend the dynamic range of a TDC into the regime in which a mass peak comprises multiple ions arriving simultaneously at the detector. The multianode data are used to determine, in real time, whether the detector is saturated. When saturation is detected, the data-acquisition system selectively enables circuitry that simultaneously determines the ion-peak intensity by measuring the time profile of the analog current or voltage detector-output signal.

Aerodynamic Heating Computations for Projectiles. Volume 2. Swept Wing Calculations Using the Planar Version of the ABRES Shape Change Code (PLNRASCC)

DTIC Science & Technology

1984-06-01

Mt n o ro " g < - OD-O)C 0N v : _grI40N40 O I0 eeg gr, Wn *, c.M b-C N Z ý VN dN N C4 C4 C4 e"Ř!02AWVý 00 0 P- 1( or . . . . . . . . . i...the ABRES Shape Change Code (ASCC)," Acurex Report TM -80-31/AS, July 1980. 3. M. J. Abbett, "Finite Difference Solution of the Subsonic/Supersonic...Development Command US Army AMCCOM Technical Support Activity ATTN: DRSMC- TDC (D) ATTN: DELSD-L DRSMC-TSS (D) Fort Monmouth, NJ 07703 DRSMC-LCA-F (D) Mr. 0

New Technologies for Distance Education: A Needs Assessment at the Delivery Site. TDC Research Report No. 4.

ERIC Educational Resources Information Center

Rubinyi, Robert; And Others

This study examined the potential applicability of educational technologies to the Minnesota Extension Service (MES), which delivers non-credit, educational programming to Minnesota citizens through 91 county extension offices in the state's 87 counties. A total of 62 MES field staff members participated in information-gathering meetings where…

High-Speed Large-Alphabet Quantum Key Distribution Using Photonic Integrated Circuits

DTIC Science & Technology

2014-01-28

polarizing beam splitter, TDC: time-to-digital converter. Extra&loss& photon/bin frame size QSER secure bpp ECC secure&key&rate& none& 0.0031 64 14...to-digital converter. photon/frame frame size QSER secure bpp ECC secure&key& rate& 1.3 16 9.5 % 2.9 layered LDPC 7.3&Mbps& Figure 24: Operating

U.S. EPA, Pesticide Product Label, TDC DICOFOL 4E, 02/19/1982

EPA Pesticide Factsheets

2011-04-21

... kJI ~ ...-I ~ ... M<1 ~ IIrf'Ie(II.-cI -- roc D«X>fOt '·E CWI be ~ 8IIOnI or 'tII"Ith ott>.f ~~ ... t9COiI ••• ded 'Pf'-r ~ • ttIouId Ml ~ ....s wtth limit or ... y ~ tIO .-piM.! ...

Results from the NA62 Gigatracker Prototype: A Low-Mass and sub-ns Time Resolution Silicon Pixel Detector

NASA Astrophysics Data System (ADS)

Fiorini, M.; Rinella, G. Aglieri; Carassiti, V.; Ceccucci, A.; Gil, E. Cortina; Ramusino, A. Cotta; Dellacasa, G.; Garbolino, S.; Jarron, P.; Kaplon, J.; Kluge, A.; Marchetto, F.; Mapelli, A.; Martin, E.; Mazza, G.; Morel, M.; Noy, M.; Nuessle, G.; Petagna, P.; Petrucci, F.; Perktold, L.; Riedler, P.; Rivetti, A.; Statera, M.; Velghe, B.

The Gigatracker (GTK) is a hybrid silicon pixel detector developed for NA62, the experiment aimed at studying ultra-rare kaon decays at the CERN SPS. Three GTK stations will provide precise momentum and angular measurements on every track of the high intensity NA62 hadron beam with a time-tagging resolution of 150 ps. Multiple scattering and hadronic interactions of beam particles in the GTK have to be minimized to keep background events at acceptable levels, hence the total material budget is fixed to 0.5% X0 per station. In addition the calculated fluence for 100 days of running is 2×1014 1 MeV neq/cm2, comparable to the one expected for the inner trackers of LHC detectors in 10 years of operation. These requirements pose challenges for the development of an efficient and low-mass cooling system, to be operated in vacuum, and on the thinning of read-out chips to 100 μm or less. The most challenging requirement is represented by the time resolution, which can be achieved by carefully compensating for the discriminator time-walk. For this purpose, two complementary read-out architectures have been designed and produced as small-scale prototypes: the first is based on the use of a Time-over-Threshold circuit followed by a TDC shared by a group of pixels, while the other uses a constant-fraction discriminator followed by an on-pixel TDC. The readout pixel ASICs are produced in 130 nm IBM CMOS technology and bump-bonded to 200 μm thick silicon sensors. The Gigatracker detector system is described with particular emphasis on recent experimental results obtained from laboratory and beam tests of prototype bump-bonded assemblies, which show a time resolution of less than 200 ps for single hits.

A Two-Stage Approach for Medical Supplies Intermodal Transportation in Large-Scale Disaster Responses

PubMed Central

Ruan, Junhu; Wang, Xuping; Shi, Yan

2014-01-01

We present a two-stage approach for the “helicopters and vehicles” intermodal transportation of medical supplies in large-scale disaster responses. In the first stage, a fuzzy-based method and its heuristic algorithm are developed to select the locations of temporary distribution centers (TDCs) and assign medial aid points (MAPs) to each TDC. In the second stage, an integer-programming model is developed to determine the delivery routes. Numerical experiments verified the effectiveness of the approach, and observed several findings: (i) More TDCs often increase the efficiency and utility of medical supplies; (ii) It is not definitely true that vehicles should load more and more medical supplies in emergency responses; (iii) The more contrasting the traveling speeds of helicopters and vehicles are, the more advantageous the intermodal transportation is. PMID:25350005

Network Coded Cooperative Communication in a Real-Time Wireless Hospital Sensor Network.

PubMed

Prakash, R; Balaji Ganesh, A; Sivabalan, Somu

2017-05-01

The paper presents a network coded cooperative communication (NC-CC) enabled wireless hospital sensor network architecture for monitoring health as well as postural activities of a patient. A wearable device, referred as a smartband is interfaced with pulse rate, body temperature sensors and an accelerometer along with wireless protocol services, such as Bluetooth and Radio-Frequency transceiver and Wi-Fi. The energy efficiency of wearable device is improved by embedding a linear acceleration based transmission duty cycling algorithm (NC-DRDC). The real-time demonstration is carried-out in a hospital environment to evaluate the performance characteristics, such as power spectral density, energy consumption, signal to noise ratio, packet delivery ratio and transmission offset. The resource sharing and energy efficiency features of network coding technique are improved by proposing an algorithm referred as network coding based dynamic retransmit/rebroadcast decision control (LA-TDC). From the experimental results, it is observed that the proposed LA-TDC algorithm reduces network traffic and end-to-end delay by an average of 27.8% and 21.6%, respectively than traditional network coded wireless transmission. The wireless architecture is deployed in a hospital environment and results are then successfully validated.

Novel metal(II) coordination polymers based on N,N'-bis-(4-pyridyl)phthalamide as supercapacitor electrode materials in an aqueous electrolyte.

PubMed

Gong, Yun; Li, Jian; Jiang, Peng-Gang; Li, Qing-Fang; Lin, Jian-Hua

2013-02-07

Based on the redox-active L (N,N'-bis-(4-pyridyl)phthalamide) ligand, two porous MOFs formulated as Zn(6)(BPC)(6)(L)(3)·9DMF (H(2)BPC = 4,4'-biphenyldicarboxylic acid) (1) and Cd(2)(TDC)(2)(L)(2)·4H(2)O (H(2)TDC = 2,5-thiophenedicarboxylic acid) (2) were synthesized and structurally characterized by single-crystal X-ray diffractions. Complex 1 features a uninodal 5-connected 3-fold interpenetrated 3D framework with {4(6).6(4)}-bnn hexagonal BN topology. Complex 2 displays a uninodal 6-connected 2-fold interpenetrated 3D framework with {4(12).6(3)}-pcu topology. When complexes 1 and 2 are used as supercapacitor electrode materials, they can provide a large voltage window as high as 2.6 V in an aqueous electrolyte, and their specific capacitances are much more than the value for the bare carbon glassy electrode. It is observed that the more the current density, the less the specific capacitance for the two kinds of supercapacitor electrode materials. The two complexes show different thermal stabilities, UV absorption and photoluminescence properties.

Picosecond Resolution Time-to-Digital Converter Using Gm-C Integrator and SAR-ADC

NASA Astrophysics Data System (ADS)

Xu, Zule; Miyahara, Masaya; Matsuzawa, Akira

2014-04-01

A picosecond resolution time-to-digital converter (TDC) is presented. The resolution of a conventional delay chain TDC is limited by the delay of a logic buffer. Various types of recent TDCs are successful in breaking this limitation, but they require a significant calibration effort to achieve picosecond resolution with a sufficient linear range. To address these issues, we propose a simple method to break the resolution limitation without any calibration: a Gm-C integrator followed by a successive approximation register analog-to-digital converter (SAR-ADC). This translates the time interval into charge, and then the charge is quantized. A prototype chip was fabricated in 90 nm CMOS. The measurement results reveal a 1 ps resolution, a -0.6/0.7 LSB differential nonlinearity (DNL), a -1.1/2.3 LSB integral nonlinearity (INL), and a 9-bit range. The measured 11.74 ps single-shot precision is caused by the noise of the integrator. We analyze the noise of the integrator and propose an improved front-end circuit to reduce this noise. The proposal is verified by simulations showing the maximum single-shot precision is less than 1 ps. The proposed front-end circuit can also diminish the mismatch effects.

A time-based front-end ASIC for the silicon micro strip sensors of the bar PANDA Micro Vertex Detector

NASA Astrophysics Data System (ADS)

Di Pietro, V.; Brinkmann, K.-Th.; Riccardi, A.; Ritman, J.; Rivetti, A.; Rolo, M. D.; Stockmanns, T.; Zambanini, A.

2016-03-01

The bar PANDA (Antiproton Annihilation at Darmstadt) experiment foresees many detectors for tracking, particle identification and calorimetry. Among them, the innermost is the MVD (Micro Vertex Detector) responsible for a precise tracking and the reconstruction of secondary vertices. This detector will be built from both hybrid pixel (two inner barrels and six forward disks) and double-sided micro strip (two outer barrels and outer rim of the last two disks) silicon sensors. A time-based approach has been chosen for the readout ASIC of the strip sensors. The PASTA (bar PANDA Strip ASIC) chip aims at high resolution time-stamping and charge information through the Time over Threshold (ToT) technique. It benefits from a Time to Digital Converter (TDC) allowing a time bin width down to 50 ps. The analog front-end was designed to serve both n-type and p-type strips and the performed simulations show remarkable performances in terms of linearity and electronic noise. The TDC consists of an analog interpolator, a digital local controller, and a digital global controller as the common back-end for all of the 64 channels.

A novel PMT test system based on waveform sampling

NASA Astrophysics Data System (ADS)

Yin, S.; Ma, L.; Ning, Z.; Qian, S.; Wang, Y.; Jiang, X.; Wang, Z.; Yu, B.; Gao, F.; Zhu, Y.; Wang, Z.

2018-01-01

Comparing with the traditional test system based on a QDC and TDC and scaler, a test system based on waveform sampling is constructed for signal sampling of the 8"R5912 and the 20"R12860 Hamamatsu PMT in different energy states from single to multiple photoelectrons. In order to achieve high throughput and to reduce the dead time in data processing, the data acquisition software based on LabVIEW is developed and runs with a parallel mechanism. The analysis algorithm is realized in LabVIEW and the spectra of charge, amplitude, signal width and rising time are analyzed offline. The results from Charge-to-Digital Converter, Time-to-Digital Converter and waveform sampling are discussed in detailed comparison.

The CBM RICH project

NASA Astrophysics Data System (ADS)

Adamczewski-Musch, J.; Akishin, P.; Becker, K.-H.; Belogurov, S.; Bendarouach, J.; Boldyreva, N.; Chernogorov, A.; Deveaux, C.; Dobyrn, V.; Dürr, M.; Eschke, J.; Förtsch, J.; Heep, J.; Höhne, C.; Kampert, K.-H.; Kochenda, L.; Kopfer, J.; Kravtsov, P.; Kres, I.; Lebedev, S.; Lebedeva, E.; Leonova, E.; Linev, S.; Mahmoud, T.; Michel, J.; Miftakhov, N.; Niebur, W.; Ovcharenko, E.; Patel, V.; Pauly, C.; Pfeifer, D.; Querchfeld, S.; Rautenberg, J.; Reinecke, S.; Riabov, Y.; Roshchin, E.; Samsonov, V.; Tarasenkova, O.; Traxler, M.; Ugur, C.; Vznuzdaev, E.; Vznuzdaev, M.

2017-02-01

The CBM RICH detector is an integral component of the future CBM experiment at FAIR, providing efficient electron identification and pion suppression necessary for the measurement of rare dileptonic probes in heavy ion collisions. The RICH design is based on CO2 gas as radiator, a segmented spherical glass focussing mirror with Al+MgF2 reflective coating, and Multianode Photomultipliers for efficient Cherenkov photon detection. Hamamatsu H12700 MAPMTs have recently been selected as photon sensors, following an extensive sensor evaluation, including irradiation tests to ensure sufficient radiation hardness of the MAPMTs. A brief overview of the detector design and concept is given, results on the radiation hardness of the photon sensors are shown, and the development of a FPGA-TDC based readout chain is discussed.

Effect of structural mount dynamics on a pair of operating Stirling Convertors

NASA Astrophysics Data System (ADS)

Goodnight, Thomas W.; Suárez, Vicente J.; Hughes, William O.; Samorezov, Sergey

2002-01-01

The U.S. Department of Energy (DOE), in conjunction with NASA John H. Glenn Research Center and Stirling Technology Company, are currently developing a Stirling convertor for a Stirling Radioisotope Generator (SRG). NASA Headquarters and DOE have identified the SRG for potential use as an advanced spacecraft power system for future NASA deep-space and Mars surface missions. Low-level dynamic base-shake tests were conducted on a dynamic simulation of the structural mount for a pair of Operating Stirling Convertors. These tests were conducted at NASA Glenn Research Center's Structural Dynamics Laboratory as part of the development of this technology. The purpose of these tests was to identify the changes in transmissibility and the effect on structural dynamic response on a pair of operating Stirling Technology Demonstration Convertors (TDCs). This paper addresses the base-shake test, setup, procedure and results conducted on the Stirling TDC mount simulator in April 2001. .

Improved False Discovery Rate Estimation Procedure for Shotgun Proteomics.

PubMed

Keich, Uri; Kertesz-Farkas, Attila; Noble, William Stafford

2015-08-07

Interpreting the potentially vast number of hypotheses generated by a shotgun proteomics experiment requires a valid and accurate procedure for assigning statistical confidence estimates to identified tandem mass spectra. Despite the crucial role such procedures play in most high-throughput proteomics experiments, the scientific literature has not reached a consensus about the best confidence estimation methodology. In this work, we evaluate, using theoretical and empirical analysis, four previously proposed protocols for estimating the false discovery rate (FDR) associated with a set of identified tandem mass spectra: two variants of the target-decoy competition protocol (TDC) of Elias and Gygi and two variants of the separate target-decoy search protocol of Käll et al. Our analysis reveals significant biases in the two separate target-decoy search protocols. Moreover, the one TDC protocol that provides an unbiased FDR estimate among the target PSMs does so at the cost of forfeiting a random subset of high-scoring spectrum identifications. We therefore propose the mix-max procedure to provide unbiased, accurate FDR estimates in the presence of well-calibrated scores. The method avoids biases associated with the two separate target-decoy search protocols and also avoids the propensity for target-decoy competition to discard a random subset of high-scoring target identifications.

Glutamine 89 is a key residue in the allosteric modulation of human serine racemase activity by ATP.

PubMed

Canosa, Andrea V; Faggiano, Serena; Marchetti, Marialaura; Armao, Stefano; Bettati, Stefano; Bruno, Stefano; Percudani, Riccardo; Campanini, Barbara; Mozzarelli, Andrea

2018-06-13

Serine racemase (SR) catalyses two reactions: the reversible racemisation of L-serine and the irreversible dehydration of L- and D-serine to pyruvate and ammonia. SRs are evolutionarily related to serine dehydratases (SDH) and degradative threonine deaminases (TdcB). Most SRs and TdcBs - but not SDHs - are regulated by nucleotides. SR binds ATP cooperatively and the nucleotide allosterically stimulates the serine dehydratase activity of the enzyme. A H-bond network comprising five residues (T52, N86, Q89, E283 and N316) and water molecules connects the active site with the ATP-binding site. Conservation analysis points to Q89 as a key residue for the allosteric communication, since its mutation to either Met or Ala is linked to the loss of control of activity by nucleotides. We verified this hypothesis by introducing the Q89M and Q89A point mutations in the human SR sequence. The allosteric communication between the active site and the allosteric site in both mutants is almost completely abolished. Indeed, the stimulation of the dehydratase activity by ATP is severely diminished and the binding of the nucleotide is no more cooperative. Ancestral state reconstruction suggests that the allosteric control by nucleotides established early in SR evolution and has been maintained in most eukaryotic lineages.

Improved False Discovery Rate Estimation Procedure for Shotgun Proteomics

PubMed Central

2016-01-01

Interpreting the potentially vast number of hypotheses generated by a shotgun proteomics experiment requires a valid and accurate procedure for assigning statistical confidence estimates to identified tandem mass spectra. Despite the crucial role such procedures play in most high-throughput proteomics experiments, the scientific literature has not reached a consensus about the best confidence estimation methodology. In this work, we evaluate, using theoretical and empirical analysis, four previously proposed protocols for estimating the false discovery rate (FDR) associated with a set of identified tandem mass spectra: two variants of the target-decoy competition protocol (TDC) of Elias and Gygi and two variants of the separate target-decoy search protocol of Käll et al. Our analysis reveals significant biases in the two separate target-decoy search protocols. Moreover, the one TDC protocol that provides an unbiased FDR estimate among the target PSMs does so at the cost of forfeiting a random subset of high-scoring spectrum identifications. We therefore propose the mix-max procedure to provide unbiased, accurate FDR estimates in the presence of well-calibrated scores. The method avoids biases associated with the two separate target-decoy search protocols and also avoids the propensity for target-decoy competition to discard a random subset of high-scoring target identifications. PMID:26152888

TDC-based readout electronics for real-time acquisition of high resolution PET bio-images

NASA Astrophysics Data System (ADS)

Marino, N.; Saponara, S.; Ambrosi, G.; Baronti, F.; Bisogni, M. G.; Cerello, P.,; Ciciriello, F.; Corsi, F.; Fanucci, L.; Ionica, M.; Licciulli, F.; Marzocca, C.; Morrocchi, M.; Pennazio, F.; Roncella, R.; Santoni, C.; Wheadon, R.; Del Guerra, A.

2013-02-01

Positron emission tomography (PET) is a clinical and research tool for in vivo metabolic imaging. The demand for better image quality entails continuous research to improve PET instrumentation. In clinical applications, PET image quality benefits from the time of flight (TOF) feature. Indeed, by measuring the photons arrival time on the detectors with a resolution less than 100 ps, the annihilation point can be estimated with centimeter resolution. This leads to better noise level, contrast and clarity of detail in the images either using analytical or iterative reconstruction algorithms. This work discusses a silicon photomultiplier (SiPM)-based magnetic-field compatible TOF-PET module with depth of interaction (DOI) correction. The detector features a 3D architecture with two tiles of SiPMs coupled to a single LYSO scintillator on both its faces. The real-time front-end electronics is based on a current-mode ASIC where a low input impedance, fast current buffer allows achieving the required time resolution. A pipelined time to digital converter (TDC) measures and digitizes the arrival time and the energy of the events with a timestamp of 100 ps and 400 ps, respectively. An FPGA clusters the data and evaluates the DOI, with a simulated z resolution of the PET image of 1.4 mm FWHM.

Tolerogenic dendritic cells inhibit antiphospholipid syndrome derived effector/memory CD4⁺ T cell response to β2GPI.

PubMed

Torres-Aguilar, Honorio; Blank, Miri; Kivity, Shaye; Misgav, Mudi; Luboshitz, Jacob; Pierangeli, Silvia S; Shoenfeld, Yehuda

2012-01-01

The importance of β(2)-glycoprotein I (β(2)GPI)-specific CD4(+) T cells in the development of pathogenic processes in patients with antiphospholipid syndrome (APS) and APS mouse models is well established. Therefore, our objective is to manipulate the β2GPI specific CD4(+) T cells using tolerogenic dendritic cells (tDCs) to induce tolerance. We aim to evaluate the capability of tDCs to induce antigen-specific tolerance in effector/memory T cells from patients with APS and to elucidate the involved mechanism. DCs and tDCs were produced from patients with APS peripheral-blood-monocytes, using specific cytokines. β(2)GPI-specific tolerance induction was investigated by coculturing control DC (cDC) or tDC, β(2)GPI-loaded, with autologous effector/memory T cells, evaluating the proliferative response, phenotype, cytokines secretion, viability and regulatory T cells. Human monocyte-derived DCs treated with interleukin (IL)-10 and transforming growth factor β-1 (10/TGF-DC) induced β(2)GPI-specific-unresponsiveness in effector/memory CD4(+) T cells (46.5% ± 26.0 less proliferation) in 16 of 20 analysed patients with APS, without affecting the proliferative response to an unrelated candidin. In five analysed patients, 10/TGF-DC-stimulated T cells acquired an IL-2(low)interferon γ(low)IL-10(high) cytokine profile, with just a propensity to express higher numbers of Foxp3(+)CTLA-4(+) cells, but with an evident suppressive ability. In four of 10 analysed patients, 10/TGF-DC-stimulated T cell hyporesponsiveness could not be reverted and showed higher percentages of late apoptosis, p<0.02. The inherent tolerance induction resistance of activated T cells present during the development of autoimmune diseases has delayed the application of tDC as an alternative therapy. This study highlights the 10/TGF-DC feasibility to induce antigen-specific unresponsiveness in autoreactive T cells generated in patients with APS by inducing apoptosis or T cells with regulatory abilities.

Bacterial synthesis of N-hydroxycinnamoyl phenethylamines and tyramines.

PubMed

Sim, Geun Young; Yang, So-Mi; Kim, Bong Gyu; Ahn, Joong-Hoon

2015-10-13

Hydroxycinnamic acids (HCAs) including cinnamic acid, p-coumaric acid, caffeic acid, and ferulic acid, are C6-C3 phenolic compounds that are synthesized via the phenylpropanoid pathway. HCAs serve as precursors for the synthesis of lignins, flavonoids, anthocyanins, stilbenes and other phenolic compounds. HCAs can also be conjugated with diverse compounds including quinic acid, hydroxyl acids, and amines. Hydroxycinnamoyl (HC) amine conjugates such as N-HC tyramines and N-HC phenethylamines have been considered as potential starting materials to develop antiviral and anticancer drugs. We synthesized N-HC tyramines and N-HC phenethylamines using three different approaches in Escherichia coli. Five N-HC phenethylamines and eight N-HC tyramines were synthesized by feeding HCAs and phenethylamine or tyramine to E. coli harboring 4CL (encoding 4-coumarate CoA:ligase) and either SHT (encoding phenethylamine N-HC transferase) or THT (encoding tyramine N-HC transferase). Also, N-(p-coumaroyl) phenethylamine and N-(p-coumaroyl) tyramine were synthesized from p-coumaric acid using E. coli harboring an additional gene, PDC (encoding phenylalanine decarboxylase) or TDC (encoding tyrosine decarboxylase). Finally, we synthesized N-(p-coumaroyl) phenethylamine and N-(p-coumaroyl) tyramine from glucose by reconstructing the metabolic pathways for their synthesis in E. coli. Productivity was maximized by optimizing the cell concentration and incubation temperature. We reconstructed the metabolic pathways for synthesis of N-HC tyramines and N-HC phenethylamines by expressing several genes including 4CL, TST or SHT, PDC or TDC, and TAL (encoding tyrosine ammonia lyase) and engineering the shikimate metabolic pathway to increase endogenous tyrosine concentration in E. coli. Approximately 101.9 mg/L N-(p-coumaroyl) phenethylamine and 495.4 mg/L N-(p-coumaroyl) tyramine were synthesized from p-coumaric acid. Furthermore, 152.5 mg/L N-(p-coumaroyl) phenethylamine and 94.7 mg/L N-(p-coumaroyl) tyramine were synthesized from glucose.

The Unique hmuY Gene Sequence as a Specific Marker of Porphyromonas gingivalis

PubMed Central

Mackiewicz, Paweł; Radwan-Oczko, Małgorzata; Kantorowicz, Małgorzata; Chomyszyn-Gajewska, Maria; Frąszczak, Magdalena; Bielecki, Marcin; Olczak, Mariusz; Olczak, Teresa

2013-01-01

Porphyromonas gingivalis, a major etiological agent of chronic periodontitis, acquires heme from host hemoproteins using the HmuY hemophore. The aim of this study was to develop a specific P. gingivalis marker based on a hmuY gene sequence. Subgingival samples were collected from 66 patients with chronic periodontitis and 40 healthy subjects and the entire hmuY gene was analyzed in positive samples. Phylogenetic analyses demonstrated that both the amino acid sequence of the HmuY protein and the nucleotide sequence of the hmuY gene are unique among P. gingivalis strains/isolates and show low identity to sequences found in other species (below 50 and 56%, respectively). In agreement with these findings, a set of hmuY gene-based primers and standard/real-time PCR with SYBR Green chemistry allowed us to specifically detect P. gingivalis in patients with chronic periodontitis (77.3%) and healthy subjects (20%), the latter possessing lower number of P. gingivalis cells and total bacterial cells. Isolates from healthy subjects possess the hmuY gene-based nucleotide sequence pattern occurring in W83/W50/A7436 (n = 4), 381/ATCC 33277 (n = 3) or TDC60 (n = 1) strains, whereas those from patients typically have TDC60 (n = 21), W83/W50/A7436 (n = 17) and 381/ATCC 33277 (n = 13) strains. We observed a significant correlation between periodontal index of risk of infectiousness (PIRI) and the presence/absence of P. gingivalis (regardless of the hmuY gene-based sequence pattern of the isolate identified [r = 0.43; P = 0.0002] and considering particular isolate pattern [r = 0.38; P = 0.0012]). In conclusion, we demonstrated that the hmuY gene sequence or its fragments may be used as one of the molecular markers of P. gingivalis. PMID:23844074

A Front-End electronics board for single photo-electron timing and charge from MaPMT

NASA Astrophysics Data System (ADS)

Giordano, F.; Breton, D.; Beigbeder, C.; De Robertis, G.; Fusco, P.; Gargano, F.; Liuzzi, R.; Loparco, F.; Mazziotta, M. N.; Rizzi, V.; Tocut, V.

2013-08-01

A Front-End (FE) design based on commercial operational amplifiers has been developed to read-out signals from a Multianode PhotoMultiplier Tube (MaPMT). The overall design has been optimised for single photo-electron signal from the Hamamatsu H8500. The signal is collected by a current sensitive preamplifier and then it is fed into both a ECL fast discriminator and a shaper for analog output readout in differential mode. The analog signal and the digital gates are then registered on VME ADC and TDC modules respectively. Performances in terms of linearity, gain and timing resolution will be discussed, presenting results obtained on a test bench with differentiated step voltage inputs and also with a prototype electronic board plugged into the H8500 PMT illuminated by a picosecond laser.

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

Kodavasal, Janardhan; Kolodziej, Christopher P.; Ciatti, Stephen A.

Gasoline compression ignition (GCI) is a low temperature combustion (LTC) concept that has been gaining increasing interest over the recent years owing to its potential to achieve diesel-like thermal efficiencies with significantly reduced engine-out nitrogen oxides (NOx) and soot emissions compared to diesel engines. In this work, closed-cycle computational fluid dynamics (CFD) simulations are performed of this combustion mode using a sector mesh in an effort to understand effects of model settings on simulation results. One goal of this work is to provide recommendations for grid resolution, combustion model, chemical kinetic mechanism, and turbulence model to accurately capture experimental combustionmore » characteristics. Grid resolutions ranging from 0.7 mm to 0.1 mm minimum cell sizes were evaluated in conjunction with both Reynolds averaged Navier-Stokes (RANS) and Large Eddy Simulation (LES) based turbulence models. Solution of chemical kinetics using the multi-zone approach is evaluated against the detailed approach of solving chemistry in every cell. The relatively small primary reference fuel (PRF) mechanism (48 species) used in this study is also evaluated against a larger 312-species gasoline mechanism. Based on these studies the following model settings are chosen keeping in mind both accuracy and computation costs – 0.175 mm minimum cell size grid, RANS turbulence model, 48-species PRF mechanism, and multi-zone chemistry solution with bin limits of 5 K in temperature and 0.05 in equivalence ratio. With these settings, the performance of the CFD model is evaluated against experimental results corresponding to a low load start of injection (SOI) timing sweep. The model is then exercised to investigate the effect of SOI on combustion phasing with constant intake valve closing (IVC) conditions and fueling over a range of SOI timings to isolate the impact of SOI on charge preparation and ignition. Simulation results indicate that there is an optimum SOI timing, in this case -30?aTDC (after top dead center), which results in the most stable combustion. Advancing injection with respect to this point leads to significant fuel mass burning in the colder squish region, leading to retarded phasing and ultimately misfire for SOI timings earlier than -42?aTDC. On the other hand, retarding injection beyond this optimum timing results in reduced residence time available for gasoline ignition kinetics, and also leads to retarded phasing, with misfire at SOI timings later than -15?aTDC.« less

The readout chain for the bar PANDA MVD strip detector

NASA Astrophysics Data System (ADS)

Schnell, R.; Brinkmann, K.-Th.; Di Pietro, V.; Kleines, H.; Goerres, A.; Riccardi, A.; Rivetti, A.; Rolo, M. D.; Sohlbach, H.; Zaunick, H.-G.

2015-02-01

The bar PANDA (antiProton ANnihilation at DArmstadt) experiment will study the strong interaction in annihilation reactions between an antiproton beam and a stationary gas jet target. The detector will comprise different sub-detectors for tracking, particle identification and calorimetry. The Micro-Vertex Detector (MVD) as the innermost part of the tracking system will allow precise tracking and detection of secondary vertices. For the readout of the double-sided silicon strip sensors a custom-made ASIC is being developed, employing the Time-over-Threshold (ToT) technique for digitization and utilize time-to-digital converters (TDC) to provide a high-precision time stamp of the hit. A custom-made Module Data Concentrator ASIC (MDC) will multiplex the data of all front-ends of one sensor towards the CERN-developed GBT chip set (GigaBit Transceiver). The MicroTCA-based MVD Multiplexer Board (MMB) at the off-detector site will receive and concentrate the data from the GBT links and transfer it to FPGA-based compute nodes for global event building.

Study of Discussion Record Analysis Using Temporal Data Crystallization and Its Application to TV Scene Analysis

DTIC Science & Technology

2015-03-31

analysis. For scene analysis, we use Temporal Data Crystallization (TDC), and for logical analysis, we use Speech Act theory and Toulmin Argumentation...utterance in the discussion record. (i) An utterance ID, and a speaker ID (ii) Speech acts (iii) Argument structure Speech act denotes...mediator is expected to use more OQs than CQs. When the speech act of an utterance is an argument, furthermore, we recognize the conclusion part

Hardware solution for continuous time-resolved burst detection of single molecules in flow

NASA Astrophysics Data System (ADS)

Wahl, Michael; Erdmann, Rainer; Lauritsen, Kristian; Rahn, Hans-Juergen

1998-04-01

Time Correlated Single Photon Counting (TCSPC) is a valuable tool for Single Molecule Detection (SMD). However, existing TCSPC systems did not support continuous data collection and processing as is desirable for applications such as SMD for e.g. DNA-sequencing in a liquid flow. First attempts at using existing instrumentation in this kind of operation mode required additional routing hardware to switch between several memory banks and were not truly continuous. We have designed a hard- and software system to perform continuous real-time TCSPC based upon a modern solid state Time to Digital Converter (TDC). Short dead times of the fully digital TDC design combined with fast Field Programmable Gay Array logic permit a continuous data throughput as high as 3 Mcounts/sec. The histogramming time may be set as short as 100 microsecond(s) . Every histogram or every single fluorescence photon can be real-time tagged at 200 ns resolution in addition to recording its arrival time relative to the excitation pulse. Continuous switching between memory banks permits concurrent histogramming and data read-out. The instrument provides a time resolution of 60 ps and up to 4096 histogram channels. The overall instrument response function in combination with a low cost picosecond diode laser and an inexpensive photomultiplier tube was found to be 180 ps and well sufficient to measure sub-nanosecond fluorescence lifetimes.

Determining the Time of Flight and Speed of Sound on Different types of Edible Oil

NASA Astrophysics Data System (ADS)

Azman, N. A.; Hamid, S. B. Abd

2017-11-01

Edible oil is most often plant-based oils that have been extracted from various seeds. There are cases where the fully virgin edible oil was found to be a fraud. The adulterated edible oil indicates the intentional, fraudulent addition of extraneous, improper or cheaper ingredients puts into the oil or the dilution or removal of some valuable ingredient of the oil in order to increase profits. Hence, decrease the reliability of the Malaysian food product quality. This research was done by using the method of time of flight obtained using the Texas Instrument board, TDC1000-TDC7200 EVM connected to an ultrasonic transducer with 1 MHz frequency. The authors measured the time of flight and temperatures controlled from 20°C to 40°C of five vegetable oils (olive oil, sunflower oil, corn oil, coconut oil, and mustard oil). The value is observed and compared with other research from the literature review. From the study, time of flight values decreases exponentially while speed of sound value increases. This relationship will be useful in spectrum unfolding method to investigate the adulteration in different type of edible oil.This research outcome is to investigate the quality value of the different type of edible oil while eliminates the issues where the quality of Malaysian food product is not reliable.

Performance evaluation of multiple (32 channels) sub-nanosecond TDC implemented in low-cost FPGA

NASA Astrophysics Data System (ADS)

Lichard, P.; Konstantinou, G.; Villar Vilanueva, A.; Palladino, V.

2014-03-01

NA62 experiment Straw tracker frontend board serves as a gas-tight detector cover and integrates two CARIOCA chips, a low cost FPGA (Cyclon III, Altera) and a set of 400Mbit/s links to the backend. The FPGA houses 16 pairs of sub-nanosecond resolution TDCs with derandomizers and an output link serializer. Evaluation methods, including simulations, and performance results of the system in the lab and on a detector prototype are presented.

Modifications to the XBR-2D Heat Conduction Code

DTIC Science & Technology

1994-04-01

for & 25-me barrel (750 Shots/min) is A mbient Tm 4R), Pr fpsi), gas vel (in/s) z : -....-.. -... .... : 530.0 14.70 0.00 b Sarrel Gemetry : ; zchrom...Ausomotive Command U.S. Army Maeiel Cummand ATTN: AMSTA-JSK (Armor Eeg . Br.) ATII: AMCAM Wre, MI 4897.5000 5001 Eisenhower Ave. Alexandria, VA 22333.001 1...and Engeering Center A er Prving ATTN.4 SMCAR- TDC Picauinny Arsenal l 07806-5000 2 Dir, USAMSAA ATTN: AMXSY-D Direcior AMXSY-MP, IL Cohe DenK Weapomn

Railway crossing risk area detection using linear regression and terrain drop compensation techniques.

PubMed

Chen, Wen-Yuan; Wang, Mei; Fu, Zhou-Xing

2014-06-16

Most railway accidents happen at railway crossings. Therefore, how to detect humans or objects present in the risk area of a railway crossing and thus prevent accidents are important tasks. In this paper, three strategies are used to detect the risk area of a railway crossing: (1) we use a terrain drop compensation (TDC) technique to solve the problem of the concavity of railway crossings; (2) we use a linear regression technique to predict the position and length of an object from image processing; (3) we have developed a novel strategy called calculating local maximum Y-coordinate object points (CLMYOP) to obtain the ground points of the object. In addition, image preprocessing is also applied to filter out the noise and successfully improve the object detection. From the experimental results, it is demonstrated that our scheme is an effective and corrective method for the detection of railway crossing risk areas.

Railway Crossing Risk Area Detection Using Linear Regression and Terrain Drop Compensation Techniques

PubMed Central

Chen, Wen-Yuan; Wang, Mei; Fu, Zhou-Xing

2014-01-01

Most railway accidents happen at railway crossings. Therefore, how to detect humans or objects present in the risk area of a railway crossing and thus prevent accidents are important tasks. In this paper, three strategies are used to detect the risk area of a railway crossing: (1) we use a terrain drop compensation (TDC) technique to solve the problem of the concavity of railway crossings; (2) we use a linear regression technique to predict the position and length of an object from image processing; (3) we have developed a novel strategy called calculating local maximum Y-coordinate object points (CLMYOP) to obtain the ground points of the object. In addition, image preprocessing is also applied to filter out the noise and successfully improve the object detection. From the experimental results, it is demonstrated that our scheme is an effective and corrective method for the detection of railway crossing risk areas. PMID:24936948

NASA GRC Technology Development Project for a Stirling Radioisotope Power System

NASA Technical Reports Server (NTRS)

Thieme, Lanny G.; Schreiber, Jeffrey G.

2000-01-01

NASA Glenn Research Center (GRC), the Department of Energy (DOE), and Stirling Technology Company (STC) are developing a Stirling convertor for an advanced radioisotope power system to provide spacecraft on-board electric power for NASA deep space missions. NASA GRC is conducting an in-house project to provide convertor, component, and materials testing and evaluation in support of the overall power system development. A first characterization of the DOE/STC 55-We Stirling Technology Demonstration Convertor (TDC) under the expected launch random vibration environment was recently completed in the NASA GRC Structural Dynamics Laboratory. Two TDCs also completed an initial electromagnetic interference (EMI) characterization at NASA GRC while being tested in a synchronized, opposed configuration. Materials testing is underway to support a life assessment of the heater head, and magnet characterization and aging tests have been initiated. Test facilities are now being established for an independent convertor performance verification and technology development. A preliminary Failure Mode Effect Analysis (FMEA), initial finite element analysis (FEA) for the linear alternator, ionizing radiation survivability assessment, and radiator parametric study have also been completed. This paper will discuss the status, plans, and results to date for these efforts.

Investigation of metrics to assess vascular flow modifications for diverter device designs using hydrodynamics and angiographic studies

NASA Astrophysics Data System (ADS)

Ionita, Ciprian N.; Bednarek, Daniel R.; Rudin, Stephen

2012-03-01

Intracranial aneurysm treatment with flow diverters (FD) is a new minimally invasive approach, recently approved for use in human patients. Attempts to correlate the flow reduction observed in angiograms with a parameter related to the FD structure have not been totally successful. To find the proper parameter, we investigated four porous-media flow models. The models describing the relation between the pressure drop and flow velocity that are investigated include the capillary theory linear model (CTLM), the drag force linear model (DFLM), the simple quadratic model (SQM) and the modified quadratic model (MQM). Proportionality parameters are referred to as permeability for the linear models and resistance for the quadratic ones. A two stage experiment was performed. First, we verified flow model validity by placing six different stainless-steel meshes, resembling FD structures, in known flow conditions. The best flow model was used for the second stage, where six different FD's were inserted in aneurysm phantoms and flow modification was estimated using angiographically derived time density curves (TDC). Finally, TDC peak variation was compared with the FD parameter. Model validity experiments indicated errors of: 70% for the linear models, 26% for the SQM and 7% for the MQM. The resistance calculated according to the MQM model correlated well with the contrast flow reduction. Results indicate that resistance calculated according to MQM is appropriate to characterize the FD and could explain the flow modification observed in angiograms.

Effects of injection pressure and injection timing to exhaust gas opacity for a conventional indirect diesel engine

NASA Astrophysics Data System (ADS)

Budiman, Agus; Majid, Akmal Irfan; Pambayun, Nirmala Adhi Yoga; Yuswono, Lilik Chaerul; Sukoco

2016-06-01

In relation to pollution control and environmental friendliness, the quality of exhaust gas from diesel engine needs to be considered. The influences of injection pressure and timing to exhaust gas opacity were investigated. A series of experiments were conducted in a one-cylinder conventional diesel engine with a naturally aspirated system and indirect injection. The default specification of injection pressure was 120 kg/cm2. To investigate the injection pressure, the engine speed was retained on 1000 rpm with pressure variations from 80 to 215 kg/cm2. On the other hand, the various injection timing (8, 10, 12, 16 degrees before TDC point and exact 18 degrees before TDC point) were used to determine their effects to exhaust gas opacity. In this case, the engine speed was varied from 1000 to 2400 rpm. The injector tester was used to measure injection pressure whereas the exhaust gas opacity was determined by the smoke meter. Those data were also statistically analyzed by product moment correlation. As the results, the injection pressure of diesel engine had a non-significant positive correlation to the exhaust gas opacity with r = 0.113 and p > 5 %. Injection pressure should be adjusted to the specification listed on the diesel engine as if it was too high or too low will lead to the higher opacity. Moreover, there was a significant positive correlation between injection timing and the exhaust gas opacity in all engine speeds.

CMOS time-to-digital converter based on a pulse-mixing scheme

NASA Astrophysics Data System (ADS)

Chen, Chun-Chi; Hwang, Chorng-Sii; Liu, Keng-Chih; Chen, Guan-Hong

2014-11-01

This paper proposes a new pulse-mixing scheme utilizing both pulse-shrinking and pulse-stretching mechanisms to improve the performance of time-to-digital converters (TDCs). The temporal resolution of the conventional pulse-shrinking mechanism is determined by the size ratio between homogeneous and inhomogeneous elements. The proposed scheme which features double-stage operation derives its resolution according to the time difference between pulse-shrinking and pulse-stretching amounts. Thus, it can achieve greater immunity against temperature and ambient variations than that of the single-stage scheme. The circuit area also can be reduced by the proposed pulse-mixing scheme. In addition, this study proposes an improved cyclic delay line to eliminate the undesirable shift in the temporal resolution successfully. Therefore, the effective resolution can be controlled completely by the pulse-mixing unit to improve accuracy. The proposed TDC composed of only one cyclic delay line and one counter is fabricated in a TSMC CMOS 0.35-μm DPQM process. The chip core occupies an extremely small area of 0.02 mm2, which is the best among the related works. The experimental result shows that an effective resolution of around 53 ps within ±13% variation over a 0-100 °C temperature range is achieved. The power consumption is 90 μW at a sample rate of 1000 samples/s. In addition to the reduced area, the proposed TDC circuit achieves its resolution with less thermal-sensitivity and better fluctuations caused by process variations.

Head and neck lymphedema management: Evaluation of a therapy program.

PubMed

Pigott, Amanda; Nixon, Jodie; Fleming, Jennifer; Porceddu, Sandro

2018-06-01

The purpose of this pilot study was to examine a therapeutic intervention for head and neck lymphedema. The 22-week intervention involved therapist-led care and participant self-management. Effectiveness was evaluated using a previously described lymphedema assessment tool, the Assessment of Lymphedema of the Head and Neck (ALOHA) to detect change over the course of the 22 weeks of treatment, and before and after a single treatment session. A prospective observational pilot study was conducted with a cohort of 10 participants assessed. Measurements of size (tape measurements) and water content (tissue dielectric constant [TDC]) were used, per the ALOHA protocol. Participants received 13 lymphedema therapy treatments at reducing frequencies over 22 weeks and daily self-management. There was an overall significant reduction in lower neck circumference (F [2.15,19.35] = 7.11; P = .004), upper neck circumference (F [5,45] = 7.27; P < .001) and TDC (F (5,45) = 8.92; P < .001) over time. There were no significant differences over the course of treatment for mean ear-to-ear measurements or before and after a single session of treatment. This pilot study found a reduction in head and neck lymphedema over the 22-week lymphedema treatment course. This intervention may be successful in reducing head and neck lymphedema; however, further studies are needed to investigate these findings in a larger sample with the use of a control group to negate improvements from healing over time. © 2018 Wiley Periodicals, Inc.

Effect of different bile salts on the relative hypoglycemia of witepsol W35 suppositories containing insulin in diabetic Beagle dogs.

PubMed

Hosny, E A; Al-Shora, H I; Elmazar, M M

2001-09-01

Insulin suppositories were formulated using Witepsol W35 as a base to investigate the effect of various bile salts/acids on the plasma glucose concentration of diabetic beagle dogs. Comparison of the effect of these formulations was made with that produced by insulin subcutaneous injections. Of the bile salts/acids studied, incorporation of 100 mg of deoxycholic acid (DCA), sodium cholate (NaC), or sodium deoxycholate (NaDC) with insulin (10 U/Kg) showed that suppositories containing NaDC produced the highest area under the curve (AUC) and relative hypoglycemia (RH) of 290 +/- 83 mg%h and 28% +/- 8.1%, respectively. To study the optimum amount of NaDC in insulin suppositories to produce the highest RH, 50-200 mg/suppository were used, and we found that 150 mg NaDC produced 35% +/- 13% RH. We also studied the influence of different doses of insulin (5-20 U/kg) in the presence of NaDC (100 mg). It was found that increase of the insulin dose was accompanied by an increase in AUC and maximum reduction in plasma glucose level Cmax. A combination of NaDC (100 mg) and NaC (50 mg) produced an AUC of 252 +/- 13mg%h and an RH of 49% +/- 2.6%, which were higher than produced by either of its individual components (NaC 50 mg or NaDC 100 mg) when used alone or when compared with an equivalent amount of NaDC (150 mg). When the effect of sodium taurocholate (NaTC) and sodium taurodeoxycholate (NaTDC) was studied, it was found that an insulin suppository containing 100 mg of either NaTC or NaTDC produced an RH equivalent to that produced previouslY with a mixture of NaDC (100 mg) and NaC (50 mg). On the other hand, NaC (50 mg) did not improve the hypoglycemic effect of NaTC any further. In conclusion, a relative hYpoglycemia of about 50% can be reached using insulin suppositories containing Witepsol W35 as a base and NaDC plus NaC (100 mg plus 50 mg, respectively), NaTDC (100mg), or NaTC (100 mg) as rectal absorption enhancers of insulin. A desirable hypoglycemia, expressed as Cmax, and/or AUC can be reached by adjusting the insulin dose in the formulation according to the degree of hyperglycemia.

Overview of NASA GRC Stirling Technology Development

NASA Technical Reports Server (NTRS)

Schreiber, Jeffrey; Thieme, Lanny

2003-01-01

The Stirling Radioisotope Generator (SRG) is currently being developed by Lockheed Martin Astronautics (LMA) under contract to the Depar1ment of Energy (DOE). The generator will be a high efficiency electric power source for NASA Space Science missions with the capability to operate in the vacuum of deep space or in an atmosphere such as on the surface of Mars. High system efficiency is obtained through the use of free-piston Stirling power conversion technology. Power output of the generator will be greater than 100 watts at the beginning of life with the decline in power being largely due to the decay of the plutonium heat source. In suppOl1 of the DOE SRG project, the NASA Glenn Research Center (GRC) has established a near-term technology effort to provide some of the critical data to ensure a successful transition to flight for what will be the first dynamic power system used in space. Initially, a limited number of technical areas were selected for the GRC effort, however this is now being expanded to more thoroughly cover a range of technical issues. The tasks include in-house testing of Stirling convertors and controllers, materials evaluation and heater head life assessment, structural dynamics, electromagnetic interference, organics evaluation, and reliability analysis. Most of these high-level tasks have several subtasks within. There is also an advanced technology effort that is complementary near-term technology effort. Many of the tests make use of the 55-We Technology Demonstration Convel10r (TDC). There have been multiple controller tests to support the LMA flight controller design effort. Preparation is continuing for a thermal/vacuum system demonstration. A pair of flight prototype TDC's have recently been placed on an extended test with unattended, continuous operation. Heater head life assessment efforts continue, with the material data being refined and the analysis moving toward the system perspective. Long-term magnet aging tests are continuing to characterize any possible aging in the strength or demagnetization resistance of the permanent magnets used in the linear alternator. In a parallel effort, higher performance magnets are also being evaluated. A reliability effort is being initiated that will help to guide the development activities with an increased focus on the necessary components and subsystems. Some other disciplines that are active in the GRC technology effort include structural dynamics, linear alternator analysis, EMI/EMC, controls, and mechanical design evaluation. This paper will provide an overview of some of the GRC technical efforts, including the current status, and a description of future efforts.

Triroc: A Multi-Channel SiPM Read-Out ASIC for PET/PET-ToF Application

NASA Astrophysics Data System (ADS)

Ahmad, Salleh; Fleury, Julien; de la Taille, Christophe; Seguin-Moreau, Nathalie; Dulucq, Frederic; Martin-Chassard, Gisele; Callier, Stephane; Thienpont, Damien; Raux, Ludovic

2015-06-01

Triroc is the latest addition to SiPM readout ASICs family developed at Weeroc, a start-up company from the Omega microelectronics group of IN2P3/CNRS. This chip is developed under the framework TRIMAGE European project which is aimed for building a cost effective tri-modal PET/MR/EEG brain scan. To ensure the flexibility and compatibility with any SiPM in the market, the ASIC is designed to be capable of accepting negative and positive polarity input signals. This 64-channel ASIC, is suitable for SiPM readout which requires high accuracy timing and charge measurements. Targeted applications would be PET prototyping with time-of-flight capability. Main features of Triroc includes high dynamic range ADC up to 2500 photoelectrons and TDC fine time binning of 40 ps. Triroc requires very minimal external components which means it is a good contender for compact multichannel PET prototyping. Triroc is designed by using AMS 0.35 μm SiGe technology and it was submitted in March 2014. The detail design of this chip will be presented.

The BELLE DAQ system

NASA Astrophysics Data System (ADS)

Suzuki, Soh Yamagata; Yamauchi, Masanori; Nakao, Mikihiko; Itoh, Ryosuke; Fujii, Hirofumi

2000-10-01

We built a data acquisition system for the BELLE experiment. The system was designed to cope with the average trigger rate up to 500 Hz at the typical event size of 30 kB. This system has five components: (1) the readout sequence controller, (2) the FASTBUS-TDC readout systems using charge-to-time conversion, (3) the barrel shifter event builder, (4) the parallel online computing farm, and (5) the data transfer system to the mass storage. This system has been in operation for physics data taking since June 1999 without serious problems.

Job Complexity and Cognitive Performance in Bank Personnel

DTIC Science & Technology

1984-09-01

Hemispheric differences in serial versus parallel processing. Journal of Experimental Psychology 97(3):349-356, 1973. Dumas, R. and Morgan, A. EEG ...7 8 9 10 J_l 12 13 14 15. 16 .17 18 19 20 i 1 n -ifl i 3^1 9 4f^^^ 1 1 M sM^ tM i ’ N eH^^^^H i 1 yllH^^^^I i sH^^^^^^^B ! i...NL Boiling Air Force Base Washington, D.C. 20332 ’ AFHRL/LRS TDC Attn: Susan Ewing Wright-Patterson AFB, OH 45433 Chief, Systems Engineering

Department of Defense Data Model, Version 1, Fy 1998, Volume 3.

DTIC Science & Technology

1998-05-31

TM E...S C A (F K ) 1- l-DC l-H z Z ZUJ zz UJ UJu. UJUJ E E Ei= SS S Sg UJUJ fr DC DC 3 O °u^S Ujfeujg = 3 LULU rr DC^ TDC < DCOC...BQ-ZZ «£ sOuiui ■ z oc UJ u z o u _l ff < u. 1- z UJ ^oc ffUJ O 0. feit ^z u. Sr1" 9 < U.Q tm LU Lut- OC < □ 10 lü ^ (/)

Versatile all-digital time interval measuring system

NASA Astrophysics Data System (ADS)

Vyhlidal, David; Cech, Miroslav

2011-06-01

This paper describes a design and performance of a versatile all-digital time interval measuring system. The measurement method is based on an interpolation principle. In this principle the time interval is first roughly digitized by a coarse counter driven by a high stability reference clock and the fractions between the clock periods are measured by two Time-to-Digital Converter chips TDC-GPX manufactured by Acam messelectronic. Control circuits allow programmable customization of the system to satisfy many applications such as laser range finding, event counting, or time-of-flight measurements in various physics experiments. The system has two reference clocks inputs and two independent channels for measuring start and stop events. Only one 40 MHz reference is required for the measurement. The second reference can be, for example, 1 PPS (Pulse per Second) signal from a GPS (Global Positioning System) to time tag events. Time intervals are measured using the highest resolution mode of the TDC-GPX chips. The resolution of each chip is software programmable and is PLL (Phase Locked Loop) stabilized against temperature and voltage variations. The system can achieve a timing resolution better than 15 ps rms with up to 90 kHz repetition rate. The time interval measurement range is from 0 ps up to 1 second. The power consumption of the whole system is 18 W including an embedded computer board and an LCD (Liquid Crystal Display) screen. The embedded computer controls the whole system, collects and evaluates measurement data and with the display provides a user interface. The system is implemented using commercially available components.

A randomized controlled trial comparing two types of pneumatic compression for breast cancer-related lymphedema treatment in the home.

PubMed

Fife, Caroline E; Davey, Suzanne; Maus, Erik A; Guilliod, Renie; Mayrovitz, Harvey N

2012-12-01

Pneumatic compression devices (PCDs) are used in the home setting as adjunctive treatment for lymphedema after acute treatment in a clinical setting. PCDs range in complexity from simple to technologically advanced. The objective of this prospective, randomized study was to determine whether an advanced PCD (APCD) provides better outcomes as measured by arm edema and tissue water reductions compared to a standard PCD (SPCD) in patients with arm lymphedema after breast cancer treatment. Subjects were randomized to an APCD (Flexitouch system, HCPCS E0652) or SPCD (Bio Compression 2004, HCPCS E0651) used for home treatment 1 h/day for 12 weeks. Pressure settings were 30 mmHg for the SPCD and upper extremity treatment program (UE01) with standard pressure for the APCD. Thirty-six subjects (18 per group) with unilateral upper extremity lymphedema with at least 5% arm edema volume at the time of enrollment, completed treatments over the 12-week period. Arm volumes were determined from arm girth measurements and suitable model calculations, and tissue water was determined based on measurements of the arm tissue dielectric constant (TDC). The APCD-treated group experienced an average of 29% reduction in edema compared to a 16% increase in the SPCD group. Mean changes in TDC values were a 5.8% reduction for the APCD group and a 1.9% increase for the SPCD group. This study suggests that for the home maintenance phase of treatment of arm lymphedema secondary to breast cancer therapy, the adjuvant treatment with an APCD provides better outcomes than with a SPCD.

Mid-Atlantic Technology Applications Center. Quarters 1-4

NASA Technical Reports Server (NTRS)

1997-01-01

Mid-atlantic Technology Application Center (MTAC) pursued a number of initiatives designed to enhance the strategic position of the Langley Research Center (LaRC) and NASA in industry. Among these was a closer association with the ISA, International Society for Measurement and Control. During 1997, MTAC placed articles regarding NASA-developed technologies in each In Tech magazine. The monthly magazine is sent to 46,000 sensors and instrumentation professionals. In addition, MTAC coordinated NASXs participation in the ISA Tech 97 Conference, securing $112,000 of free exhibit space, 1500 NASA sensors posters at no cost to NASA, and thousands of dollars of free publicity. MTAC was awarded a contract by ISA to operate its Technical Resource Center (TRC). The goal of this project is to determine what user needs are in order to identify opportunities for collaboration between NASA centers and companies. In addition, the TRC work will lay the groundwork for the Technology Development Consortium (TDC) proposed by MTAC. The purpose of the TDC is to: match current industry needs with NASA technologies available now, and to identify future needs of NASA and industry which may lead to dual use projects. The goal of these activities is twofold: to infuse NASA technologies into the sensors and instrumentation industry and to secure industry funds to support NASA technology development projects. The instrumentation and sensors industry is valued at $30 billion worldwide, with $12 billion in sales in the United States. The growth rate averages 13.5%, so that by the year 2000, the industry will produce products worth $49 billion. More than 80% of instruments, sensors and control systems are currently manufactured in the United States. NASA and the industry do not have a history of collaborative projects; MTAC's initiatives in this area are designed to foster working relationships between the two parties that will help maintain U.S. leadership in this field. Mid-atlantic Technology Applications Center (MTAC) continued to work on LaRC-SI and Thin Layer Unimorph Driver and Sensor activities. MTAC helped develop the "master license" concept and identified additional applications and potential clients. The goal of these activities was to increase the financial return to Langley Research Center, to ensure the diffusion of the technologies throughout the economy, and to attract partners for future NASA technology development efforts. In an attempt to market LaRC-SI and the Thin Layer Unimorph Driver and Sensor, MTAC developed and pioneered the use of the USRTTC Technology Commercialization Team. As a result, MTAC's sister RTTCs identified both applications and potential users for the two technologies. MTAC also benefitted from its affiliate network to locate companies throughout the region that were interested in the two technologies. MTAC is working with Allegheny Ludlum to monitor the progress of the installation and testing of ultrasonic equipment purchased as a result of Langley Research Center's assistance.

A 3-D Magnetic Analysis of a Stirling Convertor Linear Alternator Under Load

NASA Technical Reports Server (NTRS)

Geng, Steven M.; Schwarze, Gene E.; Niedra, Janis M.; Regan, Timothy F.

2001-01-01

The NASA Glenn Research Center (GRC), the Department of Energy (DOE), and the Stirling Technology Company (STC) are developing Stirling convertors for Stirling Radioisotope Power Systems (SRPS) to provide electrical power for future NASA deep space missions. STC is developing the 55-We Technology Demonstration Convertor (TDC) under contract to DOE. Of critical importance to the successful development of the Stirling convertor for space power applications is the development of a lightweight and highly efficient linear alternator. This paper presents a 3-dimensional finite element method (FEM) approach for evaluating Stirling convertor linear alternators. The model extends a magnetostatic analysis previously reported at the 35th Intersociety Energy Conversion Engineering Conference (IECEC) to include the effects of the load current. STC's 55-We linear alternator design was selected to validate the model. Spatial plots of magnetic field strength (H) are presented in the region of the exciting permanent magnets. The margin for permanent magnet demagnetization is calculated at the expected magnet operating temperature for the near earth environment and for various average magnet temperatures. These thermal conditions were selected to represent a worst-case condition for the planned deep space missions. This paper presents plots that identify regions of high H where the potential to alter the magnetic moment of the magnets exists.

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

Breton, D.; /Orsay, LAL; Delagnes, E.

There is a considerable interest to develop new time-of-flight detectors using, for example, micro-channel-plate photodetectors (MCP-PMTs). The question we pose in this paper is if new waveform digitizer ASICs, such as the WaveCatcher and TARGET, operating with a sampling rate of 2-3 GSa/s can compete with 1GHz BW CFD/TDC/ADC electronics. We have performed a series of measurements with these waveform digitizers coupled to MCP-PMTs operating at low gain and with a signal equivalent to {approx}40 photoelectrons. The tests were done with a laser diode on detectors operating under the same condition used previously in SLAC and Fermilab beam tests. Ourmore » test results indicate that one can achieve similar resolution with both methods. Although the commercial CFD-based electronics does exist and performs very well, it is difficult to implement on a very large scale, and therefore the custom electronics is needed. In addition, the analog delay line requirement makes it very difficult to incorporate CFD discriminators in ASIC designs.« less

Expansion of the gateway multisite recombination cloning toolkit.

PubMed

Shearin, Harold K; Dvarishkis, Alisa R; Kozeluh, Craig D; Stowers, R Steven

2013-01-01

Precise manipulation of transgene expression in genetic model organisms has led to advances in understanding fundamental mechanisms of development, physiology, and genetic disease. Transgene construction is, however, a precondition of transgene expression, and often limits the rate of experimental progress. Here we report an expansion of the modular Gateway MultiSite recombination-cloning platform for high efficiency transgene assembly. The expansion includes two additional destination vectors and entry clones for the LexA binary transcription system, among others. These new tools enhance the expression levels possible with Gateway MultiSite generated transgenes and make possible the generation of LexA drivers and reporters with Gateway MultiSite cloning. In vivo data from transgenic Drosophila functionally validating each novel component are presented and include neuronal LexA drivers, LexAop2 red and green fluorescent synaptic vesicle reporters, TDC2 and TRH LexA, GAL4, and QF drivers, and LexAop2, UAS, and QUAS channelrhodopsin2 T159C reporters.

Expansion of the Gateway MultiSite Recombination Cloning Toolkit

PubMed Central

Shearin, Harold K.; Dvarishkis, Alisa R.; Kozeluh, Craig D.; Stowers, R. Steven

2013-01-01

Precise manipulation of transgene expression in genetic model organisms has led to advances in understanding fundamental mechanisms of development, physiology, and genetic disease. Transgene construction is, however, a precondition of transgene expression, and often limits the rate of experimental progress. Here we report an expansion of the modular Gateway MultiSite recombination-cloning platform for high efficiency transgene assembly. The expansion includes two additional destination vectors and entry clones for the LexA binary transcription system, among others. These new tools enhance the expression levels possible with Gateway MultiSite generated transgenes and make possible the generation of LexA drivers and reporters with Gateway MultiSite cloning. In vivo data from transgenic Drosophila functionally validating each novel component are presented and include neuronal LexA drivers, LexAop2 red and green fluorescent synaptic vesicle reporters, TDC2 and TRH LexA, GAL4, and QF drivers, and LexAop2, UAS, and QUAS channelrhodopsin2 T159C reporters. PMID:24204935

Preliminary test results from a free-piston Stirling engine technology demonstration program to support advanced radioisotope space power applications

NASA Astrophysics Data System (ADS)

White, Maurice A.; Qiu, Songgang; Augenblick, Jack E.

2000-01-01

Free-piston Stirling engines offer a relatively mature, proven, long-life technology that is well-suited for advanced, high-efficiency radioisotope space power systems. Contracts from DOE and NASA are being conducted by Stirling Technology Company (STC) for the purpose of demonstrating the Stirling technology in a configuration and power level that is representative of an eventual space power system. The long-term objective is to develop a power system with an efficiency exceeding 20% that can function with a high degree of reliability for up to 15 years on deep space missions. The current technology demonstration convertors (TDC's) are completing shakedown testing and have recently demonstrated performance levels that are virtually identical to projections made during the preliminary design phase. This paper describes preliminary test results for power output, efficiency, and vibration levels. These early results demonstrate the ability of the free-piston Stirling technology to exceed objectives by approximately quadrupling the efficiency of conventional radioisotope thermoelectric generators (RTG's). .

Performance study of SKIROC2/A ASIC for ILD Si-W ECAL

NASA Astrophysics Data System (ADS)

Suehara, T.; Sekiya, I.; Callier, S.; Balagura, V.; Boudry, V.; Brient, J.-C.; de la Taille, C.; Kawagoe, K.; Irles, A.; Magniette, F.; Nanni, J.; Pöschl, R.; Yoshioka, T.

2018-03-01

The ILD Si-W ECAL is a sampling calorimeter with tungsten absorber and highly segmented silicon layers for the International Large Detector (ILD), one of the two detector concepts for the International Linear Collider. SKIROC2 is an ASIC for the ILD Si-W ECAL. To investigate the issues found in prototype detectors, we prepared dedicated ASIC evaluation boards with either BGA sockets or directly soldered SKIROC2. We report a performance study with the evaluation boards, including signal-to-noise ratio and TDC performance with comparing SKIROC2 and an updated version, SKIROC2A.

Flying Qualities of Relaxed Static Stability Aircraft. Volume 2. Ramifications of Flight-Essential/Critical Heavily-Augmented Airplane Characteristics on Flying Qualities

DTIC Science & Technology

1982-09-01

root variation am is perwltte4 to becout sort uaatlvs ( eeg ., cog. Wereeeixuly w~ved further fotowrd of the neutral potat). % w~a e t-period dh~a~a fs Cc...deg-sec) unit impulse. For sueh an input the pit~ch att.It~ tdc responses in !A’gure 11 appear with the same response shapes as those deacribed...this pair approaches the clewaical tm -degree-of-froedo. phugoid mode dwereint Z’ V/gZuAT &rglo I n this classic phugoid (Ref erence 22) the angle of

Influence of ionic liquids on the syntheses and structures of Mn(II) coordination polymers based on multidentate N-heterocyclic aromatic ligands and bridging carboxylate ligands.

PubMed

Qin, Jian-Hua; Wang, Hua-Rui; Pan, Qi; Zang, Shuang-Quan; Hou, Hongwei; Fan, Yaoting

2015-10-28

Seven Mn(ii) coordination polymers, namely {[Mn2(ptptp)Cl2(H2O)3]·H2O}n (1), {[Mn(μ-ptptp)3]2[Mn3(μ3-Cl)]2}·2Cl·16H2O (2), {[Mn2(ptptp)(ip)2(H2O)3]·H2O}n (3), {[Mn2(ptptp)(5-CH3-ip)2(H2O)3]·H2O}n (4), {[Mn4(ptptp)(5-Br-ip)3(H2O)3]·4H2O}n (5), {[Mn2(ptptp)(Hbtc)(H2O)2]·2H2O}n (6) and {[Mn2(ptptp)(tdc)(H2O)2]·1.5H2O}n (7), have been prepared based on multidentate N-heterocyclic aromatic ligands and bridging carboxylate ligands (H2ptptp = 2-(5-{6-[5-(pyrazin-2-yl)-1H-1,2,4-triazol-3-yl]pyridin-2-yl}-1H-1,2,4-triazol-3-yl)pyrazine; R-isophthalic acids, H2ip-R: R = -H (3), -CH3 (4), -Br (5); H3btc = trimesic acid (6); H2tdc = thiophene-2,5-dicarboxylic acid (7)), in order to further probe the multiple roles of [RMI]Br ionic liquids in the hydro/solvothermal synthesis (RMI = 1-alkyl-3-methylimidazolium, R = ethyl, or propyl, or butyl). The successful syntheses of complexes 2-6 suggest that in hydro/solvothermal synthesis the addition of a small amount of [RMI]Br plays a crucial role. Complex 1 exhibits single right-handed helices constructed by ptptp ligands and Mn(ii) ions. Complex 2 possesses octanuclear helicate structures in which two propeller-shaped [Mn(μ-ptptp)3](4-) units embrace two [Mn3(μ3-Cl)](5+) cluster cores inside. Complexes 3 and 4 are isostructural and display a 1D double chain formed by two kinds of pseudo meso-helices: (Mn-ptptp)n and (Mn-5-R-ip)n. Complex 5 has a 2D structure containing 1D Mn(ii) ion chains formed through carboxylates and [ptptp](2-)-N,N bridges. Complex 6 shows a 2D structure formed by a meso-helix (Mn-ptptp)n and the partly deprotonated Hbtc ligands. Complex 7 features a heterochiral [2 + 2] coaxially nested double-helical column formed by using the outer double-helices (Mn-ptptp)n as a template to encapsulate the inner double-helices (Mn-tdc)n with opposite orientation. All complexes were characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis, single-crystal X-ray crystallography and powder X-ray diffraction. The magnetic properties of 1-7 were also investigated.

Optimum sensor placement for microphone arrays

NASA Astrophysics Data System (ADS)

Rabinkin, Daniel V.

Microphone arrays can be used for high-quality sound pickup in reverberant and noisy environments. Sound capture using conventional single microphone methods suffers severe degradation under these conditions. The beamforming capabilities of microphone array systems allow highly directional sound capture, providing enhanced signal-to-noise ratio (SNR) when compared to single microphone performance. The overall performance of an array system is governed by its ability to locate and track sound sources and its ability to capture sound from desired spatial volumes. These abilities are strongly affected by the spatial placement of microphone sensors. A method is needed to optimize placement for a specified number of sensors in a given acoustical environment. The objective of the optimization is to obtain the greatest average system SNR for sound capture in the region of interest. A two-step sound source location method is presented. In the first step, time delay of arrival (TDOA) estimates for select microphone pairs are determined using a modified version of the Omologo-Svaizer cross-power spectrum phase expression. In the second step, the TDOA estimates are used in a least-mean-squares gradient descent search algorithm to obtain a location estimate. Statistics for TDOA estimate error as a function of microphone pair/sound source geometry and acoustic environment are gathered from a set of experiments. These statistics are used to model position estimation accuracy for a given array geometry. The effectiveness of sound source capture is also dependent on array geometry and the acoustical environment. Simple beamforming and time delay compensation (TDC) methods provide spatial selectivity but suffer performance degradation in reverberant environments. Matched filter array (MFA) processing can mitigate the effects of reverberation. The shape and gain advantage of the capture region for these techniques is described and shown to be highly influenced by the placement of array sensors. A procedure is developed to evaluate a given array configuration based on the above-mentioned metrics. Constrained placement optimizations are performed that maximize SNR for both TDC and MFA capture methods. Results are compared for various acoustic environments and various enclosure sizes. General guidelines are presented for placement strategy and bandwidth dependence, as they relate to reverberation levels, ambient noise, and enclosure geometry. An overall performance function is described based on these metrics. Performance of the microphone array system is also constrained by the design limitations of the supporting hardware. Two newly developed hardware architectures are presented that support the described algorithms. A low- cost 8-channel system with off-the-shelf componentry was designed and its performance evaluated. A massively parallel 512-channel custom-built system is in development-its capabilities and the rationale for its design are described.

IR spectroscopy analysis of pancreatic lipase-related protein 2 interaction with phospholipids: 3. Monitoring DPPC lipolysis in mixed micelles.

PubMed

Mateos-Diaz, Eduardo; Sutto-Ortiz, Priscila; Sahaka, Moulay; Rodriguez, Jorge A; Carrière, Frédéric

2018-03-01

Usual methods for the continuous assay of lipolytic enzyme activities are mainly based on the titration of free fatty acids, surface pressure monitoring or spectrophotometry using substrates labeled with specific probes. These approaches only give a partial information on the chemistry of the lipolysis reaction and additional end-point analyses are often required to quantify both residual substrate and lipolysis products. We used transmission infrared (IR) spectroscopy to monitor simultaneously the hydrolysis of phospholipids by guinea pig pancreatic lipase-related protein 2 (GPLRP2) and the release of lipolysis products. The substrate (DPPC, 1,2-Dipalmitoyl phosphatidylcholine) was mixed with sodium taurodeoxycholate (NaTDC) to form mixed micelles in D 2 O buffer at pD 6 and 8. After hydrogen/deuterium exchange, DPPC hydrolysis by GPLRP2 (100nM) was monitored at 35°C in a liquid cell by recording IR spectra and time-course variations in the CO stretching region. These changes were correlated to variations in the concentrations of DPPC, lysophospholipids (lysoPC) and palmitic acid (Pam) using calibration curves established with these compounds individually mixed with NaTDC. We were thus able to quantify each compound and its time-course variations during the phospholipolysis reaction and to estimate the enzyme activity. To validate the IR analysis, variations in residual DPPC, lysoPC and Pam were also quantified by thin-layer chromatography coupled to densitometry and similar hydrolysis profiles were obtained using both methods. IR spectroscopy can therefore be used to monitor the enzymatic hydrolysis of phospholipids and obtain simultaneously chemical and physicochemical information on substrate and all reaction products (H-bonding, hydration, acyl chain mobility). Copyright © 2017 Elsevier B.V. All rights reserved.

Data acquisition architecture and online processing system for the HAWC gamma-ray observatory

NASA Astrophysics Data System (ADS)

Abeysekara, A. U.; Alfaro, R.; Alvarez, C.; Álvarez, J. D.; Arceo, R.; Arteaga-Velázquez, J. C.; Ayala Solares, H. A.; Barber, A. S.; Baughman, B. M.; Bautista-Elivar, N.; Becerra Gonzalez, J.; Belmont-Moreno, E.; BenZvi, S. Y.; Berley, D.; Bonilla Rosales, M.; Braun, J.; Caballero-Lopez, R. A.; Caballero-Mora, K. S.; Carramiñana, A.; Castillo, M.; Cotti, U.; Cotzomi, J.; de la Fuente, E.; De León, C.; DeYoung, T.; Diaz-Cruz, J.; Diaz Hernandez, R.; Díaz-Vélez, J. C.; Dingus, B. L.; DuVernois, M. A.; Ellsworth, R. W.; Fiorino, D. W.; Fraija, N.; Galindo, A.; Garfias, F.; González, M. M.; Goodman, J. A.; Grabski, V.; Gussert, M.; Hampel-Arias, Z.; Harding, J. P.; Hui, C. M.; Hüntemeyer, P.; Imran, A.; Iriarte, A.; Karn, P.; Kieda, D.; Kunde, G. J.; Lara, A.; Lauer, R. J.; Lee, W. H.; Lennarz, D.; León Vargas, H.; Linares, E. C.; Linnemann, J. T.; Longo Proper, M.; Luna-García, R.; Malone, K.; Marinelli, A.; Marinelli, S. S.; Martinez, O.; Martínez-Castro, J.; Martínez-Huerta, H.; Matthews, J. A. J.; McEnery, J.; Mendoza Torres, E.; Miranda-Romagnoli, P.; Moreno, E.; Mostafá, M.; Nellen, L.; Newbold, M.; Noriega-Papaqui, R.; Oceguera-Becerra, T.; Patricelli, B.; Pelayo, R.; Pérez-Pérez, E. G.; Pretz, J.; Rivière, C.; Rosa-González, D.; Ruiz-Velasco, E.; Ryan, J.; Salazar, H.; Salesa Greus, F.; Sanchez, F. E.; Sandoval, A.; Schneider, M.; Silich, S.; Sinnis, G.; Smith, A. J.; Sparks Woodle, K.; Springer, R. W.; Taboada, I.; Toale, P. A.; Tollefson, K.; Torres, I.; Ukwatta, T. N.; Villaseñor, L.; Weisgarber, T.; Westerhoff, S.; Wisher, I. G.; Wood, J.; Yapici, T.; Yodh, G. B.; Younk, P. W.; Zaborov, D.; Zepeda, A.; Zhou, H.

2018-04-01

The High Altitude Water Cherenkov observatory (HAWC) is an air shower array devised for TeV gamma-ray astronomy. HAWC is located at an altitude of 4100 m a.s.l. in Sierra Negra, Mexico. HAWC consists of 300 Water Cherenkov Detectors, each instrumented with 4 photomultiplier tubes (PMTs). HAWC re-uses the Front-End Boards from the Milagro experiment to receive the PMT signals. These boards are used in combination with Time to Digital Converters (TDCs) to record the time and the amount of light in each PMT hit (light flash). A set of VME TDC modules (128 channels each) is operated in a continuous (dead time free) mode. The TDCs are read out via the VME bus by Single-Board Computers (SBCs), which in turn are connected to a gigabit Ethernet network. The complete system produces ≈500 MB/s of raw data. A high-throughput data processing system has been designed and built to enable real-time data analysis. The system relies on off-the-shelf hardware components, an open-source software technology for data transfers (ZeroMQ) and a custom software framework for data analysis (AERIE). Multiple trigger and reconstruction algorithms can be combined and run on blocks of data in a parallel fashion, producing a set of output data streams which can be analyzed in real time with minimal latency (<5 s). This paper provides an overview of the hardware set-up and an in-depth description of the software design, covering both the TDC data acquisition system and the real-time data processing system. The performance of these systems is also discussed.

Time density curve analysis for C-arm FDCT PBV imaging.

PubMed

Kamran, Mudassar; Byrne, James V

2016-04-01

Parenchymal blood volume (PBV) estimation using C-arm flat detector computed tomography (FDCT) assumes a steady-state contrast concentration in cerebral vasculature for the scan duration. Using time density curve (TDC) analysis, we explored if the steady-state assumption is met for C-arm CT PBV scans, and how consistent the contrast-material dynamics in cerebral vasculature are across patients. Thirty C-arm FDCT datasets of 26 patients with aneurysmal-SAH, acquired as part of a prospective study comparing C-arm CT PBV with MR-PWI, were analysed. TDCs were extracted from the 2D rotational projections. Goodness-of-fit of TDCs to a steady-state horizontal-line-model and the statistical similarity among the individual TDCs were tested. Influence of the differences in TDC characteristics on the agreement of resulting PBV measurements with MR-CBV was calculated. Despite identical scan parameters and contrast-injection-protocol, the individual TDCs were statistically non-identical (p < 0.01). Using Dunn's multiple comparisons test, of the total 435 individual comparisons among the 30 TDCs, 330 comparisons (62%) reached statistical significance for difference. All TDCs deviated significantly (p < 0.01) from the steady-state horizontal-line-model. PBV values of those datasets for which the TDCs showed largest deviations from the steady-state model demonstrated poor agreement and correlation with MR-CBV, compared with the PBV values of those datasets for which the TDCs were closer to steady-state. For clinical C-arm CT PBV examinations, the administered contrast material does not reach the assumed 'ideal steady-state' for the duration of scan. Using a prolonged injection protocol, the degree to which the TDCs approximate the ideal steady-state influences the agreement of resulting PBV measurements with MR-CBV. © The Author(s) 2016.

Time density curve analysis for C-arm FDCT PBV imaging

PubMed Central

Byrne, James V

2016-01-01

Introduction Parenchymal blood volume (PBV) estimation using C-arm flat detector computed tomography (FDCT) assumes a steady-state contrast concentration in cerebral vasculature for the scan duration. Using time density curve (TDC) analysis, we explored if the steady-state assumption is met for C-arm CT PBV scans, and how consistent the contrast-material dynamics in cerebral vasculature are across patients. Methods Thirty C-arm FDCT datasets of 26 patients with aneurysmal-SAH, acquired as part of a prospective study comparing C-arm CT PBV with MR-PWI, were analysed. TDCs were extracted from the 2D rotational projections. Goodness-of-fit of TDCs to a steady-state horizontal-line-model and the statistical similarity among the individual TDCs were tested. Influence of the differences in TDC characteristics on the agreement of resulting PBV measurements with MR-CBV was calculated. Results Despite identical scan parameters and contrast-injection-protocol, the individual TDCs were statistically non-identical (p < 0.01). Using Dunn's multiple comparisons test, of the total 435 individual comparisons among the 30 TDCs, 330 comparisons (62%) reached statistical significance for difference. All TDCs deviated significantly (p < 0.01) from the steady-state horizontal-line-model. PBV values of those datasets for which the TDCs showed largest deviations from the steady-state model demonstrated poor agreement and correlation with MR-CBV, compared with the PBV values of those datasets for which the TDCs were closer to steady-state. Conclusion For clinical C-arm CT PBV examinations, the administered contrast material does not reach the assumed ‘ideal steady-state’ for the duration of scan. Using a prolonged injection protocol, the degree to which the TDCs approximate the ideal steady-state influences the agreement of resulting PBV measurements with MR-CBV. PMID:26769736

Modification and performance evaluation of a mono-valve engine

NASA Astrophysics Data System (ADS)

Behrens, Justin W.

A four-stroke engine utilizing one tappet valve for both the intake and exhaust gas exchange processes has been built and evaluated. The engine operates under its own power, but has a reduced power capacity than the conventional 2-valve engine. The reduction in power is traced to higher than expected amounts of exhaust gases flowing back into the intake system. Design changes to the cylinder head will fix the back flow problems, but the future capacity of mono-valve engine technology cannot be estimated. The back flow of exhaust gases increases the exhaust gas recirculation (EGR) rate and deteriorates combustion. Intake pressure data shows the mono-valve engine requires an advanced intake valve closing (IVC) time to prevent back flow of charge air. A single actuation camshaft with advanced IVC was tested in the mono-valve engine, and was found to improve exhaust scavenging at TDC and nearly eliminated all charge air back flow at IVC. The optimum IVC timing is shown to be approximately 30 crank angle degrees after BDC. The mono-valve cylinder head utilizes a rotary valve positioned above the tappet valve. The open spaces inside the rotary valveand between the rotary valve and tappet valve represent a common volume that needs to be reduced in order to reduce the base EGR rate. Multiple rotary valve configurations were tested, and the size of the common volume was found to have no effect on back flow but a direct effect on the EGR rate and engine performance. The position of the rotary valve with respect to crank angle has a direct effect on the scavenging process. Optimum scavenging occurs when the intake port is opened just after TDC.

Time-domain calculations of the polarized Raman spectra, the transient infrared absorption anisotropy, and the extent of delocalization of the OH stretching mode of liquid water.

PubMed

Torii, Hajime

2006-08-03

The polarized Raman spectrum and the time dependence of the transient infrared (TRIR) absorption anisotropy are calculated for the OH stretching mode of liquid water (neat liquid H2O) by using time-domain formulations, which include the effects of both the diagonal frequency modulations (of individual oscillators) induced by the interactions between the dipole derivatives and the intermolecular electric field, and the off-diagonal (intermolecular) vibrational coupling described by the transition dipole coupling (TDC) mechanism. The IR spectrum of neat liquid H2O and the TRIR anisotropy of a liquid mixture of H2O/HDO/D2O are also calculated. It is shown that the calculated features of these optical signals, including the temperature dependence of the polarized Raman and IR spectra, are in reasonable agreement with the experimental results, indicating that the frequency separation between the isotropic and anisotropic components of the polarized Raman spectrum and the rapid decay (approximately 0.1 ps) of the TRIR anisotropy of the OH stretching mode of neat liquid H2O are mainly controlled by the resonant intermolecular vibrational coupling described by the TDC mechanism. Comparing with the time evolution of vibrational excitations, it is suggested that the TRIR anisotropy decays in the time needed for the initially localized vibrational excitations to delocalize over a few oscillators. It is also shown that the enhancement of the dipole derivatives by the interactions with surrounding molecules is an important factor in generating the spectral profiles of the OH stretching Raman band. The time-domain behavior of the molecular motions that affect the spectroscopic features is discussed.

Clinical performance of cements as luting agents for telescopic double crown-retained removable partial and complete overdentures.

PubMed

Behr, Michael; Kolbeck, Carola; Lang, Reinhold; Hahnel, Sebastian; Dirschl, Lisa; Handel, Gerhard

2009-01-01

The aim of this study was to investigate the survival rates and technical failures of removable prostheses (RPs) supported by telescopic double crown (TDC)-retained abutment teeth luted with zinc-phosphate or glass-ionomer cement. Clinical records of 577 patients (288 women, 289 men) who received 577 TDC-retained RPs supported by 1,807 abutments at the Department of Prosthodontics of the University Hospital Regensburg, Regensburg, Germany, between 1984 and 2007 were analyzed. The 577 prostheses included 200 attached to telescopic crowns with friction fit (FFs), 62 to conical crowns (CCs), and 315 to parallel-sided telescopic crowns with clearance fit (CFs). Survival probabilities were evaluated for the RPs, loss of cementation of the inner copings, secondary caries, and abutment teeth that required endodontic treatment using the Kaplan-Meier method. A Cox regression analysis determined the impact of covariates such as sex, denture location (maxilla/mandible), Eichner classification, number of abutment teeth, and the type of double crown system used. The 10-year survival probability was 98.8% +/- 0.09% for FFs, 92.9% +/- 0.41% for CCs, and 86.6% +/- 0.05% for CFs. During the observation period, loss of cementation was frequently observed (FFs: 32%, CCs: 53.2%, CFs: 21.3%). After 15 years, more than 75% of patients had experienced at least one "loss of cementation" event. In this respect, zinc-oxide phosphate and glass-ionomer cements did not show any significant difference. The long-term successful outcome of the RP experience was not compromised, although numerous clinical visits were required for maintenance. The predominant maintenance procedure was the need for recementation of the inner copings.

Effect of vitamin E on lead exposure-induced learning and memory impairment in rats.

PubMed

Khodamoradi, Nasrin; Komaki, Alireza; Salehi, Iraj; Shahidi, Siamak; Sarihi, Abdolrahman

2015-05-15

Chronic lead (Pb(2+)) exposure has been associated with learning and memory impairments, whereas vitamin E improves cognitive deficits. In this study, using a passive avoidance learning model in rats, we investigated the effects of vitamin E on Pb(2+) exposure-induced learning and memory impairments in rats. In the present study, 56 Wistar male rats (weighting 230-250g) were divided into eight groups (n=7). The Pb(2+) exposure involved gavages of lead acetate solution using three different doses (0.05%, 0.1%, and 0.2%) and the vitamin E consisted of three different doses (10, 25, 50μg/rat) for 30days. After the 30-day period, the rats were tested using a passive avoidance task (acquisition test). In a retrieval test conducted 48h after the training, step through latency (STL) and time in the dark compartment (TDC) were recorded. The statistical analysis of data was performed using ANOVA followed by Tukey's post hoc analysis. In all cases, differences were considered significant if p<0.05. The results of the present study showed that chronic exposure to high doses of Pb(2+) significantly increased both the number of trails required for learning and the TDC, whereas it decreased the STL in the passive avoidance test. Administration of vitamin E ameliorated the effects of Pb(2+) on animal behavior in the passive avoidance learning and memory task. Our results indicate that impairments of learning and memory in Pb(2+)-exposed rats are dose dependent and can be inhibited by antioxidants such as vitamin E. Copyright © 2015 Elsevier Inc. All rights reserved.

Chosen results of field tests of synthetic aperture radar system installed on board UAV

NASA Astrophysics Data System (ADS)

Kaniewski, Piotr; Komorniczak, Wojciech; Lesnik, Czeslaw; Cyrek, Jacek; Serafin, Piotr; Labowski, Michal; Wajszczyk, Bronislaw

2017-04-01

The paper presents a synthetic information on a UAV-based radar terrain imaging system, its purpose, structure and working principle as well as terrain images obtained from flight experiments. A SAR technology demonstrator has been built as a result of a research project conducted by the Military University of Technology and WB Electronics S.A. under the name WATSAR. The developed system allows to obtain high resolution radar images, both in on-line and off-line modes, independently of the light conditions over the observed area. The software developed for the system allows to determine geographic coordinates of the imaged objects with high accuracy. Four LFM-CW radar sensors were built during the project: two for S band and two for Ku band, working with different signal bandwidths. Acquired signals were processed with the TDC algorithm, which allowed for a number of analyses in order to evaluate the performance of the system. The impact of the navigational corrections on a SAR image quality was assessed as well. The research methodology of the in-flight experiments of the system is presented in the paper. The projects results show that the developed system may be implemented as an aid to tactical C4ISR systems.

Polyamide microcapsules containing jojoba oil prepared by inter-facial polymerization.

PubMed

Persico, P; Carfagna, C; Danicher, L; Frere, Y

2005-08-01

Jojoba oil containing polyamide microcapsules having diameter of approximately 5 microm were prepared by inter-facial polycondensation by direct method (oil-in-water). Qualitative effects of both the formulation and the process parameters on microcapsules characteristics were investigated by SEM observations. Morphological analysis showed the dependence of the external membrane compactness on the chemical nature of the water-soluble polyamine and the oil-soluble acid polychloride: 1,6-hexamethylenediamine (HMDA) and terephthaloyl dichloride (TDC) were found to favour the production of smooth and dense surfaces. The use of ultrasonic irradiations during the dispersion step to get a further reduction of microcapsules size was also evaluated.

Oxidation of Thiodiglycol (2,2’-Thiobis-ethanol) by Alcohol Dehydrogenase: Comparison of Human Isoenzymes

DTIC Science & Technology

2000-01-01

Ethanol by ADH Isozymes0 Isozyme TDC Ethanol Class K „ b *cat/-Nn K , *cat Kall ^m I act 8.6 (7.9 ± 1.2)e 63 7 4.2 54 13 PiPi 3.5 (4.2 ± 0.4) 34 8 0.05...the appropriate concentration of substrate in 0.85% saline was added. The reaction was followed by measuring the change in absorbance at 340 nm...ß2ß2 from Kedishvili et al. [271. * K „ values obtained from Lineweaver-Burk plots (Figure 1). ’Values in parentheses are X„s ± S.E. calculated from

Toxic Hazards in Aviation.

DTIC Science & Technology

1981-04-01

TM T7M T7T2M Skin Leiomyoma (B) 0/170 1/161 0/146 0/147 Squamous Cell Carcinoma (P) 0/170 1/161 0/146 0/147 Trichoepithelioma (B) 0/170 1/161 0/146 0...The activity’ Is expressed as~I OT 1’,. 4C ~i- ’outined Iln Figure l, egend. W, ENFO TM ,miue Bi8-1 TOXICITE DES GAZ OE DECOMiPOSITION THERIQgUE DES...ntWest que tdc 7 p. cent lorsqtion passe de 1 ’air ht ut) inlanqe bi 1 p). cent tie [C02?. I ’ aoiqment at ion det I at fr~tilerrice reap irat oi re

Lidar Luminance Quantizer

NASA Technical Reports Server (NTRS)

Quilligan, Gerard; DeMonthier, Jeffrey; Suarez, George

2011-01-01

This innovation addresses challenges in lidar imaging, particularly with the detection scheme and the shapes of the detected signals. Ideally, the echoed pulse widths should be extremely narrow to resolve fine detail at high event rates. However, narrow pulses require wideband detection circuitry with increased power dissipation to minimize thermal noise. Filtering is also required to shape each received signal into a form suitable for processing by a constant fraction discriminator (CFD) followed by a time-to-digital converter (TDC). As the intervals between the echoes decrease, the finite bandwidth of the shaping circuits blends the pulses into an analog signal (luminance) with multiple modes, reducing the ability of the CFD to discriminate individual events

Fast front-end electronics for semiconductor tracking detectors: Trends and perspectives

NASA Astrophysics Data System (ADS)

Rivetti, Angelo

2014-11-01

In the past few years, extensive research efforts pursued by both the industry and the academia have lead to major improvements in the performance of Analog to Digital Converters (ADCs) and Time to Digital Converters (TDCs). ADCs achieving 8-10 bit resolution, 50-100 MHz conversion frequency and less than 1 mW power consumption are the today's standard, while TDCs have reached sub-picosecond time resolution. These results have been made possible by architectural upgrades combined with the use of ultra deep submicron CMOS technologies with minimum feature size of 130 nm or smaller. Front-end ASICs in which a prompt digitization is followed by signal conditioning in the digital domain can now be envisaged also within the tight power budget typically available in high density tracking systems. Furthermore, tracking detectors embedding high resolution timing capabilities are gaining interest. In the paper, ADC's and TDC's developments which are of particular relevance for the design front-end electronics for semiconductor trackers are discussed along with the benefits and challenges of exploiting such high performance building blocks in implementing the next generation of ASICs for high granularity particle detectors.

High-Efficiency Co/CoxSy@S,N-Codoped Porous Carbon Electrocatalysts Fabricated from Controllably Grown Sulfur- and Nitrogen-Including Cobalt-Based MOFs for Rechargeable Zinc-Air Batteries.

PubMed

Liu, Shengwen; Zhang, Xian; Wang, Guozhong; Zhang, Yunxia; Zhang, Haimin

2017-10-04

Developing bifunctional oxygen electrocatalysts with superior catalytic activities of oxygen reduction reaction (ORR) and oxygen revolution reaction (OER) is crucial to their practical energy storage and conversion applications. In this work, we report the fabrication of Co/Co x S y @S,N-codoped porous carbon structures with various morphologies, specific surface areas, and pore structures, derived from controllably grown Co-based metal-organic frameworks with S- and N-containing organic ligands (thiophene-2,5-dicarboxylate, Tdc; and 4,4'-bipyridine, bpy) utilizing solvent effect (e.g., water and methanol) under room temperature and hydrothermal conditions. The results demonstrate that Co/Co x S y @S,N-codoped carbon fibers fabricated at a pyrolytic temperature of 800 °C (Co/Co x S y @SNCF-800) from Co-MOFs fibers fabricated in methanol under hydrothermal conditions as electrocatalysts exhibit superior bifunctional ORR and OER activities in alkaline media, endowing them as air cathodic catalysts in rechargeable zinc-air batteries with high power density and good durability.

A portable telescope based on the ALIBAVA system for test beam studies

NASA Astrophysics Data System (ADS)

Bernabeu, J.; Casse, G.; Garcia, C.; Greenall, A.; Lacasta, C.; Lozano, M.; Marti-Garcia, S.; Pellegrini, G.; Rodriguez, J.; Ullan, M.; Tsurin, I.

2013-12-01

A test beam telescope has been built using the ALIBAVA system to drive its data acquisition. The basic telescope planes consist of four XYT stations. Each station is built from a detector board with two strip sensors, mounted one in each side (strips crossing at 90°). The ensemble is coupled to an ALIBAVA daughter board. These stations act as reference frame and allow a precise track reconstruction. The system is triggered by the coincidence signal of the two scintillators located up and down stream. The telescope can hold several devices under tests. Each ALIBAVA daughter board is linked to its corresponding mother board. The system can hold up to 16 mother boards. A master board synchronizes and controls all the mother boards and collects their data. The off-line analysis software has been developed to study the charge collection, cluster width, tracking efficiency, resolution, etc., of the devices under test. Moreover, the built-in ALIBAVA TDC allows the analysis of the time profile of the device signal. The ALIBAVA telescope has been successfully operated in two test runs at the DESY and CERN-SPS beam lines.

A Single-Photon Avalanche Diode Array for Fluorescence Lifetime Imaging Microscopy.

PubMed

Schwartz, David Eric; Charbon, Edoardo; Shepard, Kenneth L

2008-11-21

We describe the design, characterization, and demonstration of a fully integrated single-photon avalanche diode (SPAD) imager for use in time-resolved fluorescence imaging. The imager consists of a 64-by-64 array of active SPAD pixels and an on-chip time-to-digital converter (TDC) based on a delay-locked loop (DLL) and calibrated interpolators. The imager can perform both standard time-correlated single-photon counting (TCSPC) and an alternative gated-window detection useful for avoiding pulse pile-up when measuring bright signal levels. To illustrate the use of the imager, we present measurements of the decay lifetimes of fluorescent dyes of several types with a timing resolution of 350 ps.

SPAD array based TOF SoC design for unmanned vehicle

NASA Astrophysics Data System (ADS)

Pan, An; Xu, Yuan; Xie, Gang; Huang, Zhiyu; Zheng, Yanghao; Shi, Weiwei

2018-03-01

As for the requirement of unmanned-vehicle mobile Lidar system, this paper presents a SoC design based on pulsed TOF depth image sensor. This SoC has a detection range of 300m and detecting resolution of 1.5cm. Pixels are made of SPAD. Meanwhile, SoC adopts a structure of multi-pixel sharing TDC, which significantly reduces chip area and improve the fill factor of light-sensing surface area. SoC integrates a TCSPC module to achieve the functionality of receiving each photon, measuring photon flight time and processing depth information in one chip. The SOC is designed in the SMIC 0.13μm CIS CMOS technology

A Single-Photon Avalanche Diode Array for Fluorescence Lifetime Imaging Microscopy

PubMed Central

Schwartz, David Eric; Charbon, Edoardo; Shepard, Kenneth L.

2013-01-01

We describe the design, characterization, and demonstration of a fully integrated single-photon avalanche diode (SPAD) imager for use in time-resolved fluorescence imaging. The imager consists of a 64-by-64 array of active SPAD pixels and an on-chip time-to-digital converter (TDC) based on a delay-locked loop (DLL) and calibrated interpolators. The imager can perform both standard time-correlated single-photon counting (TCSPC) and an alternative gated-window detection useful for avoiding pulse pile-up when measuring bright signal levels. To illustrate the use of the imager, we present measurements of the decay lifetimes of fluorescent dyes of several types with a timing resolution of 350 ps. PMID:23976789

A new beam diagnostic system for the MASHA setup

NASA Astrophysics Data System (ADS)

Motycak, S.; Rodin, A. M.; Novoselov, A. S.; Podshibyakin, A. V.; Krupa, L.; Belozerov, A. V.; Vedeneyev, V. Yu.; Gulyaev, A. V.; Gulyaeva, A. V.; Kliman, J.; Salamatin, V. S.; Stepantsov, S. V.; Chernysheva, E. V.; Yuchimchuk, S. A.; Komarov, A. B.; Kamas, D.

2016-09-01

A new beam diagnostic system based on the PXI standard was developed, tested, and used in the MASHA setup experiment. The beam energy and beam current measurements were carried out using several methods. The online time-of-flight energy measurements were carried out using three pick-up detectors. We used two electronic systems to measure the time between the pick-ups. The first system was based on fast Agilent digitizers (2-channel, 4-GHz sampling rate), and the second one was based on a constant fraction discriminator (CFD) connected to a time-to-digital converter (TDC, 5-ps resolution). A new graphical interface to monitor the electronic devices and to perform the online calculations of energy was developed using MFC C++. The second system based on microchannel plate (time-of-flight) and silicon detectors for the determination of beam energy and the type of accelerated particles was also used. The beam current measurements were carried out with two different sensors. The first sensor is a rotating Faraday cup placed in front of the target, and the second one is an emission detector installed at the rear of the target. This system is now used in experiments for the synthesis of superheavy elements at the U400M cyclotron of the Flerov Laboratory of Nuclear Reactions (FLNR).

Application of the Medipix2 technology to space radiation dosimetry and hadron therapy beam monitoring

NASA Astrophysics Data System (ADS)

Pinsky, Lawrence; Stoffle, Nicholas; Jakubek, Jan; Pospisil, Stanislav; Leroy, Claude; Gutierrez, Andrea; Kitamura, Hisashi; Yasuda, Nakahiro; Uchihori, Yulio

2011-02-01

The Medipix2 Collaboration, based at CERN, has developed the TimePix version of the Medipix pixel readout chip, which has the ability to provide either an ADC or TDC capability separately in each of its 256×256 pixels. When coupled to a Si detector layer, the device is an excellent candidate for application as an active dosimeter for use in space radiation environments. In order to facilitate such a development, data have been taken with heavy ions at the HIMAC facility in Chiba, Japan. In particular, the problem of determining the resolution of such a detector system with respect to heavy ions of differing charges and energies, but with similar d E/d x values has been explored for several ions. The ultimate problem is to parse the information in the pixel "footprint" images from the drift of the charge cloud produced in the detector layer. In addition, with the use of convertor materials, the detector can be used as a neutron detector, and it has been used both as a charged particle and neutron detector to evaluate the detailed properties of the radiation fields produced by hadron therapy beams. New versions of the basic chip design are ongoing.

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

Choong, W. -S.; Abu-Nimeh, F.; Moses, W. W.

Here, we present a 16-channel front-end readout board for the OpenPET electronics system. A major task in developing a nuclear medical imaging system, such as a positron emission computed tomograph (PET) or a single-photon emission computed tomograph (SPECT), is the electronics system. While there are a wide variety of detector and camera design concepts, the relatively simple nature of the acquired data allows for a common set of electronics requirements that can be met by a flexible, scalable, and high-performance OpenPET electronics system. The analog signals from the different types of detectors used in medical imaging share similar characteristics, whichmore » allows for a common analog signal processing. The OpenPET electronics processes the analog signals with Detector Boards. Here we report on the development of a 16-channel Detector Board. Each signal is digitized by a continuously sampled analog-to-digital converter (ADC), which is processed by a field programmable gate array (FPGA) to extract pulse height information. A leading edge discriminator creates a timing edge that is "time stamped" by a time-to-digital converter (TDC) implemented inside the FPGA. In conclusion, this digital information from each channel is sent to an FPGA that services 16 analog channels, and then information from multiple channels is processed by this FPGA to perform logic for crystal lookup, DOI calculation, calibration, etc.« less

Demagnetization Tests Performed on a Linear Alternator for a Stirling Power Convertor

NASA Technical Reports Server (NTRS)

Geng, Steven M.; Niedra, Janis M.; Schwarze, Gene E.

2012-01-01

The NASA Glenn Research Center (GRC) is conducting in-house research on rare-earth permanent magnets and linear alternators to assist in developing free-piston Stirling convertors for radioisotope space power systems and for developing advanced linear alternator technology. This research continues at GRC, but, with the exception of Advanced Stirling Radioisotope Generator references, the work presented in this paper was conducted in 2005. A special arc-magnet characterization fixture was designed and built to measure the M-H characteristics of the magnets used in Technology Demonstration Convertors developed under the 110-W Stirling Radioisotope Generator (SRG110) project. This fixture was used to measure these characteristics of the arc magnets and to predict alternator demagnetization temperatures in the SRG110 application. Demagnetization tests using the TDC alternator on the Alternator Test Rig were conducted for two different magnet grades: Sumitomo Neomax 44AH and 42AH. The purpose of these tests was to determine the demagnetization temperatures of the magnets for the alternator under nominal loads. Measurements made during the tests included the linear alternator terminal voltage, current, average power, magnet temperatures, and stator temperatures. The results of these tests were found to be in good agreement with predictions. Alternator demagnetization temperatures in the Advanced Stirling Convertor (ASC-developed under the Advanced Stirling Radioisotope Generator project) were predicted as well because the prediction method had been validated through the SRG110 alternator tests. These predictions led to a specification for maximum temperatures of the ASC pressure vessel.

A multi-threshold sampling method for TOF-PET signal processing

NASA Astrophysics Data System (ADS)

Kim, H.; Kao, C. M.; Xie, Q.; Chen, C. T.; Zhou, L.; Tang, F.; Frisch, H.; Moses, W. W.; Choong, W. S.

2009-04-01

As an approach to realizing all-digital data acquisition for positron emission tomography (PET), we have previously proposed and studied a multi-threshold sampling method to generate samples of a PET event waveform with respect to a few user-defined amplitudes. In this sampling scheme, one can extract both the energy and timing information for an event. In this paper, we report our prototype implementation of this sampling method and the performance results obtained with this prototype. The prototype consists of two multi-threshold discriminator boards and a time-to-digital converter (TDC) board. Each of the multi-threshold discriminator boards takes one input and provides up to eight threshold levels, which can be defined by users, for sampling the input signal. The TDC board employs the CERN HPTDC chip that determines the digitized times of the leading and falling edges of the discriminator output pulses. We connect our prototype electronics to the outputs of two Hamamatsu R9800 photomultiplier tubes (PMTs) that are individually coupled to a 6.25×6.25×25 mm3 LSO crystal. By analyzing waveform samples generated by using four thresholds, we obtain a coincidence timing resolution of about 340 ps and an ˜18% energy resolution at 511 keV. We are also able to estimate the decay-time constant from the resulting samples and obtain a mean value of 44 ns with an ˜9 ns FWHM. In comparison, using digitized waveforms obtained at a 20 GSps sampling rate for the same LSO/PMT modules we obtain ˜300 ps coincidence timing resolution, ˜14% energy resolution at 511 keV, and ˜5 ns FWHM for the estimated decay-time constant. Details of the results on the timing and energy resolutions by using the multi-threshold method indicate that it is a promising approach for implementing digital PET data acquisition.

Hydraulic seals and their origin: Evidence from the stable isotope geochemistry of dolomites in the Middle Ordovician St. Peter Sandstone, Michigan basin

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

Winter, B.L.; Johnson, C.M.; Valley, J.W.

1995-01-01

Regionally extensive, overpressured natural gas pools within the St. Peter Sandstone (Middle Ordovician) of the Michigan basin are bounded by rock types that include 3-7-m-thick zones of low-permeability, low-porosity carbonates or diagenetically banded quartz sandstones. Replacive dolomite from an approximately 5-m-thick carbonate interval in the east-central portion of the Michigan basin has very low {delta}{sup 13}C values that systematically decrease from approximately -5% at the top to -10% (PDB) at the base. {delta}{sup 18}O values for the replacive dolomite also decrease systematically with depth from approximately 27 to 23% (SMOW). These data suggest an upward decrease in isotope exchange betweenmore » the replacive dolomitization fluid and the precursors rock (i.e., the system was rock dominated at the top of the carbonate interval), which implies upward, cross-formational movement of the dolomitizing fluid. Fluid-rock interaction modeling suggest that the dolomitizing fluid had a total dissolved carbon (TDC) content of approximately 4000 ppm and a {delta}{sup 13}C value of -27%, which indicates that the carbon was primarily derived from organic diagenesis. Sr isotope and major element data suggest that this dolomitizing fluid had a modified seawater origin. The {delta}{sup 13}C values of sandstone intervals from three locations in the central portion of the Michigan basin range from -9 to -4% and are relatively invariant at a particular locality; therefore, the TDC of the dolomitizing fluid in the central Michigan basin is interpreted to have contained only about 20-30% organic carbon. The fact that all dolomites analyzed in the St. Peter Sandstone have much lower {Delta}{sup 13}C values that carbonates in adjacent formations indicates that dolomitization and the formation of hydraulic seals were related to organic matter diagenesis.« less

Multifunctional Metal-Organic Frameworks Based on Redox-Active Rhenium Octahedral Clusters.

PubMed

Litvinova, Yulia M; Gayfulin, Yakov M; Kovalenko, Konstantin A; Samsonenko, Denis G; van Leusen, Jan; Korolkov, Ilya V; Fedin, Vladimir P; Mironov, Yuri V

2018-02-19

The redox-active rhenium octahedral cluster unit [Re 6 Se 8 (CN) 6 ] 4- was combined with Gd 3+ ions and dicarboxylate linkers in novel types of metal-organic frameworks (MOFs) that display a set of functional properties. The hydrolytically stable complexes [{Gd(H 2 O) 3 } 2 (L)Re 6 Se 8 (CN) 6 ]·nH 2 O (1, L = furan-2,5-dicarboxylate, fdc; 2, L = thiophene-2,5-dicarboxylate, tdc) exhibit a 3D framework of trigonal symmetry where 1D chains of [{Gd(H 2 O) 3 } 2 (L)] 4+ are connected by [Re 6 Se 8 (CN) 6 ] 4- clusters. Frameworks contain spacious channels filled with H 2 O. Solvent molecules can be easily removed under vacuum to produce permanently porous solids with high volumetric CO 2 uptake and remarkable CO 2 /N 2 selectivity at room temperature. The frameworks demonstrate an ability for reversible redox transformations of the cluster fragment. The orange powders of compounds 1 and 2 react with Br 2 , yielding dark-green powders of [{Gd(H 2 O) 3 } 2 (L)Re 6 Se 8 (CN) 6 ]Br·nH 2 O (3, L = fdc; 4, L = tdc). Compounds 3 and 4 are isostructural with 1 and 2 and also have permanently porous frameworks but display different optical, magnetic, and sorption properties. In particular, oxidation of the cluster fragment "switches off" its luminescence in the red region, and the incorporation of Br - leads to a decrease of the solvent-accessible volume in the channels of 3 and 4. Finally, the green powders of 3 and 4 can be reduced back to the orange powders of 1 and 2 by reaction with hydrazine, thus displaying a rare ability for fully reversible chemical redox transitions. Compounds 1-4 are mentioned as a new class of redox-active cluster-based MOFs with potential usage as multifunctional materials for gas separation and chemical contamination sensors.

LinoSPAD: a time-resolved 256×1 CMOS SPAD line sensor system featuring 64 FPGA-based TDC channels running at up to 8.5 giga-events per second

NASA Astrophysics Data System (ADS)

Burri, Samuel; Homulle, Harald; Bruschini, Claudio; Charbon, Edoardo

2016-04-01

LinoSPAD is a reconfigurable camera sensor with a 256×1 CMOS SPAD (single-photon avalanche diode) pixel array connected to a low cost Xilinx Spartan 6 FPGA. The LinoSPAD sensor's line of pixels has a pitch of 24 μm and 40% fill factor. The FPGA implements an array of 64 TDCs and histogram engines capable of processing up to 8.5 giga-photons per second. The LinoSPAD sensor measures 1.68 mm×6.8 mm and each pixel has a direct digital output to connect to the FPGA. The chip is bonded on a carrier PCB to connect to the FPGA motherboard. 64 carry chain based TDCs sampled at 400 MHz can generate a timestamp every 7.5 ns with a mean time resolution below 25 ps per code. The 64 histogram engines provide time-of-arrival histograms covering up to 50 ns. An alternative mode allows the readout of 28 bit timestamps which have a range of up to 4.5 ms. Since the FPGA TDCs have considerable non-linearity we implemented a correction module capable of increasing histogram linearity at real-time. The TDC array is interfaced to a computer using a super-speed USB3 link to transfer over 150k histograms per second for the 12.5 ns reference period used in our characterization. After characterization and subsequent programming of the post-processing we measure an instrument response histogram shorter than 100 ps FWHM using a strong laser pulse with 50 ps FWHM. A timing resolution that when combined with the high fill factor makes the sensor well suited for a wide variety of applications from fluorescence lifetime microscopy over Raman spectroscopy to 3D time-of-flight.

Commissioning of the CMS Hadron Forward Calorimeters Phase I Upgrade

NASA Astrophysics Data System (ADS)

Bilki, B.; Onel, Y.

2018-03-01

The final phase of the CMS Hadron Forward Calorimeters Phase I Upgrade was performed during the Extended Year End Technical Stop of 2016-2017. In the framework of the upgrade, the PMT boxes were reworked to implement two channel readout in order to exploit the benefits of the multi-anode PMTs in background tagging and signal recovery. The front-end electronics were also upgraded to QIE10-based electronics which implement larger dynamic range and a 6-bit TDC. Following this major upgrade, the Hadron Forward Calorimeters were commissioned for operation readiness in 2017. Here we describe the details and the components of the upgrade, and discuss the operational experience and results obtained during the upgrade and commissioning.

Flight Operations Noise Tests of Eight Helicopters

DTIC Science & Technology

1985-08-01

permit data corrections for nonstandard atmospheric conditions. iIl1 I a r U I i a p I S S I. u TDC T IOCN 9This report presentsz data irom eiont...T1PEI CWT INSTRLOINT PA E TM LIDIOLOP’I A~eG w~l CA.4LkAIKD WITHIN 3i ECO TECL-C MICRPHNE4 OITICIN A-22 NORMAL TAKEOFF S76 90-J 85- I-i- w75 - 00 60- 200...4 0 4 4 om" I.D . 1.3 1.7, 2.7 2.7 2,3 "" ", CI .9 1.3 3 1.6! 3.1 27 -- A-JO * *4 I II I I ’~ * I A--WIDMTED SOUND LEVEL (DB) HgLICO* TMs SIKORIKY 516

A Study of Communication Processor Systems

DTIC Science & Technology

1979-12-01

STUDYSCOFONLA (A . TIS R I8TIO S" - EEG R AN T-i R $a t 17. DITR UTO STTEeN in h b’*l.elldi 1Ok 0 ~45ft i9~a R,1OI)7 -C S. APeMr’wl NOTES Uh a DC gt~ & C...MM Fig. 3.3 Pluribus syste m II 24 -4~ I tm ap B u s- ----I FP K K Cmi Cornrnjer MeodUlO Fig. 3.4 Carnegie "iellLfn CmI* 25 0I M r K K P M K KP M K...144 bits incurs a mean transmission delay (o ) of 0.29 milli- seconds. The maximum transmission delays TDF and TDC can be obtained as 15 milliseconds

Extended Operation Testing of Stirling Convertors in Support of Stirling Radioisotope Power System Development

NASA Technical Reports Server (NTRS)

Lewandowski, Edward J.; Schreiber, Jeffre G.; Wilson, Scott D.; oriti, Salvatore M.; Cornell, Peggy; Schifer, Nicholas

2008-01-01

100 We class Stirling convertors began extended operation testing at NASA Glenn Research Center (GRC) in 2003 with a pair of Technology Demonstration Convertors (TDCs) operating in air. Currently, the number of convertors on extended operation test has grown to 12, including both TDCs and Advanced Stirling Convertors (ASCs) operating both in air and in thermal vacuum. Additional convertors and an electrically heated radioisotope generator will be put on test in the near future. This testing has provided data to support life and reliability estimates and the quality improvements and design changes that have been made to the convertor. The convertors operated 24/7 at the nominal amplitude and power levels. Performance data were recorded on an hourly basis. Techniques to monitor the convertors for change in internal operation included gas analysis, vibration measurements and acoustic emission measurements. This data provided a baseline for future comparison. This paper summarizes the results of over 145,000 hours of TDC testing and 40,000 hours of ASC testing and discusses trends in the data. Data shows the importance of improved materials, hermetic sealing, and quality processes in maintaining convertor performance over long life.

Extended Operation Testing of Stirling Convertors in Support of Stirling Radioisotope Power System Development

NASA Technical Reports Server (NTRS)

Lewandowski, Edward J.; Schreiber, Jeffrey G.; Wilson, Scott D.; Oriti, Salvatore M.; Cornell, Peggy; Schifer, Nicholas

2009-01-01

100 We class Stirling convertors began extended operation testing at NASA Glenn Research Center (GRC) in 2003 with a pair of Technology Demonstration Convertors (TDCs) operating in air. Currently, the number of convertors on extended operation test has grown to 12, including both TDCs and Advanced Stirling Convertors (ASCs) operating both in air and in thermal vacuum. Additional convertors and an electrically heated radioisotope generator will be put on test in the near future. This testing has provided data to support life and reliability estimates and the quality improvements and design changes that have been made to the convertor. The convertors operated 24/7 at the nominal amplitude and power levels. Performance data were recorded on an hourly basis. Techniques to monitor the convertors for change in internal operation included gas analysis, vibration measurements, and acoustic emission measurements. This data provided a baseline for future comparison. This paper summarizes the results of over 145,000 hr of TDC testing and 40,000 hr of ASC testing and discusses trends in the data. Data shows the importance of improved materials, hermetic sealing, and quality processes in maintaining convertor performance over long life.

Realization of a multipath ultrasonic gas flowmeter based on transit-time technique.

PubMed

Chen, Qiang; Li, Weihua; Wu, Jiangtao

2014-01-01

A microcomputer-based ultrasonic gas flowmeter with transit-time method is presented. Modules of the flowmeter are designed systematically, including the acoustic path arrangement, ultrasound emission and reception module, transit-time measurement module, the software and so on. Four 200 kHz transducers forming two acoustic paths are used to send and receive ultrasound simultaneously. The synchronization of the transducers can eliminate the influence caused by the inherent switch time in simple chord flowmeter. The distribution of the acoustic paths on the mechanical apparatus follows the Tailored integration, which could reduce the inherent error by 2-3% compared with the Gaussian integration commonly used in the ultrasonic flowmeter now. This work also develops timing modules to determine the flight time of the acoustic signal. The timing mechanism is different from the traditional method. The timing circuit here adopts high capability chip TDC-GP2, with the typical resolution of 50 ps. The software of Labview is used to receive data from the circuit and calculate the gas flow value. Finally, the two paths flowmeter has been calibrated and validated on the test facilities for air flow in Shaanxi Institute of Measurement & Testing. Copyright © 2013 Elsevier B.V. All rights reserved.

A front-end readout Detector Board for the OpenPET electronics system

NASA Astrophysics Data System (ADS)

Choong, W.-S.; Abu-Nimeh, F.; Moses, W. W.; Peng, Q.; Vu, C. Q.; Wu, J.-Y.

2015-08-01

We present a 16-channel front-end readout board for the OpenPET electronics system. A major task in developing a nuclear medical imaging system, such as a positron emission computed tomograph (PET) or a single-photon emission computed tomograph (SPECT), is the electronics system. While there are a wide variety of detector and camera design concepts, the relatively simple nature of the acquired data allows for a common set of electronics requirements that can be met by a flexible, scalable, and high-performance OpenPET electronics system. The analog signals from the different types of detectors used in medical imaging share similar characteristics, which allows for a common analog signal processing. The OpenPET electronics processes the analog signals with Detector Boards. Here we report on the development of a 16-channel Detector Board. Each signal is digitized by a continuously sampled analog-to-digital converter (ADC), which is processed by a field programmable gate array (FPGA) to extract pulse height information. A leading edge discriminator creates a timing edge that is ``time stamped'' by a time-to-digital converter (TDC) implemented inside the FPGA . This digital information from each channel is sent to an FPGA that services 16 analog channels, and then information from multiple channels is processed by this FPGA to perform logic for crystal lookup, DOI calculation, calibration, etc.

A front-end readout Detector Board for the OpenPET electronics system

DOE PAGES

Choong, W. -S.; Abu-Nimeh, F.; Moses, W. W.; ...

2015-08-12

Here, we present a 16-channel front-end readout board for the OpenPET electronics system. A major task in developing a nuclear medical imaging system, such as a positron emission computed tomograph (PET) or a single-photon emission computed tomograph (SPECT), is the electronics system. While there are a wide variety of detector and camera design concepts, the relatively simple nature of the acquired data allows for a common set of electronics requirements that can be met by a flexible, scalable, and high-performance OpenPET electronics system. The analog signals from the different types of detectors used in medical imaging share similar characteristics, whichmore » allows for a common analog signal processing. The OpenPET electronics processes the analog signals with Detector Boards. Here we report on the development of a 16-channel Detector Board. Each signal is digitized by a continuously sampled analog-to-digital converter (ADC), which is processed by a field programmable gate array (FPGA) to extract pulse height information. A leading edge discriminator creates a timing edge that is "time stamped" by a time-to-digital converter (TDC) implemented inside the FPGA. In conclusion, this digital information from each channel is sent to an FPGA that services 16 analog channels, and then information from multiple channels is processed by this FPGA to perform logic for crystal lookup, DOI calculation, calibration, etc.« less

Study, design and integration of an FPGA-based system for the time-of-flight calculation applied to PET equipment

NASA Astrophysics Data System (ADS)

Aguilar Talens, D. Albert

Nuclear Medicine has undergone significant advances in recent years due to improvements in materials, electronics, software techniques, processing etc., which has allowed to considerably extend its application. One technique that has progressed in this area has been the Positron Emission Tomography (PET) based on a non-invasive method with its especial relevance in the evaluation of cancer diagnosis and assessment, among others. This system is based on the principle of data collection and processing from which images of the spatial and temporal distribution of the metabolic processes that are generated inside the body are obtained. The imaging system consists of a set of detectors, normally placed in a ring geometry, so that each one provides information about events that have occurred inside. One of the reasons that have significantly evolved in PET systems is the development of techniques to determine the Time-of-Flight (TOF) of the photons that are generated due to the annihilation of positrons with their antiparticle, the electron. Determining TOF allows one for a more precise location of the events that are generated inside the ring and, therefore, facilitates the task of image reconstruction that ultimately use the medical equipment for the diagnosis and/or treatment. This Thesis begins with the assumption of developing a system based on Field Programmable Gate Arrays (FPGAs) for the integration of a Time- to-Digital Converter (TDC) in order to precisely carry out time measurements. This would permit the estimation of the TOF of the gamma particles for subsequent application in PET systems. First of all, the environment for the application is introduced, justifying the need of the purposed system. Following, the basic principles of PET and the state-of-the-art of similar systems are introduced. Then, the principles of Time-of-Flight based on FPGAs are discussed, and the adopted scheme explained, going into detail in each of its parts. After the development, the initial time measurement results are presented, achieving time resolutions below 100 ps for multiple channels. Once characterized, the system is tested with a breast PET prototype, whose technology detectors are based on Position Sensitive PhotoMultiplier Tubes (PSPMTs), performing TOF measurements for different scenarios. After this point, tests based on two Silicon Photomultipliers (SiPMs) modules were carried out. SiPMs are immune to magnetic fields, among other advantages. This is an important feature since there is a significant interest in combining PET and Magnetic Resonances (MR). Each of the two detector modules used are composed of a single crystal pixel. The electronic conditioning circuits are designed, taking into account the most influential parameters in time resolution. After these results, an array of 144 SiPMs is tested, optimizing several parameters, which directly impact on the system performance. Having demonstrated the system capabilities, an optimization process is devised. On the one hand, TDC measurements are enhanced up to 40 ps of precision. On the other hand, a coincidence algorithm is developed, which is responsible of identifying detector pairs that have registered an event within certain time window. Finally, the Thesis conclusions and the future work are presented, followed by the references. A list of publications and attended congresses are also provided.

Study of Molecular Clouds, Variable Stars and Related Topics at NUU and UBAI

NASA Astrophysics Data System (ADS)

Hojaev, A. S.

2017-07-01

The search of young PMS stars made by our team at Maidanak, Lulin and Beijing observatories, especially in NGC 6820/23 area, as well as monitoring of a sample of open clusters will be described and results will be presented. We consider physical conditions in different star forming regions, particularly in TDC and around Vul OB1, estimate SFE and SFR, energy balance and instability processes in these regions. We also reviewed all data on molecular clouds in the Galaxy and in other galaxies where the clouds were observed to prepare general catalog of molecular clouds, to study physical conditions, unsteadiness and possible star formation in them, the formation and evolution of molecular cloud systems, to analyze their role in formation of different types of galaxies and structural features therein.

Note: All-digital CMOS MOS-capacitor-based pulse-shrinking mechanism suitable for time-to-digital converters

NASA Astrophysics Data System (ADS)

Chen, Chun-Chi; Hwang, Chorng-Sii; Lin, You-Ting; Liu, Keng-Chih

2015-12-01

This paper presents an all-digital CMOS pulse-shrinking mechanism suitable for time-to-digital converters (TDCs). A simple MOS capacitor is used as a pulse-shrinking cell to perform time attenuation for time resolving. Compared with a previous pulse-shrinking mechanism, the proposed mechanism provides an appreciably improved temporal resolution with high linearity. Furthermore, the use of a binary-weighted pulse-shrinking unit with scaled MOS capacitors is proposed for achieving a programmable resolution. A TDC involving the proposed mechanism was fabricated using a TSMC (Taiwan Semiconductor Manufacturing Company) 0.18-μm CMOS process, and it has a small area of nearly 0.02 mm2 and an integral nonlinearity error of ±0.8 LSB for a resolution of 24 ps.

The DIRC front-end electronics chain for BaBar

NASA Astrophysics Data System (ADS)

Bailly, P.; Chauveau, J.; Del Buono, L.; Genat, J. F.; Lebbolo, H.; Roos, L.; Zhang, B.; Beigbeder, C.; Bernier, R.; Breton, D.; Caceres, T.; Chase, R.; Ducorps, A.; Hrisoho, A.; Imbert, P.; Sen, S.; Tocut, V.; Truong, K.; Wormser, G.; Zomer, F.; Bonneaud, G.; Dohou, F.; Gastaldi, F.; Matricon, P.; Renard, C.; Thiebaux, C.; Vasileiadis, G.; Verderi, M.; Oxoby, G.; Va'Vra, J.; Warner, D.; Wilson, R. J.

1999-08-01

The detector of Internally Reflected Cherenkov light (DIRC) of the BaBar detector (SLAC Stanford, USA) measures better than 1 ns the arrival time of Cherenkov photoelectrons, detected in a 11 000 phototubes array and their amplitude spectra. It mainly comprises of 64-channel DIRC Front-End Boards (DFB) equipped with eight full-custom Analog chips performing zero-cross discrimination with 2 mV threshold and pulse shaping, four full-custom Digital TDC chips for timing measurements with 500 ps binning and a readout logic selecting hits in the trigger window, and DIRC Crate Controller cards (DCC) serializing the data collected from up to 16 DFBs onto a 1.2 Gb/s optical link. Extensive test of the pre-production chips have been performed as well as system tests.

Department of Defense Data Model, Version 1, Fy 1998, Volume 5.

DTIC Science & Technology

1998-05-31

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Department of Defense Data Model, Version 1, Fy 1998, Volume 2.

DTIC Science & Technology

1998-05-31

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Secondary ligand-directed assembly of Co(II) coordination polymers based on a pyridine carboxylate ligand

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

Cao, Ke-Li; Zhang, Yi-Ping; Cai, Yi-Ni

2014-07-01

To investigate the influence of hydrogen bonds and secondary ligands on the structures and properties of the resulting frameworks, five new Co(II) compounds have been synthesized by the reactions of Co(II) salts and 3,5-bis(pyridin-4-ylmethoxy)benzoic acid (HL) with four rationally selected dicarboxylic acid ligands. Without secondary ligand, we got one compound [CoL{sub 2}(H{sub 2}O){sub 2}]{sub n}·2nH{sub 2}O (1), which possesses a 1D chain structure. In the presence of ancillary ligands, namely, 1,3-adamantanedicarboxylic acid (H{sub 2}adbc), terephthalic acid (H{sub 2}tpa), thiophene-2,5-dicarboxylic acid (H{sub 2}tdc) and 1,4-benzenedithioacetic acid (H{sub 2}bdtc), four 3D structures [Co{sub 2}L{sub 2}(adbc)]{sub n}·nH{sub 2}O (2), [Co{sub 2}L{sub 2}(tpa)]{sub n}more » (3), [Co{sub 2}L{sub 2}(tdc)]{sub n} (4), [Co{sub 2}L{sub 2}(bdtc)(H{sub 2}O)]{sub n} (5) were obtained, respectively. It can be observed from the architectures of 1–5 that hydrogen bonds and secondary ligands both have great effects on the spatial connective fashions, resulting in the formation of various dimensional compounds. The XRPD, TGA data of title polymers and the magnetic properties for 2 and 5 have also been investigated. - Graphical abstract: The structural differences show that the ancillary ligands have great effects on the spatial connective fashions, resulting in the formation of various dimensional compounds. - Highlights: • Five new Co(II) coordination polymers have been synthesized by solvothermal reactions based on 3,5-bis(pyridin-4-ylmethoxy)benzoic acid (HL). • The long-flexible ligand (HL) is a good candidate to produce interpenetrating architectures. • The secondary dicarboxylic acid ligands play important roles in the spatial connective fashions and the formation of various dimensional compounds. • The magnetism studies show that both 2 and 5 exhibit antiferromagnetic interactions.« less

Organic nitrogen and carbon in atmospheric dry and wet depositions in the southern East China Sea: its implication for new production in coastal region

NASA Astrophysics Data System (ADS)

Chen, H. Y.; Yeh, J. X.; Lin, C. T.

2016-02-01

We collected 11 sets of size-segregated particulate aerosol (include coarse and fine particles) and 53 rain samples from January to December 2014 at a coastal city (Keelung) on the southern East China Sea. Here we present measurements of water-soluble inorganic/organic nitrogen and carbon (WSIN/WSON and WSIC/WSOC, respectively) in aerosol samples and dissolved inorganic/organic nitrogen and carbon (DIN/DON and DIC/DOC, respectively) in rain samples. In addition, 4-d back trajectories of air masses arriving daily at the sampling site were calculated to determine the potential aerosol source regions. The concentrations of water-soluble species in particulate aerosols were relatively high in March (WSON: 223±48 nmol m-3; WSOC: 203±51 nmol m-3) and dissolved species in rain samples were high in December (DON: 157±69 μM; DOC: 294±168 μM), which occur frequently during the spring and winter. The monsoon system of East Asia play a key role on the atmospheric composition of nitrogen and carbon, with higher loadings in northerly (winter to spring) than southerly (summer to autumn) monsoon periods, owing to strong emissions from the East Asian continent. Our results indicate that biomass burning and dust events yielded the largest concentrations of ON and OC not only on particulate aerosols but also in precipitations. For aerosols, the amounts of WSON and WSOC accounted for 42±8% and 80±7% of the water-soluble total nitrogen (WSTN) and carbon (WSTC), respectively. Additionally, the concentrations of DON and DOC accounted for 40±5% and 75±3% of total dissolved nitrogen (TDN) and carbon (TDC), respectively, for precipitations. By using dry and wet deposition flux estimations, we estimated that the fluxes of WSTN/TDN and WSTC/TDC were 47.1±24.4 / 266±20 mmol m-2 yr-1 and 23±9 / 153±3 mmol m-2 yr-1, respectively. These results suggest that atmospheric deposition contributed approximately 25-34% of the annual biological new production in the southern East China Sea.

ASIC Readout Circuit Architecture for Large Geiger Photodiode Arrays

NASA Technical Reports Server (NTRS)

Vasile, Stefan; Lipson, Jerold

2012-01-01

The objective of this work was to develop a new class of readout integrated circuit (ROIC) arrays to be operated with Geiger avalanche photodiode (GPD) arrays, by integrating multiple functions at the pixel level (smart-pixel or active pixel technology) in 250-nm CMOS (complementary metal oxide semiconductor) processes. In order to pack a maximum of functions within a minimum pixel size, the ROIC array is a full, custom application-specific integrated circuit (ASIC) design using a mixed-signal CMOS process with compact primitive layout cells. The ROIC array was processed to allow assembly in bump-bonding technology with photon-counting infrared detector arrays into 3-D imaging cameras (LADAR). The ROIC architecture was designed to work with either common- anode Si GPD arrays or common-cathode InGaAs GPD arrays. The current ROIC pixel design is hardwired prior to processing one of the two GPD array configurations, and it has the provision to allow soft reconfiguration to either array (to be implemented into the next ROIC array generation). The ROIC pixel architecture implements the Geiger avalanche quenching, bias, reset, and time to digital conversion (TDC) functions in full-digital design, and uses time domain over-sampling (vernier) to allow high temporal resolution at low clock rates, increased data yield, and improved utilization of the laser beam.

Status and performance of the AS array of the Tibet AS sub. gamma. experiment

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

Amenomori, M.; Bai, Z.W.; Cao, Z.

1991-04-05

The Tibet AS{gamma} experiment, which has started since January, 1990, is located at an altitude of 4,300m at Yangbaging in Tibet, China (90.5{degree} E, 301{degree} N). The air-shower array is composed of 49 scintillation counters for fast timing (FT), each counter having an area of 0.5 m{sup 2}, in a grid pattern with a spacing of 15 m and 16 density detectors. The density detectors surrounding the FT detectors are planned to select the showers of which core are inside the FT array. For the constant and continuous opeation, the system for laser calibration, the ADC,TDC module calibration and themore » power check system were installed. A Rb clock is used for the phase analysis of {gamma}-rays.« less

Stirling Convertor Extended Operation Testing and Data Analysis at GRC

NASA Technical Reports Server (NTRS)

Cornell, Peggy A.; Lewandowski, Edward J.; Oriti, Salvatore M.; Wilson, Scott D.

2009-01-01

This paper focuses on extended operation testing and data analysis of free-piston Stirling convertors at the NASA Glenn Research Center (GRC). Extended operation testing is essential to the development of radioisotope power systems and their potential use for long duration missions. To document the reliability of the convertors, regular monitoring and analysis of the extended operation data is particularly valuable; allowing us to better understand and quantity the long life characteristics of the convertors. Further, investigation and comparison of the extended operation data to baseline performance data provides us an opportunity for understanding system behavior should any off-nominal performance occur. GRC currently has 14 Stirling convertors under 24-hour unattended extended operation testing, including two operating the Advanced Stirling Radioisotope Generator Engineering Unit (ASRG-EU). 10 of the 14 Stirling convertors at GRC are the Advanced Stirling Convertors (ASC) developed by Sunpower, Incorporated. These are highly efficient (up to > 33.5% conversion efficiency), low mass convertors that have evolved through technologically progressive convertor builds. The remaining four convertors at GRC are Technology Demonstration Convertors (TDC) from Infinia Corporation. They have achieved> 27% conversion efficiency and have accumulated over 178,000 of the total 250,622 hours of extended operation currently at GRC. A synopsis of the Stirling convertor extended operation testing and data analysis at NASA GRC is presented in this paper, as well as how this testing has contributed to the Stirling convertor's progression toward flight.

Advanced Photon Counting Imaging Detectors with 100ps Timing for Astronomical and Space Sensing Applications

NASA Astrophysics Data System (ADS)

Siegmund, O.; Vallerga, J.; Welsh, B.; Rabin, M.; Bloch, J.

In recent years EAG has implemented a variety of high-resolution, large format, photon-counting MCP detectors in space instrumentation for satellite FUSE, GALEX, IMAGE, SOHO, HST-COS, rocket, and shuttle payloads. Our scheme of choice has been delay line readouts encoding photon event position centroids, by determination of the difference in arrival time of the event charge at the two ends of a distributed resistive-capacitive (RC) delay line. Our most commonly used delay line configuration is the cross delay line (XDL). In its simplest form the delay-line encoding electronics consists of a fast amplifier for each end of the delay line, followed by time-to-digital converters (TDC's). We have achieved resolutions of < 25 μm in tests over 65 mm x 65 mm (3k x3k resolution elements) with excellent linearity. Using high speed TDC's, we have been able to encode event positions for random photon rates of ~1 MHz, while time tagging events using the MCP output signal to better than 100 ps. The unique ability to record photon X,Y,T high fidelity information has advantages over "frame driven" recording devices for some important applications. For example we have built open face and sealed tube cross delay line detectors used for biological fluorescence lifetime imaging, observation of flare stars, orbital satellites and space debris with the GALEX satellite, and time resolved imaging of the Crab Pulsar with a telescope as small as 1m. Although microchannel plate delay line detectors meet many of the imaging and timing demands of various applications, they have limitations. The relatively high gain (107) reduces lifetime and local counting rate, and the fixed delay (10's of ns) makes multiple simultaneous event recording problematic. To overcome these limitations we have begun development of cross strip readout anodes for microchannel plate detectors. The cross strip (XS) anode is a coarse (~0.5 mm) multi-layer metal and ceramic pattern of crossed fingers on an alumina substrate. The charge cloud is matched to the anode period so that it is collected on several neighboring fingers to ensure an accurate event charge centroid can be determined. Each finger of the anode is connected to a low noise charge sensitive amplifier and followed by subsequent A/D conversion of individual strip charge values and a hardware centroid determination of better than 1/100 of a strip are possible. Recently we have commissioned a full 32 x 32 mm XS open face laboratory detector and demonstrated excellent resolution (<6 μm FWHM, ~5k x 5k resolution) using low MCP gain (<5 x 105) thus increasing the MCP local counting rate capacity and overall lifetime of the detector system. In collaboration with Los Alamos National Laboratory, NASA and NSF we are developing high rate (>107 Hz) XS encoding electronics that will encode temporally simultaneous events (non spatially overlapping). Sealed tube XS detectors with GaAs and other photocathodes are also under development to increase detection efficiency and extend the sensitivity range. This type of sensor could be a significant enabling technology for several important applications, including airborne and space situational awareness, high-speed adaptive optics (by increasing the SNR and speed in the control loop), astronomy of transient and time-variable sources, optical metrology, and secure quantum communication (as a receiver of cryptographic keys for three-dimensional imaging), single-molecule fluorescence lifetime microscopy (simultaneously tracking and measuring ~1000 molecules), optical/NIR LIDAR, hybrid mass spectrometry and optical night-time/reconnaissance (LANL-ASPIRE).

A fast-locking all-digital delay-locked loop for phase/delay generation in an FPGA

NASA Astrophysics Data System (ADS)

Zhujia, Chen; Haigang, Yang; Fei, Liu; Yu, Wang

2011-10-01

A fast-locking all-digital delay-locked loop (ADDLL) is proposed for the DDR SDRAM controller interface in a field programmable gate array (FPGA). The ADDLL performs a 90° phase-shift so that the data strobe (DQS) can enlarge the data valid window in order to minimize skew. In order to further reduce the locking time and to prevent the harmonic locking problem, a time-to-digital converter (TDC) is proposed. A duty cycle corrector (DCC) is also designed in the ADDLL to adjust the output duty cycle to 50%. The ADDLL, implemented in a commercial 0.13 μm CMOS process, occupies a total of 0.017 mm2 of active area. Measurement results show that the ADDLL has an operating frequency range of 75 to 350 MHz and a total delay resolution of 15 ps. The time interval error (TIE) of the proposed circuit is 60.7 ps.

Safety Evaluation of Enterocin Producer Enterococcus sp. Strains Isolated from Traditional Turkish Cheeses.

PubMed

Avcı, Mine; Özden Tuncer, Banu

2017-07-06

The purpose of this study was to determine the antimicrobial activity and occurrence of bacteriocin structural genes in Enterococcus spp. isolated from different cheeses and also investigate some of their virulence factors. Enterococcus strains were isolated from 33 different cheeses. Enterococcus faecium (6 strains) and Enterococcus faecalis (5 strains) enterocin-producing strains were identified by 16S rDNA analyses. Structural genes entA, entB, entP and entX were detected in some isolates. Multiple enterocin structural genes were found in 7 strains. None of the tested enterococci demonstrated anyβ-haemolytic activity and only one strain had gelatinase activity. Six strains showed multiple antibiotic resistance patterns and in addition, vanA and several virulence genes were detected in many strains. Only E. faecalis MBE1-9 showed tyrosine decarboxylase activity and tdc gene was detected only in this strain.

KTAG: The Kaon Identification Detector for CERN experiment NA62

NASA Astrophysics Data System (ADS)

Fry, J. R.; CERN NA62 Collaboration

2016-07-01

In the study of ultra-rare kaon decays, CERN experiment NA62 exploits an unseparated monochromatic (75 GeV/c) beam of charged particles of flux 800 MHz, of which 50 MHz are K+. Kaons are identified with more than 95% efficiency, a time resolution of better than 100 ps, and misidentification of less than 10-4 using KTAG, a differential, ring-focussed, Cherenkov detector. KTAG utilises 8 sets of 48 Hamamatsu PMTs, of which 32 are of type 9880 and 16 of type 7400, with signals fed directly to the differential inputs of NINO front-end boards and then to TDC cards within the TEL62 system. Leading and trailing edges of the PMT signal are digitised, enabling slewing corrections to be made, and a mean hit rate of 5 MHz per PMT is supported. The electronics is housed within a cooled and insulated Faraday cage with environmental monitoring capabilities.

MuTRiG: a mixed signal Silicon Photomultiplier readout ASIC with high timing resolution and gigabit data link

NASA Astrophysics Data System (ADS)

Chen, H.; Briggl, K.; Eckert, P.; Harion, T.; Munwes, Y.; Shen, W.; Stankova, V.; Schultz-Coulon, H. C.

2017-01-01

MuTRiG is a mixed signal Silicon Photomultiplier readout ASIC designed in UMC 180 nm CMOS technology for precise timing and high event rate applications in high energy physics experiments and medical imaging. It is dedicated to the readout of the scintillating fiber detector and the scintillating tile detector of the Mu3e experiment. The MuTRiG chip extends the excellent timing performance of the STiCv3 chip with a fast digital readout for high rate applications. The high timing performance of the fully differential SiPM readout channels and 50 ps time binning TDCs are complemented by an upgraded digital readout logic and a 1.28 Gbps LVDS serial data link. The design of the chip and the characterization results of the analog front-end, TDC and the LVDS data link are presented.

Studies on exhaust emissions of mahua oil operated compression ignition engine.

PubMed

Kapilan, N; Reddy, R P

2009-07-01

The world is confronted with fossil fuel depletion and environmental degradation. The energy demand and pollution problems lead to research for an alternative renewable energy sources. Vegetable oils and biodiesel present a very promising alternative fuel to diesel. In this work, an experimental work was carried out to study the feasibility of using raw mahua oil (MO) as a substitute for diesel in dual fuel engine. A single cylinder diesel engine was modified to work in dual fuel mode and liquefied petroleum gas (LPG) was used as primary fuel and mahua oil was used as pilot fuel. The results show that the performance of the dual fuel engine at the injector opening pressure of 220 bar and the advanced injection timing of 30 degrees bTDC results in performance close to diesel base line (DBL) operation and lower smoke and oxides of nitrogen emission.

Hydrogen Gas as a Fuel in Direct Injection Diesel Engine

NASA Astrophysics Data System (ADS)

Dhanasekaran, Chinnathambi; Mohankumar, Gabriael

2016-04-01

Hydrogen is expected to be one of the most important fuels in the near future for solving the problem caused by the greenhouse gases, for protecting environment and saving conventional fuels. In this study, a dual fuel engine of hydrogen and diesel was investigated. Hydrogen was conceded through the intake port, and simultaneously air and diesel was pervaded into the cylinder. Using electronic gas injector and electronic control unit, the injection timing and duration varied. In this investigation, a single cylinder, KIRLOSKAR AV1, DI Diesel engine was used. Hydrogen injection timing was fixed at TDC and injection duration was timed for 30°, 60°, and 90° crank angles. The injection timing of diesel was fixed at 23° BTDC. When hydrogen is mixed with inlet air, emanation of HC, CO and CO2 decreased without any emission (exhaustion) of smoke while increasing the brake thermal efficiency.

The DIRC front-end electronics chain for BaBar

NASA Astrophysics Data System (ADS)

Bailly, P.; Beigbeder, C.; Bernier, R.; Breton, D.; Bonneaud, G.; Caceres, T.; Chase, R.; Chauveau, J.; Del Buono, L.; Dohou, F.; Ducorps, A.; Gastaldi, F.; Genat, J. F.; Hrisoho, A.; Imbert, P.; Lebbolo, H.; Matricon, P.; Oxoby, G.; Renard, C.; Roos, L.; Sen, S.; Thiebaux, C.; Truong, K.; Tocut, V.; Vasileiadis, G.; Va'Vra, J.; Verderi, M.; Warner, D.; Wilson, R. J.; Wormser, G.; Zhang, B.; Zomer, F.

2000-12-01

Recent results from the Front-End electronics of the Detector of Internally Reflected Cerenkov light (DIRC) for the BaBar experiment at SLAC (Stanford, USA) are presented. It measures to better than 1 ns the arrival time of Cerenkov photoelectrons detected in a 11000 phototubes array and their amplitude spectra. It mainly comprises 64-channel DIRC Front-End Boards (DFB) equipped with eight full-custom analog chips performing zero-cross discrimination with 2 mV threshold and pulse shaping, four full-custom digital time to digital chips (TDC) for timing measurements with 500 ps binning and a readout logic selecting hits in the trigger window, and DIRC Crate Controller cards (DCC) serializing the data collected front up to 16 DFBs onto a 1.2 Gb/s optical link. Extensive test results of the pre-production chips are presented, as well as system tests.

Data Presentation Report, Army Spill Sites, South Plants Manufacturing Complex. Version 3.2. Phase I

DTIC Science & Technology

1988-09-01

M d C ’, pC c0 a, on 4. 10 C *0 o * ... 44 4. 14. 0 4 A. 0 tfl Vf M m Al 4, 1 Vam 77ey cS b. C tM 0 ’a .4 1 c 0 *ý 0 n 3* z aE~ c - aa42a 6%-E. a m...0 do I0 aa lp 4A - S CE 00 .1 .2.. .1.2 in .3 .2 .3 V)L 10. a MCA 6* . 6 6 mm 41 41 a 0 0 In 0 .0 4 a to0 ,C v I0 IP EEG %C.3 .3.3 .3.2 . C~~~- on 00...CLC2AThiodiglycol Thiodiglycol ( TDC ) TDGCL jAGET PRIO CHRQ D= Isopropylmethylphosphonic Isopropylmethylphosphonate IMPA acid ANIONS /IONCHROM Chloride Chloride CL

Design, fabrication and characterization of a double layer solid oxide fuel cell (DLFC)

NASA Astrophysics Data System (ADS)

Wang, Guangjun; Wu, Xiangying; Cai, Yixiao; Ji, Yuan; Yaqub, Azra; Zhu, Bin

2016-11-01

A double layer solid oxide fuel cell (DLSOFC) without using the electrolyte (layer) has been designed by integrating advantages of positive electrode material of lithium ion battery(LiNi0.8Co0.15Al0.05O2) and oxygen-permeable membranes material (trace amount cobalt incorporated terbium doped ceria, TDC + Co) based on the semiconductor physics principle. Instead of using an electrolyte layer, the depletion layer between the anode and cathode served as an electronic insulator to block the electrons but to maintain the electrolyte function for ionic transport. Thus the device with two layers can realize the function of SOFC and at the same time avoids the electronic short circuiting problem. Such novel DLFC showed good performance at low temperatures, for instance, a maximum power density of 230 mWcm-2 was achieved at 500 °C. The working principle of the new device is presented.

Development of a multiplexed readout with high position resolution for positron emission tomography

NASA Astrophysics Data System (ADS)

Lee, Sangwon; Choi, Yong; Kang, Jihoon; Jung, Jin Ho

2017-04-01

Detector signals for positron emission tomography (PET) are commonly multiplexed to reduce the number of digital processing channels so that the system can remain cost effective while also maintaining imaging performance. In this work, a multiplexed readout combining Anger position estimation algorithm and position decoder circuit (PDC) was developed to reduce the number of readout channels by a factor of 24, 96-to-4. The data acquisition module consisted of a TDC (50 ps resolution), 4-channel ADCs (12 bit, 105 MHz sampling rate), 2 GB SDRAM and USB3.0. The performance of the multiplexed readout was assessed with a high-resolution PET detector block composed of 2×3 detector modules, each consisting of an 8×8 array of 1.52×1.52×6 mm3 LYSO, a 4×4 array of 3×3 mm2 silicon photomultiplier (SiPM) and 13.4×13.4 mm2 light guide with 0.7 mm thickness. The acquired flood histogram showed that all 384 crystals could be resolved. The average energy resolution at 511 keV was 13.7±1.6% full-width-at-half-maximum (FWHM) and the peak-to-valley ratios of the flood histogram on the horizontal and vertical lines were 18.8±0.8 and 22.8±1.3, respectively. The coincidence resolving time of a pair of detector blocks was 6.2 ns FWHM. The reconstructed phantom image showed that rods down to a diameter of 1.6 mm could be resolved. The results of this study indicate that the multiplexed readout would be useful in developing a PET with a spatial resolution less than the pixel size of the photosensor, such as a SiPM array.

Thiamine Deficiency Complex Workshop final report: November 6-7, 2008, Ann Arbor, MI

USGS Publications Warehouse

Honeyfield, Dale C.; Tillitt, Donald E.; Riley, Stephen C.

2008-01-01

Fry mortality which was first observed in the late 1960s in Great Lakes salmonines and in Baltic Sea salmon in 1974 has now been linked to thiamine deficiency (historically referred to as Early Mortality Syndrome, or EMS and M74, respectively). Over the past 14 years significant strides have been made in our understanding of this perplexing problem. It is now known that thiamine deficiency causes embryonic mortality in these salmonids. Both overt mortality and secondary effects of thiamine deficiency are observed in juvenile and adult animals. Collectively the morbidity and mortality (fry and adult mortality, secondary metabolic and behavior affects in juveniles and adult fish) are referred to as Thiamine Deficiency Complex (TDC). A workshop was held in Ann Arbor, MI on 6-7 November 2008 that brought together 38 federal, state, provincial, tribal and university scientists to share information, present data and discuss the latest observations on thiamine status of aquatic animals with thiamine deficiency and the causative agent, thiaminase. Twenty presentations (13 oral and 7 posters) detailed current knowledge. In Lake Huron, low alewife Alosa pseudoharengus abundance has persisted and egg thiamine concentrations in salmonines continue to increase, along with evidence of natural reproduction in lake trout Salvelinus namaycush. Lake Michigan Chinook salmon Oncorhynchus tshawytscha appear to have a lower thiamine requirement than other salmonids in the lake. Lake Ontario American eel Anguilla rostrata foraging on alewife have approximately one third the muscle thiamine compared to eels not feeding on alewife, suggesting that eels may be suffering from thiamine deficiency. Secondary effects of low thiamine exist in Great Lakes salmonines and should not be ignored. Thiaminase activity in dreissenid mussels is extremely high but a connection to TDC has not been made. Thiaminase in net plankton was found more consistently in lakes Michigan and Ontario than other lakes evaluated. The biological role of thiaminase I, associated with thiamine deficiency, remains to be determined whereas thiaminase II has been reported to be part of a salvage pathway leading to thiamine synthesis. The use of gene array technology and 3-dimensional histology is adding new understanding to the affects of thiamine deficiency. Research is needed to determine the thiamine status of species feeding on dreissenids, the environmental sources of thiaminase and the biological role of thiaminase I.

TDC Array Tradeoffs in Current and Upcoming Digital SiPM Detectors for Time-of-Flight PET

NASA Astrophysics Data System (ADS)

Tétrault, Marc-André; Therrien, Audrey Corbeil; Lemaire, William; Fontaine, Réjean; Pratte, Jean-François

2017-03-01

Radiation detection used in positron emission tomography (PET) exploits the timing information to remove background noise and refine position measurement through time-of-flight information. Fine time resolution in the order of 10 ps full-width at half-maximum (FWHM) would not only improve contrast in the image, but would also enable direct image reconstruction without iterative or back-projected algorithms. Currently, PET experimental setups based on silicon photomultipliers (SiPMs) reach 73 ps FWHM, where the scintillation process plays the larger role in spreading the timing resolution. This will change with the optimization of faster light emission mechanisms (prompt photons), where readout optoelectronics will once more have a noticeable contribution to the timing resolution limit. In addition to reducing electronic jitter as much as possible, other aspects of the design space must also explored, especially for digital SiPMs. Unlike traditional SiPMs, digital SiPMs can integrate circuits like time-to-digital converters (TDCs) directly with individual or groups of light sensing cells. Designers should consider the number of TDCs to integrate, the area they occupy, their power consumption, their resolution, and the impact of signal processing algorithms and find a compromise with the figure of merit and the coincidence timing resolution (CTR). This paper presents a parametric simulation flow for digital SiPM microsystems that evaluates CTR based on these aspects and on the best linear unbiased estimator (BLUE) in order to guide their design for present and future PET systems. For a small 1.1 × 1.1 × 3.0 mm3 LYSO crystal, the simulations indicate that for a low jitter digital SiPM microsystem with 18.2% photon detection efficiency, fewer than four timestamps with any multi-TDC configuration scheme nearly obtain the optimal CTR with BLUE (just below 100 ps FWHM), but with limited 5% improvement over only using the first observed photon. On the other hand, if a similar crystal but with 2.5% prompt photon fraction is considered, BLUE provides an improvement between 80% and 200% (depending on electronic jitter) over using only the first observed photon. In this case, a few tens of timestamps are required, yielding very different design guidelines than for standard LYSO scintillators.

Transcriptomic analysis of Portunus trituberculatus reveals a critical role for WNT4 and WNT signalling in limb regeneration.

PubMed

Liu, Lei; Fu, Yuanyuan; Zhu, Fang; Mu, Changkao; Li, Ronghua; Song, Weiwei; Shi, Ce; Ye, Yangfang; Wang, Chunlin

2018-06-05

The swimming crab (Portunus trituberculatus) is among the most economically important seawater crustacean species in Asia. Despite its commercial importance and being well-studied status, genomic and transcriptomic data are scarce for this crab species. In the present study, limb bud tissue was collected at different developmental stages post amputation for transcriptomic analysis. Illumina RNA-sequencing was applied to characterise the limb regeneration transcriptome and identify the most characteristic genes. A total of 289,018 transcripts were obtained by clustering and assembly of clean reads, producing 150,869 unigenes with an average length of 956 bp. Subsequent analysis revealed WNT signalling as the key pathway involved in limb regeneration, with WNT4 a key mediator. Overall, limb regeneration appears to be regulated by multiple signalling pathways, with numerous cell differentiation, muscle growth, moult, metabolism, and immune-related genes upregulated, including WNT4, LAMA, FIP2, FSTL5, TNC, HUS1, SWI5, NCGL, SLC22, PLA2, Tdc2, SMOX, GDH, and SMPD4. This is the first experimental study done on regenerating claws of P. trituberculatus. These findings expand existing sequence resources for crab species, and will likely accelerate research into regeneration and development in crustaceans, particularly functional studies on genes involved in limb regeneration. Copyright © 2018 Elsevier B.V. All rights reserved.

STIC3 - Silicon Photomultiplier Timing Chip with picosecond resolution

NASA Astrophysics Data System (ADS)

Stankova, Vera; Shen, Wei; Briggl, Konrad; Chen, Huangshan; Fischer, Peter; Gil, Alejandro; Harion, Tobias; Kiworra, Volker; Munwes, Yonathan; Ritzert, Michael; Schultz-Coulon, Hans-Christian

2015-07-01

The diagnostic of pancreas and prostate cancer is a challenging task due to the background noise coming from the closer organs. The EndoToFPET-US project aims to combine the synergy between metabolic and anatomical (ultrasound) image in order to improve the precision in the tumor localization. The goal of the project is to develop a Positron Emission Tomography (PET) system that provides a time-of-flight resolution of 200 ps FWHM for improving the signal to noise ratio and further to improve the medical image quality. In order to achieve this purpose an ASIC has been designed for very high timing resolution in time-of-flight (ToF) applications. In this paper we present the ASIC performance and the first characterization measurements with the 64-channels prototype version (STiC3). Measurements are performed with LYSO scintillator crystal and a Multi Pixel Photon Counter (MPPC). Measurements with the chip show an analog-front-end stage jitter of 35 ps for the first photo-electron equivalent charge and reach 18 ps for the third photo-electron. Coincidence time resolution (CTR) of 240 ps FWHM is measured with 3.1×3.1×15 mm3 LYSO crystal and 50 μm pixel pitch MPPC. Further optimization including the Time-to-Digital Converter (TDC) non-linearity corrections and setup fine tuning are ongoing for achieving the desired CTR of 200 ps FWHM.

Validation of a highly integrated SiPM readout system with a TOF-PET demonstrator

NASA Astrophysics Data System (ADS)

Niknejad, T.; Setayeshi, S.; Tavernier, S.; Bugalho, R.; Ferramacho, L.; Di Francesco, A.; Leong, C.; Rolo, M. D.; Shamshirsaz, M.; Silva, J. C.; Silva, R.; Silveira, M.; Zorraquino, C.; Varela, J.

2016-12-01

We have developed a highly integrated, fast and compact readout electronics for Silicon Photomultiplier (SiPM) based Time of Flight Positron Emission Tomography (TOF-PET) scanners. The readout is based on the use of TOP-PET Application Specific Integrated Circuit (PETsys TOFPET1 ASIC) with 64 channels, each with its amplifier, discriminator, Time to Digital Converter (TDC) and amplitude determination using Time Over Threshold (TOT). The ASIC has 25 ps r.m.s. intrinsic time resolution and fully digital output. The system is optimised for high rates, good timing, low power consumption and low cost. For validating the readout electronics, we have built a technical PET scanner, hereafter called ``demonstrator'', with 2'048 SiPM channels. The PET demonstrator has 16 compact Detector Modules (DM). Each DM has two ASICs reading 128 SiPM pixels in one-to-one coupling to 128 Lutetium Yttrium Orthosilicate (LYSO) crystals measuring 3.1 × 3.1 × 15 mm3 each. The data acquisition system for the demonstrator has two Front End Boards type D (FEB/D), each collecting the data of 1'024 channels (8 DMs), and transmitting assembled data frames through a serial link (4.8 Gbps), to a single Data Acquisition (DAQ) board plugged into the Peripheral Component Interconnect Express (PCIe) bus of the data acquisition PC. Results obtained with this PET demonstrator are presented.

Mother-child play: children with Down syndrome and typical development.

PubMed

Venuti, P; de Falco, S; Esposito, G; Bornstein, Marc H

2009-07-01

Child solitary and collaborative mother-child play with 21 children with Down syndrome and 33 mental-age-matched typically developing children were compared. In solitary play, children with Down syndrome showed less exploratory but similar symbolic play compared to typically developing children. From solitary to collaborative play, children with Down syndrome increased their exploratory play, attaining the same level as typically developing children. Pretense significantly increased from solitary to collaborative play only in typically developing children. Differences between mothers' play in the two groups mirrored those between their children. Both groups showed similar attunement and synchrony. Mothers contribute to the play development of children with Down syndrome through their own adaptation to their children's limitations and potentialities.

[An investigation of the imitation skills in children with autism spectrum disorder and their association with receptive-expressive language development].

PubMed

Turan, Figen; Ökçün Akçamuş, Meral Çilem

2013-01-01

This study aimed to compare imitation skills in children with autism spectrum disorder, and age-matched typically developing children and children with developmental delay, as well as to examine the association between imitation skills, and receptive and expressive language development in children with autism spectrum disorder. Imitation skills in children with autism spectrum disorder (n=18), and age-matched children with developmental delay (n=15) and typically developing children (n= 16) were assessed using the Motor Imitation Scale and Imitation Battery, and the differences in mean imitation scores between the groups were examined. Receptive language and expressive language development in the children with autism spectrum disorder were assessed using the Turkish Communicative Development Inventory (TCDI), and their association with imitation scores was explored. The children with autism spectrum disorder had significantly lower imitation scores than the children with developmental delay and typically developing children; however, there wasn't a significant difference in imitation scores between the children with developmental delay and typically developing children. A significant association between imitation scores, and receptive and expressive language development was observed in the children with autism spectrum disorder. The present findings indicate that deficient imitation skills are a distinctive feature of children with autism spectrum disorder and that imitation skills play a crucial role in children's language development.

Performance of motor imitation in children with and without dyspraxia.

PubMed

Ruttanathantong, Korrawan; Siritaratiwat, Wantana; Sriphetcharawut, Sarinya; Emasithi, Alongkot; Saengsuwan, Jiamjit; Saengsuwan, Jittima

2013-07-01

Motor imitation is truly essential for young children to learn new motor skills, social behavior and skilled acts or praxis. The present study aimed to investigate motor imitation ability between typically-developing children and dyspraxic children and to examine the development trends in both children groups. The comparison ofmotor imitation was studied in 55 typically-developing children and 59 dyspraxic children aged 5 to 8 years. The Motor Imitation subtest consisted of two sections, imitation of postures and imitation of verbal instructions. Typically-developing children and dyspraxic children were examined for developmental trends. The independent samples t-test was used to analyze the differences between both groups. Two-way analysis of variance (ANOVA) was used to analyze inter-age differences for each age group. The results revealed significant differences between dyspraxic and typically-developing children. Both typically-developing and dyspraxic children demonstrated age trends. The older children scored higher than younger children. Imitation is a primary learning strategy of young children. It is essential that children with dyspraxia receive early detection and need effective intervention. Typically-developing children and dyspraxic children showed higher mean score on the Imitation of Posture section than the Verbal Instructions section. Motor imitation competency, therefore, changes and improves with age.

Recognition of Emotion from Facial Expressions with Direct or Averted Eye Gaze and Varying Expression Intensities in Children with Autism Disorder and Typically Developing Children

PubMed Central

Tell, Dina; Davidson, Denise; Camras, Linda A.

2014-01-01

Eye gaze direction and expression intensity effects on emotion recognition in children with autism disorder and typically developing children were investigated. Children with autism disorder and typically developing children identified happy and angry expressions equally well. Children with autism disorder, however, were less accurate in identifying fear expressions across intensities and eye gaze directions. Children with autism disorder rated expressions with direct eyes, and 50% expressions, as more intense than typically developing children. A trend was also found for sad expressions, as children with autism disorder were less accurate in recognizing sadness at 100% intensity with direct eyes than typically developing children. Although the present research showed that children with autism disorder are sensitive to eye gaze direction, impairments in the recognition of fear, and possibly sadness, exist. Furthermore, children with autism disorder and typically developing children perceive the intensity of emotional expressions differently. PMID:24804098

Language and literacy development of deaf and hard-of-hearing children: successes and challenges.

PubMed

Lederberg, Amy R; Schick, Brenda; Spencer, Patricia E

2013-01-01

Childhood hearing loss presents challenges to language development, especially spoken language. In this article, we review existing literature on deaf and hard-of-hearing (DHH) children's patterns and trajectories of language as well as development of theory of mind and literacy. Individual trajectories vary significantly, reflecting access to early identification/intervention, advanced technologies (e.g., cochlear implants), and perceptually accessible language models. DHH children develop sign language in a similar manner as hearing children develop spoken language, provided they are in a language-rich environment. This occurs naturally for DHH children of deaf parents, who constitute 5% of the deaf population. For DHH children of hearing parents, sign language development depends on the age that they are exposed to a perceptually accessible 1st language as well as the richness of input. Most DHH children are born to hearing families who have spoken language as a goal, and such development is now feasible for many children. Some DHH children develop spoken language in bilingual (sign-spoken language) contexts. For the majority of DHH children, spoken language development occurs in either auditory-only contexts or with sign supports. Although developmental trajectories of DHH children with hearing parents have improved with early identification and appropriate interventions, the majority of children are still delayed compared with hearing children. These DHH children show particular weaknesses in the development of grammar. Language deficits and differences have cascading effects in language-related areas of development, such as theory of mind and literacy development.

Weapon System Costing Methodology for Aircraft Airframes and Basic Structures Volume II - Estimating Handbook and User’s Manual, Part 2

DTIC Science & Technology

1975-05-01

4bo» i) (46u t2) ( 4tib > 3 ) ( 4bD » fa) .1 .1 .1 .1 LÜG LÜG LÜG LUG LÜG LUG LÜG Lud LÜG LUG LUG LUG LÜG LÜG LUG Lüb LÜG LUG...PC2UI LUG PC310 LUG PL 111 LuG PC211 LÜG PL 31 1 LÜG PL212 PL312 .OB LUG LUG LÄWüING GEAR «LWüRK (4bb»1) + (468»1) (4bbf2) + (46P»2) ( 4bD »3...JiJCDtJCDCDt3(JCDO»-tOOCDC3tDC3i-J_7CD( t^cJtJCJ(D^J Ducju>ot-Jt-Jur>j > 03 J- IT J- -* IP ip >r IP 0- *S -* <D O rj >1 O --i TD -D -i TD O 4 * UJ

Engineering of Escherichia coli for the synthesis of N-hydroxycinnamoyl tryptamine and serotonin.

PubMed

Lee, Su Jin; Sim, Geun-Young; Lee, Youngshim; Kim, Bong-Gyu; Ahn, Joong-Hoon

2017-11-01

Plants synthesize various phenol amides. Among them, hydroxycinnamoyl (HC) tryptamines and serotonins exhibit antioxidant, anti-inflammatory, and anti-atherogenic activities. We synthesized HC-tryptamines and HC-serotonin from several HCs and either tryptamine or serotonin using Escherichia coli harboring the 4CL (4-coumaroyl CoA ligase) and CaHCTT [hydroxycinnamoyl-coenzyme A:serotonin N-(hydroxycinnamoyl)transferase] genes. E. coli was engineered to synthesize N-cinnamoyl tryptamine from glucose. TDC (tryptophan decarboxylase) and PAL (phenylalanine ammonia lyase) along with 4CL and CaHCTT were introduced into E. coli and the phenylalanine biosynthetic pathway of E. coli was engineered. Using this strategy, approximately 110.6 mg/L of N-cinnamoyl tryptamine was synthesized. By feeding 100 μM serotonin into the E. coli culture, which could induce the synthesis of cinnamic acid or p-coumaric acid, more than 99 μM of N-cinnamoyl serotonin and N-(p-coumaroyl) serotonin were synthesized.

Experimental Studies of Diestrol-Micro Emulsion Fuel in a Direct Injection Compression Ignition Engine under Varying Injection Pressures and Timings

NASA Astrophysics Data System (ADS)

Kannan, Gopal Radhakrishnan

2018-02-01

The research work on biodiesel becomes more attractive in the context of limited availability of petroleum fuels and rapid increase of harmful emissions from diesel engine using conventional fossil fuels. The present investigation has dealt with the influence of biodiesel-diesel-ethanol (diestrol) water micro emulsion fuel (B60D20E20M) on the performance, emission and combustion characteristics of a diesel engine under different injection pressure and timing. The results revealed that the maximum brake thermal efficiency of 32.4% was observed at an injection pressure of 260 bar and injection timing of 25.5°bTDC. In comparison with diesel, micro emulsion fuel showed reduction in carbon monoxide (CO) and total hydrocarbon (THC) by 40 and 24%, respectively. Further, micro emulsion fuel decreased nitric oxide (NO) emission and smoke emission by 7 and 20.7%, while the carbon dioxide (CO2) emission is similar to that of diesel.

GridPix detectors: Production and beam test results

NASA Astrophysics Data System (ADS)

Koppert, W. J. C.; van Bakel, N.; Bilevych, Y.; Colas, P.; Desch, K.; Fransen, M.; van der Graaf, H.; Hartjes, F.; Hessey, N. P.; Kaminski, J.; Schmitz, J.; Schön, R.; Zappon, F.

2013-12-01

The innovative GridPix detector is a Time Projection Chamber (TPC) that is read out with a Timepix-1 pixel chip. By using wafer post-processing techniques an aluminium grid is placed on top of the chip. When operated, the electric field between the grid and the chip is sufficient to create electron induced avalanches which are detected by the pixels. The time-to-digital converter (TDC) records the drift time enabling the reconstruction of high precision 3D track segments. Recently GridPixes were produced on full wafer scale, to meet the demand for more reliable and cheaper devices in large quantities. In a recent beam test the contribution of both diffusion and time walk to the spatial and angular resolutions of a GridPix detector with a 1.2 mm drift gap are studied in detail. In addition long term tests show that in a significant fraction of the chips the protection layer successfully quenches discharges, preventing harm to the chip.

Timing Results Using an FPGA-Based TDC with Large Arrays of 144 SiPMs

NASA Astrophysics Data System (ADS)

Aguilar, A.; González, A. J.; Torres, J.; García-Olcina, R.; Martos, J.; Soret, J.; Conde, P.; Hernández, L.; Sánchez, F.; Benlloch, J. M.

2015-02-01

Silicon photomultipliers (SiPMs) have become an alternative to traditional tubes due to several features. However, their implementation to form large arrays is still a challenge especially due to their relatively high intrinsic noise, depending on the chosen readout. In this contribution, two modules composed of 12 ×12 SiPMs with an area of roughly 50 mm×50 mm are used in coincidence. Coincidence resolving time (CRT) results with a field-programmable gate array, in combination with a time to digital converter, are shown as a function of both the sensor bias voltage and the digitizer threshold. The dependence of the CRT on the sensor matrix temperature, the amount of SiPM active area and the crystal type is also analyzed. Measurements carried out with a crystal array of 2 mm pixel size and 10 mm height have shown time resolutions for the entire 288 SiPM two-detector set-up as good as 800 ps full width at half maximum (FWHM).

Influence of Waveform Characteristics on LiDAR Ranging Accuracy and Precision

PubMed Central

Yang, Bingwei; Xie, Xinhao; Li, Duan

2018-01-01

Time of flight (TOF) based light detection and ranging (LiDAR) is a technology for calculating distance between start/stop signals of time of flight. In lab-built LiDAR, two ranging systems for measuring flying time between start/stop signals include time-to-digital converter (TDC) that counts time between trigger signals and analog-to-digital converter (ADC) that processes the sampled start/stop pulses waveform for time estimation. We study the influence of waveform characteristics on range accuracy and precision of two kinds of ranging system. Comparing waveform based ranging (WR) with analog discrete return system based ranging (AR), a peak detection method (WR-PK) shows the best ranging performance because of less execution time, high ranging accuracy, and stable precision. Based on a novel statistic mathematical method maximal information coefficient (MIC), WR-PK precision has a high linear relationship with the received pulse width standard deviation. Thus keeping the received pulse width of measuring a constant distance as stable as possible can improve ranging precision. PMID:29642639

Dollar Summary of Federal Supply Classification and Service Category by Company. Part 1 (AA11-AZ16)

DTIC Science & Technology

1990-01-01

4 -4 4 I ~ z I % - . - 4 : -4 )1 4 : 41 -I I I I Z NI 0m m - 4 a _4 it m 4 cc -D 0 m m 4- _4 LU LU 0 24 tm x. 0. IL4 ..4 x. ’x x. . ILC C-) 0) 414- C1...Ql I CKI < 2 0 (4) I cm m 0 c. w 00wcom 0 --4 r- co w l c, W 0000 0000 ( tm ’ N -o "- -4 o’ V.L t v w L - w - o -40( cl m LA m44 -4 Cl) 1, en -4 L...l ) C 4 ) 0 ) ) tdC ) 0 t a C) a) C ) cl 0 I C)1 I I I I I = - -4 I I I n -4 Im -0 LU w 4L 4 4 - 4o 0 01 I 4 L. I oA CO 0 41 1 0 IV C) (13 ml Cl IV

Working memory arrest in children with high-functioning autism compared to children with attention-deficit/hyperactivity disorder: results from a 2-year longitudinal study.

PubMed

Andersen, Per N; Skogli, Erik W; Hovik, Kjell T; Geurts, Hilde; Egeland, Jens; Øie, Merete

2015-05-01

The aim of this study was to analyse the development of verbal working memory in children with high-functioning autism compared to children with attention-deficit/hyperactivity disorder and typically developing children. A total of 34 children with high-functioning autism, 72 children with attention-deficit/hyperactivity disorder and 45 typically developing children (age 9-16 years) were included at baseline and followed up approximately 25 months later. The children were given a letter/number sequencing task to assess verbal working memory. The performance of children with high-functioning autism on verbal working memory did not improve after 2 years, while improvement was observed in children with attention-deficit/hyperactivity disorder and typically developing children. The results indicate a different developmental trajectory for verbal working memory in children with high-functioning autism compared to children with attention-deficit/hyperactivity disorder and typically developing children. More research is needed to construct a developmental framework more suitable for children with autism spectrum disorder. © The Author(s) 2014.

Tolerogenic dendritic cells in autoimmune diseases: crucial players in induction and prevention of autoimmunity.

PubMed

Torres-Aguilar, Honorio; Blank, Miri; Jara, Luis J; Shoenfeld, Yehuda

2010-11-01

The immune system has evolved to coordinate responses against numerous invading pathogens and simultaneously remain silent facing self-antigens and those derived from commensal organisms. But, if both processes are not maintained in strict balance, a potential threat can emerge due to the risk of chronic inflammation and/or autoimmunity development. Therefore, there is a negative immune regulation where tolerogenic dendritic cells (tDCs) participate actively. Under steady-state conditions, tDC are notably involved in the elimination of autoreactive T cells at the thymus, and in the control of T cells specific to self and harmless antigens in the periphery. But in the presence of foreign antigens in an inflammatory milieu, dendritic cells (DCs) mature and induce T cells activation and their migration to B cell areas to assist in antibody production. Additionally, there are other factors such as infections, anti tumoral immune responses, trauma-mediated disruption, etc. that may induce alterations in the balance between tolerogenic and immunogenic functions of DCs and instigate the development of autoimmune diseases (ADs). Therefore, in recent years, DCs have emerged as therapeutic targets to control of ADs. Diverse strategies in vitro and/or in animal models of ADs have explored the tolerogenic functions of DCs and demonstrated their feasibility to prevent or control an autoimmune process, but still leaving a void in their application in clinical assays. The purpose of this paper is to give a general overview of the current literature on the significance of tDCs in tolerance maintenance to self and innocuous antigens, the most relevant alterations involved in the pathophysiology of ADs, the cellular and molecular mechanisms involved in their tolerogenic function and the current strategies used to exploit their tolerogenic potential. Published by Elsevier B.V.

The Central Logic Board for the KM3NeT detector: Design and production

NASA Astrophysics Data System (ADS)

Musico, P.; KM3NeT Collaboration

2016-07-01

The KM3NeT deep sea neutrino observatory will include a very large number of multi-Photomultiplier (PMT) optical modules (DOM) to detect the Cherenkov light generated by secondary particles produced in neutrino interactions. The Central Logic Board (CLB) has been developed to acquire timing and amplitude information from the PMT signals, implementing time-to-digital conversion (TDC) with time over threshold (TOT) technique. The board is also used to configure all the DOM subsystems, to assist in the DOM position and orientation, calibration and to monitor temperature and humidity in the DOM itself. All the collected data are transmitted to shore using a wide-bandwidth optical network. Moreover, through the optical network, all the DOMs are kept synchronized in time within 1 ns precision using the White Rabbit (WR) Precision Time Protocol (PTP) over an Ethernet connection. A large Field Programmable Gate Array (FPGA) has been adopted to implement all the specifications witht the requested performances. The CLB will be also used in the base container of the detection unit (DU) to set-up and monitor all the requested functionalities: in this scenario a dedicated firmware and software will be deployed on board. The design has been started in early 2013 and several prototypes have been developed. After deep test carried on in different EU laboratories, the final mass production batch of 600 boards has been ordered and built: all the CLB are now ready for integration in the DOMs and base containers. The first two KM3NeT DU will be deployed in summer 2015 and all other units are in advanced stage of integration.

Hand Strength, Handwriting, and Functional Skills in Children With Autism.

PubMed

Alaniz, Michele L; Galit, Eleanor; Necesito, Corina Isabel; Rosario, Emily R

2015-01-01

To establish hand strength development trends in children with autism and to investigate correlations between grip and pinch strength, components of handwriting, and functional activities in children with and without autism. Fifty-one children were divided into two groups: typically developing children and children on the autism spectrum. Each child completed testing for pinch and grip strength, handwriting legibility, pencil control, and independence in functional activities. The children with autism followed the same strength development trends as the typically developing children. Grip strength correlated with pencil control in both groups and with handwriting legibility in the typically developing children but not in the children with autism. Grip and pinch strength correlated with independence with functional activities in both groups. This study provides evidence that grip and pinch strength are important components in developing pencil control, handwriting legibility, and independence with functional fine motor tasks. Copyright © 2015 by the American Occupational Therapy Association, Inc.

Mother-Child Play: Children with Down Syndrome and Typical Development

ERIC Educational Resources Information Center

Venuti, P.; de Falco, S.; Esposito, G.; Bornstein, Marc H.

2009-01-01

Child solitary and collaborative mother-child play with 21 children with Down syndrome and 33 mental-age-matched typically developing children were compared. In solitary play, children with Down syndrome showed less exploratory but similar symbolic play compared to typically developing children. From solitary to collaborative play, children with…

Mealtime Behaviors of Preschool Children: Comparison of Children with Autism Spectrum Disorder and Children with Typical Development

ERIC Educational Resources Information Center

Provost, Beth; Crowe, Terry K.; Osbourn, Patricia L.; McClain, Catherine; Skipper, Betty J.

2010-01-01

This study identified mealtime behaviors of young children (3-6 years old) with autism spectrum disorder (ASD) and compared these behaviors to children with typical development matched for age, gender, and ethnicity. The parents of children with ASD (n = 24) and children with typical development (n = 24) completed a mealtime survey to assess early…

The KLOE-2 high energy taggers

NASA Astrophysics Data System (ADS)

Curciarello, F.

2017-06-01

The precision measurement of the π0 → γγ width allows to gain insights into the low-energy QCD dynamics. A way to achieve the precision needed (1%) in order to test theory predictions is to study the π0 production through γγ fusion in the e+e- → e+e-γ*γ* → e+e-π0 reaction. The KLOE-2 experiment, currently running at the DAΦNE facility in Frascati, aims to perform this measurement. For this reason, new detectors, which allow to tag final state leptons, have been installed along the DAΦNE beam line in order to reduce the background coming from phi-meson decays. The High Energy Tagger (HET) detector measures the deviation of leptons from their main orbit by determining their position and timing. The HET detectors are placed in roman pots just at the exit of the DAΦNE dipole magnets, 11 m away from the IP, both on positron and electron sides. The HET sensitive area is made up of a set of 28 plastic scintillators. A dedicated DAQ electronic board, based on a Xilinx Virtex-5 FPGA, has been developed for this detector. It provides a MultiHit TDC with a time resolution of 550(1) ps and the possibility to clearly identify the correct bunch crossing (ΔTbunch ~ 2.7 ns). The most relevant features of the KLOE-2 tagging system operation as time performance, stability and the techniques used to determine the time overlap between the KLOE and HET asynchronous DAQs will be presented.

The Escherichia coli O157:H7 cattle immuno-proteome includes outer membrane protein A (OmpA), a modulator of adherence to bovine recto-anal junction squamous epithelial (RSE) cells

PubMed Central

Kudva, Indira T.; Krastins, Bryan; Torres, Alfredo G.; Griffin, Robert W.; Sheng, Haiqing; Sarracino, David A.; Hovde, Carolyn J.; Calderwood, Stephen B.; John, Manohar

2015-01-01

SUMMARY Building on previous studies, we defined the repertoire of proteins comprising the immuno-proteome of E. coli O157:H7 (O157) cultured in DMEM supplemented with norepinephrine (NE; O157 immuno-proteome), a β-adrenergic hormone that regulates E. coli O157 gene expression in the gastrointestinal tract, using a variation of a novel proteomics-based platform proteome mining tool for antigen discovery, called Proteomics-based Expression Library Screening (PELS; Kudva et al., 2006). The E. coli O157 immuno-proteome (O157-IP) comprised 91 proteins, and included those identified previously using PELS, and also proteins comprising DMEM- and bovine rumen fluid- proteomes. Outer membrane protein A (OmpA), a common component of the above proteomes, and reportedly a contributor to E. coli O157 adherence to cultured Hep-2 epithelial cells, was interestingly found to be a modulator rather than a contributor to E. coli O157 adherence to bovine recto-anal junction squamous epithelial (RSE) cells. Our results point to a role for yet to be identified members of the O157-IP in E. coli O157 adherence to RSE-cells, and additionally implicate a possible role for the OmpA regulator, TdcA, in the expression of such adhesins. Our observations have implications for development of efficacious vaccines for preventing E. coli O157 colonization of the bovine gastrointestinal tract. PMID:25643951

Precision tracking with a single gaseous pixel detector

NASA Astrophysics Data System (ADS)

Tsigaridas, S.; van Bakel, N.; Bilevych, Y.; Gromov, V.; Hartjes, F.; Hessey, N. P.; de Jong, P.; Kluit, R.

2015-09-01

The importance of micro-pattern gaseous detectors has grown over the past few years after successful usage in a large number of applications in physics experiments and medicine. We develop gaseous pixel detectors using micromegas-based amplification structures on top of CMOS pixel readout chips. Using wafer post-processing we add a spark-protection layer and a grid to create an amplification region above the chip, allowing individual electrons released above the grid by the passage of ionising radiation to be recorded. The electron creation point is measured in 3D, using the pixel position for (x, y) and the drift time for z. The track can be reconstructed by fitting a straight line to these points. In this work we have used a pixel-readout-chip which is a small-scale prototype of Timepix3 chip (designed for both silicon and gaseous detection media). This prototype chip has several advantages over the existing Timepix chip, including a faster front-end (pre-amplifier and discriminator) and a faster TDC which reduce timewalk's contribution to the z position error. Although the chip is very small (sensitive area of 0.88 × 0.88mm2), we have built it into a detector with a short drift gap (1.3 mm), and measured its tracking performance in an electron beam at DESY. We present the results obtained, which lead to a significant improvement for the resolutions with respect to Timepix-based detectors.

Development of the Parent Form of the Preschool Children's Communication Skills Scale and Comparison of the Communication Skills of Children with Normal Development and with Autism Spectrum Disorder

ERIC Educational Resources Information Center

Aydin, Aydan

2016-01-01

This study aims at developing an assessment scale for identifying preschool children's communication skills, at distinguishing children with communication deficiencies and at comparing the communication skills of children with normal development (ND) and those with autism spectrum disorder (ASD). Participants were 427 children of up to 6 years of…

A Dyadic Analysis of the Effects of Setting and Communication Partner on Elicited and Spontaneous Communication of Children with Autism Spectrum Disorder and Typically Developing Children

ERIC Educational Resources Information Center

Forde, Ita; Holloway, Jennifer; Healy, Olive; Brosnan, Julie

2011-01-01

The study examined the effects of condition and communication partner on spontaneous and elicited communication in children with Autism Spectrum Disorder (ASD) in comparison to age matched typically developing children. Eighteen children participated in the study (nine children diagnosed with ASD and nine typically developing children). Each…

The influence of maternal language responsiveness on the expressive speech production of children with autism spectrum disorders: a microanalysis of mother-child play interactions.

PubMed

Walton, Katherine M; Ingersoll, Brooke R

2015-05-01

Adult responsiveness is related to language development both in young typically developing children and in children with autism spectrum disorders, such that parents who use more responsive language with their children have children who develop better language skills over time. This study used a micro-analytic technique to examine how two facets of maternal utterances, relationship to child focus of attention and degree of demandingness, influenced the immediate use of appropriate expressive language of preschool-aged children with autism spectrum disorders (n = 28) and toddlers with typical development (n = 16) within a naturalistic mother-child play session. Mothers' use of follow-in demanding language was most likely to elicit appropriate expressive speech in both children with autism spectrum disorders and children with typical development. For children with autism spectrum disorders, but not children with typical development, mothers' use of orienting cues conferred an additional benefit for expressive speech production. These findings are consistent with the naturalistic behavioral intervention philosophy and suggest that following a child's lead while prompting for language is likely to elicit speech production in children with autism spectrum disorders and children with typical development. Furthermore, using orienting cues may help children with autism spectrum disorders to verbally respond. © The Author(s) 2014.

Influence of Linguistic Environment on Children's Language Development: Flemish versus Dutch Children

ERIC Educational Resources Information Center

Wiefferink, C. H.; Spaai, G. W. G.; Uilenburg, N.; Vermeij, B. A. M.; De Raeve, L.

2008-01-01

In the present study, language development of Dutch children with a cochlear implant (CI) in a bilingual educational setting and Flemish children with a CI in a dominantly monolingual educational setting is compared. In addition, we compared the development of spoken language with the development of sign language in Dutch children. Eighteen…

Lipreading Ability and Its Cognitive Correlates in Typically Developing Children and Children with Specific Language Impairment

ERIC Educational Resources Information Center

Heikkilä, Jenni; Lonka, Eila; Ahola, Sanna; Meronen, Auli; Tiippana, Kaisa

2017-01-01

Purpose: Lipreading and its cognitive correlates were studied in school-age children with typical language development and delayed language development due to specific language impairment (SLI). Method: Forty-two children with typical language development and 20 children with SLI were tested by using a word-level lipreading test and an extensive…

Development of Non-Verbal Intellectual Capacity in School-Age Children with Cerebral Palsy

ERIC Educational Resources Information Center

Smits, D. W.; Ketelaar, M.; Gorter, J. W.; van Schie, P. E.; Becher, J. G.; Lindeman, E.; Jongmans, M. J.

2011-01-01

Background: Children with cerebral palsy (CP) are at greater risk for a limited intellectual development than typically developing children. Little information is available which children with CP are most at risk. This study aimed to describe the development of non-verbal intellectual capacity of school-age children with CP and to examine the…

BIOMARKERS FOR ASSESSING REPRODUCTIVE DEVELOPMENT AND HEALTH: PART 1 - PUBERTAL DEVELOPMENT

EPA Science Inventory

The proposed National Children?s Study has helped raise awareness of the issues related to children?s health and the importance of monitoring the growth and development of children from preconception through to adulthood. Many genetic predispositions can adversely impact the nor...

How May Children's Development Be Seen Historically?

ERIC Educational Resources Information Center

Modell, John

2000-01-01

Reevaluates Lev Vygotsky's theory of children's development. Argues that we can understand development as history only when we think simultaneously about how changing contexts affect what children appropriate from them, and how children's appropriations modify the contexts that guide development. (JPB)

Play preference of children with ADHD and typically developing children in Brazil: a pilot study.

PubMed

Pfeifer, Luzia Iara; Terra, Lauana Nogueira; dos Santos, Jair Lício Ferreira; Stagnitti, Karen Ellen; Panúncio-Pinto, Maria Paula

2011-12-01

Children with attention deficit hyperactivity disorder (ADHD) have been reported to have play deficits, which can cause problems in occupational development. The aim of this paper was to report research findings on children with ADHD and typically developing children in relation to preference of play partners, play places, toys and type of play. Thirty-two school aged children from low socioeconomic status were divided into two groups. One group of 16 children with ADHD were matched with 16 typically developing children. There were no significant differences between the two groups in relation to play partners, with classmates being the most frequent play partner for both groups. There were significant differences between the two groups in preferred place to play. Children with ADHD preferred to play in school and typically developing children preferred to play on the street. There were significant differences in relation to toys and type of play engaged in with children with ADHD preferring educational materials and typically developing children preferring electronic games. These findings add to knowledge of Brazilian children with ADHD and their play preferences. Comparisons are made with research with Australian children with and without ADHD. © 2011 The Authors. Australian Occupational Therapy Journal © 2011 Occupational Therapy Australia.

Event-based prospective memory in mildly and severely autistic children.

PubMed

Sheppard, Daniel P; Kvavilashvili, Lia; Ryder, Nuala

2016-01-01

There is a growing body of research into the development of prospective memory (PM) in typically developing children but research is limited in autistic children (Aut) and rarely includes children with more severe symptoms. This study is the first to specifically compare event-based PM in severely autistic children to mildly autistic and typically developing children. Fourteen mildly autistic children and 14 severely autistic children, aged 5-13 years, were matched for educational attainment with 26 typically developing children aged 5-6 years. Three PM tasks and a retrospective memory task were administered. Results showed that severely autistic children performed less well than typically developing children on two PM tasks but mildly autistic children did not differ from either group. No group differences were found on the most motivating (a toy reward) task. The findings suggest naturalistic tasks and motivation are important factors in PM success in severely autistic children and highlights the need to consider the heterogeneity of autism and symptom severity in relation to performance on event-based PM tasks. Copyright © 2015 Elsevier Ltd. All rights reserved.

A longitudinal study on gross motor development in children with learning disorders.

PubMed

Westendorp, Marieke; Hartman, Esther; Houwen, Suzanne; Huijgen, Barbara C H; Smith, Joanne; Visscher, Chris

2014-02-01

This longitudinal study examined the development of gross motor skills, and sex-differences therein, in 7- to 11-years-old children with learning disorders (LD) and compared the results with typically developing children to determine the performance level of children with LD. In children with LD (n=56; 39 boys, 17 girls), gross motor skills were assessed with the Test of Gross Motor Development-2 and measured annually during a 3-year period. Motor scores of 253 typically developing children (125 boys, 112 girls) were collected for references values. The multilevel analyses showed that the ball skills of children with LD improved with age (p<.001), especially between 7 and 9 years, but the locomotor skills did not (p=.50). Boys had higher ball skill scores than girls (p=.002) and these differences were constant over time. Typically developing children outperformed the children with LD on the locomotor skills and ball skills at all ages, except the locomotor skills at age 7. Children with LD develop their ball skills later in the primary school-period compared to typically developing peers. However, 11 year-old children with LD had a lag in locomotor skills and ball skills of at least four and three years, respectively, compared to their peers. Copyright © 2013 Elsevier Ltd. All rights reserved.

A Comparison of the Development of Audiovisual Integration in Children with Autism Spectrum Disorders and Typically Developing Children

ERIC Educational Resources Information Center

Taylor, Natalie; Isaac, Claire; Milne, Elizabeth

2010-01-01

This study aimed to investigate the development of audiovisual integration in children with Autism Spectrum Disorder (ASD). Audiovisual integration was measured using the McGurk effect in children with ASD aged 7-16 years and typically developing children (control group) matched approximately for age, sex, nonverbal ability and verbal ability.…

Automated Vocal Analysis of Children with Hearing Loss and Their Typical and Atypical Peers

PubMed Central

VanDam, Mark; Oller, D. Kimbrough; Ambrose, Sophie E.; Gray, Sharmistha; Richards, Jeffrey A.; Xu, Dongxin; Gilkerson, Jill; Silbert, Noah H.; Moeller, Mary Pat

2014-01-01

Objectives This study investigated automatic assessment of vocal development in children with hearing loss as compared with children who are typically developing, have language delays, and autism spectrum disorder. Statistical models are examined for performance in a classification model and to predict age within the four groups of children. Design The vocal analysis system analyzed over 1900 whole-day, naturalistic acoustic recordings from 273 toddlers and preschoolers comprising children who were typically developing, hard of hearing, language delayed, or autistic. Results Samples from children who were hard-of-hearing patterned more similarly to those of typically-developing children than to the language-delayed or autistic samples. The statistical models were able to classify children from the four groups examined and estimate developmental age based on automated vocal analysis. Conclusions This work shows a broad similarity between children with hearing loss and typically developing children, although children with hearing loss show some delay in their production of speech. Automatic acoustic analysis can now be used to quantitatively compare vocal development in children with and without speech-related disorders. The work may serve to better distinguish among various developmental disorders and ultimately contribute to improved intervention. PMID:25587667

Prosodic skills in children with Down syndrome and in typically developing children.

PubMed

Zampini, Laura; Fasolo, Mirco; Spinelli, Maria; Zanchi, Paola; Suttora, Chiara; Salerni, Nicoletta

2016-01-01

Many studies have analysed language development in children with Down syndrome to understand better the nature of their linguistic delays and the reason why these delays, particularly those in the morphosyntactic area, seem greater than their cognitive impairment. However, the prosodic characteristics of language development in children with Down syndrome have been scarcely investigated. To analyse the prosodic skills of children with Down syndrome in the production of multi-word utterances. Data on the prosodic skills of these children were compared with data on typically developing children matched on developmental age and vocabulary size. Between-group differences and the relationships between prosodic and syntactic skills were investigated. The participants were nine children with Down syndrome (who ranged in chronological age from 45 to 63 months and had a mean developmental age of 30 months) and 12 30-month-old typically developing children. The children in both groups had a vocabulary size of approximately 450 words. The children's spontaneous productions were recorded during observations of mother-child play sessions. Data analyses showed that despite their morphosyntactic difficulties, children with Down syndrome were able to master some aspects of prosody in multi-word utterances. They were able to produce single intonation multi-word utterances on the same level as typically developing children. In addition, the intonation contour of their utterances was not negatively influenced by syntactic complexity, contrary to what occurred in typically developing children, although it has to be considered that the utterances produced by children with Down syndrome were less complex than those produced by children in the control group. However, children with Down syndrome appeared to be less able than typically developing children to use intonation to express the pragmatic interrogative function. The findings are discussed considering the effects of social experience on the utterance prosodic realization. © 2015 Royal College of Speech and Language Therapists.

[A comparative study on psychological and behavioral development in children aged 1 to 3 years fostered by grandparents and by parents].

PubMed

Wang, Ping; Song, Pu; Chen, Cai-Ping; Liang, Juan; Jian, Fang-Fang; Zhang, Jin-Bao

2009-12-01

To investigate the differences of psychological and behavioral development between children aged 1 to 3 years fostered by grandparents and those by parents. Psychological and behavioral development of 443 children aged 1 to 3 years fostered by their grandparents and of aged-matched 443 children fostered by their parents were assessed with DST, an intellectual developmental screening test developed by Pediatric Hospital of Fudan University in Shanghai. The abilities of social adaptation and intelligence development in children fostered by their grandparents were obviously retarded as compared with those in children fostered by their parents. There are shortcomings in psychological and behavioral development in children aged 1 to 3 years fostered by grandparents.

The Development of Individual Styles in Children's Drawing.

ERIC Educational Resources Information Center

Watson, Malcolm W.; Schwartz, Susan Nozyce

2000-01-01

Investigated the development of individual style in 3- to 10-year-old children's drawings. Assessed about one-third of children as having distinctive styles; these children were most frequently younger and showed higher aesthetic and creativity ratings in their drawings. Considered the probable sequence in children's development of artistic style.…

[Characteristics of growth and development in children from families at social risk].

PubMed

Stojadinović, A

2001-01-01

Body height and weight are important indicators of children's health status. There are many evidences that children from disadvantaged families have lower height and weight than children of the same age from families without social risk. The aim of this study was to investigate characteristics of growth and development of children from economically disadvantaged families. The study was partly retrospective and partly prospective. The retrospective study included 509 children from disadvantaged families hospitalized at the Institute of Child and Adolescent Health Care in Novi Sad, during a five-year period. The prospective study included 90 children from disadvantaged families (experimental group) and 132 children from families without social risk (control group) hospitalized at the Institute during a six month period. Height/length, weight, head circumference, and psychomotor/intellectual development have been examined. In the retrospective study results were compared with theoretically expected values, whereas the prospective study results of experimental and control group were compared. In the retrospective study that included only children from disadvantaged families, 136 (26.7%) children had height/length, 173 (34%) had weight, and 86 (16.9%) children had head circumference below 10th percentile. Delay in psychomotor/intellectual development was established in 177 (34.8%) children. Children from families with social risk have significantly more often height/length, weight, head circumference and developmental delay than theoretically expected. In the prospective study 40 (44.4%) children from experimental group had height/length, 29 (32.2%) had weight, 20 (22.2%) children had head circumference below 10th percentile, and 17 (26.2%) had delay in psychomotor/intellectual development. Children from disadvantaged families (experimental group) significantly more often had delay in growth and development comparing with children from families without social risk (control group). Children from disadvantaged families significantly more often exhibit delay in growth and development, comparing with children of the same age from families without social risk. Therefore, pediatricians should consider social risk factors whenever treating children with growth or developmental delay.

Restricted Arm Swing Affects Gait Stability and Increased Walking Speed Alters Trunk Movements in Children with Cerebral Palsy

PubMed Central

Delabastita, Tijs; Desloovere, Kaat; Meyns, Pieter

2016-01-01

Observational research suggests that in children with cerebral palsy, the altered arm swing is linked to instability during walking. Therefore, the current study investigates whether children with cerebral palsy use their arms more than typically developing children, to enhance gait stability. Evidence also suggests an influence of walking speed on gait stability. Moreover, previous research highlighted a link between walking speed and arm swing. Hence, the experiment aimed to explore differences between typically developing children and children with cerebral palsy taking into account the combined influence of restricting arm swing and increasing walking speed on gait stability. Spatiotemporal gait characteristics, trunk movement parameters and margins of stability were obtained using three dimensional gait analysis to assess gait stability of 26 children with cerebral palsy and 24 typically developing children. Four walking conditions were evaluated: (i) free arm swing and preferred walking speed; (ii) restricted arm swing and preferred walking speed; (iii) free arm swing and high walking speed; and (iv) restricted arm swing and high walking speed. Double support time and trunk acceleration variability increased more when arm swing was restricted in children with bilateral cerebral palsy compared to typically developing children and children with unilateral cerebral palsy. Trunk sway velocity increased more when walking speed was increased in children with unilateral cerebral palsy compared to children with bilateral cerebral palsy and typically developing children and in children with bilateral cerebral palsy compared to typically developing children. Trunk sway velocity increased more when both arm swing was restricted and walking speed was increased in children with bilateral cerebral palsy compared to typically developing children. It is proposed that facilitating arm swing during gait rehabilitation can improve gait stability and decrease trunk movements in children with cerebral palsy. The current results thereby partly support the suggestion that facilitating arm swing in specific situations possibly enhances safety and reduces the risk of falling in children with cerebral palsy. PMID:27471457

Parenting stress and affective symptoms in parents of autistic children.

PubMed

Gong, Yun; Du, YaSong; Li, HuiLin; Zhang, XiYan; An, Yu; Wu, Bai-Lin

2015-10-01

We examined parenting stress and mental health status in parents of autistic children and assessed factors associated with such stress. Participants were parents of 188 autistic children diagnosed with DSM-IV criteria and parents of 144 normally developing children. Parents of autistic children reported higher levels of stress, depression, and anxiety than parents of normally developing children. Mothers of autistic children had a higher risk of depression and anxiety than that did parents of normally developing children. Mothers compared to fathers of autistic children were more vulnerable to depression. Age, behavior problems of autistic children, and mothers' anxiety were significantly associated with parenting stress.

Attainment of gross motor milestones in children with Down syndrome in Kosovo - developmental perspective.

PubMed

Beqaj, Samire; Jusaj, Njomza; Živković, Vujica

2017-08-01

Aim To investigate the age (in months) at which motor skills are developed in children with Down syndrome (DS), and compare it to the age of the development of the same skills in both, children with typical development (TD), and children with DS reported by four other studies. Methods Sixteen children (7 girls and 9 boys) were monthly assessed for the development of nineteen motor skills between 2008 and 2011. The mean ages when the skills were accomplished were presented using descriptive statistics. Independent T-samples test (significance < 0.05) was used to compare the mean developmental ages from our study with those seen in children with TD (Comparison 1) and also in children with DS reported by four other authors (Comparison 2a-2d). Results Children with DS developed at a significantly slower pace compared to children with TD (p=0.005). Generally, delay and variance of developmental age in children with DS increased chronologically with the complexity of the skills. No significant difference was found between developmental age in children from the present study and children with DS from other studies. Conclusion The rate of attainment of motor skills is delayed in children with DS in comparison to children with TD, however, the developmental sequence is the same. The delayed development is more prominent in more complex skills. Copyright© by the Medical Assotiation of Zenica-Doboj Canton.

Auditory, speech and language development in young children with cochlear implants compared with children with normal hearing.

PubMed

Schramm, Bianka; Bohnert, Andrea; Keilmann, Annerose

2010-07-01

This study had two aims: (1) to document the auditory and lexical development of children who are deaf and received the first cochlear implant (CI) by the age of 16 months and the second CI by the age of 31 months and (2) to compare these children's results with those of children with normal hearing (NH). This longitudinal study included five children with NH and five with sensorineural deafness. All children of the second group were observed for 36 months after the first fitting of the device (cochlear implant). The auditory development of the CI group was documented every 3 months up to the age of two years in hearing age and chronological age and for the NH group in chronological age. The language development of each NH child was assessed at 12, 18, 24 and 36 months of chronological age. Children with CIs were examined at the same age intervals at chronological and hearing age. In both groups, children showed individual patterns of auditory and language development. The children with CIs developed differently in the amount of receptive and expressive vocabulary compared with the NH control group. Three children in the CI group needed almost 6 months to make gains in speech development that were consistent with what would be expected for their chronological age. Overall, the receptive and expressive development in all children of the implanted group increased with their hearing age. These results indicate that early identification and early implantation is advisable to give children with sensorineural hearing loss a realistic chance to develop satisfactory expressive and receptive vocabulary and also to develop stable phonological, morphological and syntactical skills for school life. On the basis of these longitudinal data, we will be able to develop new diagnostic tools that enable clinicians to assess child's progress in hearing and speech development. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.

The interrelationships between motor, cognitive, and language development in children with and without intellectual and developmental disabilities.

PubMed

Houwen, Suzanne; Visser, Linda; van der Putten, Annette; Vlaskamp, Carla

2016-01-01

It is generally agreed that cognitive and language development are dependent on the emergence of motor skills. As the literature on this issue concerning children with developmental disabilities is scarce, we examined the interrelationships between motor, cognitive, and language development in children with intellectual and developmental disabilities (IDD) and compared them to those in children without IDD. In addition, we investigated whether these relationships differ between children with different levels of cognitive delay. Seventy-seven children with IDD (calendar age between 1;0 and 9;10 years; mean developmental age: 1;8 years) and 130 typically developing children (calendar age between 0;3 and 3;6 years; mean developmental age: 1;10 years) were tested with the Dutch Bayley Scales of Infant and Toddler Development, Third Edition, which assesses development across three domains using five subscales: fine motor development, gross motor development (motor), cognition (cognitive), receptive communication, and expressive communication (language). Results showed that correlations between the motor, cognitive, and language domains were strong, namely .61 to .94 in children with IDD and weak to strong, namely .24 to .56 in children without IDD. Furthermore, the correlations showed a tendency to increase with the severity of IDD. It can be concluded that both fine and gross motor development are more strongly associated with cognition, and consequently language, in children with IDD than in children without IDD. The findings of this study emphasize the importance of early interventions that boost both motor and cognitive development, and suggest that such interventions will also enhance language development. Copyright © 2016 Elsevier Ltd. All rights reserved.

Thoughts on the nature of identity: disorders of sex development and gender identity.

PubMed

Reiner, William G; Reiner, D Townsend

2011-10-01

Children with disorders of sex development have similarities to, but also marked contrasts with, children with normal anatomy but who have gender dysphoria. Understanding gender identity development in children with sex disorders will probably help us understand typical gender identity development more than in understanding gender development in children with gender identity disorder.

Psychosexual Development in Infants and Young Children: Implications for Caregivers.

ERIC Educational Resources Information Center

Honig, Alice Sterling

Psychosexual development in young children is a topic that early childhood educators often ignore in the belief that children are not sexual beings. This paper discusses psychosexual development in young children, noting that preschoolers are often puzzled by sexual anatomical differences, that children need names for sexual body parts, and that…

Social Experience and the Development of Social Cognition in Orthopedically Disabled and Non Disabled Children.

ERIC Educational Resources Information Center

Volpe, Richard

Evaluated were the cognitive and social development of 40 orthopedially handicapped children ages 6 to 12 years. Social development was measured by the Children's Social Relations Rating Scale, the Children's Social Relations Interview Schedule, and the Children's Role Taking Task. The Concrete Operations Tasks assessed cognitive ability. Data…

Vocal and Gestural Productions of 24-Month-Old Children with Sex Chromosome Trisomies

ERIC Educational Resources Information Center

Zampini, Laura; Draghi, Lara; Silibello, Gaia; Dall'Ara, Francesca; Rigamonti, Claudia; Suttora, Chiara; Zanchi, Paola; Salerni, Nicoletta; Lalatta, Faustina; Vizziello, Paola

2018-01-01

Background: Children with sex chromosome trisomies (SCT) frequently show problems in language development. However, a clear description of the communicative patterns of these children is still lacking. Aims: To describe the first stages of language development in children with SCT in comparison with those in typically developing (TD) children. The…

77 FR 36264 - Applications for New Awards; Personnel Development To Improve Services and Results for Children...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-18

... improve professional development for personnel working with infants, toddlers, and preschool children with... development system so that all personnel providing services to infants, toddlers, and preschool children with... professional development system for personnel working with infants, toddlers, and preschool children with...

Internationally adopted children from non-European countries: general development during the first two years in the adoptive family.

PubMed

Dalen, Monica; Theie, Steinar

2012-01-01

Internationally adopted children are often delayed in their development and demonstrate more behaviour problems than nonadopted children due to adverse preadoption circumstances. This is especially true for children adopted from Eastern European countries. Few studies have focused on children adopted from non-European countries. This paper presents results from an ongoing longitudinal study of 119 internationally adopted children from non-European countries during their first two years in Norway. Several scales measuring different aspects of the children's development are included in the study: communication and gross motor development, temperamental characteristics, and behaviour problems. The results show that internationally adopted children are delayed in their general development when they first arrive in their adoptive families. After two years the children have made significant progress in development. However, they still lag behind in communication and motor skills compared to non-adopted children. The temperamental characteristics seem very stable from time of adoption until two years after adoption. The children demonstrate a low frequency of behaviour problems. However, the behaviour problems have changed during the two years. At time of adoption they show more nonphysically challenging behaviour while after two years their physically challenging behaviour has increased.

Nutritional and socioeconomic status in cognitive development of Santal children of Purulia district, India.

PubMed

Chowdhury, Sutanu Dutta; Ghosh, Tusharkanti

2011-03-01

Cognitive development of children depends on nutritional and socioeconomic factors. The objectives of the present study were to assess the cognitive development and to investigate the relationship of nutritional and socioeconomic status (SES) to cognitive development in 5-12 year old Santal children of Purulia district of West Bengal, India. The nutritional status of each child was assessed by z-score of height-for-age, weight-for-height and weight-for-age parameters. SES was measured using the updated Kuppusswami scale. Cognitive development was measured by Raven's Coloured Progressive Matrices (RCPM). The growth curve of RCPM scores of Santal children remained around the 5(th) percentile values of British children. The RCPM scores of the adequately nourished children and upper-lower SES were significantly higher (p < 0.05) than the children with lower SES and nutritional status. About 42.96% and 27.69% of Santal children were found to be in the intellectually deficient and below average groups, respectively. RCPM scores of Santal children were significantly correlated with nutritional status and socioeconomic factors (p < 0.01). The surveyed children showed poor cognitive functions. The vulnerable nutritional and socioeconomic statuses of Santal children are the major causes for their poor cognitive development.

Participation of Children with Intellectual Disability Compared with Typically Developing Children

ERIC Educational Resources Information Center

King, Matthew; Shields, Nora; Imms, Christine; Black, Monique; Ardern, Clare

2013-01-01

We compared participation in out-of-school activities between children with intellectual disability and children with typical development using the Children's Assessment of Participation and Enjoyment and Preferences for Activities of Children questionnaires. Thirty-eight pairs of children were matched for age (mean age 12.3 plus or minus 2.7…

Comparing Levels of Mastery Motivation in Children with Cerebral Palsy (CP) and Typically Developing Children.

PubMed

Salavati, Mahyar; Vameghi, Roshanak; Hosseini, Seyed Ali; Saeedi, Ahmad; Gharib, Masoud

2018-02-01

The present study aimed to compare motivation in school-age children with CP and typically developing children. 229 parents of children with cerebral palsy and 212 parents of typically developing children participated in the present cross sectional study and completed demographic and DMQ18 forms. The rest of information was measured by an occupational therapist. Average age was equal to 127.12±24.56 months for children with cerebral palsy (CP) and 128.08±15.90 for typically developing children. Independent t-test used to compare two groups; and Pearson correlation coefficient by SPSS software applied to study correlation with other factors. There were differences between DMQ subscales of CP and typically developing groups in terms of all subscales ( P <0.05). The lowest motivation scores of subscales obtained in gross motor persistence (2.4870±.81047) and cognitive-oriented persistence (2.8529±.84223) in children with CP. Motivation was correlated with Gross Motor function Classification System (r= -0.831, P<0.001), Manual ability classification system (r=-0.782, P<0.001) and cognitive impairment (r=-0.161, P<0.05). Children with CP had lower mastery motivation than typically developing children. Rehabilitation efforts should take to enhance motivation, so that children felt empowered to do tasks or practices.

Parents' Translations of Child Gesture Facilitate Word Learning in Children with Autism, Down Syndrome and Typical Development

PubMed Central

Dimitrova, Nevena; Özçalışkan, Şeyda; Adamson, Lauren B.

2016-01-01

Typically-developing (TD) children frequently refer to objects uniquely in gesture. Parents translate these gestures into words, facilitating children's acquisition of these words (Goldin-Meadow et al., 2007). We ask whether this pattern holds for children with autism (AU) and with Down syndrome (DS) who show delayed vocabulary development. We observed 23 children with ASD, 23 with DS, and 23 TD children with their parents over a year. Children used gestures to indicate objects before labeling them and parents translated their gestures into words. Importantly, children benefited from this input, acquiring more words for the translated gestures than the not translated ones. Results highlight the role contingent parental input to child gesture plays in language development of children with developmental disorders. PMID:26362150

A comparison of the function, activity and participation and quality of life between down syndrome children and typically developing children.

PubMed

Jung, Hee-Kyoung; Chung, EunJung; Lee, Byoung-Hee

2017-08-01

[Purpose] To compare function, activity, participation, and quality of life of Down syndrome children and typically developing children according to age. [Subjects and Methods] A total of 16 Down syndrome children and 20 children with typical development were included as subjects for this study. International Classification of Functioning, Disability, and Health (ICF) Child and Youth version (CY) developed by the World Health Organization (WHO) and a questionnaire were used to measure children's functioning, activity, and participation. To measure quality of life, KIDSCREEN 52-HRQOL questionnaire was used in this study. [Results] ICF-CY function, activity, participation, and quality of life showed statistically significant differences between Down syndrome children and typically developing children. Down syndrome children with higher functions showed higher activities and participation. Higher function, activity and participation features were correlated with better quality of life. Higher function resulted in better quality of life. [Conclusion] Function, activity, participation, quality of life, and several common factors of Down syndrome children depend on the ability of children. Function of Down syndrome children affects their activity, participation, and quality of life. Activities and participations also affect quality of life. Therefore, children's functional aspect is the foundation for quality of life.

[Association between family environment and developmental coordination disorder in preschool children].

PubMed

Liu, Li-Fei; Lu, Lan; Yue, Hong-Ni; Huan, Bei; Gu, Gui-Xiong; Jin, Hua; Wang, Yu-Mei

2017-09-01

To investigate the influence of family environment on developmental coordination disorder (DCD) in preschool children. Stratified random cluster sampling was used to select 1 727 children (4-6 years old). The Movement Assessment Battery for Children was used to screen out the children with DCD. The Family Environment Scale on Motor Development for Preschool Urban Children and a self-designed questionnaire were used to assess family environment. A total of 117 children were confirmed with DCD. There were significant differences in mother's education level and family structure between the DCD and normal control groups. There were also significant differences in the scores of "Let children manage their daily items" and "Arrange all affairs" between the DCD and normal control groups. The multivariate logistic regression analysis indicated that when children's age and gender were controlled, mother's education level, family structure, "Let children manage their daily items", and "Arrange all affairs" were main factors influencing the development of DCD in children (P<0.05). Family environment may affect the development of DCD in preschool children. Therefore, parents should not arrange all affairs for children and should provide more opportunities for children to manage their daily life, in order to promote the development of early motor coordination and prevent the development of DCD.

Early-, middle-, and late-developing sounds in monolingual and bilingual children: an exploratory investigation.

PubMed

Fabiano-Smith, Leah; Goldstein, Brian A

2010-02-01

To examine the accuracy of early-, middle-, and late-developing (EML) sounds in Spanish-English bilingual children and their monolingual peers. Twenty-four typically developing children, age 3-4 years, were included in this study: 8 bilingual Spanish-English-speaking children, 8 monolingual Spanish speakers, and 8 monolingual English speakers. Single-word speech samples were obtained to examine (a) differences on the accuracy of EML sounds between Spanish-English bilingual children and monolingual Spanish and monolingual English children and (b) the developmental trend on the accuracy of EML sounds within languages for Spanish-English bilingual children and monolingual Spanish and monolingual English children. Findings support those of Shriberg (1993) for English-speaking children and suggest possible EML categories for monolingual Spanish-speaking children and bilingual Spanish-English-speaking children. These exploratory findings indicate the need for longitudinal examination of EML categories with a larger cohort of children to observe similarities and differences between monolingual and bilingual development.

Similarities and differences between internationally adopted and nonadopted children in their toddler years: Outcomes from a longitudinal study.

PubMed

Dalen, Monica; Theie, Steinar

2014-07-01

In this study, we compare internationally adopted children's communication, gross motor development, temperament, and challenging behavior with the same characteristics in nonadopted children at age 24 and 36 months. At 24 months, adopted children lag behind in communication and in gross motor development. The adopted children are less active and show less physically challenging behavior. At age 36 months, most of these differences have diminished, but the adopted children still lag behind in communication. This is an important finding because communication skills in the toddler years are a crucial factor in children's attachment, social development, and later language and cognitive development. Looking at the overall outcomes during early toddler years, internationally adopted children are developing very well considering the preadoption adversity to which many of them have been exposed.

Development in Reading and Math in Children from Different SES Backgrounds: The Moderating Role of Child Temperament

ERIC Educational Resources Information Center

Wang, Zhe; Soden, Brooke; Deater-Deckard, Kirby; Lukowski, Sarah L.; Schenker, Victoria J.; Willcutt, Erik G.; Thompson, Lee A.; Petrill, Stephen A.

2017-01-01

Socioeconomic risks (SES risks) are robust risk factors influencing children's academic development. However, it is unclear whether the effects of SES on academic development operate universally in all children equally or whether they vary differentially in children with particular characteristics. The current study aimed to explore children's…

Humour among Chinese and Greek Preschool Children in Relation to Cognitive Development

ERIC Educational Resources Information Center

Guo, Juan; Zhang, XiangKui; Wang, Yong; Xeromeritou, Aphrodite

2011-01-01

The researchers studied humour among Chinese and Greek preschool children in relation to cognitive development. The sample included 55 Chinese children and 50 Greek children ages 4½ to 5½ years. Results showed that both Chinese and Greek children's humour recognition were significantly and positively correlated to their cognitive development, but…

The Development of Vocabulary in Spanish Children with Down Syndrome: Comprehension, Production, and Gestures

ERIC Educational Resources Information Center

Galeote, Miguel; Sebastian, Eugenia; Checa, Elena; Rey, Rocio; Soto, Pilar

2011-01-01

Background: Our main purpose was to compare the lexical development of Spanish children with Down syndrome (DS) and children with typical development (TD) to investigate the relationship between cognitive and vocabulary development in comprehension and oral and gestural production. Method: Participants were 186 children with DS and 186 children…

Case Study of Teen Mothers' Perceptions of Their Influence on Preschoolers' Language Development

ERIC Educational Resources Information Center

Duncan, Mary

2016-01-01

Children born to teen mothers tend to score lower on language development assessments and to have school readiness delays. To support teen mothers and their children in improving language development, educators need information about mothers' daily interactions with their children and how they contribute to their children's language development.…

Maternal and paternal pragmatic speech directed to young children with Down syndrome and typical development

PubMed Central

de Falco, Simona; Venuti, Paola; Esposito, Gianluca; Bornstein, Marc H.

2011-01-01

The aim of this study was to compare functional features of maternal and paternal speech directed to children with Down syndrome and developmental age-matched typically developing children. Altogether 88 parents (44 mothers and 44 fathers) and their 44 young children (22 children with Down syndrome and 22 typically developing children) participated. Parents’ speech directed to children was obtained through observation of naturalistic parent–child dyadic interactions. Verbatim transcripts of maternal and paternal language were categorized in terms of the primary function of each speech unit. Parents (both mothers and fathers) of children with Down syndrome used more affect-salient speech compared to parents of typically developing children. Although parents used the same amounts of information-salient speech, parents of children with Down syndrome used more direct statements and asked fewer questions than did parents of typically developing children. Concerning parent gender, in both groups mothers used more language than fathers and specifically more descriptions. These findings held controlling for child age and MLU and family SES. This study highlights strengths and weaknesses of parental communication to children with Down syndrome and helps to identify areas of potential improvement through intervention. PMID:21215458

Maternal and paternal pragmatic speech directed to young children with Down syndrome and typical development.

PubMed

de Falco, Simona; Venuti, Paola; Esposito, Gianluca; Bornstein, Marc H

2011-02-01

The aim of this study was to compare functional features of maternal and paternal speech directed to children with Down syndrome and developmental age-matched typically developing children. Altogether 88 parents (44 mothers and 44 fathers) and their 44 young children (22 children with Down syndrome and 22 typically developing children) participated. Parents' speech directed to children was obtained through observation of naturalistic parent-child dyadic interactions. Verbatim transcripts of maternal and paternal language were categorized in terms of the primary function of each speech unit. Parents (both mothers and fathers) of children with Down syndrome used more affect-salient speech compared to parents of typically developing children. Although parents used the same amounts of information-salient speech, parents of children with Down syndrome used more direct statements and asked fewer questions than did parents of typically developing children. Concerning parent gender, in both groups mothers used more language than fathers and specifically more descriptions. These findings held controlling for child age and MLU and family SES. This study highlights strengths and weaknesses of parental communication to children with Down syndrome and helps to identify areas of potential improvement through intervention. Copyright © 2010 Elsevier Inc. All rights reserved.

Context and sequelae of food insecurity in children's development.

PubMed

Belsky, Daniel W; Moffitt, Terrie E; Arseneault, Louise; Melchior, Maria; Caspi, Avshalom

2010-10-01

The authors examined the role of food insecurity in the etiology of children's cognitive and mental health problems. Data from a prospective longitudinal study of 1,116 United Kingdom families with twins (sample constructed in 1999-2000) were used to test associations among household food insecurity; income; maternal personality; household sensitivity to children's needs; and children's cognitive, behavioral, and emotional development. Food-insecure children had lower IQs and higher levels of behavioral and emotional problems relative to their peers. After differences in household income, the personalities of children's mothers, and the sensitivity of household organization to children's needs were accounted for, food-insecure children had moderately higher levels of emotional problems relative to food-secure children (β = 0.22, P = 0.02). Differences in children's cognitive development were accounted for by household income, and differences in their behavioral development were accounted for by their mothers' personalities and their households' sensitivity to children's needs. Results suggest that food insecurity was associated with school-aged children's emotional problems but not with their cognitive or behavioral problems after accounting for differences in the home environments in which children were reared. Mothers' personality and household sensitivity to children's needs may present challenges to improving outcomes of children with food insecurity.

Memory Profiles in Children with Mild Intellectual Disabilities: Strengths and Weaknesses

ERIC Educational Resources Information Center

Van der Molen, Mariet J.; Van Luit, Johannes E. H.; Jongmans, Marian J.; Van der Molen, Maurits W.

2009-01-01

Strengths and weaknesses in short-term memory (STM) and working memory (WM) were identified in children with mild intellectual disabilities (MID) by comparing their performance to typically developing children matched on chronological age (CA children) and to younger typically developing children with similar mental capacities (MA children).…

Parents' Translations of Child Gesture Facilitate Word Learning in Children with Autism, Down Syndrome and Typical Development.

PubMed

Dimitrova, Nevena; Özçalışkan, Şeyda; Adamson, Lauren B

2016-01-01

Typically-developing (TD) children frequently refer to objects uniquely in gesture. Parents translate these gestures into words, facilitating children's acquisition of these words (Goldin-Meadow et al. in Dev Sci 10(6):778-785, 2007). We ask whether this pattern holds for children with autism (AU) and with Down syndrome (DS) who show delayed vocabulary development. We observed 23 children with AU, 23 with DS, and 23 TD children with their parents over a year. Children used gestures to indicate objects before labeling them and parents translated their gestures into words. Importantly, children benefited from this input, acquiring more words for the translated gestures than the not translated ones. Results highlight the role contingent parental input to child gesture plays in language development of children with developmental disorders.

Anthropometric data peculiarities in early school children population.

PubMed

Jorjoliani, L; Karseladze, R; Vekua, M; Chkhartishvili, E; Bigvava, T

2011-01-01

The anthropometric data were studied in early school aged (6-7 years old) children and the degree of harmonization during physical development was evaluated. Representative population of 400 otherwise healthy early school aged children was included in study group. Study period covered the end of school year. In the selected under observation focused population the level of individual anthropometric data was determined in percentile intervals according its position. Anthropometric data assessments by using percentile method it was revealed in early school aged (6-7 years of old children) excess in body height and weight in comparison with normal values. This phenomenon indicates the prevalence of acceleration and weight gain. Anthropometric data in boys were increased while comparing with physical development data in girls. This result difference has the tendency to statistically insignificant. Physical development harmonization values were studied in 200 children. Harmonized physical development revealed in 50 children (25%); disharmonized physical development I 50 children (15%), among them with I degree weight gain were 48 (24%), and with I degree weight deficit were 2 (1%). Markedly disharmonized development had 100 children (50%), among them with II degree weight gain were 98 (49%), and with II degree weight deficit were 2 (1%). According to the children's anthropometric data and assessment by physical development harmonization percentiles tables three groups of children were organized: main, risk group and the group with deviation in physical development. On the basis of resulted data the study of early school age children's physical development gives possibility for risk groups stratification, which in turn itself makes a strong basis for reasonable preventive measurements and stepwise monitoring implementation.

The impact of wealth on the cognitive development of children who were preterm infants.

PubMed

Braid, Susan; Donohue, Pamela K; Strobino, Donna M

2012-08-01

: The purpose of this study was to explore the influence wealth has on cognitive development in 2-year-old children who were born preterm, and to determine whether racial/ethnic differences in wealth explained disparities in cognitive development. : A nationally representative sample of 1400 children who were born between 22 and 36 weeks' gestation. : Cohort study. : Secondary data analysis of the Early Childhood Longitudinal Survey-Birth Cohort (ECLS-B). The ECLS-B was a prospective national longitudinal study of infants born in the United States during the calendar year 2001 drawn from birth certificates in the United States. : The impact wealth (parental homeownership and investments) had on cognitive development at 2 years and whether wealth eliminated the cognitive disparity seen between white, African American, and Hispanic children. : Wealth (homeownership and investments) did not have an independent effect on cognitive development, but it did eliminate the disparity between white children and African American children (P ≥ .05). However, wealth did not eliminate the disparity in cognitive development between white children and Hispanic children. Hispanic children scored 3.91 points lower than white children (P ≤ .001). : In contrast to other follow-up studies showing persistent differences in cognitive development between white children and African American children, this study found that wealth indicators attenuated the difference. Wealth may be a more accurate proxy for socioeconomic status in studying factors influencing cognitive outcomes in children born preterm than just using measures such as maternal education and income. In future follow-up studies of multiracial preterm children, indicators that represent wealth should be included for an accurate representation of social economic status.

Time use of parents raising children with severe or profound intellectual and multiple disabilities.

PubMed

Luijkx, J; van der Putten, A A J; Vlaskamp, C

2017-07-01

Raising children with severe or profound intellectual and multiple disabilities (PIMD) is expected to put extreme pressure on parental time use patterns. The aim of this study was to examine the total time use of mothers and fathers raising children with PIMD and compare it with the time use of parents of typically developing children. Twenty-seven fathers and 30 mothers raising children with PIMD completed a time use diary on a mobile phone or tablet app, as did 66 fathers and 109 mothers of typically developing children. Independent t-tests and Mann-Whitney tests were performed to compare mean time use. There are no differences in the time use of parents of children with PIMD on contracted time (paid work and educational activities) and necessary time (personal care, eating and drinking and sleeping) when compared with parents of typically developing children. There are significant differences between the parents of children with PIMD and the parents of typically developing children in terms of committed time (time for domestic work and the care and supervision of their children) and free time. The mothers of children with PIMD spend significantly less time on domestic work and more time on care and supervision than mothers of typically developing children. This study shows that the parents of children with PIMD have to spend a significant amount of time on care tasks and have on average 1.5 h less free time per day than parents of typically developing children. This is a striking difference, because leisure time can substantially contribute to well-being. Therefore, it is important not only to consider a child with PIMD's support needs but also to identify what parents need to continue their children's daily care and supervision. © 2017 John Wiley & Sons Ltd.

Input and language development in bilingually developing children.

PubMed

Hoff, Erika; Core, Cynthia

2013-11-01

Language skills in young bilingual children are highly varied as a result of the variability in their language experiences, making it difficult for speech-language pathologists to differentiate language disorder from language difference in bilingual children. Understanding the sources of variability in bilingual contexts and the resulting variability in children's skills will help improve language assessment practices by speech-language pathologists. In this article, we review literature on bilingual first language development for children under 5 years of age. We describe the rate of development in single and total language growth, we describe effects of quantity of input and quality of input on growth, and we describe effects of family composition on language input and language growth in bilingual children. We provide recommendations for language assessment of young bilingual children and consider implications for optimizing children's dual language development. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Mother-child play in children with Down syndrome and typical development

PubMed Central

Venuti, P.; de Falco, S.; Esposito, G.; Bornstein, Marc H.

2014-01-01

The present study compares child solitary and collaborative play with mother in 21 children with Down syndrome (DS) and 33 mental-age-matched typically developing (TD) children. In solitary play, children with DS showed less exploratory but similar symbolic play compared to TD children. From solitary to collaborative play, children with DS increased their exploratory play attaining the same level as TD children; Pretense significantly increased from solitary to collaborative play only in TD children . Differences between mothers’ play in the two groups mirrored those between their children. Child and mother play in both groups showed similar attunement and synchrony. Mothers contribute to the play development of children with DS through their own adaptation to their children’s limitations and potentialities alike. PMID:19642713

Developmental potential in the first 5 years for children in developing countries

PubMed Central

Grantham-McGregor, Sally; Cheung, Yin Bun; Cueto, Santiago; Glewwe, Paul; Richter, Linda; Strupp, Barbara

2007-01-01

Summary Many children younger than 5 years in developing countries are exposed to multiple risks, including poverty, malnutrition, poor health, and unstimulating home environments, which detrimentally affect their cognitive, motor, and social-emotional development. There are few national statistics on the development of young children in developing countries. We therefore identified two factors with available worldwide data—the prevalence of early childhood stunting and the number of people living in absolute poverty—to use as indicators of poor development. We show that both indicators are closely associated with poor cognitive and educational performance in children and use them to estimate that over 200 million children under 5 years are not fulfilling their developmental potential. Most of these children live in south Asia and sub-Saharan Africa. These disadvantaged children are likely to do poorly in school and subsequently have low incomes, high fertility, and provide poor care for their children, thus contributing to the intergenerational transmission of poverty. PMID:17208643

Role development of nurses for technology-dependent children attending mainstream schools in Japan.

PubMed

Shimizu, Fumie; Suzuki, Machiko

2015-04-01

To describe the role development of nurses caring for medical technology-dependent children attending Japanese mainstream schools. Semi-structured interviews with 21 nurses caring for technology-dependent children were conducted and analyzed using the modified grounded theory approach. Nurses developed roles centered on maintaining technology-dependent children's physical health to support children's learning with each other, through building relationships, learning how to interact with children, understanding the children and the school community, and realizing the meaning of supporting technology-dependent children. These findings support nurses to build relationships of mutual trust with teachers and children, and learn on the job in mainstream schools. © 2015, Wiley Periodicals, Inc.

Constructing an understanding of mind: the development of children's social understanding within social interaction.

PubMed

Carpendale, Jeremy I M; Lewis, Charlie

2004-02-01

Theories of children's developing understanding of mind tend to emphasize either individualistic processes of theory formation, maturation, or introspection, or the process of enculturation. However, such theories must be able to account for the accumulating evidence of the role of social interaction in the development of social understanding. We propose an alternative account, according to which the development of children's social understanding occurs within triadic interaction involving the child's experience of the world as well as communicative interaction with others about their experience and beliefs (Chapman 1991; 1999). It is through such triadic interaction that children gradually construct knowledge of the world as well as knowledge of other people. We contend that the extent and nature of the social interaction children experience will influence the development of children's social understanding. Increased opportunity to engage in cooperative social interaction and exposure to talk about mental states should facilitate the development of social understanding. We review evidence suggesting that children's understanding of mind develops gradually in the context of social interaction. Therefore, we need a theory of development in this area that accords a fundamental role to social interaction, yet does not assume that children simply adopt socially available knowledge but rather that children construct an understanding of mind within social interaction.

Etiology of Childhood Infectious Diarrhea in a Developed Region of China: Compared to Childhood Diarrhea in a Developing Region and Adult Diarrhea in a Developed Region.

PubMed

Wang, Xin; Wang, Jing; Sun, Hao; Xia, Shengli; Duan, Ran; Liang, Junrong; Xiao, Yuchun; Qiu, Haiyan; Shan, Guangliang; Jing, Huaiqi

2015-01-01

In China, great differences in economy, social characteristics and hygiene exist between developing and developed regions. A comparative study of infectious diarrhea between two regions was needed. Three groups of diarrheal patients were collected: children ≤5 year-olds from Beijing (developed region) and Henan Province (developing region), and adults over 18 year-olds from Beijing. A questionnaire was used to survey and feces samples were examined for 16 enteropathogens. We enrolled 1422 children and 1047 adults from developed region and 755 children from developing region. Virus positive rates were 32.98% for children and 23.67% for adults in developed region. The most prevalent pathogen for children was rotavirus whereas for adults was norovirus. Bacterial isolation rates were 13.92% for children from developed region, while 29.14% for children from the developing regions. For the greatest difference, Shigella accounted for 50.79% and was the dominant pathogen in the developing region, whereas in the developed region it was only 1.45%. There was no significant relationship between the local levels of development with diarrheogenic Escherichia coli (DEC) categories. But it was seen the notable differences between the population with different age: enteropathogenic E.coli (EPEC) and enteroaggregative E.coli (EAggEC) were the primary classes of DEC in children from both regions, whereas it was enterotoxigenic E.coli (ETEC) in adults. The symptoms of Shigella and Salmonella infection, such as bloody stools, white blood cells (WBC) and red blood cells (RBC) positivity and fever were similar in children, which may lead to the misidentification. Yersinia enterocolitica and shiga toxin-producing E.coli (STEC) infections were firstly reported in Beijing. There was a large difference in etiology of bacterial diarrhea between children in developing and developed regions of China.

Effects of music therapy in the treatment of children with delayed speech development - results of a pilot study.

PubMed

Gross, Wibke; Linden, Ulrike; Ostermann, Thomas

2010-07-21

Language development is one of the most significant processes of early childhood development. Children with delayed speech development are more at risk of acquiring other cognitive, social-emotional, and school-related problems. Music therapy appears to facilitate speech development in children, even within a short period of time. The aim of this pilot study is to explore the effects of music therapy in children with delayed speech development. A total of 18 children aged 3.5 to 6 years with delayed speech development took part in this observational study in which music therapy and no treatment were compared to demonstrate effectiveness. Individual music therapy was provided on an outpatient basis. An ABAB reversal design with alternations between music therapy and no treatment with an interval of approximately eight weeks between the blocks was chosen. Before and after each study period, a speech development test, a non-verbal intelligence test for children, and music therapy assessment scales were used to evaluate the speech development of the children. Compared to the baseline, we found a positive development in the study group after receiving music therapy. Both phonological capacity and the children's understanding of speech increased under treatment, as well as their cognitive structures, action patterns, and level of intelligence. Throughout the study period, developmental age converged with their biological age. Ratings according to the Nordoff-Robbins scales showed clinically significant changes in the children, namely in the areas of client-therapist relationship and communication. This study suggests that music therapy may have a measurable effect on the speech development of children through the treatment's interactions with fundamental aspects of speech development, including the ability to form and maintain relationships and prosodic abilities. Thus, music therapy may provide a basic and supportive therapy for children with delayed speech development. Further studies should be conducted to investigate the mechanisms of these interactions in greater depth. The trial is registered in the German clinical trials register; Trial-No.: DRKS00000343.

Grammaticality Sensitivity in Children with Early Focal Brain Injury and Children with Specific Language Impairment

ERIC Educational Resources Information Center

Wulfeck, Beverly; Bates, Elizabeth; Krupa-Kwiatkowski, Magda; Saltzman, Danna

2004-01-01

Grammaticality judgments and processing times associated with violation detection were examined in typically developing children, children with focal brain lesions (FL) acquired early in life, and children with specific language impairment (SLI). Grammatical sensitivity in the FL group, while below typically developing children, was above levels…

The Development of Complex Sentence Interpretation in Typically Developing Children Compared with Children with Specific Language Impairments or Early Unilateral Focal Lesions

ERIC Educational Resources Information Center

Dick, Frederic; Wulfeck, Beverly; Krupa-Kwiatkowski, Magda; Bates, Elizabeth

2004-01-01

This study compared sentence comprehension skills in typically developing children 5-17 years of age, children with language impairment (LI) and children with focal brain injuries (FL) acquired in the pre/perinatal period. Participants were asked to process sentences "on-line", choosing the agent in sentences that varied in syntactic complexity…

Child Development: Workshop I.

ERIC Educational Resources Information Center

Ismail, Maznah; And Others

Workshops on child development explored the cognitive development of children, mass media and its effects on children, parenting, the emotional and personality development of children, and educating the exceptional child, including the gifted. The discussion of cognitive development focused on the need to collect information about cognitive…

[Impacts of biological and family factors on lexical and intellectual development in Mandarin-speaking children].

PubMed

Niu, Jie; Chen, Yong-Xiang; Zhu, Li-Qi

2015-07-01

To investigate the impacts of biological factors (age and sex) and family factors (socioeconomic status and parenting style) on the early lexical and intellectual development of children in a longitudinal tracking study. A total of 38 Mandarin-speaking children aged from 18 to 24 months were surveyed using the Putonghua Chinese Communicative Development Inventory (PCDI), the Ages and Stages Questionnaire (ASQ), and a self-designed Questionnaire for Parents. All of the subjects were retested using PCDI and ASQ after 6 months. Biological factors accounted for 65% of the variance in lexical development, 10% of which was attributed to gender, in the first survey. After six months, the contribution of age decreased to 26% and gender had no significant impact. Lexical development could positively predict the intellectual development of children. When age and gender were controlled, it accounted for 22% of the variance in intellectual development. Family socioeconomic factors had no significant impacts on lexical and intellectual development. Children's recognition of people and objects around them with guidance of parents in parenting styles could positively predict the intellectual development of children six months later, which accounted for 10% of the variance. Biological factors play an important role in the early lexical development of children. However, the influence decreases with the increase of age (months). Biological factors, lexical development, and parenting style have a combined influence on children's intellectual development.

Fundamental movement skills and physical activity among children with and without cerebral palsy.

PubMed

Capio, Catherine M; Sit, Cindy H P; Abernethy, Bruce; Masters, Rich S W

2012-01-01

Fundamental movement skills (FMS) proficiency is believed to influence children's physical activity (PA), with those more proficient tending to be more active. Children with cerebral palsy (CP), who represent the largest diagnostic group treated in pediatric rehabilitation, have been found to be less active than typically developing children. This study examined the association of FMS proficiency with PA in a group of children with CP, and compared the data with a group of typically developing children. Five FMS (run, jump, kick, throw, catch) were tested using process- and product-oriented measures, and accelerometers were used to monitor PA over a 7-day period. The results showed that children with CP spent less time in moderate to vigorous physical activity (MVPA), but more time in sedentary behavior than typically developing children. FMS proficiency was negatively associated with sedentary time and positively associated with time spent in MVPA in both groups of children. Process-oriented FMS measures (movement patterns) were found to have a stronger influence on PA in children with CP than in typically developing children. The findings provide evidence that FMS proficiency facilitates activity accrual among children with CP, suggesting that rehabilitation and physical education programs that support FMS development may contribute to PA-related health benefits. Copyright © 2012 Elsevier Ltd. All rights reserved.

Comic strips help children understand medical research: targeting the informed consent procedure to children's needs.

PubMed

Grootens-Wiegers, Petronella; de Vries, Martine C; van Beusekom, Mara M; van Dijck, Laura; van den Broek, Jos M

2015-04-01

Children involved in medical research often fail to comprehend essential research aspects. In order to improve information provision, a participatory approach was used to develop new information material explaining essential concepts of medical research. A draft of a comic strip was developed by a science communicator in collaboration with pediatricians. The draft was presented to children participating in a clinical trial and to two school classes. Children were consulted for further development in surveys and interviews. Subsequently, the material was revised and re-evaluated in four school classes with children of varying ages and educational levels. In the first evaluation, children provided feedback on the storyline, wording and layout. Children thought the comic strip was 'fun' and 'informative'. Understanding of 8 basic research aspects was on average 83% and all above 65%, illustrating that children understood and remembered key messages. A comic strip was developed to support the informed consent process. Children were consulted and provided feedback. The resulting material was well understood and accepted. Involving children in the development of information material can substantially contribute to the quality of the material. Children were excited to participate and to 'be a part of science'. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Theory of mind understanding and empathic behavior in children with autism spectrum disorders.

PubMed

Peterson, Candida

2014-12-01

This paper begins with a review of past research on theory of mind and empathy in children with ASD. Using varied operational definitions of empathy ranging from physiological heart rate through story vignettes to reports by privileged observers (e.g., teachers) of children's empathic behavior, results of previous studies are limited and contradictory. Thus new evidence is needed to answer two key questions: Are children with ASD less empathic than typically developing children? Do individual differences in theory of mind (ToM) understanding among children with ASD predict differences in their behavioral empathy? An original empirical study of 76 children aged 3-12 years (37 with ASD; 39 with typical development) addressed these. Results showed that children with ASD were significantly less empathic, according to their teachers, than typically developing children. However, this was not because of their slower ToM development. Findings showed equally clearly that ToM understanding was unrelated to empathy in children with ASD. The same was true for typically developing children once age and verbal maturity were controlled. Indeed, even the subgroup of older children with ASD in the sample who passed false belief tests were significantly less empathic than younger preschoolers who failed them. Copyright © 2014 ISDN. Published by Elsevier Ltd. All rights reserved.

Pragmatic Language Development in Language Impaired and Typically Developing Children: Incorrect Answers in Context

ERIC Educational Resources Information Center

Ryder, Nuala; Leinonen, Eeva

2014-01-01

This study focused on young children's incorrect answers to pragmatically demanding questions. Children with specific language impairment (SLI), including a subgroup with pragmatic language difficulties (PLD) and typically developing children answered questions targeting implicatures, based on a storybook and short verbal scenarios.…

Parental Influence on Mainland Chinese Children's Career Aspirations: Child and Parental Perspectives

ERIC Educational Resources Information Center

Liu, Jianwei; McMahon, Mary; Watson, Mark

2015-01-01

Career aspirations developed in childhood may impact on future career development in adolescence and adulthood. Family is an important context in which children develop their career aspirations. This study examined how parents influence children's career aspirations in mainland China from both the parents' and children's perspectives. Eight…

Parenting Behaviours and Children's Development from Infancy to Early Childhood: Changes, Continuities and Contributions

ERIC Educational Resources Information Center

Gutman, Leslie Morrison; Feinstein, Leon

2010-01-01

This study investigated trajectories of parenting behaviours and children's development from infancy to early childhood, associations between parenting behaviours and children's development and how these associations vary according to socioeconomic indicators. Mothers and children were examined from an ongoing longitudinal study of families…

Developing Thinking and Understanding in Young Children: An Introduction for Students. Second Edition

ERIC Educational Resources Information Center

Robson, Sue

2012-01-01

Developing "Thinking and Understanding in Young Children" presents a comprehensive and accessible overview of contemporary theory and research about young children's developing thinking and understanding. Throughout this second edition, the ideas and theories presented are enlivened by transcripts of children's activities and conversations taken…

45 CFR 1355.25 - Principles of child and family services.

Code of Federal Regulations, 2013 CFR

2013-10-01

... DEVELOPMENT SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES THE ADMINISTRATION ON CHILDREN, YOUTH AND... development of children. One important way to keep children safe is to stop violence in the family including... functioning and well-being. (c) Services promote the healthy development of children and youth, promote...

Growth, behavior, development and intelligence in rural children between 1-3 years of life.

PubMed

Agarwal, D K; Awasthy, A; Upadhyay, S K; Singh, P; Kumar, J; Agarwal, K N

1992-04-01

In a rural cohort of 625 children registered from 1981 to 1983 in 10 villages of K.V. Block, Varanasi, 196 children were assessed for physical growth, development, intelligence and concept development between 1 and 3 years of age. Home environment was also assessed using Caldwell Home inventory. These rural children remained below 3rd centile of NCHS standard for weight, height, skull and mid-arm circumferences throughout the study. Malnourished children scored poorly in all the areas of development, i.e., motor, adaptive, language and personal social, 9% in Grade I and 16.6% children in Grade II + III had IQ less than 79 (inferior). Concept for color shape and size was poorly developed in malnourished children. Maternal involvement and stimulation was strongly associated with better behavior development and intelligence. Multiple regression analysis showed that the effect of home environment on development and intelligence was of a higher magnitude as compared to status and family variables and nutritional status during 1-3 years of age.

Working Memory Arrest in Children with High-Functioning Autism Compared to Children with Attention-Deficit/Hyperactivity Disorder: Results from a 2-Year Longitudinal Study

ERIC Educational Resources Information Center

Andersen, Per N.; Skogli, Erik W.; Hovik, Kjell T.; Geurts, Hilde; Egeland, Jens; Øie, Merete

2015-01-01

The aim of this study was to analyse the development of verbal working memory in children with high-functioning autism compared to children with attention-deficit/hyperactivity disorder and typically developing children. A total of 34 children with high-functioning autism, 72 children with attention-deficit/hyperactivity disorder and 45 typically…

The vocabulary profile of Slovak children with primary language impairment compared to typically developing Slovak children measured by LITMUS-CLT.

PubMed

Kapalková, Svetlana; Slančová, Daniela

2017-01-01

This study compared a sample of children with primary language impairment (PLI) and typically developing age-matched children using the crosslinguistic lexical tasks (CLT-SK). We also compared the PLI children with typically developing language-matched younger children who were matched on the basis of receptive vocabulary. Overall, statistical testing showed that the vocabulary of the PLI children was significantly different from the vocabulary of the age-matched children, but not statistically different from the younger children who were matched on the basis of their receptive vocabulary size. Qualitative analysis of the correct answers revealed that the PLI children showed higher rigidity compared to the younger language-matched children who are able to use more synonyms or derivations across word class in naming tasks. Similarly, an examination of the children's naming errors indicated that the language-matched children exhibited more semantic errors, whereas PLI children showed more associative errors.

Gesturing with an injured brain: How gesture helps children with early brain injury learn linguistic constructions

PubMed Central

Özçalışkan, Şeyda; Levine, Susan C.; Goldin-Meadow, Susan

2013-01-01

Children with pre/perinatal unilateral brain lesions (PL) show remarkable plasticity for language development. Is this plasticity characterized by the same developmental trajectory that characterizes typically developing (TD) children, with gesture leading the way into speech? We explored this question, comparing 11 children with PL—matched to 30 TD children on expressive vocabulary—in the second year of life. Children with PL showed similarities to TD children for simple but not complex sentence types. Children with PL produced simple sentences across gesture and speech several months before producing them entirely in speech, exhibiting parallel delays in both gesture+speech and speech-alone. However, unlike TD children, children with PL produced complex sentence types first in speech-alone. Overall, the gesture-speech system appears to be a robust feature of language-learning for simple—but not complex—sentence constructions, acting as a harbinger of change in language development even when that language is developing in an injured brain. PMID:23217292

Causes and Triggers

MedlinePlus

... Seborrheic Dermatitis in Children Treatment For Children Eczema & Child Development Tools for School Living Well Resources Eczema and ... Seborrheic Dermatitis in Children Treatment For Children Eczema & Child Development Tools for School Living Well Resources Eczema and ...

Sleep and Daytime Functioning: A Short-Term Longitudinal Study of Three Preschool-Age Comparison Groups

ERIC Educational Resources Information Center

Anders, Thomas; Iosif, Ana-Maria; Schwichtenberg, A. J.; Tang, Karen; Goodlin-Jones, Beth

2012-01-01

This study examined sleep, sleepiness, and daytime performance in 68 children with autism, 57 children with intellectual disability (ID), and 69 typically developing preschool children. Children in the autism and ID groups had poorer daytime performance and behaviors than the typically developing children. Children in the ID group also were…

Comparison of Physical Activity between Children with Autism Spectrum Disorders and Typically Developing Children

ERIC Educational Resources Information Center

Bandini, Linda G.; Gleason, James; Curtin, Carol; Lividini, Keith; Anderson, Sarah E.; Cermak, Sharon A.; Maslin, Melissa; Must, Aviva

2013-01-01

Regular physical activity is important for promoting health and well-being; however, physical activity behaviors in children with autism spectrum disorders (ASD) have received little attention. We compared physical activity levels among 53 children with ASD and 58 typically developing children aged 3-11 years who participated in the Children's…

Coping and Well-Being in Parents of Children with Autism Spectrum Disorders (ASD)

ERIC Educational Resources Information Center

Lai, Wei Wei; Goh, Tze Jui; Oei, Tian P.; Sung, Min

2015-01-01

This study examined psychological well-being and coping in parents of children with ASD and parents of typically developing children. 73 parents of children with ASD and 63 parents of typically developing children completed a survey. Parents of children with ASD reported significantly more parenting stress symptoms (i.e., negative parental…

Coping and Well-Being in Parents of Children with Autism Spectrum Disorders (ASD).

PubMed

Lai, Wei Wei; Goh, Tze Jui; Oei, Tian P S; Sung, Min

2015-08-01

This study examined psychological well-being and coping in parents of children with ASD and parents of typically developing children. 73 parents of children with ASD and 63 parents of typically developing children completed a survey. Parents of children with ASD reported significantly more parenting stress symptoms (i.e., negative parental self-views, lower satisfaction with parent-child bond, and experiences of difficult child behaviors), more depression symptoms, and more frequent use of Active Avoidance coping, than parents of typically developing children. Parents of children with ASD did not differ significantly in psychological well-being and coping when compared as according to child's diagnosis. Study results reinforced the importance of addressing well-being and coping needs of parents of children with ASD.

The Influence of Maternal Language Responsiveness on the Expressive Speech Production of Children with Autism Spectrum Disorders: A Microanalysis of Mother-Child Play Interactions

ERIC Educational Resources Information Center

Walton, Katherine M.; Ingersoll, Brooke R.

2015-01-01

Adult responsiveness is related to language development both in young typically developing children and in children with autism spectrum disorders, such that parents who use more responsive language with their children have children who develop better language skills over time. This study used a micro-analytic technique to examine how two facets…

Characteristics of Phonological Development as a Risk Factor for Language Development in Italian-Speaking Pre-Term Children: A Longitudinal Study

ERIC Educational Resources Information Center

D'Odorico, Laura; Majorano, Marinella; Fasolo, Mirco; Salerni, Nicoletta; Suttora, Chiara

2011-01-01

This study analysed the early linguistic development of Italian pre-term children. Samples of spontaneous pre-linguistic and verbal production were recorded at 12 and 18 months of age from two groups of children: 24 pre-term children and 15 full-term children. The Italian version of the MacArthur-Bates Questionnaire was administered at 24 months…

Fricative Contrast and Coarticulation in Children With and Without Speech Sound Disorders

PubMed Central

Mailend, Marja-Liisa

2017-01-01

Purpose The purpose of this study was, first, to expand our understanding of typical speech development regarding segmental contrast and anticipatory coarticulation, and second, to explore the potential diagnostic utility of acoustic measures of fricative contrast and anticipatory coarticulation in children with speech sound disorders (SSD). Method In a cross-sectional design, 10 adults, 17 typically developing children, and 11 children with SSD repeated carrier phrases with novel words with fricatives (/s/, /ʃ/). Dependent measures were 2 ratios derived from spectral mean, obtained from perceptually accurate tokens. Group analyses compared adults and typically developing children; individual children with SSD were compared to their respective typically developing peers. Results Typically developing children demonstrated smaller fricative acoustic contrast than adults but similar coarticulatory patterns. Three children with SSD showed smaller fricative acoustic contrast than their typically developing peers, and 2 children showed abnormal coarticulation. The 2 children with abnormal coarticulation both had a clinical diagnosis of childhood apraxia of speech; no clear pattern was evident regarding SSD subtype for smaller fricative contrast. Conclusions Children have not reached adult-like speech motor control for fricative production by age 10 even when fricatives are perceptually accurate. Present findings also suggest that abnormal coarticulation but not reduced fricative contrast is SSD-subtype–specific. Supplemental Materials S1: https://doi.org/10.23641/asha.5103070. S2 and S3: https://doi.org/10.23641/asha.5106508 PMID:28654946

Optimization of Rice bran biodiesel blends on CI engine and investigating its effects

NASA Astrophysics Data System (ADS)

Jayaprabakar, J.; Dey, Biraj; Dey, Krishanu; Hareesh, Batchu; Anish, M.

2017-05-01

Bio-diesel can be produced from various plant oils like soybean, sunflower or rice bran. Here the focus is on converting the rice bran oil into bio-diesel which is produced by transesterifying the rice bran oil with a low molecular weight alcohol (methanol) and a non-conventional catalyst (lipase). Using a lipase based catalyst brings down the cost of bio diesel production significantly by reducing the number of washing cycles and its ability to be reused further. Four different blends of B10, B20, B30, B40 and straight diesel are tested in a single cylinder, fourstroke, vertical air cooled Kirloskar Diesel Engine having ignition timing of 23° before Top Dead Centre (TDC). As compared to straight diesel the Brake Thermal Efficiency (BTE) value for all the blends are higher. The Specific Fuel Consumption (BSFC) values for most of the blends are less as compared to diesel. Emissions of CO, CO2 and HC for all the blends decreased quite significantly. As a summary, the blend B20 records better performance as well as emission characteristics as compared to diesel.

Design and performance of a custom ASIC digitizer for wire chamber readout in 65 nm CMOS technology

NASA Astrophysics Data System (ADS)

Lee, M. J.; Brown, D. N.; Chang, J. K.; Ding, D.; Gnani, D.; Grace, C. R.; Jones, J. A.; Kolomensky, Y. G.; von der Lippe, H.; Mcvittie, P. J.; Stettler, M. W.; Walder, J.-P.

2015-06-01

We present the design and performance of a prototype ASIC digitizer for integrated wire chamber readout, implemented in 65 nm commercial CMOS technology. Each channel of the 4-channel prototype is composed of two 16-bit Time-to-Digital Converters (TDCs), one 8-bit Analog-to-Digital Converter (ADC), a front-end preamplifier and shaper, plus digital and analog buffers that support a variety of digitization chains. The prototype has a multiplexed digital backend that executes a state machine, distributes control and timing signals, and buffers data for serial output. Laboratory bench tests measure the absolute TDC resolution between 74 ps and 480 ps, growing with the absolute delay, and a relative time resolution of 19 ps. Resolution outliers due to cross-talk between clock signals and supply or reference voltages are seen. After calibration, the ADC displays good linearity and noise performance, with an effective number of bits of 6.9. Under normal operating conditions the circuit consumes 32 mW per channel. Potential design improvements to address the resolution drift and tails are discussed.

Experimental Study on 3D Chi - Hap Scaffolds for Thyroid Cartilage Repairing

NASA Astrophysics Data System (ADS)

Sun, Nannan; Shi, Tingchun; Fan, Yuan; Hu, Binbin

2018-01-01

Due to the limitation of self-repairing capability for cartilage injury, the construction of tissue engineering in vitro has been an ideal treatment to repair tissue injury. In this paper, hydroxyapatite (Hap) and chitosan (Chi) were selected to fabricate the scaffold through low temperature deposition manufacturing (LDM) technique. The scaffold was characterized with interconnected structure and high porosity, as well as lower toxicity to cells (TDC-5-EGPE). Animal experiment was performed, Twelve white New Zealand rabbits were randomly divided into two groups, the side of the thyroid cartilage was removed, Chi-HAP composite scaffold was implanted into the cartilage defect as the experimental group A. Group B was treated for thyroid cartilage defects without any treatment. After 10 weeks, hematoxylin-eosin (HE) staining and S-O staining were carried out on the injured tissues. The result showed that newborn chondrocytes were found in repaired areas for group A, and there are no new cells found for group B. Therefore, Chi-HAP composite scaffolds formed by LDM possess biological activity for repairing injury cartilage.

Sustained Attention and Social Competence in Typically Developing Preschool-Aged Children

ERIC Educational Resources Information Center

Murphy, Laura M. Bennett; Laurie-Rose, Cynthia; Brinkman, Tara M.; McNamara, Kelly A.

2007-01-01

The current study examines the relationship between sustained attention and social competence in preschool children. While studies demonstrate that children with attention deficit hyperactivity disorder (ADHD) exhibit poor social competence, less is known about typically developing children. Since children with ADHD have associated behavior…

Development in reading and math in children from different SES backgrounds: the moderating role of child temperament.

PubMed

Wang, Zhe; Soden, Brooke; Deater-Deckard, Kirby; Lukowski, Sarah L; Schenker, Victoria J; Willcutt, Erik G; Thompson, Lee A; Petrill, Stephen A

2017-05-01

Socioeconomic risks (SES risks) are robust risk factors influencing children's academic development. However, it is unclear whether the effects of SES on academic development operate universally in all children equally or whether they vary differentially in children with particular characteristics. The current study aimed to explore children's temperament as protective or risk factors that potentially moderate the associations between SES risks and academic development. Specifically, latent growth modeling (LGM) was used in two longitudinal datasets with a total of 2236 children to examine how family SES risks and children's temperament interactively predicted the development of reading and math from middle childhood to early adolescence. Results showed that low negative affect, high effortful control, and low surgency mitigated the negative associations between SES risks and both reading and math development in this developmental period. These findings underline the heterogeneous nature of the negative associations between SES risks and academic development and highlight the importance of the interplay between biological and social factors on individual differences in development. © 2015 John Wiley & Sons Ltd.

A Comparative Study of the Effects of a Developmentally Based Instructional Model on Young Children with Autism and Young Children with Other Disorders of Behavior and Development.

ERIC Educational Resources Information Center

Rogers, Sally J.; DiLalla, David L.

1991-01-01

This study, which applied an instructional model based on Piaget's theory of cognitive development, pragmatics theory of language development, and Mahler's theory of development of interpersonal relationships, found that 49 preschool children with autism did not make less progress than a comparison group of 27 children with other…

Purification and characterization of a newly serine protease inhibitor from Rhamnus frangula with potential for use as therapeutic drug.

PubMed

Bacha, Abir Ben; Jemel, Ikram; Moubayed, Nadine M S; Abdelmalek, Imen Ben

2017-06-01

Protease inhibitors from plants are well known to be potent inhibitors of the growth of bacteria, fungi, and even certain viruses which make them excellent candidates for use as the lead compounds for the development of novel antimicrobial agents for applications in medicine. In this study, Rhamnus frangula was selected as a protease inhibitor source. The maximum recovery of the protease inhibitor against trypsin was recorded in the crude extract made in 0.1 M phosphate buffer (pH 7.0) and isolated from the mature leaves. Then, the protease inhibitor designated as RfIP1 was purified to homogeneity by Sephadex G50 with an apparent molecular mass of 22.5 kDa and its N-terminal sequence exhibited a high degree of homology with known serine protease inhibitor sequences. The RfIP1 displayed maximal activity at pH 7 and 37 °C. It maintained almost 80% of its maximal activity through a large pH range. The thermo-stability of RfIP1 was markedly enhanced by BSA, CaCl 2, and sorbitol, whereas the addition of Mg 2+ , Zn 2+ , NaTDC, SDS, DTT, and β-ME significantly promoted inhibitory activity. The protease inhibitor displayed high inhibitory activity toward some known proteases (cathepsin B, chymotrypsin, collagenase, thrombin, and trypsin) that have more importance in pharmaceutical industry and it acted as potent inhibitor of some commercially proteases from Aspergillus oryzae, Bacillus sp, and Bacillus licheniformis. The protease inhibitor also possessed an appreciable antibacterial effect against both Gram-positive and Gram-negative bacteria.

SU-E-QI-06: Design and Initial Validation of a Precise Capillary Phantom to Test Perfusion Systems

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

Wood, R; Iacobucci, G; Khobragade, P

2014-06-15

Purpose: To design a precise perfusion phantom mimicking capillaries of the brain vasculature which could be used to test various perfusion protocols and algorithms which generate perfusion maps. Methods: A perfusion phantom was designed in Solidworks and built using additive manufacturing. The phantom was an overall cylindrical shape of diameter and height 20mm and containing capillaries of 200μm or 300μm which were parallel and in contact making up the inside volume where flow was allowed. We created a flow loop using a peristaltic pump and contrast agent was injected manually. Digital Subtraction Angiographic images and low contrast images with conemore » beam CT were acquired after the contrast was injected. These images were analyzed by our own code in LabVIEW software and Time-Density Curve, MTT and TTP was calculated. Results: Perfused area was visible in the cone beam CT images; however, individual capillaries were not distinguishable. The Time-Density Curve acquired was accurate, sensitive and repeatable. The parameters MTT, and TTP offered by the phantom were very sensitive to slight changes in the TDC shape. Conclusion: We have created a robust calibrating model for evaluation of existing perfusion data analysis systems. This approach is extremely sensitive to changes in the flow due to the high temporal resolution and could be used as a golden standard to assist developers in calibrating and testing of imaging perfusion systems and software algorithms. Supported by NIH Grant: 2R01EB002873 and an equipment grant from Toshiba Medical Systems Corporation.« less

Are gross motor skills and sports participation related in children with intellectual disabilities?

PubMed

Westendorp, Marieke; Houwen, Suzanne; Hartman, Esther; Visscher, Chris

2011-01-01

This study compared the specific gross motor skills of 156 children with intellectual disabilities (ID) (50 ≤ IQ ≥ 79) with that of 255 typically developing children, aged 7-12 years. Additionally, the relationship between the specific gross motor skills and organized sports participation was examined in both groups. The Test of Gross Motor Development-2 and a self-report measure were used to assess children's gross motor skills and sports participation, respectively. The children with ID scored significantly lower on almost all specific motor skill items than the typically developing children. Children with mild ID scored lower on the locomotor skills than children with borderline ID. Furthermore, we found in all groups that children with higher object-control scores participated more in organized sports than children with lower object-control scores. Our results support the importance of attention for well-developed gross motor skills in children with borderline and mild ID, especially to object-control skills, which might contribute positively to their sports participation. Copyright © 2011 Elsevier Ltd. All rights reserved.

Factors Which Influence the Development of Intelligence and Performance Among Nigerian Children.

ERIC Educational Resources Information Center

Odebunmi, Akin

Several themes relevant to the personality development and intellectual functioning of children are presented in this position paper. Inferences for the education of Nigerian children are also drawn. Among general factors considered influential in children's intellectual development, three are emphasized: the way in which intelligence is defined,…

Early Grammatical Development in Spanish Children with Down Syndrome

ERIC Educational Resources Information Center

Galeote, Miguel; Soto, Pilar; Sebastian, Eugenia; Checa, Elena; Sanchez-Palacios, Concepcion

2014-01-01

The objective of this work was to analyze morphosyntactic development in a wide sample of children with Down syndrome (DS) ("n" = 92) and children with typical development (TD) ("n" = 92) with a mental age (MA) of 20 to 29 months. Children were individually matched for gender and MA (Analysis 1) and for vocabulary size…

Children's Text Development: Drawing, Pictures, and Writing

ERIC Educational Resources Information Center

Christianakis, Mary

2011-01-01

Using a sociohistoric developmental lens, this paper traces the construction of texts composed by fifth graders in an urban classroom in order to answer the following questions: How do children develop as writers in school? How do writing and drawing function in children's texts? How do teaching practices shape children's writing development?…

Young Children's Computer Skills Development from Kindergarten to Third Grade

ERIC Educational Resources Information Center

Sackes, Mesut; Trundle, Kathy Cabe; Bell, Randy L.

2011-01-01

This investigation explores young children's computer skills development from kindergarten to third grade using the Early Childhood Longitudinal Study-Kindergarten (ECLS-K) dataset. The sample size of the study was 8642 children. Latent growth curve modeling analysis was used as an analytical tool to examine the development of children's computer…

A Longitudinal Study of Pragmatic Language Development in Three Children with Cochlear Implants

ERIC Educational Resources Information Center

Dammeyer, Jesper

2012-01-01

Research has shown how cochlear implants (CIs), in children with hearing impairments, have improved speech perception and production, but very little is known about the children's pragmatic language development. During a 4-year longitudinal study of three children with CIs, certain aspects of pragmatic language development were observed in free…