ESS/Special Education Teacher's Guide.

ERIC Educational Resources Information Center

Ball, Daniel W.

This teacher's guide provides Elementary Science Study (ESS) units that can be used with students in grades 1-12 in special education programs. The ESS units represent an interdisciplinary approach to learning and emphasize "hands-on" activities. Activities include Mirror Cards, Pattern Blocks, Clay Boats, Mapping, Earthworms, and…

Firing patterns of spontaneously active motor units in spinal cord-injured subjects

PubMed Central

Zijdewind, Inge; Thomas, Christine K

2012-01-01

Involuntary motor unit activity at low rates is common in hand muscles paralysed by spinal cord injury. Our aim was to describe these patterns of motor unit behaviour in relation to motoneurone and motor unit properties. Intramuscular electromyographic activity (EMG), surface EMG and force were recorded for 30 min from thenar muscles of nine men with chronic cervical SCI. Motor units fired for sustained periods (>10 min) at regular (coefficient of variation ≤ 0.15, CV, n = 19 units) or irregular intervals (CV > 0.15, n = 14). Regularly firing units started and stopped firing independently suggesting that intrinsic motoneurone properties were important for recruitment and derecruitment. Recruitment (3.6 Hz, SD 1.2), maximal (10.2 Hz, SD 2.3, range: 7.5–15.4 Hz) and derecruitment frequencies were low (3.3 Hz, SD 1.6), as were firing rate increases after recruitment (∼20 intervals in 3 s). Once active, firing often covaried, promoting the idea that units received common inputs. Half of the regularly firing units showed a very slow decline (>40 s) in discharge before derecruitment and had interspike intervals longer than their estimated afterhyperpolarisation potential (AHP) duration (estimated by death rate and breakpoint analyses). The other units were derecruited more abruptly and had shorter estimated AHP durations. Overall, regularly firing units had longer estimated AHP durations and were weaker than irregularly firing units, suggesting they were lower threshold units. Sustained firing of units at regular rates may reflect activation of persistent inward currents, visible here in the absence of voluntary drive, whereas irregularly firing units may only respond to synaptic noise. PMID:22310313

Genetic variation of trypsin and chymotrypsin inhibitors in pigeonpea [Cajanus cajan (L.) Millsp.] and its wild relatives.

PubMed

Kollipara, K P; Singh, L; Hymowitz, T

1994-09-01

Variation in the trypsin inhibitors (TIs) and the chymotrypsin inhibitors (CIs) among 69 pigeonpea [Cajanus cajan (L.) Millsp.] strains from a wide geographical distribution and among 17 accessions representing seven wild Cajanus species was studied by electrophoretic banding pattern comparisons and by spectrophotometric activity assays. The TI and CI electrophoretic migration patterns among the pigeonpea strains were highly uniform but varied in the inhibitor band intensities. The migration patterns of the inhibitors in the wild Cajanus species were highly species specific. The mean TI activity of pigeonpea strains (2279 units) was significantly higher than that of the wild Cajanus species (1407 units). However, the mean CI activity in the pigeonpea strains (62 units) was much lower than that in the wild species (162 units). Kenya 2 and ICP 9151 were the lowest and the highest, respectively, in both the TI and CI activities among all the pigeonpea strains used in this study. A highly-significant positive correlation was observed between the TI and CI activities. The Bowman-Birk type inhibitors with both TI and CI activities were identified in all the pigeonpea strains and also in the accessions of all the wild species except C. volubilis (Blanco) Blanco. The C. volubilis accession ICPW 169 was found to be 'null' for both CI bands and CI activity. Environment, strain, and environment x strain interaction showed highly-significant effects on both the TI and CI activities. Growing the pigeonpea strains at a different environment from their area of adaptation increased TI and CI activities and also altered the maturity period.

Ideas for Studying About the United States in Europe.

ERIC Educational Resources Information Center

Wright, David

1986-01-01

Suggests six activities for teaching United Kingdom students about the United States and vice versa. Ideas include word associations, map and globe work to discover climate and habitation patterns, exchange of student projects, and relevant textbook passages. (JDH)

Motor unit recruitment during neuromuscular electrical stimulation: a critical appraisal.

PubMed

Bickel, C Scott; Gregory, Chris M; Dean, Jesse C

2011-10-01

Neuromuscular electrical stimulation (NMES) is commonly used in clinical settings to activate skeletal muscle in an effort to mimic voluntary contractions and enhance the rehabilitation of human skeletal muscles. It is also used as a tool in research to assess muscle performance and/or neuromuscular activation levels. However, there are fundamental differences between voluntary- and artificial-activation of motor units that need to be appreciated before NMES protocol design can be most effective. The unique effects of NMES have been attributed to several mechanisms, most notably, a reversal of the voluntary recruitment pattern that is known to occur during voluntary muscle contractions. This review outlines the assertion that electrical stimulation recruits motor units in a nonselective, spatially fixed, and temporally synchronous pattern. Additionally, it synthesizes the evidence that supports the contention that this recruitment pattern contributes to increased muscle fatigue when compared with voluntary actions and provides some commentary on the parameters of electrical stimulation as well as emerging technologies being developed to facilitate NMES implementation. A greater understanding of how electrical stimulation recruits motor units, as well as the benefits and limitations of its use, is highly relevant when using this tool for testing and training in rehabilitation, exercise, and/or research.

Motor unit recruitment for dynamic tasks: current understanding and future directions.

PubMed

Hodson-Tole, Emma F; Wakeling, James M

2009-01-01

Skeletal muscle contains many muscle fibres that are functionally grouped into motor units. For any motor task there are many possible combinations of motor units that could be recruited and it has been proposed that a simple rule, the 'size principle', governs the selection of motor units recruited for different contractions. Motor units can be characterised by their different contractile, energetic and fatigue properties and it is important that the selection of motor units recruited for given movements allows units with the appropriate properties to be activated. Here we review what is currently understood about motor unit recruitment patterns, and assess how different recruitment patterns are more or less appropriate for different movement tasks. During natural movements the motor unit recruitment patterns vary (not always holding to the size principle) and it is proposed that motor unit recruitment is likely related to the mechanical function of the muscles. Many factors such as mechanics, sensory feedback, and central control influence recruitment patterns and consequently an integrative approach (rather than reductionist) is required to understand how recruitment is controlled during different movement tasks. Currently, the best way to achieve this is through in vivo studies that relate recruitment to mechanics and behaviour. Various methods for determining motor unit recruitment patterns are discussed, in particular the recent wavelet-analysis approaches that have allowed motor unit recruitment to be assessed during natural movements. Directions for future studies into motor recruitment within and between functional task groups and muscle compartments are suggested.

Convergence of pattern generator outputs on a common mechanism of diaphragm motor unit recruitment.

PubMed

Mantilla, Carlos B; Seven, Yasin B; Sieck, Gary C

2014-01-01

Motor units are the final element of neuromotor control. In manner analogous to the organization of neuromotor control in other skeletal muscles, diaphragm motor units comprise phrenic motoneurons located in the cervical spinal cord that innervate the diaphragm muscle, the main inspiratory muscle in mammals. Diaphragm motor units play a primary role in sustaining ventilation but are also active in other nonventilatory behaviors, including coughing, sneezing, vomiting, defecation, and parturition. Diaphragm muscle fibers comprise all fiber types. Thus, diaphragm motor units display substantial differences in contractile and fatigue properties, but importantly, properties of the motoneuron and muscle fibers within a motor unit are matched. As in other skeletal muscles, diaphragm motor units are recruited in order such that motor units that display greater fatigue resistance are recruited earlier and more often than more fatigable motor units. The properties of the motor unit population are critical determinants of the function of a skeletal muscle across the range of possible motor tasks. Accordingly, fatigue-resistant motor units are sufficient to generate the forces necessary for ventilatory behaviors, whereas more fatigable units are only activated during expulsive behaviors important for airway clearance. Neuromotor control of diaphragm motor units may reflect selective inputs from distinct pattern generators distributed according to the motor unit properties necessary to accomplish these different motor tasks. In contrast, widely distributed inputs to phrenic motoneurons from various pattern generators (e.g., for breathing, coughing, or vocalization) would dictate recruitment order based on intrinsic electrophysiological properties. © 2014 Elsevier B.V. All rights reserved.

Single-unit muscle sympathetic nervous activity and its relation to cardiac noradrenaline spillover

PubMed Central

Lambert, Elisabeth A; Schlaich, Markus P; Dawood, Tye; Sari, Carolina; Chopra, Reena; Barton, David A; Kaye, David M; Elam, Mikael; Esler, Murray D; Lambert, Gavin W

2011-01-01

Abstract Recent work using single-unit sympathetic nerve recording techniques has demonstrated aberrations in the firing pattern of sympathetic nerves in a variety of patient groups. We sought to examine whether nerve firing pattern is associated with increased noradrenaline release. Using single-unit muscle sympathetic nerve recording techniques coupled with direct cardiac catheterisation and noradrenaline isotope dilution methodology we examined the relationship between single-unit firing patterns and cardiac and whole body noradrenaline spillover to plasma. Participants comprised patients with hypertension (n = 6), depression (n = 7) and panic disorder (n = 9) who were drawn from our ongoing studies. The patient groups examined did not differ in their single-unit muscle sympathetic nerve firing characteristics nor in the rate of spillover of noradrenaline to plasma from the heart. The median incidence of multiple spikes per beat was 9%. Patients were stratified according to the firing pattern: low level of incidence (less than 9% incidence of multiple spikes per beat) and high level of incidence (greater than 9% incidence of multiple spikes per beat). High incidence of multiple spikes within a cardiac cycle was associated with higher firing rates (P < 0.0001) and increased probability of firing (P < 0.0001). Whole body noradrenaline spillover to plasma and (multi-unit) muscle sympathetic nerve activity in subjects with low incidence of multiple spikes was not different to that of those with high incidence of multiple spikes. In those with high incidence of multiple spikes there occurred a parallel activation of the sympathetic outflow to the heart, with cardiac noradrenaline spillover to plasma being two times that of subjects with low nerve firing rates (11.0 ± 1.5 vs. 22.0 ± 4.5 ng min−1, P < 0.05). This study indicates that multiple within-burst firing and increased single-unit firing rates of the sympathetic outflow to the skeletal muscle vasculature is associated with high cardiac noradrenaline spillover. PMID:21486790

The Implications of Null Patterns and Output Unit Activation Functions on Simulation Studies of Learning: A Case Study of Patterning

ERIC Educational Resources Information Center

Yaremchuk, V.; Willson, L.R.; Spetch, M.L.; Dawson, M.R.W.

2005-01-01

Animal learning researchers have argued that one example of a linearly nonseparable problem is negative patterning, and therefore they have used more complicated multilayer networks to study this kind of discriminant learning. However, it is shown in this paper that previous attempts to define negative patterning problems to artificial neural…

Variations in motor unit recruitment patterns occur within and between muscles in the running rat (Rattus norvegicus).

PubMed

Hodson-Tole, E F; Wakeling, J M

2007-07-01

Motor units are generally considered to follow a set, orderly pattern of recruitment within each muscle with activation occurring in the slowest through to the fastest units. A growing body of evidence, however, suggests that recruitment patterns may not always follow such an orderly sequence. Here we investigate whether motor unit recruitment patterns vary within and between the ankle extensor muscles of the rat running at 40 cm s(-1) on a level treadmill. In the past it has been difficult to quantify motor unit recruitment patterns during locomotion; however, recent application of wavelet analysis techniques has made such detailed analysis of motor unit recruitment possible. Here we present methods for quantifying the interplay of fast and slow motor unit recruitment based on their myoelectric signals. Myoelectric data were collected from soleus, plantaris and medial gastrocnemius muscles representing populations of slow, mixed and fast fibres, respectively, and providing a good opportunity to relate myoelectric frequency content to motor unit recruitment patterns. Following wavelet transformation, principal component analysis quantified signal intensity and relative frequency content. Significant differences in signal frequency content occurred between different time points within a stride (P<0.001). We optimised high- and low-frequency wavelets to the major signals from the fast and slow motor units. The goodness-of-fit of the optimised wavelets to the signal intensity was high for all three muscles (r2>0.98). The low-frequency band had a significantly better fit to signals from the soleus muscle (P<0.001), while the high-frequency band had a significantly better fit to the medial gastrocnemius (P<0.001).

The Cluster Variation Method: A Primer for Neuroscientists.

PubMed

Maren, Alianna J

2016-09-30

Effective Brain-Computer Interfaces (BCIs) require that the time-varying activation patterns of 2-D neural ensembles be modelled. The cluster variation method (CVM) offers a means for the characterization of 2-D local pattern distributions. This paper provides neuroscientists and BCI researchers with a CVM tutorial that will help them to understand how the CVM statistical thermodynamics formulation can model 2-D pattern distributions expressing structural and functional dynamics in the brain. The premise is that local-in-time free energy minimization works alongside neural connectivity adaptation, supporting the development and stabilization of consistent stimulus-specific responsive activation patterns. The equilibrium distribution of local patterns, or configuration variables , is defined in terms of a single interaction enthalpy parameter ( h ) for the case of an equiprobable distribution of bistate (neural/neural ensemble) units. Thus, either one enthalpy parameter (or two, for the case of non-equiprobable distribution) yields equilibrium configuration variable values. Modeling 2-D neural activation distribution patterns with the representational layer of a computational engine, we can thus correlate variational free energy minimization with specific configuration variable distributions. The CVM triplet configuration variables also map well to the notion of a M = 3 functional motif. This paper addresses the special case of an equiprobable unit distribution, for which an analytic solution can be found.

The Cluster Variation Method: A Primer for Neuroscientists

PubMed Central

Maren, Alianna J.

2016-01-01

Effective Brain–Computer Interfaces (BCIs) require that the time-varying activation patterns of 2-D neural ensembles be modelled. The cluster variation method (CVM) offers a means for the characterization of 2-D local pattern distributions. This paper provides neuroscientists and BCI researchers with a CVM tutorial that will help them to understand how the CVM statistical thermodynamics formulation can model 2-D pattern distributions expressing structural and functional dynamics in the brain. The premise is that local-in-time free energy minimization works alongside neural connectivity adaptation, supporting the development and stabilization of consistent stimulus-specific responsive activation patterns. The equilibrium distribution of local patterns, or configuration variables, is defined in terms of a single interaction enthalpy parameter (h) for the case of an equiprobable distribution of bistate (neural/neural ensemble) units. Thus, either one enthalpy parameter (or two, for the case of non-equiprobable distribution) yields equilibrium configuration variable values. Modeling 2-D neural activation distribution patterns with the representational layer of a computational engine, we can thus correlate variational free energy minimization with specific configuration variable distributions. The CVM triplet configuration variables also map well to the notion of a M = 3 functional motif. This paper addresses the special case of an equiprobable unit distribution, for which an analytic solution can be found. PMID:27706022

Motor unit recruitment and derecruitment induced by brief increase in contraction amplitude of the human trapezius muscle

PubMed Central

Westad, C; Westgaard, R H; De Luca, C J

2003-01-01

The activity pattern of low-threshold human trapezius motor units was examined in response to brief, voluntary increases in contraction amplitude (‘EMG pulse’) superimposed on a constant contraction at 4–7% of the surface electromyographic (EMG) response at maximal voluntary contraction (4–7% EMGmax). EMG pulses at 15–20% EMGmax were superimposed every minute on contractions of 5, 10, or 30 min duration. A quadrifilar fine-wire electrode recorded single motor unit activity and a surface electrode recorded simultaneously the surface EMG signal. Low-threshold motor units recruited at the start of the contraction were observed to stop firing while motor units of higher recruitment threshold stayed active. Derecruitment of a motor unit coincided with the end of an EMG pulse. The lowest-threshold motor units showed only brief silent periods. Some motor units with recruitment threshold up to 5% EMGmax higher than the constant contraction level were recruited during an EMG pulse and kept firing throughout the contraction. Following an EMG pulse, there was a marked reduction in motor unit firing rates upon return of the surface EMG signal to the constant contraction level, outlasting the EMG pulse by 4 s on average. The reduction in firing rates may serve as a trigger to induce derecruitment. We speculate that the silent periods following derecruitment may be due to deactivation of non-inactivating inward current (‘plateau potentials’). The firing behaviour of trapezius motor units in these experiments may thus illustrate a mechanism and a control strategy to reduce fatigue of motor units with sustained activity patterns. PMID:14561844

Asian Studies Unit One: Asian Man and His Environment, Pilot Program; [And] Asian Studies Unit Two: Cultural Patterns of Asian Man, Field Test.

ERIC Educational Resources Information Center

Chicago Board of Education, IL.

Two units of Asian materials for secondary students comprise this document. The first unit presents a brief history of Asian man and his environment, including geography, climate, ethnic groups, resources, food, and population. Following the historical narrative are community references and various learning experiences and activities which further…

Interpretation of fusimotor activity in cat masseter nerve during reflex jaw movements.

PubMed Central

Gottlieb, S; Taylor, A

1983-01-01

Simultaneous recordings were made from fusimotor axons in the central ends of filaments of the masseter nerve, and from masseter and temporalis spindle afferents in the mesencephalic nucleus of the fifth cranial nerve in lightly anaesthetized cats. Fusimotor and alpha-motor units in the masseter nerve were differentiated on the basis of their response to passive ramp and hold stretches applied to the jaw. Spindle afferents were identified as primary or secondary according to their dynamic index after administration of suxamethonium. The activity of a given fusimotor unit during reflex movements of the jaw followed one of two distinct patterns: so-called 'tonic' units showed a general increase in activity during a movement, without detailed relation to lengthening or shortening, while 'modulated' units displayed a striking modulation of their activity with shortening, and were usually silent during subsequent lengthening. Comparison of the simultaneously recorded fusimotor and spindle afferent activity suggests that modulated units may be representative of a population of static fusimotor neurones, and tonic units of a population of dynamic fusimotor neurones. In these lightly anaesthetized animals, both primary and secondary spindle afferents showed increased firing during muscle shortening as well as during lengthening. This increase during shortening is not usually seen in conscious animals and reasons are given for the view that it is due to greater depression of alpha-motor activity than of static fusimotor activity during anaesthesia. The results are discussed in relation to the theories of 'alpha-gamma co-activation' and of 'servo-assistance'; and it is suggested that static fusimotor neurones provide a 'temporal template' of the intended movement, while dynamic fusimotor neurones set the required dynamic sensitivity to deviations from the intended movement pattern. PMID:6229627

Self-Employment in the United Kingdom and Germany.

ERIC Educational Resources Information Center

Meager, Nigel; And Others

In a comparison of self-employment patterns in Germany and the United Kingdom, data from the Labour Force Survey (United Kingdom) and Mikrozensus (Germany) were analyzed to identify the personal characteristics of self-employed individuals in the two countries, the characteristics of their self-employed activity, and movement in and out of…

Stimulus-induced dissociation of neuronal firing rates and local field potential gamma power and its relationship to the blood oxygen level-dependent signal in macaque primary visual cortex

PubMed Central

Bartolo, M J; Gieselmann, M A; Vuksanovic, V; Hunter, D; Sun, L; Chen, X; Delicato, L S; Thiele, A

2011-01-01

The functional magnetic resonance imaging (fMRI) blood oxygenation level-dependent (BOLD) signal is regularly used to assign neuronal activity to cognitive function. Recent analyses have shown that the local field potential (LFP) gamma power is a better predictor of the fMRI BOLD signal than spiking activity. However, LFP gamma power and spiking activity are usually correlated, clouding the analysis of the neural basis of the BOLD signal. We show that changes in LFP gamma power and spiking activity in the primary visual cortex (V1) of the awake primate can be dissociated by using grating and plaid pattern stimuli, which differentially engage surround suppression and cross-orientation inhibition/facilitation within and between cortical columns. Grating presentation yielded substantial V1 LFP gamma frequency oscillations and significant multi-unit activity. Plaid pattern presentation significantly reduced the LFP gamma power while increasing population multi-unit activity. The fMRI BOLD activity followed the LFP gamma power changes, not the multi-unit activity. Inference of neuronal activity from the fMRI BOLD signal thus requires detailed a priori knowledge of how different stimuli or tasks activate the cortical network. PMID:22081989

Using a decision support system to estimate departures of present forest landscape patterns from historical reference condition—an example from the inland Northwest region of the United States.

Treesearch

P.F. Hessburg; K.M. Reynolds; R.B. Salter; M.B. Richmond

2004-01-01

Human settlement and management activities have altered the patterns and processes of forest landscapes across the inland northwest region of the United States (Hessburg et al. 2000C; Hessburg and Agee in press). As a consequence, many attributes of current disturbance regimes (e.g., the frequency, duration, severity, and extent of fires) differ markedly from those of...

Prediction of Human Activity by Discovering Temporal Sequence Patterns.

PubMed

Li, Kang; Fu, Yun

2014-08-01

Early prediction of ongoing human activity has become more valuable in a large variety of time-critical applications. To build an effective representation for prediction, human activities can be characterized by a complex temporal composition of constituent simple actions and interacting objects. Different from early detection on short-duration simple actions, we propose a novel framework for long -duration complex activity prediction by discovering three key aspects of activity: Causality, Context-cue, and Predictability. The major contributions of our work include: (1) a general framework is proposed to systematically address the problem of complex activity prediction by mining temporal sequence patterns; (2) probabilistic suffix tree (PST) is introduced to model causal relationships between constituent actions, where both large and small order Markov dependencies between action units are captured; (3) the context-cue, especially interactive objects information, is modeled through sequential pattern mining (SPM), where a series of action and object co-occurrence are encoded as a complex symbolic sequence; (4) we also present a predictive accumulative function (PAF) to depict the predictability of each kind of activity. The effectiveness of our approach is evaluated on two experimental scenarios with two data sets for each: action-only prediction and context-aware prediction. Our method achieves superior performance for predicting global activity classes and local action units.

EMG analysis tuned for determining the timing and level of activation in different motor units

PubMed Central

Lee, Sabrina S.M.; de Boef Miara, Maria; Arnold, Allison S.; Biewener, Andrew A.; Wakeling, James M.

2011-01-01

Recruitment patterns and activation dynamics of different motor units greatly influence the temporal pattern and magnitude of muscle force development, yet these features are not often considered in muscle models. The purpose of this study was to characterize the recruitment and activation dynamics of slow and fast motor units from electromyographic (EMG) recordings and twitch force profiles recorded directly from animal muscles. EMG and force data from the gastrocnemius muscles of seven goats were recorded during in vivo tendon-tap reflex and in situ nerve stimulation experiments. These experiments elicited EMG signals with significant differences in frequency content (p<0.001). The frequency content was characterized using wavelet and principal components analysis, and optimized wavelets with centre frequencies, 149.94Hz and 323.13Hz, were obtained. The optimized wavelets were used to calculate the EMG intensities and, with the reconstructed twitch force profiles, to derive transfer functions for slow and fast motor units that estimate the activation state of the muscle from the EMG signal. The resulting activation-deactivation time constants gave r values of 0.98 to 0.99 between the activation state and the force profiles. This work establishes a framework for developing improved muscle models that consider the intrinsic properties of slow and fast fibres within a mixed muscle, and that can more accurately predict muscle force output from EMG. PMID:21570317

EMG analysis tuned for determining the timing and level of activation in different motor units.

PubMed

Lee, Sabrina S M; Miara, Maria de Boef; Arnold, Allison S; Biewener, Andrew A; Wakeling, James M

2011-08-01

Recruitment patterns and activation dynamics of different motor units greatly influence the temporal pattern and magnitude of muscle force development, yet these features are not often considered in muscle models. The purpose of this study was to characterize the recruitment and activation dynamics of slow and fast motor units from electromyographic (EMG) recordings and twitch force profiles recorded directly from animal muscles. EMG and force data from the gastrocnemius muscles of seven goats were recorded during in vivo tendon-tap reflex and in situ nerve stimulation experiments. These experiments elicited EMG signals with significant differences in frequency content (p<0.001). The frequency content was characterized using wavelet and principal components analysis, and optimized wavelets with centre frequencies, 149.94 Hz and 323.13 Hz, were obtained. The optimized wavelets were used to calculate the EMG intensities and, with the reconstructed twitch force profiles, to derive transfer functions for slow and fast motor units that estimate the activation state of the muscle from the EMG signal. The resulting activation-deactivation time constants gave r values of 0.98-0.99 between the activation state and the force profiles. This work establishes a framework for developing improved muscle models that consider the intrinsic properties of slow and fast fibres within a mixed muscle, and that can more accurately predict muscle force output from EMG. Copyright © 2011 Elsevier Ltd. All rights reserved.

Modification of medullary respiratory-related discharge patterns by behaviors and states of arousal.

PubMed

Chang, F C

1992-02-07

The modulatory influences of behaviors and states of arousal on bulbar respiratory-related unit (RRU) discharge patterns were studied in an unanesthetized, freely behaving guinea pig respiratory model system. When fully instrumented, this model system permits concurrent monitoring and recording of (i) single units from either Bötzinger complex or nucleus para-ambiguus; (ii) electrocorticogram; and, (iii) diaphragmatic EMG. In addition to being used in surveys of RRU discharge patterns in freely behaving states, the model system also offered a unique opportunity in investigating the effects of pentobarbital on RRU discharge patterns before, throughout the course of, and during recovery from anesthesia. In anesthetized preparations, a particular RRU discharge pattern (such as tonic, incrementing or decrementing) typically displayed little, if any notable variation. The most striking development following pentobarbital was a state of progressive bradypnea attributable to a significantly augmented RRU cycle duration, burst duration and an increase in the RRU spike frequencies during anesthesia. In freely behaving states, medullary RRU activities rarely adhered to a fixed, immutable discharge pattern. More specifically, the temporal organization (such as burst duration, cycle duration, and the extent of modulation of within-burst spike frequencies) of RRU discharge patterns regularly showed complex and striking variations, not only with states of arousal (sleep/wakefulness, anesthesia) but also with discrete alterations in electrocorticogram (ECoG) activities and a multitude of on-going behavioral repertoires such as volitional movement, postural modification, phonation, mastication, deglutition, sniffing/exploratory behavior, alerting/startle reflexes. Only during sleep, and on occasions when the animal assumed a motionless, resting posture, could burst patterns of relatively invariable periodicity and uniform temporal attributes be observed. RRU activities during sniffing reflex is worthy of further note in that, based on power spectrum analyses of concurrently recorded ECoG activities, this particular discharge pattern was clearly associated with the activation of a 6-10 Hz theta rhythm. These findings indicated that bulbar RRU activity patterns are subject to change by not only behaviors and sleep/wakefulness cycles, but also a variety of modulatory influences and feedback/feedforward biases from other central and peripheral physiological control mechanisms.

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

PubMed

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

2017-01-01

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

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

PubMed Central

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

2017-01-01

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

County Business Patterns: United States, 2002.

ERIC Educational Resources Information Center

US Department of Commerce, 2004

2004-01-01

In this report, subnational economic data by industry, including Educational Services, is provided. County Business Patterns is useful for studying the economic activity of small areas; analyzing economic changes over time; and as a benchmark for statistical series, surveys, and databases between economic censuses. The number of establishments,…

Manufacturing. Evaluation Report from a Limited School Trial of a Teaching Unit of the High School Geography Project.

ERIC Educational Resources Information Center

Bogatz, Gerry Ann

The methodology used in the evaluation of this unit is the same as that described in SO 000 433. The same seventy teachers were involved along with 2,400 seventh through twelfth grade students. There were nine activities in this unit: 1) Geographic Patterns of Manufacturing in the United States; 2) Definition of Manufacturing; 3) and 4)…

Motor unit activation patterns during concentric wrist flexion in humans with different muscle fibre composition.

PubMed

Søgaard, K; Christensen, H; Fallentin, N; Mizuno, M; Quistorff, B; Sjøgaard, G

1998-10-01

Muscle activity was recorded from the flexor carpi radialis muscle during static and dynamic-concentric wrist flexion in six subjects, who had exhibited large differences in histochemically identified muscle fibre composition. Motor unit recruitment patterns were identified by sampling 310 motor units and counting firing rates in pulses per second (pps). During concentric wrist flexion at 30% of maximal exercise intensity the mean firing rate was 27 (SD 13) pps. This was around twice the value of 12 (SD 5) pps recorded during sustained static contraction at 30% of maximal voluntary contraction, despite a larger absolute force level during the static contraction. A similar pattern of higher firing rates during dynamic exercise was seen when concentric wrist flexion at 60% of maximal exercise intensity [30 (SD 14) pps] was compared with sustained static contraction at 60% of maximal voluntary contraction [19 (SD 8) pps]. The increase in dynamic exercise intensity was accomplished by recruitment of additional motor units rather than by increasing the firing rate as during static contractions. No difference in mean firing rates was found among subjects with different muscle fibre composition, who had previously exhibited marked differences in metabolic response during corresponding dynamic contractions. It was concluded that during submaximal dynamic contractions motor unit firing rate cannot be deduced from observations during static contractions and that muscle fibre composition may play a minor role.

Dietary Patterns Exhibit Sex-Specific Associations with Adiposity and Metabolic Risk in a Cross-Sectional Study in Urban Mexican Adolescents.

PubMed

Perng, Wei; Fernandez, Carmen; Peterson, Karen E; Zhang, ZhenZhen; Cantoral, Alejandra; Sanchez, Brisa N; Solano-González, Maritsa; Téllez-Rojo, Martha Maria; Baylin, Ana

2017-10-01

Background: Studies in Western nations have shown associations of certain dietary patterns with obesity and metabolic risk in youth. Little is known about these relations in newly industrialized countries where obesity prevalence is surpassing those of developed countries. Objective: We sought to characterize dietary patterns in a cross-sectional study in 224 adolescents aged 8-14 y in Mexico and to investigate associations of the dietary patterns with adiposity and metabolic risk. Methods: We used principal components analysis to derive dietary patterns from food-frequency questionnaire data. By using linear regression models that accounted for mother's marital status, education, and smoking habits and child's age and physical activity, we examined associations of the dietary patterns with adiposity [body mass index z score, waist circumference, the sum and ratio of the subscapular and triceps skinfold thicknesses, blood pressure, serum fasting glucose and a C-peptide-based measure of insulin resistance (CP-IR), lipid profile, and a metabolic syndrome risk z score (MetS z score)]. Results: We identified a "prudent" dietary pattern characterized by high intakes of vegetables, fruit, fish, chicken, and legumes and a "transitioning" dietary pattern, which comprises processed meats, Mexican foods, and sweetened beverages. Each unit increase in the prudent pattern factor score corresponded with 0.33 ng/mL (95% CI: 0.09, 0.57 ng/mL) lower C-peptide, 0.08 units (95% CI: 0.02, 0.13 units) lower CP-IR, and a 0.14 unit (0.00, 0.27 unit) lower MetS z score in boys. In girls, the transitioning pattern corresponded with higher subscapular + triceps skinfold thickness (per 1-unit increase in the factor score: 2.46 mm; 95% CI: 0.10, 4.81 mm). These results did not change after accounting for pubertal status. Conclusions: A prudent dietary pattern was protective against metabolic risk in adolescent boys, whereas a transitioning dietary pattern corresponded with higher adiposity among adolescent girls. Given that adolescence is a key developmental period for long-term health, efforts to elucidate dietary determinants of metabolic risk during this life stage may have long-term benefits. © 2017 American Society for Nutrition.

Motor unit recruitment patterns 1: responses to changes in locomotor velocity and incline.

PubMed

Hodson-Tole, Emma F; Wakeling, James M

2008-06-01

Mammalian skeletal muscles are composed of a mixture of motor unit types, which contribute a range of mechanical and physiological properties to the muscle. For a muscle to effectively contribute to smooth, co-ordinated movement it must activate an appropriate number and combination of motor units to generate the required force over a suitable time period. Much evidence exists indicating that motor units are activated in an orderly fashion, from the slowest through to the fastest. A growing body of evidence, however, indicates that such a recruitment strategy does not always hold true. Here we investigate how motor unit recruitment patterns were influenced by changes in locomotor velocity and incline. Kinematics data and myoelectric signals were collected from three rat ankle extensor muscles during running on a treadmill at nine velocity and incline combinations. Wavelet and principal component analysis were used to simultaneously decompose the signals into time and frequency space. The relative frequency components of the signals were quantified during 20 time windows of a stride from each locomotor condition. Differences in signal frequency components existed between muscles and locomotor conditions. Faster locomotor velocities led to a relative increase in high frequency components, whereas greater inclines led to a relative increase in the low frequency components. These data were interpreted as representing changes in motor unit recruitment patterns in response to changes in the locomotor demand. Motor units were not always recruited in an orderly manner, indicating that recruitment is a multi-factorial phenomenon that is not yet fully understood.

Patterns of motor recruitment can be determined using surface EMG.

PubMed

Wakeling, James M

2009-04-01

Previous studies have reported how different populations of motor units (MUs) can be recruited during dynamic and locomotor tasks. It was hypothesised that the higher-threshold units would contribute higher-frequency components to the sEMG spectra due to their faster conduction velocities, and thus recruitment patterns that increase the proportion of high-threshold units active would lead to higher-frequency elements in the sEMG spectra. This idea was tested by using a model of varying recruitment coupled to a three-layer volume conductor model to generate a series of sEMG signals. The recruitment varied from (A) orderly recruitment where the lowest-threshold MUs were initially activated and higher-threshold MUs were sequentially recruited as the contraction progressed, (B) a recurrent inhibition model that started with orderly recruitment, but as the higher-threshold units were activated they inhibited the lower-threshold MUs (C) nine models with intermediate properties that were graded between these two extremes. The sEMG was processed using wavelet analysis and the spectral properties quantified by their mean frequency, and an angle theta that was determined from the principal components of the spectra. Recruitment strategies that resulted in a greater proportion of faster MUs being active had a significantly lower theta and higher mean frequency.

Female pheromones modulate flight muscle activation patterns during preflight warm-up.

PubMed

Crespo, José G; Vickers, Neil J; Goller, Franz

2013-08-01

At low ambient temperature Helicoverpa zea male moths engage in warm-up behavior prior to taking flight in response to an attractive female pheromone blend. Male H. zea warm up at a faster rate when sensing the attractive pheromone blend compared with unattractive blends or blank controls (Crespo et al. 2012), but the mechanisms involved in this olfactory modulation of the heating rate during preflight warm-up are unknown. Here, we test three possible mechanisms for increasing heat production: 1) increased rate of muscle contraction; 2) reduction in mechanical movement by increased overlap in activation of the antagonistic flight muscles; and 3) increased activation of motor units. To test which mechanisms play a role, we simultaneously recorded electrical activation patterns of the main flight muscles (dorsolongitudinal and dorsoventral muscles), wing movement, and thoracic temperature in moths exposed to both the attractive pheromone blend and a blank control. Results indicate that the main mechanism responsible for the observed increase in thoracic heating rate with pheromone stimulation is the differential activation of motor units during each muscle contraction cycle in both antagonistic flight muscles. This additional activation lengthens the contracted state within each cycle and thus accounts for the greater heat production. Interestingly, the rate of activation (frequency of contraction cycles) of motor units, which is temperature dependent, did not vary between treatments. This result suggests that the activation rate is determined by a temperature-dependent oscillator, which is not affected by the olfactory stimulus, but activation of motor units is modulated during each cycle.

Female pheromones modulate flight muscle activation patterns during preflight warm-up

PubMed Central

Vickers, Neil J.; Goller, Franz

2013-01-01

At low ambient temperature Helicoverpa zea male moths engage in warm-up behavior prior to taking flight in response to an attractive female pheromone blend. Male H. zea warm up at a faster rate when sensing the attractive pheromone blend compared with unattractive blends or blank controls (Crespo et al. 2012), but the mechanisms involved in this olfactory modulation of the heating rate during preflight warm-up are unknown. Here, we test three possible mechanisms for increasing heat production: 1) increased rate of muscle contraction; 2) reduction in mechanical movement by increased overlap in activation of the antagonistic flight muscles; and 3) increased activation of motor units. To test which mechanisms play a role, we simultaneously recorded electrical activation patterns of the main flight muscles (dorsolongitudinal and dorsoventral muscles), wing movement, and thoracic temperature in moths exposed to both the attractive pheromone blend and a blank control. Results indicate that the main mechanism responsible for the observed increase in thoracic heating rate with pheromone stimulation is the differential activation of motor units during each muscle contraction cycle in both antagonistic flight muscles. This additional activation lengthens the contracted state within each cycle and thus accounts for the greater heat production. Interestingly, the rate of activation (frequency of contraction cycles) of motor units, which is temperature dependent, did not vary between treatments. This result suggests that the activation rate is determined by a temperature-dependent oscillator, which is not affected by the olfactory stimulus, but activation of motor units is modulated during each cycle. PMID:23699056

76 FR 79646 - Agency Information Collection Activities: Proposed Collection; Comments Request-Nutrition...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-22

... DEPARTMENT OF AGRICULTURE Food And Nutrition Service Agency Information Collection Activities: Proposed Collection; Comments Request--Nutrition Assistance in Farmers' Markets: Understanding the Shopping Patterns of SNAP Participants AGENCY: Food and Nutrition Service (FNS), United States Department of...

Motor unit firing rate patterns during voluntary muscle force generation: a simulation study

NASA Astrophysics Data System (ADS)

Hu, Xiaogang; Rymer, William Z.; Suresh, Nina L.

2014-04-01

Objective. Muscle force is generated by a combination of motor unit (MU) recruitment and changes in the discharge rate of active MUs. There have been two basic MU recruitment and firing rate paradigms reported in the literature, which describe the control of the MUs during force generation. The first (termed the reverse ‘onion skin’ profile), exhibits lower firing rates for lower threshold units, with higher firing rates occurring in higher threshold units. The second (termed the ‘onion skin’ profile), exhibits an inverse arrangement, with lower threshold units reaching higher firing rates. Approach. Using a simulation of the MU activity in a hand muscle, this study examined the force generation capacity and the variability of the muscle force magnitude at different excitation levels of the MU pool under these two different MU control paradigms. We sought to determine which rate/recruitment scheme was more efficient for force generation, and which scheme gave rise to the lowest force variability. Main results. We found that the force output of both firing patterns leads to graded force output at low excitation levels, and that the force generation capacity of the two different paradigms diverged around 50% excitation. In the reverse ‘onion skin’ pattern, at 100% excitation, the force output reached up to 88% of maximum force, whereas for the ‘onion skin’ pattern, the force output only reached up to 54% of maximum force at 100% excitation. The force variability was lower at the low to moderate force levels under the ‘onion skin’ paradigm than with the reverse ‘onion skin’ firing patterns, but this effect was reversed at high force levels. Significance. This study captures the influence of MU recruitment and firing rate organization on muscle force properties, and our results suggest that the different firing organizations can be beneficial at different levels of voluntary muscle force generation and perhaps for different tasks.

Understanding spatial and temporal patterning of astrocyte calcium transients via interactions between network transport and extracellular diffusion

NASA Astrophysics Data System (ADS)

Shtrahman, E.; Maruyama, D.; Olariu, E.; Fink, C. G.; Zochowski, M.

2017-02-01

Astrocytes form interconnected networks in the brain and communicate via calcium signaling. We investigate how modes of coupling between astrocytes influence the spatio-temporal patterns of calcium signaling within astrocyte networks and specifically how these network interactions promote coordination within this group of cells. To investigate these complex phenomena, we study reduced cultured networks of astrocytes and neurons. We image the spatial temporal patterns of astrocyte calcium activity and quantify how perturbing the coupling between astrocytes influences astrocyte activity patterns. To gain insight into the pattern formation observed in these cultured networks, we compare the experimentally observed calcium activity patterns to the patterns produced by a reduced computational model, where we represent astrocytes as simple units that integrate input through two mechanisms: gap junction coupling (network transport) and chemical release (extracellular diffusion). We examine the activity patterns in the simulated astrocyte network and their dependence upon these two coupling mechanisms. We find that gap junctions and extracellular chemical release interact in astrocyte networks to modulate the spatiotemporal patterns of their calcium dynamics. We show agreement between the computational and experimental findings, which suggests that the complex global patterns can be understood as a result of simple local coupling mechanisms.

Nordic Walking: A Simple Lifetime Physical Activity for Every Student

ERIC Educational Resources Information Center

Santos, Luis; Fernandez-Rio, Javier

2013-01-01

Children who become competent in a wide variety of motor skills and movement patterns are more likely to remain physically active for life. Physical education can achieve this goal by providing an extensive selection of activities and by including learning units that encourage students to increase their skill level and stay active year-round.…

Failure to suppress low-frequency neuronal oscillatory activity underlies the reduced effectiveness of random patterns of deep brain stimulation.

PubMed

McConnell, George C; So, Rosa Q; Grill, Warren M

2016-06-01

Subthalamic nucleus (STN) deep brain stimulation (DBS) is an established treatment for the motor symptoms of Parkinson's disease (PD). However, the mechanisms of action of DBS are unknown. Random temporal patterns of DBS are less effective than regular DBS, but the neuronal basis for this dependence on temporal pattern of stimulation is unclear. Using a rat model of PD, we quantified the changes in behavior and single-unit activity in globus pallidus externa and substantia nigra pars reticulata during high-frequency STN DBS with different degrees of irregularity. Although all stimulus trains had the same average rate, 130-Hz regular DBS more effectively reversed motor symptoms, including circling and akinesia, than 130-Hz irregular DBS. A mixture of excitatory and inhibitory neuronal responses was present during all stimulation patterns, and mean firing rate did not change during DBS. Low-frequency (7-10 Hz) oscillations of single-unit firing times present in hemiparkinsonian rats were suppressed by regular DBS, and neuronal firing patterns were entrained to 130 Hz. Irregular patterns of DBS less effectively suppressed 7- to 10-Hz oscillations and did not regularize firing patterns. Random DBS resulted in a larger proportion of neuron pairs with increased coherence at 7-10 Hz compared with regular 130-Hz DBS, which suggested that long pauses (interpulse interval >50 ms) during random DBS facilitated abnormal low-frequency oscillations in the basal ganglia. These results suggest that the efficacy of high-frequency DBS stems from its ability to regularize patterns of neuronal firing and thereby suppress abnormal oscillatory neural activity within the basal ganglia. Copyright © 2016 the American Physiological Society.

Visualizing geographic and temporal trends in rotavirus activity in the United States, 1991 to 1996. National Respiratory and Enteric Virus Surveillance System Collaborating Laboratories.

PubMed

Török, T J; Kilgore, P E; Clarke, M J; Holman, R C; Bresee, J S; Glass, R I

1997-10-01

Rotavirus is the leading cause of severe pediatric gastroenteritis worldwide. A vaccine may soon be licensed for use in the United States to prevent this disease. To characterize US geographic and temporal trends in rotavirus activity, we made contour maps showing the timing of peak rotavirus activity. From July, 1991, through June, 1996, 79 laboratories participating in the National Respiratory and Enteric Virus Surveillance System reported on a weekly basis the number of stool specimens that tested positive for rotavirus. The peak weeks in rotavirus detections from each laboratory were mapped using kriging, a modeling technique originally developed for geostatistics. During the 5-year period 118,716 fecal specimens were examined, of which 27,616 (23%) were positive for rotavirus. Timing of rotavirus activity varied by geographic location in a characteristic pattern in which peak activity occurred first in the Southwest from October through December and last in the Northeast in April or May. The Northwest exhibited considerable year-to-year variability (range, December to May) in the timing of peak activity, whereas the temporal pattern in the remainder of the contiguous 48 states was relatively constant. Kriging is a useful method for visualizing geographic and temporal trends in rotavirus activity in the United States. This analysis confirmed trends reported in previous years, and it also identified unexpected variability in the timing of peak rotavirus activity in the Northwest. The causes of the seasonal differences in rotavirus activity by region are unknown. Tracking of laboratory detections of rotavirus may provide an effective surveillance tool to assess the impact of a rotavirus vaccination campaign in the United States.

Physical Activity Patterns of Acute Stroke Patients Managed in a Rehabilitation Focused Stroke Unit

PubMed Central

2013-01-01

Background. Comprehensive stroke unit care, incorporating acute care and rehabilitation, may promote early physical activity after stroke. However, previous information regarding physical activity specific to the acute phase of stroke and the comprehensive stroke unit setting is limited to one stroke unit. This study describes the physical activity undertaken by patients within 14 days after stroke admitted to a comprehensive stroke unit. Methods. This study was a prospective observational study. Behavioural mapping was used to determine the proportion of the day spent in different activities. Therapist reports were used to determine the amount of formal therapy received on the day of observation. The timing of commencement of activity out of bed was obtained from the medical records. Results. On average, patients spent 45% (SD 25) of the day in some form of physical activity and received 58 (SD 34) minutes per day of physiotherapy and occupational therapy combined. Mean time to first mobilisation out of bed was 46 (SD 32) hours post-stroke. Conclusions. This study suggests that commencement of physical activity occurs earlier and physical activity is at a higher level early after stroke in this comprehensive stroke unit, when compared to studies of other acute stroke models of care. PMID:24024192

Wildfire atlas of the northeastern and north central states.

Treesearch

Donald A. Haines; Von J. Johnson; William A. Main

1975-01-01

Describes patterns of forest fire activity across the northeastern and north central United States. Gives average dates of greening ad curing of herbaceous plants, medium size of fires in various fuels, and annual profiles of peak fire activity. It also examines combinations of major fire cause and day-of-week activity.

Dynamical origin of complex motor patterns

NASA Astrophysics Data System (ADS)

Alonso, L. M.; Alliende, J. A.; Mindlin, G. B.

2010-11-01

Behavior emerges as the nervous system generates motor patterns in charge of driving a peripheral biomechanical device. For several cases in the animal kingdom, it has been identified that the motor patterns used in order to accomplish a diversity of tasks are the different solutions of a simple, low dimensional nonlinear dynamical system. Yet, motor patterns emerge from the interaction of an enormous number of individual dynamical units. In this work, we study the dynamics of the average activity of a large set of coupled excitable units which are periodically forced. We show that low dimensional, yet non trivial dynamics emerges. As a case study, we analyze the air sac pressure patterns used by domestic canaries during song, which consists of a succession of repetitions of different syllable types. We show that the pressure patterns used to generate different syllables can be approximated by the solutions of the investigated model. In this way, we are capable of integrating different description scales of our problem.

Changes in muscle fiber conduction velocity indicate recruitment of distinct motor unit populations.

PubMed

Houtman, C J; Stegeman, D F; Van Dijk, J P; Zwarts, M J

2003-09-01

To obtain more insight into the changes in mean muscle fiber conduction velocity (MFCV) during sustained isometric exercise at relatively low contraction levels, we performed an in-depth study of the human tibialis anterior muscle by using multichannel surface electromyogram. The results show an increase in MFCV after an initial decrease of MFCV at 30 or 40% maximum voluntary contraction in all of the five subjects studied. With a peak velocity analysis, we calculated the distribution of conduction velocities of action potentials in the bipolar electromyogram signal. It shows two populations of peak velocities occurring simultaneously halfway through the exercise. The MFCV pattern implies the recruitment of two different populations of motor units. Because of the lowering of MFCV of the first activated population of motor units, the newly recruited second population of motor units becomes visible. It is most likely that the MFCV pattern can be ascribed to the fatiguing of already recruited predominantly type I motor units, followed by the recruitment of fresh, predominantly type II, motor units.

Hip position and sex differences in motor unit firing patterns of the vastus medialis and vastus medialis oblique in healthy individuals.

PubMed

Peng, Yi-Ling; Tenan, Matthew S; Griffin, Lisa

2018-06-01

Weakness of the vastus medialis oblique (VMO) has been proposed to explain the high prevalence of knee pain in female subjects. Clinicians commonly use exercises in an attempt to preferentially activate the VMO. Recently, our group found evidence to support clinical theory that the VMO is neurologically distinct from the vastus medialis (VM). However, the ability to voluntarily activate these muscle subsections is still disputed. The aim of this study was to determine if VM and VMO activation varies between sexes and if control of the two muscles is different between rehabilitation exercises. Thirteen men and 13 women performed isometric straight leg raises in two hip positions, neutral hip rotation and 30 degrees lateral hip rotation. Bipolar intramuscular fine-wire electrodes were inserted into the VM and VMO to obtain motor unit recruitment thresholds and initial firing rates at recruitment. Linear mixed models and Tukey post hoc tests were used to assess significant differences in 654 motor units. Women demonstrated faster motor unit firing rate at recruitment, 1.18 ± 0.56 Hz higher than men. Motor units fired 0.47 ± 0.19 Hz faster during neutral hip rotation compared with lateral hip rotation. The VMO motor units were recruited 2.92 ± 1.28% earlier than the VM. All motor units were recruited 3.74 ± 1.27% earlier during neutral hip rotation than lateral hip rotation. Thus the VM and the VMO can be activated differentially, and their motor unit recruitment properties are affected by sex and hip position. NEW & NOTEWORTHY This is the first study to reveal differential activation of the vastus medialis oblique from the vastus medialis in clinical exercise protocols. Our research group used fine-wire electrodes to examine EMG signals of the vastus medialis oblique and vastus medialis to avoid possible cross talk. We also consider the effect of sex on motor unit firing patterns because of higher prevalence of knee pain in women, and yet few studies evaluating the sex differences in neuromuscular control.

A Mathematical Exploration of "Grandpa's Quilt"

ERIC Educational Resources Information Center

Reynolds, Anne; Cassel, Darlinda; Lillard, Eileen

2006-01-01

This article describes a mathematics unit developed with second-grade students based on the story, "Grandpa's Quilt." The activities encourage students to make connections with a number of areas of mathematics, particularly patterns and relationships, measurement, geometry, and spatial sense as well as multiplication activities. (Contains 7…

Adaptable Inquiry-Based Activities about National Patterns of Coal and Energy Use

ERIC Educational Resources Information Center

Bembenic, Meredith Hill; Cratsley, Chira Endress; Hartwell, Bradley; Guertin, Laura; Furman, Tanya

2012-01-01

As the United States strives to achieve energy independence, students need to be literate about energy and environmental issues. In this article, the authors present a lesson about the nation's electricity resources that is part 1 of a free, comprehensive unit on coal and energy that is available online (http://tinyurl.com/coalenergyunit). The…

Social Embeddedness and Late-Life Parenthood: Community Activity, Close Ties, and Support Networks

ERIC Educational Resources Information Center

Wenger, G. Clare; Dykstra, Pearl A.; Melkas, Tuula; Knipscheer, Kees C. P. M.

2007-01-01

This article focuses on the ways in which patterns of marriage and fertility shape older people's involvement in community groups and their support networks. The data are from Australia, Finland, Germany, Israel, Japan, the Netherlands, Spain, the United Kingdom, and the United States. Findings show that childless older adults, regardless of…

Spatiotemporal patterns of unburned areas within fire perimeters in the northwestern United States from 1984 to 2014

Treesearch

Arjan J. H. Meddens; Crystal A. Kolden; James A. Lutz; John T. Abatzoglou; Andrew T. Hudak

2018-01-01

A warming climate, fire exclusion, and land cover changes are altering the conditions that produced historical fire regimes and facilitating increased recent wildfire activity in the northwestern United States. Understanding the impacts of changing fire regimes on forest recruitment and succession, species distributions, carbon cycling, and ecosystem services is...

Neuronal pattern separation of motion-relevant input in LIP activity

PubMed Central

Berberian, Nareg; MacPherson, Amanda; Giraud, Eloïse; Richardson, Lydia

2016-01-01

In various regions of the brain, neurons discriminate sensory stimuli by decreasing the similarity between ambiguous input patterns. Here, we examine whether this process of pattern separation may drive the rapid discrimination of visual motion stimuli in the lateral intraparietal area (LIP). Starting with a simple mean-rate population model that captures neuronal activity in LIP, we show that overlapping input patterns can be reformatted dynamically to give rise to separated patterns of neuronal activity. The population model predicts that a key ingredient of pattern separation is the presence of heterogeneity in the response of individual units. Furthermore, the model proposes that pattern separation relies on heterogeneity in the temporal dynamics of neural activity and not merely in the mean firing rates of individual neurons over time. We confirm these predictions in recordings of macaque LIP neurons and show that the accuracy of pattern separation is a strong predictor of behavioral performance. Overall, results propose that LIP relies on neuronal pattern separation to facilitate decision-relevant discrimination of sensory stimuli. NEW & NOTEWORTHY A new hypothesis is proposed on the role of the lateral intraparietal (LIP) region of cortex during rapid decision making. This hypothesis suggests that LIP alters the representation of ambiguous inputs to reduce their overlap, thus improving sensory discrimination. A combination of computational modeling, theoretical analysis, and electrophysiological data shows that the pattern separation hypothesis links neural activity to behavior and offers novel predictions on the role of LIP during sensory discrimination. PMID:27881719

Design and realization of an active SAR calibrator for TerraSAR-X

NASA Astrophysics Data System (ADS)

Dummer, Georg; Lenz, Rainer; Lutz, Benjamin; Kühl, Markus; Müller-Glaser, Klaus D.; Wiesbeck, Werner

2005-10-01

TerraSAR-X is a new earth observing satellite which will be launched in spring 2006. It carries a high resolution X-band SAR sensor. For high image data quality, accurate ground calibration targets are necessary. This paper describes a novel system concept for an active and highly integrated, digitally controlled SAR system calibrator. A total of 16 active transponder and receiver systems and 17 receiver only systems will be fabricated for a calibration campaign. The calibration units serve for absolute radiometric calibration of the SAR image data. Additionally, they are equipped with an extra receiver path for two dimensional satellite antenna pattern recognition. The calibrator is controlled by a dedicated digital Electronic Control Unit (ECU). The different voltages needed by the calibrator and the ECU are provided by the third main unit called Power Management Unit (PMU).

Encoding Time in Feedforward Trajectories of a Recurrent Neural Network Model.

PubMed

Hardy, N F; Buonomano, Dean V

2018-02-01

Brain activity evolves through time, creating trajectories of activity that underlie sensorimotor processing, behavior, and learning and memory. Therefore, understanding the temporal nature of neural dynamics is essential to understanding brain function and behavior. In vivo studies have demonstrated that sequential transient activation of neurons can encode time. However, it remains unclear whether these patterns emerge from feedforward network architectures or from recurrent networks and, furthermore, what role network structure plays in timing. We address these issues using a recurrent neural network (RNN) model with distinct populations of excitatory and inhibitory units. Consistent with experimental data, a single RNN could autonomously produce multiple functionally feedforward trajectories, thus potentially encoding multiple timed motor patterns lasting up to several seconds. Importantly, the model accounted for Weber's law, a hallmark of timing behavior. Analysis of network connectivity revealed that efficiency-a measure of network interconnectedness-decreased as the number of stored trajectories increased. Additionally, the balance of excitation (E) and inhibition (I) shifted toward excitation during each unit's activation time, generating the prediction that observed sequential activity relies on dynamic control of the E/I balance. Our results establish for the first time that the same RNN can generate multiple functionally feedforward patterns of activity as a result of dynamic shifts in the E/I balance imposed by the connectome of the RNN. We conclude that recurrent network architectures account for sequential neural activity, as well as for a fundamental signature of timing behavior: Weber's law.

Physical activity patterns among Latinos in the United States: putting the pieces together.

PubMed

Ham, Sandra A; Yore, Michelle M; Kruger, Judy; Heath, Gregory W; Moeti, Refilwe

2007-10-01

Estimates of participation in physical activity among Latinos are inconsistent across studies. To obtain better estimates and examine possible reasons for inconsistencies, we assessed 1) patterns of participation in various categories of physical activity among Latino adults, 2) changes in their activity patterns with acculturation, and 3) variations in their activity patterns by region of origin. Using data from four national surveillance systems (the National Health and Nutrition Examination Survey, 1999-2002; the Behavioral Risk Factor Surveillance System, 2003; the National Household Travel Survey, 2001; and the National Health Interview Survey Cancer Supplement, 2000), we estimated the percentage of Latinos who participated at least once per week in leisure-time, household, occupational, or transportation-related physical activity, as well as in an active pattern of usual daily activity. We reported prevalences by acculturation measures and region of origin. The percentage of Latinos who participated in the various types of physical activity ranged from 28.7% for having an active level of usual daily activity (usually walking most of the day and usually carrying or lifting objects) to 42.8% for participating in leisure-time physical activity at least once per week. The percentage who participated in leisure-time and household activities increased with acculturation, whereas the percentage who participated in occupational and transportation-related activities decreased with acculturation. Participation in an active level of usual daily activity did not change significantly. The prevalence of participation in transportation-related physical activity and of an active level of usual daily activity among Latino immigrants varied by region of origin. Physical activity patterns among Latinos vary with acculturation and region of origin. To assess physical activity levels in Latino communities, researchers should measure all types of physical activity and the effects of acculturation on each type of activity.

Evolution of rDNA in Nicotiana Allopolyploids: A Potential Link between rDNA Homogenization and Epigenetics

PubMed Central

Kovarik, Ales; Dadejova, Martina; Lim, Yoong K.; Chase, Mark W.; Clarkson, James J.; Knapp, Sandra; Leitch, Andrew R.

2008-01-01

Background The evolution and biology of rDNA have interested biologists for many years, in part, because of two intriguing processes: (1) nucleolar dominance and (2) sequence homogenization. We review patterns of evolution in rDNA in the angiosperm genus Nicotiana to determine consequences of allopolyploidy on these processes. Scope Allopolyploid species of Nicotiana are ideal for studying rDNA evolution because phylogenetic reconstruction of DNA sequences has revealed patterns of species divergence and their parents. From these studies we also know that polyploids formed over widely different timeframes (thousands to millions of years), enabling comparative and temporal studies of rDNA structure, activity and chromosomal distribution. In addition studies on synthetic polyploids enable the consequences of de novo polyploidy on rDNA activity to be determined. Conclusions We propose that rDNA epigenetic expression patterns established even in F1 hybrids have a material influence on the likely patterns of divergence of rDNA. It is the active rDNA units that are vulnerable to homogenization, which probably acts to reduce mutational load across the active array. Those rDNA units that are epigenetically silenced may be less vulnerable to sequence homogenization. Selection cannot act on these silenced genes, and they are likely to accumulate mutations and eventually be eliminated from the genome. It is likely that whole silenced arrays will be deleted in polyploids of 1 million years of age and older. PMID:18310159

Sleep/wake firing patterns of human genioglossus motor units.

PubMed

Bailey, E Fiona; Fridel, Keith W; Rice, Amber D

2007-12-01

Although studies of the principal tongue protrudor muscle genioglossus (GG) suggest that whole muscle GG electromyographic (EMG) activities are preserved in nonrapid eye movement (NREM) sleep, it is unclear what influence sleep exerts on individual GG motor unit (MU) activities. We characterized the firing patterns of human GG MUs in wakefulness and NREM sleep with the aim of determining 1) whether the range of MU discharge patterns evident in wakefulness is preserved in sleep and 2) what effect the removal of the "wakefulness" input has on the magnitude of the respiratory modulation of MU activities. Microelectrodes inserted into the extrinsic tongue protrudor muscle, the genioglossus, were used to follow the discharge of single MUs. We categorized MU activities on the basis of the temporal relationship between the spike train and the respiration cycle and quantified the magnitude of the respiratory modulation of each MU using the eta (eta(2)) index, in wakefulness and sleep. The majority of MUs exhibited subtle increases or decreases in respiratory modulation but were otherwise unaffected by NREM sleep. In contrast, 30% of MUs exhibited marked sleep-associated changes in discharge frequency and respiratory modulation. We suggest that GG MUs should not be considered exclusively tonic or phasic; rather, the discharge pattern appears to be a flexible feature of GG activities in healthy young adults. Whether such flexibility is important in the response to changes in the chemical and/or mechanical environment and whether it is preserved as a function of aging or in individuals with obstructive sleep apnea are critical questions for future research.

Myosin Heavy Chain Composition of the Human Genioglossus Muscle

ERIC Educational Resources Information Center

Daugherty, Megan; Luo, Qingwei; Sokoloff, Alan J.

2012-01-01

Background: The human tongue muscle genioglossus (GG) is active in speech, swallowing, respiration, and oral transport, behaviors encompassing a wide range of tongue shapes and movement speeds. Studies demonstrate substantial diversity in patterns of human GG motor unit activation, but whether this is accompanied by complex expression of muscle…

Tiling, Tessellating and Quilting.

ERIC Educational Resources Information Center

Young, Sandy

1994-01-01

Describes a three-week unit that explores the mathematical concept of spatial sense through literature books, moving from activities of tiling, to tessellation, to quilting, and ending with transfer of patterns to T-shirts. (BB)

The Adventures of the Gray Whale: An Integrated Approach to Learning about the Long Migration

ERIC Educational Resources Information Center

Britton, Stacey; Tippins, Deborah; Cajigal, Aris; Cox, Melissa; Cole, Gerri; Vazquez, Max; Trejo, Martha Cabrera; Guzman, Amelia

2010-01-01

Using migration as a springboard, students can begin to understand patterns of survival and interdependence that exist within nature, as well as humankind's role in modifying these patterns. This mini-unit involves a series of integrated activities designed to take middle school students (fifth through eighth grades) on a journey of the eastern…

Implications of Boy Scout group use of public lands for natural resource managers: a regional comparison

Treesearch

Gail A. Vander Stoep

1992-01-01

Resource managers can apply group-specific rather than generic communications and management strategies to different public land user groups. This study compares use patterns of one user group, Boy Scout troops, from two regions of the United States. It identifies their public land use patterns, activities, needs, and motivations. Results can be used by resource...

Motor unit recruitment in human genioglossus muscle in response to hypercapnia.

PubMed

Nicholas, Christian L; Bei, Bei; Worsnop, Christopher; Malhotra, Atul; Jordan, Amy S; Saboisky, Julian P; Chan, Julia K M; Duckworth, Ella; White, David P; Trinder, John

2010-11-01

single motor unit recordings of the genioglossus (GG) muscle indicate that GG motor units have a variety of discharge patterns, including units that have higher discharge rates during inspiration (inspiratory phasic and inspiratory tonic), or expiration (expiratory phasic and expiratory tonic), or do not modify their rate with respiration (tonic). Previous studies have shown that an increase in GG muscle activity is a consequence of increased activity in inspiratory units. However, there are differences between studies as to whether this increase is primarily due to recruitment of new motor units (motor unit recruitment) or to increased discharge rate of already active units (rate coding). Sleep-wake state studies in humans have suggested the former, while hypercapnia experiments in rats have suggested the latter. In this study, we investigated the effect of hypercapnia on GG motor unit activity in humans during wakefulness. sleep research laboratory. sixteen healthy men. each participant was administered at least 6 trials with P(et)CO(2) being elevated 8.4 (SD = 1.96) mm Hg over 2 min following a 30-s baseline. Subjects were instrumented for GG EMG and respiratory measurements with 4 fine wire electrodes inserted subcutaneously into the muscle. One hundred forty-one motor units were identified during the baseline: 47% were inspiratory modulated, 29% expiratory modulated, and 24% showed no respiratory related modulation. Sixty-two new units were recruited during hypercapnia. The distribution of recruited units was significantly different from the baseline distribution, with 84% being inspiratory modulated (P < 0.001). Neither units active during baseline, nor new units recruited during hypercapnia, increased their discharge rate as P(et)CO(2) increased (P > 0.05 for all comparisons). increased GG muscle activity in humans occurs because of recruitment of previously inactive inspiratory modulated units.

Fractal Patterns of Neural Activity Exist within the Suprachiasmatic Nucleus and Require Extrinsic Network Interactions

PubMed Central

Hu, Kun; Meijer, Johanna H.; Shea, Steven A.; vanderLeest, Henk Tjebbe; Pittman-Polletta, Benjamin; Houben, Thijs; van Oosterhout, Floor; Deboer, Tom; Scheer, Frank A. J. L.

2012-01-01

The mammalian central circadian pacemaker (the suprachiasmatic nucleus, SCN) contains thousands of neurons that are coupled through a complex network of interactions. In addition to the established role of the SCN in generating rhythms of ∼24 hours in many physiological functions, the SCN was recently shown to be necessary for normal self-similar/fractal organization of motor activity and heart rate over a wide range of time scales—from minutes to 24 hours. To test whether the neural network within the SCN is sufficient to generate such fractal patterns, we studied multi-unit neural activity of in vivo and in vitro SCNs in rodents. In vivo SCN-neural activity exhibited fractal patterns that are virtually identical in mice and rats and are similar to those in motor activity at time scales from minutes up to 10 hours. In addition, these patterns remained unchanged when the main afferent signal to the SCN, namely light, was removed. However, the fractal patterns of SCN-neural activity are not autonomous within the SCN as these patterns completely broke down in the isolated in vitro SCN despite persistence of circadian rhythmicity. Thus, SCN-neural activity is fractal in the intact organism and these fractal patterns require network interactions between the SCN and extra-SCN nodes. Such a fractal control network could underlie the fractal regulation observed in many physiological functions that involve the SCN, including motor control and heart rate regulation. PMID:23185285

Activity Parameters of Subthalamic Nucleus Neurons Selectively Predict Motor Symptom Severity in Parkinson's Disease

PubMed Central

Gulberti, Alessandro; Zittel, Simone; Tudor Jones, Adam A.; Fickel, Ulrich; Münchau, Alexander; Köppen, Johannes A.; Gerloff, Christian; Westphal, Manfred; Buhmann, Carsten; Hamel, Wolfgang; Engel, Andreas K.

2014-01-01

Parkinson's disease (PD) is a heterogeneous disorder that leads to variable expression of several different motor symptoms. While changes in firing rate, pattern, and oscillation of basal ganglia neurons have been observed in PD patients and experimental animals, there is limited evidence linking them to specific motor symptoms. Here we examined this relationship using extracellular recordings of subthalamic nucleus neurons from 19 PD patients undergoing surgery for deep brain stimulation. For each patient, ≥10 single units and/or multi-units were recorded in the OFF medication state. We correlated the proportion of neurons displaying different activities with preoperative Unified Parkinson's Disease Rating Scale subscores (OFF medication). The mean spectral power at sub-beta frequencies and percentage of units oscillating at beta frequencies were positively correlated with the axial and limb rigidity scores, respectively. The percentage of units oscillating at gamma frequency was negatively correlated with the bradykinesia scores. The mean intraburst rate was positively correlated with both bradykinesia and axial scores, while the related ratio of interspike intervals below/above 10 ms was positively correlated with these symptoms and limb rigidity. None of the activity parameters correlated with tremor. The grand average of all the significantly correlated subthalamic nucleus activities accounted for >60% of the variance of the combined bradykinetic-rigid and axial scores. Our results demonstrate that the occurrence of alterations in the rate and pattern of basal ganglia neurons could partly underlie the variability in parkinsonian phenotype. PMID:24790198

Predesigned surface patterns and topological defects control the active matter.

NASA Astrophysics Data System (ADS)

Turiv, Taras; Peng, Chenhui; Guo, Yubing; Wei, Qi-Huo; Lavrentovich, Oleg

Active matter exhibits remarkable patterns of never-ending dynamics with giant fluctuations of concentration, varying order, nucleating and annihilating topological defects. These patterns can be seen in active systems of both biological and artificial origin. A fundamental question is whether and how one can control this chaotic out-of-equilibrium behavior. We demonstrate a robust control of local concentration, trajectories of active self-propelled units and the net flows of active bacteria Bacillus Substilis by imposing pre-designed surface patterns of orientational order in a water-based lyotropic chromonic liquid crystal. The patterns force the bacteria to gather into dynamic swarms with spatially modulated concentration and well-defined polarity of motion. Topological defects produce net motion of bacteria with a unidirectional circulation, while pairs of defects induce a pumping action. The qualitative features of the dynamics can be explained by interplay of curvature and activity, in particular, by ability of mixed splay-bend curvatures to generate threshold-less active flows. The demonstrated level of control opens opportunities in engineering materials and devices that mimic rich functionality of living systems. This work was supported by NSF Grants DMR-1507637, DMS-1434185, CMMI-1436565, by the Petroleum Research Grant PRF# 56046-ND7 administered by the American Chemical Society.

The Concept of Culture and Sojourner Assimilation into the Host Environment: An Example of Foreign Students in the United States.

ERIC Educational Resources Information Center

Okoli, Emeka Jonathan

Accepting a definition of culture as "the total accumulation of an identifiable group's beliefs, norms, activities, institutions, and communication patterns," this paper, in an extensive literature review, conjectures that the environment has a far-reaching impact on the performance of the foreign student in the United States. The paper…

Grade 10 Thai students' scientific argumentation in learning about electric field through science, technology, and society (STS) approach

NASA Astrophysics Data System (ADS)

Chitnork, Amporn; Yuenyong, Chokchai

2018-01-01

The research aimed to enhance Grade 10 Thai students' scientific argumentation in learning about electric field through science, technology, and society (STS) approach. The participants included 45 Grade 10 students who were studying in a school in Nongsonghong, Khon Kaen, Thailand. Methodology regarded interpretive paradigm. The intervention was the force unit which was provided based on Yuenyong (2006) STS approach. Students learned about the STS electric field unit for 4 weeks. The students' scientific argumentation was interpreted based on Toulmin's argument pattern or TAP. The TAP provided six components of argumentation including data, claim, warrants, qualifiers, rebuttals and backing. Tools of interpretation included students' activity sheets, conversation, journal writing, classroom observation and interview. The findings revealed that students held the different pattern of argumentation. Then, they change pattern of argumentation close to the TAP. It indicates that the intervention of STS electric field unit enhance students to develop scientific argumentation. This finding may has implication of further enhancing scientific argumentation in Thailand.

Participating in Sport and Music Activities in Adolescence: The Role of Activity Participation and Motivational Beliefs during Elementary School

ERIC Educational Resources Information Center

Simpkins, Sandra D.; Vest, Andrea E.; Becnel, Jennifer N.

2010-01-01

This investigation examined the precursors of adolescents' participation in sport and music activities in the United States by testing a developmental model across 7 years. Data were drawn from youth questionnaires in the Childhood and Beyond Study (92% European American; N = 594). Findings suggest that patterns of participation across a 3-year…

Self-organization of network dynamics into local quantized states

DOE PAGES

Nicolaides, Christos; Juanes, Ruben; Cueto-Felgueroso, Luis

2016-02-17

Self-organization and pattern formation in network-organized systems emerges from the collective activation and interaction of many interconnected units. A striking feature of these non-equilibrium structures is that they are often localized and robust: only a small subset of the nodes, or cell assembly, is activated. Understanding the role of cell assemblies as basic functional units in neural networks and socio-technical systems emerges as a fundamental challenge in network theory. A key open question is how these elementary building blocks emerge, and how they operate, linking structure and function in complex networks. Here we show that a network analogue of themore » Swift-Hohenberg continuum model—a minimal-ingredients model of nodal activation and interaction within a complex network—is able to produce a complex suite of localized patterns. Thus, the spontaneous formation of robust operational cell assemblies in complex networks can be explained as the result of self-organization, even in the absence of synaptic reinforcements.« less

Self-organization of network dynamics into local quantized states.

PubMed

Nicolaides, Christos; Juanes, Ruben; Cueto-Felgueroso, Luis

2016-02-17

Self-organization and pattern formation in network-organized systems emerges from the collective activation and interaction of many interconnected units. A striking feature of these non-equilibrium structures is that they are often localized and robust: only a small subset of the nodes, or cell assembly, is activated. Understanding the role of cell assemblies as basic functional units in neural networks and socio-technical systems emerges as a fundamental challenge in network theory. A key open question is how these elementary building blocks emerge, and how they operate, linking structure and function in complex networks. Here we show that a network analogue of the Swift-Hohenberg continuum model-a minimal-ingredients model of nodal activation and interaction within a complex network-is able to produce a complex suite of localized patterns. Hence, the spontaneous formation of robust operational cell assemblies in complex networks can be explained as the result of self-organization, even in the absence of synaptic reinforcements.

Self-organization of network dynamics into local quantized states

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

Nicolaides, Christos; Juanes, Ruben; Cueto-Felgueroso, Luis

Self-organization and pattern formation in network-organized systems emerges from the collective activation and interaction of many interconnected units. A striking feature of these non-equilibrium structures is that they are often localized and robust: only a small subset of the nodes, or cell assembly, is activated. Understanding the role of cell assemblies as basic functional units in neural networks and socio-technical systems emerges as a fundamental challenge in network theory. A key open question is how these elementary building blocks emerge, and how they operate, linking structure and function in complex networks. Here we show that a network analogue of themore » Swift-Hohenberg continuum model—a minimal-ingredients model of nodal activation and interaction within a complex network—is able to produce a complex suite of localized patterns. Thus, the spontaneous formation of robust operational cell assemblies in complex networks can be explained as the result of self-organization, even in the absence of synaptic reinforcements.« less

Understanding Skill in EVA Mass Handling. Volume 3; Empirical Developments and Conclusions

NASA Technical Reports Server (NTRS)

Riccio, Gary E.; McDonald, P. Vernon

1998-01-01

Key attributes of skilled mass handling were identified through an examination of lessons learned by the extravehicular activity operational community. These qualities were translated into measurable quantities. The operational validity of the ground-based investigation was improved by building a device that increased the degrees of freedom of extravehicular mobility unit motion on the Precision Air-Bearing Floor. The results revealed subtle patterns of interaction between motions of an orbital replacement unit mockup and mass handler that should be important for effective performance on orbit. The investigation also demonstrated that such patterns can be measured with a variety of common instruments and under imperfect conditions of observation.

Introduction to Sea Island Folklife.

ERIC Educational Resources Information Center

Twining, Mary A.; Baird, Keith E.

1980-01-01

Examines the economic activity, language, world view, kinship patterns, and religion of contemporary Sea Islanders in order to illustrate the Islands' cultural conservatism and, thus, their appropriateness for the study of Africanism in the United States. (GC)

Large-scale patterns of insect and disease activity in the conterminous United States and Alaska from the National Insect and Disease Detection Survey Database, 2010

Treesearch

Kevin M. Potter; Jeanine L. Paschke

2013-01-01

Analyzing patterns of forest pest infestations, diseases occurrences, forest declines and related biotic stress factors is necessary to monitor the health of forested ecosystems and their potential impacts on forest structure, composition, biodiversity, and species distributions (Castello and others 1995). Introduced nonnative insects and diseases, in particular, can...

Large-scale patterns of insect and disease activity in the conterminous United States and Alaska from the national insect and disease detection survey, 2009

Treesearch

Kevin M. Potter

2013-01-01

Analyzing patterns of forest pest infestation, disease occurrences, forest declines, and related biotic stress factors is necessary to monitor the health of forested ecosystems and their potential impacts on forest structure, composition, biodiversity, and species distributions (Castello and others 1995). Introduced nonnative insects and diseases, in particular, can...

Useful Spanish for Medical and Hospital Personnel with a Bibliography on Hispanic Peoples in the United States.

ERIC Educational Resources Information Center

Cordasco, Francesco; Alvarez, Pablo Rivera

The manual gives vocabulary and sentence patterns which are considered basic or essential to medical personnel who work with Spanish-speaking patients. In most instances, only one way is given to express an idea or to ask a question. Sentence patterns and vocabulary that should be made active are repeated many times. The manual includes (1)…

Interannual variations in fire weather, fire extent, and synoptic-scale circulation patterns in northern California and Oregon

Treesearch

Valerie Trouet; Alan H. Taylor; Andrew M. Carleton; Carl N. Skinner

2009-01-01

The Mediterranean climate region on the west coast of the United States is characterized by wet winters and dry summers, and by high fire activity. The importance of synoptic-scale circulation patterns (ENSO, PDO, PNA) on fire-climate interactions is evident in contemporary fire data sets and in pre-Euroamerican tree-ring-based fire records. We investigated how...

Spatial distribution of 12 class B notifiable infectious diseases in China: A retrospective study.

PubMed

Zhu, Bin; Fu, Yang; Liu, Jinlin; Mao, Ying

2018-01-01

China is the largest developing country with a relatively developed public health system. To further prevent and eliminate the spread of infectious diseases, China has listed 39 notifiable infectious diseases characterized by wide prevalence or great harm, and classified them into classes A, B, and C, with severity decreasing across classes. Class A diseases have been almost eradicated in China, thus making class B diseases a priority in infectious disease prevention and control. In this retrospective study, we analyze the spatial distribution patterns of 12 class B notifiable infectious diseases that remain active all over China. Global and local Moran's I and corresponding graphic tools are adopted to explore and visualize the global and local spatial distribution of the incidence of the selected epidemics, respectively. Inter-correlations of clustering patterns of each pair of diseases and a cumulative summary of the high/low cluster frequency of the provincial units are also provided by means of figures and maps. Of the 12 most commonly notifiable class B infectious diseases, viral hepatitis and tuberculosis show high incidence rates and account for more than half of the reported cases. Almost all the diseases, except pertussis, exhibit positive spatial autocorrelation at the provincial level. All diseases feature varying spatial concentrations. Nevertheless, associations exist between spatial distribution patterns, with some provincial units displaying the same type of cluster features for two or more infectious diseases. Overall, high-low (unit with high incidence surrounded by units with high incidence, the same below) and high-high spatial cluster areas tend to be prevalent in the provincial units located in western and southwest China, whereas low-low and low-high spatial cluster areas abound in provincial units in north and east China. Despite the various distribution patterns of 12 class B notifiable infectious diseases, certain similarities between their spatial distributions are present. Substantial evidence is available to support disease-specific, location-specific, and disease-combined interventions. Regarding provinces that show high-high/high-low patterns of multiple diseases, comprehensive interventions targeting different diseases should be established. As to the adjacent provincial units revealing similar patterns, coordinated actions need to be taken across borders.

Status of native fishes in the western United States and issues for fire and fuels management

Treesearch

Bruce Rieman; Danny Lee; Dave Burns; Robert Gresswell; Michael Young; Rick Stowell; John Rinne; Philip Howell

2003-01-01

Conservation of native fishes and changing patterns in wildfire and fuels are defining challenges for managers of forested landscapes in the western United States. Many species and populations of native fishes have declined in recorded history and some now occur as isolated remnants of what once were larger more complex systems. Land management activities have been...

Theta and gamma coordination of hippocampal networks during waking and rapid eye movement sleep.

PubMed

Montgomery, Sean M; Sirota, Anton; Buzsáki, György

2008-06-25

Rapid eye movement (REM) sleep has been considered a paradoxical state because, despite the high behavioral threshold to arousing perturbations, gross physiological patterns in the forebrain resemble those of waking states. To understand how intrahippocampal networks interact during REM sleep, we used 96 site silicon probes to record from different hippocampal subregions and compared the patterns of activity during waking exploration and REM sleep. Dentate/CA3 theta and gamma synchrony was significantly higher during REM sleep compared with active waking. In contrast, gamma power in CA1 and CA3-CA1 gamma coherence showed significant decreases in REM sleep. Changes in unit firing rhythmicity and unit-field coherence specified the local generation of these patterns. Although these patterns of hippocampal network coordination characterized the more common tonic periods of REM sleep (approximately 95% of total REM), we also detected large phasic bursts of local field potential power in the dentate molecular layer that were accompanied by transient increases in the firing of dentate and CA1 neurons. In contrast to tonic REM periods, phasic REM epochs were characterized by higher theta and gamma synchrony among the dentate, CA3, and CA1 regions. These data suggest enhanced dentate processing, but limited CA3-CA1 coordination during tonic REM sleep. In contrast, phasic bursts of activity during REM sleep may provide windows of opportunity to synchronize the hippocampal trisynaptic loop and increase output to cortical targets. We hypothesize that tonic REM sleep may support off-line mnemonic processing, whereas phasic bursts of activity during REM may promote memory consolidation.

Heterogeneous neuronal firing patterns during interictal epileptiform discharges in the human cortex

PubMed Central

Keller, Corey J.; Truccolo, Wilson; Gale, John T.; Eskandar, Emad; Thesen, Thomas; Carlson, Chad; Devinsky, Orrin; Kuzniecky, Ruben; Doyle, Werner K.; Madsen, Joseph R.; Schomer, Donald L.; Mehta, Ashesh D.; Brown, Emery N.; Hochberg, Leigh R.; Ulbert, István; Halgren, Eric

2010-01-01

Epileptic cortex is characterized by paroxysmal electrical discharges. Analysis of these interictal discharges typically manifests as spike–wave complexes on electroencephalography, and plays a critical role in diagnosing and treating epilepsy. Despite their fundamental importance, little is known about the neurophysiological mechanisms generating these events in human focal epilepsy. Using three different systems of microelectrodes, we recorded local field potentials and single-unit action potentials during interictal discharges in patients with medically intractable focal epilepsy undergoing diagnostic workup for localization of seizure foci. We studied 336 single units in 20 patients. Ten different cortical areas and the hippocampus, including regions both inside and outside the seizure focus, were sampled. In three of these patients, high density microelectrode arrays simultaneously recorded between 43 and 166 single units from a small (4 mm × 4 mm) patch of cortex. We examined how the firing rates of individual neurons changed during interictal discharges by determining whether the firing rate during the event was the same, above or below a median baseline firing rate estimated from interictal discharge-free periods (Kruskal–Wallis one-way analysis, P<0.05). Only 48% of the recorded units showed such a modulation in firing rate within 500 ms of the discharge. Units modulated during the discharge exhibited significantly higher baseline firing and bursting rates than unmodulated units. As expected, many units (27% of the modulated population) showed an increase in firing rate during the fast segment of the discharge (±35 ms from the peak of the discharge), while 50% showed a decrease during the slow wave. Notably, in direct contrast to predictions based on models of a pure paroxysmal depolarizing shift, 7.7% of modulated units recorded in or near the seizure focus showed a decrease in activity well ahead (0–300 ms) of the discharge onset, while 12.2% of units increased in activity in this period. No such pre-discharge changes were seen in regions well outside the seizure focus. In many recordings there was also a decrease in broadband field potential activity during this same pre-discharge period. The different patterns of interictal discharge-modulated firing were classified into more than 15 different categories. This heterogeneity in single unit activity was present within small cortical regions as well as inside and outside the seizure onset zone, suggesting that interictal epileptiform activity in patients with epilepsy is not a simple paroxysm of hypersynchronous excitatory activity, but rather represents an interplay of multiple distinct neuronal types within complex neuronal networks. PMID:20511283

Operant conditioning of synaptic and spiking activity patterns in single hippocampal neurons.

PubMed

Ishikawa, Daisuke; Matsumoto, Nobuyoshi; Sakaguchi, Tetsuya; Matsuki, Norio; Ikegaya, Yuji

2014-04-02

Learning is a process of plastic adaptation through which a neural circuit generates a more preferable outcome; however, at a microscopic level, little is known about how synaptic activity is patterned into a desired configuration. Here, we report that animals can generate a specific form of synaptic activity in a given neuron in the hippocampus. In awake, head-restricted mice, we applied electrical stimulation to the lateral hypothalamus, a reward-associated brain region, when whole-cell patch-clamped CA1 neurons exhibited spontaneous synaptic activity that met preset criteria. Within 15 min, the mice learned to generate frequently the excitatory synaptic input pattern that satisfied the criteria. This reinforcement learning of synaptic activity was not observed for inhibitory input patterns. When a burst unit activity pattern was conditioned in paired and nonpaired paradigms, the frequency of burst-spiking events increased and decreased, respectively. The burst reinforcement occurred in the conditioned neuron but not in other adjacent neurons; however, ripple field oscillations were concomitantly reinforced. Neural conditioning depended on activation of NMDA receptors and dopamine D1 receptors. Acutely stressed mice and depression model mice that were subjected to forced swimming failed to exhibit the neural conditioning. This learning deficit was rescued by repetitive treatment with fluoxetine, an antidepressant. Therefore, internally motivated animals are capable of routing an ongoing action potential series into a specific neural pathway of the hippocampal network.

Achieving Equity in Physical Activity Participation: ACSM Experience and Next Steps.

PubMed

Hasson, Rebecca E; Brown, David R; Dorn, Joan; Barkley, Lisa; Torgan, Carol; Whitt-Glover, Melicia; Ainsworth, Barbara; Keith, Nicole

2017-04-01

There is clear and consistent evidence that regular physical activity is an important component of healthy lifestyles and fundamental to promoting health and preventing disease. Despite the known benefits of physical activity participation, many people in the United States remain inactive. More specifically, physical activity behavior is socially patterned with lower participation rates among women; racial/ethnic minorities; sexual minority youth; individuals with less education; persons with physical, mental, and cognitive disabilities; individuals >65 yr of age; and those living in the southeast region of the United States. Many health-related outcomes follow a pattern that is similar to physical activity participation. In response to the problem of inequities in physical activity and overall health in the United States, the American College of Sports Medicine (ACSM) has developed a national roadmap that supports achieving health equity through a physically active lifestyle. The actionable, integrated pathways that provide the foundation of ACSM's roadmap include the following: 1) communication-raising awareness of the issue and magnitude of health inequities and conveying the power of physical activity in promoting health equity; 2) education-developing educational resources to improve cultural competency for health care providers and fitness professionals as well as developing new community-based programs for lay health workers; 3) collaboration-building partnerships and programs that integrate existing infrastructures and leverage institutional knowledge, reach, and voices of public, private, and community organizations; and 4) evaluation-ensuring that ACSM attains measurable progress in reducing physical activity disparities to promote health equity. This article provides a conceptual overview of these four pathways of ACSM's roadmap, an understanding of the challenges and advantages of implementing these components, and the organizational and economic benefits of achieving health equity.

Large-scale patterns of insect and disease activity in the Conterminous United States and Alaska from the National Insect and Disease Detection Survey Database, 2007 and 2008

Treesearch

Kevin M. Potter

2012-01-01

Analyzing patterns of forest pest infestation is necessary for monitoring the health of forested ecosystems because of the impacts that insects and diseases can have on forest structure, composition, biodiversity, and species distributions (Castello and others 1995). In particular, introduced nonnative insects and diseases can extensively damage the diversity, ecology...

Academic R&D Spending Maintains Growth from All Major Sources in FY 2001. Info Brief.

ERIC Educational Resources Information Center

Machen, M. Marge; Shackelford, Brandon

Data from the Academic Research and Development (R&D) Survey and other surveys were used to analyze patterns of R&D activity in the United States. For the purpose of this analysis, the most recent data update from the report "National Patterns of R&D Resources" adjusts university and college R&D performance to net out R&D expenditures reported as…

[Diagnosis and the technology for optimizing the medical support of a troop unit].

PubMed

Korshever, N G; Polkovov, S V; Lavrinenko, O V; Krupnov, P A; Anastasov, K N

2000-05-01

The work is devoted to investigation of the system of military unit medical support with the use of principles and states of organizational diagnosis; development of the method allowing to assess its functional activity; and determination of optimization trends. Basing on the conducted organizational diagnosis and expert inquiry the informative criteria were determined which characterize the stages of functioning of the military unit medical support system. To evaluate the success of military unit medical support the complex multi-criteria pattern was developed and algorithm of this process optimization was substantiated. Using the results obtained, particularly realization of principles and states of decision taking theory in machine program it is possible to solve more complex problem of comparison between any number of military units: to dispose them according to priority decrease; to select the programmed number of the best and worst; to determine the trends of activity optimization in corresponding medical service personnel.

Respiration-related discharge of hyoglossus muscle motor units in the rat.

PubMed

Powell, Gregory L; Rice, Amber; Bennett-Cross, Seres J; Fregosi, Ralph F

2014-01-01

Although respiratory muscle motor units have been studied during natural breathing, simultaneous measures of muscle force have never been obtained. Tongue retractor muscles, such as the hyoglossus (HG), play an important role in swallowing, licking, chewing, breathing, and, in humans, speech. The HG is phasically recruited during the inspiratory phase of the respiratory cycle. Moreover, in urethane anesthetized rats the drive to the HG waxes and wanes spontaneously, providing a unique opportunity to study motor unit firing patterns as the muscle is driven naturally by the central pattern generator for breathing. We recorded tongue retraction force, the whole HG muscle EMG and the activity of 38 HG motor units in spontaneously breathing anesthetized rats under low-force and high-force conditions. Activity in all cases was confined to the inspiratory phase of the respiratory cycle. Changes in the EMG were correlated significantly with corresponding changes in force, with the change in EMG able to predict 53-68% of the force variation. Mean and peak motor unit firing rates were greater under high-force conditions, although the magnitude of discharge rate modulation varied widely across the population. Changes in mean and peak firing rates were significantly correlated with the corresponding changes in force, but the correlations were weak (r(2) = 0.27 and 0.25, respectively). These data indicate that, during spontaneous breathing, recruitment of HG motor units plays a critical role in the control of muscle force, with firing rate modulation playing an important but lesser role.

Nicotine dependence and transitional shifts in exercise behavior among young U.S. adult smokers.

PubMed

Loprinzi, Paul D; Walker, Jerome F; Cardinal, Bradley J

2014-08-01

The aim of this study is to examine the association between nicotine dependence and longitudinal exercise transitional shift patterns among young U.S. adult daily smokers. Data from the 2003-2005 National Youth Smoking Cessation Survey was used, which is a longitudinal study over a two year period. Participants included 1168 US adult daily smokers (18-24years). Nicotine dependence was assessed using the modified Fagerstrom Test for Nicotine Dependence. Four transitional shift patterns were created based on meeting current exercise guidelines; stable inactive (inactive across time), activity relapsers (starts out active and then becomes inactive), activity adopters (inactive and then becomes active), and stable active (active across time). After adjustments, for every 1-unit increase in baseline nicotine dependence, participants had 16% (OR=1.16, p=0.01) greater odds of being in the stable inactive group compared to the stable active group. Nicotine dependence appears to play an important role in shaping longitudinal exercise patterns among young U.S. adult smokers. Copyright © 2014 Elsevier Inc. All rights reserved.

Relationships between solar activity and climate change

NASA Technical Reports Server (NTRS)

Roberts, W. O.

1975-01-01

The relationship between recurrent droughts in the High Plains of the United States and the double sunspot cycle is discussed in detail. It is suggested that high solar activity is generally related to an increase in meridional circulation and blocking patterns at high and intermediate latitudes, especially in winter, and the effect is related to the sudden formation of cirrus clouds during strong geomagnetic activity that originates in the solar corpuscular emission.

Ampullary Electroreceptors in Neurophysiological Instruction.

ERIC Educational Resources Information Center

Peters, R. C.; And Others

1988-01-01

Presents a model system designed for the electrophysiological investigation of single unit activity in intact anaesthetized animals. Illustrates how information is coded into action potential patterns by sense organs. Uses the ampullary electroreceptor of the brown bullhead catfish as an example. (Author/CW)

Dynamic information routing in complex networks

PubMed Central

Kirst, Christoph; Timme, Marc; Battaglia, Demian

2016-01-01

Flexible information routing fundamentally underlies the function of many biological and artificial networks. Yet, how such systems may specifically communicate and dynamically route information is not well understood. Here we identify a generic mechanism to route information on top of collective dynamical reference states in complex networks. Switching between collective dynamics induces flexible reorganization of information sharing and routing patterns, as quantified by delayed mutual information and transfer entropy measures between activities of a network's units. We demonstrate the power of this mechanism specifically for oscillatory dynamics and analyse how individual unit properties, the network topology and external inputs co-act to systematically organize information routing. For multi-scale, modular architectures, we resolve routing patterns at all levels. Interestingly, local interventions within one sub-network may remotely determine nonlocal network-wide communication. These results help understanding and designing information routing patterns across systems where collective dynamics co-occurs with a communication function. PMID:27067257

Cholinergic Plasticity of Oscillating Neuronal Assemblies in Mouse Hippocampal Slices

PubMed Central

Zylla, Maura M.; Zhang, Xiaomin; Reichinnek, Susanne; Draguhn, Andreas; Both, Martin

2013-01-01

The mammalian hippocampus expresses several types of network oscillations which entrain neurons into transiently stable assemblies. These groups of co-active neurons are believed to support the formation, consolidation and recall of context-dependent memories. Formation of new assemblies occurs during theta- and gamma-oscillations under conditions of high cholinergic activity. Memory consolidation is linked to sharp wave-ripple oscillations (SPW-R) during decreased cholinergic tone. We hypothesized that increased cholinergic tone supports plastic changes of assemblies while low cholinergic tone favors their stability. Coherent spatiotemporal network patterns were measured during SPW-R activity in mouse hippocampal slices. We compared neuronal activity within the oscillating assemblies before and after a transient phase of carbachol-induced gamma oscillations. Single units maintained their coupling to SPW-R throughout the experiment and could be re-identified after the transient phase of gamma oscillations. However, the frequency of SPW-R-related unit firing was enhanced after muscarinic stimulation. At the network level, these changes resulted in altered patterns of extracellularly recorded SPW-R waveforms. In contrast, recording of ongoing SPW-R activity without intermittent cholinergic stimulation revealed remarkably stable repetitive activation of assemblies. These results show that activation of cholinergic receptors induces plasticity at the level of oscillating hippocampal assemblies, in line with the different role of gamma- and SPW-R network activity for memory formation and –consolidation, respectively. PMID:24260462

Increasing Spontaneous Retinal Activity before Eye Opening Accelerates the Development of Geniculate Receptive Fields

PubMed Central

Davis, Zachary W.; Chapman, Barbara

2015-01-01

Visually evoked activity is necessary for the normal development of the visual system. However, little is known about the capacity for patterned spontaneous activity to drive the maturation of receptive fields before visual experience. Retinal waves provide instructive retinotopic information for the anatomical organization of the visual thalamus. To determine whether retinal waves also drive the maturation of functional responses, we increased the frequency of retinal waves pharmacologically in the ferret (Mustela putorius furo) during a period of retinogeniculate development before eye opening. The development of geniculate receptive fields after receiving these increased neural activities was measured using single-unit electrophysiology. We found that increased retinal waves accelerate the developmental reduction of geniculate receptive field sizes. This reduction is due to a decrease in receptive field center size rather than an increase in inhibitory surround strength. This work reveals an instructive role for patterned spontaneous activity in guiding the functional development of neural circuits. SIGNIFICANCE STATEMENT Patterned spontaneous neural activity that occurs during development is known to be necessary for the proper formation of neural circuits. However, it is unknown whether the spontaneous activity alone is sufficient to drive the maturation of the functional properties of neurons. Our work demonstrates for the first time an acceleration in the maturation of neural function as a consequence of driving patterned spontaneous activity during development. This work has implications for our understanding of how neural circuits can be modified actively to improve function prematurely or to recover from injury with guided interventions of patterned neural activity. PMID:26511250

Preceding muscle activity influences motor unit discharge and rate of torque development during ballistic contractions in humans

PubMed Central

Van Cutsem, Michaël; Duchateau, Jacques

2005-01-01

To investigate the effect of initial conditions on the modulation of motor unit discharge during fast voluntary contractions, we compared ballistic isometric contractions of the ankle dorsiflexor muscles that were produced from either a resting state or superimposed on a sustained contraction. The torque of the dorsiflexors and the surface and intramuscular EMGs from the tibialis anterior were recorded. The results showed that the performance of a ballistic contraction from a sustained contraction (∼25% maximal voluntary contraction (MVC)) had a negative effect on the maximal rate of torque development. Although the electromechanical delay was shortened, the EMG activity during the ballistic contraction was less synchronized. These observations were associated with a significant decline in the average discharge rate of single motor units (89.8 ± 3.8 versus 115 ± 5.8 Hz) and in the percentage of units (6.2 versus 15.5% of the whole sample) that exhibited double discharges at brief intervals (= 5 ms). High-threshold units that were not recruited during the sustained contraction displayed the same activation pattern, which indicates that the mechanisms responsible for the decline in discharge rate were not restricted to previously activated units, but appear to influence the entire motor unit pool. When a premotor silent period (SP) was observed at the transition from the sustained muscular activity to the ballistic contraction (19% of the trials), these adjustments in motor unit activity were not present, and the ballistic contractions were similar to those performed from a resting state. Together, these results indicate that initial conditions can influence the capacity for motor unit discharge rate and hence the performance of a fast voluntary contraction. PMID:15539402

Masturbation in the United States.

PubMed

Das, Aniruddha

2007-01-01

Using data from the nationally representative National Health and Social Life Survey, this study queried the correlates of masturbation in the United States in 1992. Among those aged 18-60, 38% (CI, 35-41) of women and 61% (CI, 57-65) of men reported any masturbation over the preceding year. The system of factors underlying masturbation was similar for both genders, consistent with a convergence in gender patterns of sexual expression in the United States. Among both women and men, masturbation responded to a stable sexualized personality pattern, catalyzed by early-life factors and manifested in current sexual traits. Strikingly, the masturbation-partnered sex linkage, often conceptualized either as compensating for unsatisfying sex or complementing a satisfactory sex life, appeared to be bimodal for both genders. For some, masturbation complemented an active and pleasurable sex life, while among others, it compensated for a lack of partnered sex or satisfaction in sex.

HOTS: A Hierarchy of Event-Based Time-Surfaces for Pattern Recognition.

PubMed

Lagorce, Xavier; Orchard, Garrick; Galluppi, Francesco; Shi, Bertram E; Benosman, Ryad B

2017-07-01

This paper describes novel event-based spatio-temporal features called time-surfaces and how they can be used to create a hierarchical event-based pattern recognition architecture. Unlike existing hierarchical architectures for pattern recognition, the presented model relies on a time oriented approach to extract spatio-temporal features from the asynchronously acquired dynamics of a visual scene. These dynamics are acquired using biologically inspired frameless asynchronous event-driven vision sensors. Similarly to cortical structures, subsequent layers in our hierarchy extract increasingly abstract features using increasingly large spatio-temporal windows. The central concept is to use the rich temporal information provided by events to create contexts in the form of time-surfaces which represent the recent temporal activity within a local spatial neighborhood. We demonstrate that this concept can robustly be used at all stages of an event-based hierarchical model. First layer feature units operate on groups of pixels, while subsequent layer feature units operate on the output of lower level feature units. We report results on a previously published 36 class character recognition task and a four class canonical dynamic card pip task, achieving near 100 percent accuracy on each. We introduce a new seven class moving face recognition task, achieving 79 percent accuracy.This paper describes novel event-based spatio-temporal features called time-surfaces and how they can be used to create a hierarchical event-based pattern recognition architecture. Unlike existing hierarchical architectures for pattern recognition, the presented model relies on a time oriented approach to extract spatio-temporal features from the asynchronously acquired dynamics of a visual scene. These dynamics are acquired using biologically inspired frameless asynchronous event-driven vision sensors. Similarly to cortical structures, subsequent layers in our hierarchy extract increasingly abstract features using increasingly large spatio-temporal windows. The central concept is to use the rich temporal information provided by events to create contexts in the form of time-surfaces which represent the recent temporal activity within a local spatial neighborhood. We demonstrate that this concept can robustly be used at all stages of an event-based hierarchical model. First layer feature units operate on groups of pixels, while subsequent layer feature units operate on the output of lower level feature units. We report results on a previously published 36 class character recognition task and a four class canonical dynamic card pip task, achieving near 100 percent accuracy on each. We introduce a new seven class moving face recognition task, achieving 79 percent accuracy.

Spatial distribution of 12 class B notifiable infectious diseases in China: A retrospective study

PubMed Central

Zhu, Bin; Fu, Yang; Liu, Jinlin

2018-01-01

Background China is the largest developing country with a relatively developed public health system. To further prevent and eliminate the spread of infectious diseases, China has listed 39 notifiable infectious diseases characterized by wide prevalence or great harm, and classified them into classes A, B, and C, with severity decreasing across classes. Class A diseases have been almost eradicated in China, thus making class B diseases a priority in infectious disease prevention and control. In this retrospective study, we analyze the spatial distribution patterns of 12 class B notifiable infectious diseases that remain active all over China. Methods Global and local Moran’s I and corresponding graphic tools are adopted to explore and visualize the global and local spatial distribution of the incidence of the selected epidemics, respectively. Inter-correlations of clustering patterns of each pair of diseases and a cumulative summary of the high/low cluster frequency of the provincial units are also provided by means of figures and maps. Results Of the 12 most commonly notifiable class B infectious diseases, viral hepatitis and tuberculosis show high incidence rates and account for more than half of the reported cases. Almost all the diseases, except pertussis, exhibit positive spatial autocorrelation at the provincial level. All diseases feature varying spatial concentrations. Nevertheless, associations exist between spatial distribution patterns, with some provincial units displaying the same type of cluster features for two or more infectious diseases. Overall, high–low (unit with high incidence surrounded by units with high incidence, the same below) and high–high spatial cluster areas tend to be prevalent in the provincial units located in western and southwest China, whereas low–low and low–high spatial cluster areas abound in provincial units in north and east China. Conclusion Despite the various distribution patterns of 12 class B notifiable infectious diseases, certain similarities between their spatial distributions are present. Substantial evidence is available to support disease-specific, location-specific, and disease-combined interventions. Regarding provinces that show high–high/high–low patterns of multiple diseases, comprehensive interventions targeting different diseases should be established. As to the adjacent provincial units revealing similar patterns, coordinated actions need to be taken across borders. PMID:29621351

Assessment of the effect of acculturation on dietary and physical activity behaviors of Arab mothers in Lubbock, Texas.

PubMed

Tami, Suzan H; Reed, Debra B; Boylan, Mallory; Zvonkovic, Anisa

2012-01-01

Our study was conducted to collect exploratory data on Arab mothers in the United States regarding their dietary and physical activity behaviors and to assess the relationship of acculturation to these behaviors. Focus groups and interviews were conducted to collect data on dietary and physical activity behaviors of Arab mothers in Lubbock, Texas. The Social Cognitive Theory guided the development of questions related to the role of acculturation on the dietary and physical activity behaviors. The Male Arab-American Acculturation Scale was used to measure acculturation. A bicultural dietary pattern of Arab mothers emerged. Negative behaviors included skipping meals, increased intake of high-fat fast foods and meat consumption, and lack of traditional physical activity. Some reported reasons for the negative behaviors included children's preferences, lack of access to traditional foods, preference for convenience, the low cost of some foods, and lack of time. Positive changes for some Arab mothers included healthier cooking techniques, reading nutritional labels, and making new healthy food choices due to increased awareness of healthy foods, availability and affordability of many healthy choices in the United States, and Arab mothers' attempts to enrich their families' meals with vegetables in order to keep the Arabic dietary pattern. Positive dietary and physical activity changes should be supported. Nutrition interventions are needed that address the major barriers to diet and physical activity changes reported by these Arab mothers.

The effects of ingested petroleum on the maphthalene-metabolizing properties of the liver tissue in seawater-adapted mallard ducks (Anas platyrhynchos)

USGS Publications Warehouse

Gorsline, J.; Holmes, W.N.; Cronshaw, J.

1981-01-01

Hepatic mixed function oxidase activities were estimated in seawater-adapted mallard ducks (Anas platyrhynchos) that had been consuming food contaminated with one of five different types of crude oil. After 50 days of exposure to contaminated food, enzyme activities of liver microsomal preparations were assessed in terms of their naphthalenemetabolizing properties in vitro. Although dose-dependent increases in the total hepatic enzyme activities (nmole naphthalene metabolized per minute per unit mass body weight) were observed in birds consuming food contaminated with each type of crude oil, three patterns of response were apparent. Crude oils from South Louisiana and Kuwait stimulated large and significant increases in the specific activity of the enzyme system (nmole naphthalene metabolized per minute per unit mass microsomal protein), whereas little or no increase in either microsomal protein content or relative liver weight were observed. In contrast, two crude oils from Santa Barbara, Calif., induced only small increases in specific activity but significant increases occurred in hepatic microsomal protein concentration and relative liver weight. The crude oil from Prudhoe Bay, Ala., evoked intermediate patterns of response. The possible significance of these data is discussed in relation to the survival of seabirds consuming petroleum-contaminated food and drinking water.

Patterns of Occurrence and Marine Mammal Acoustic Behavior in Relation to Navy Sonar Activity Off Jacksonville, Florida.

PubMed

Oswald, Julie N; Norris, Thomas F; Yack, Tina M; Ferguson, Elizabeth L; Kumar, Anurag; Nissen, Jene; Bell, Joel

2016-01-01

Passive acoustic data collected from marine autonomous recording units deployed off Jacksonville, FL (from 13 September to 8 October 2009 and 3 December 2009 to 8 January 2010), were analyzed for detection of cetaceans and Navy sonar. Cetaceans detected included Balaenoptera acutorostrata, Eubalaena glacialis, B. borealis, Physeter macrocephalus, blackfish, and delphinids. E. glacialis were detected at shallow and, somewhat unexpectedly, deep sites. P. macrocephalus were characterized by a strong diel pattern. B. acutorostrata showed the strongest relationship between sonar activity and vocal behavior. These results provide a preliminary assessment of cetacean occurrence off Jacksonville and new insights on vocal responses to sonar.

Utility of Acculturation in Physical Activity Research in Latina Adults: An Integrative Review of Literature.

PubMed

Benitez, Tanya J; Dodgson, Joan E; Coe, Kathryn; Keller, Colleen

2016-06-01

Latina adults in the United States have a disproportionately higher prevalence of chronic diseases related to low physical activity levels than non-Hispanic women. Literature indicates that acculturation may be a contributing factor to being physically active, but the extent of this association remains unclear. An integrative review of literature was conducted on studies that examined acculturation as it relates to physical activity in Latinas in the United States. Our review of 33 studies revealed inconsistent measurement and conceptualization of acculturation and physical activity across studies. Findings from this review reinforce the importance and continued use of acculturation by behavioral researchers; however, acculturation, as conceptualized in the studies reviewed, may not have had an influence on health as much as traditions, life patterns, and resources of Latinas. © 2015 Society for Public Health Education.

CD1c presentation of synthetic glycolipid antigens with foreign alkyl branching motifs

PubMed Central

de Jong, Annemieke; Arce, Eva Casas; Cheng, Tan-Yun; van Summeren, Ruben P.; Feringa, Ben L.; Dudkin, Vadim; Crich, David; Matsunaga, Isamu; Minnaard, Adriaan J.; Moody, D. Branch

2009-01-01

Summary Human CD1c is a protein that activates αβ T cells by presenting self antigens, synthetic mannosyl phosphodolichols and mycobacterial mannosyl phosphopolyketides. To determine which molecular structures of antigens mediate a T cell response, we measured activation by structurally divergent M. tuberculosis mannosyl-β1-phosphomycoketides as well as by synthetic analogs produced by two methods that yield either stereorandom or stereospecific methyl branching patterns. T cell responses required both a phosphate and a β-linked mannose unit, and showed preference for C30–34 lipid units with methyl branches in the S-configuration. Thus, in all cases T cell responses were strongest for synthetic compounds that mimicked the natural branched lipids produced by mycobacterial polyketide synthase 12. Incorporation of methylmalonate to form branched lipids is a common bacterial lipid synthesis pathway that is absent in vertebrates, so the preferential recognition of branched lipids may represent a new type of lipid-based pathogen associated molecular pattern (PAMP). PMID:18022562

Validation of Hill-Type Muscle Models in Relation to Neuromuscular Recruitment and Force–Velocity Properties: Predicting Patterns of In Vivo Muscle Force

PubMed Central

Biewener, Andrew A.; Wakeling, James M.; Lee, Sabrina S.; Arnold, Allison S.

2014-01-01

We review here the use and reliability of Hill-type muscle models to predict muscle performance under varying conditions, ranging from in situ production of isometric force to in vivo dynamics of muscle length change and force in response to activation. Muscle models are frequently used in musculoskeletal simulations of movement, particularly when applied to studies of human motor performance in which surgically implanted transducers have limited use. Musculoskeletal simulations of different animal species also are being developed to evaluate comparative and evolutionary aspects of locomotor performance. However, such models are rarely validated against direct measures of fascicle strain or recordings of muscle–tendon force. Historically, Hill-type models simplify properties of whole muscle by scaling salient properties of single fibers to whole muscles, typically accounting for a muscle’s architecture and series elasticity. Activation of the model’s single contractile element (assigned the properties of homogenous fibers) is also simplified and is often based on temporal features of myoelectric (EMG) activation recorded from the muscle. Comparison of standard one-element models with a novel two-element model and with in situ and in vivo measures of EMG, fascicle strain, and force recorded from the gastrocnemius muscles of goats shows that a two-element Hill-type model, which allows independent recruitment of slow and fast units, better predicts temporal patterns of in situ and in vivo force. Recruitment patterns of slow/fast units based on wavelet decomposition of EMG activity in frequency–time space are generally correlated with the intensity spectra of the EMG signals, the strain rates of the fascicles, and the muscle–tendon forces measured in vivo, with faster units linked to greater strain rates and to more rapid forces. Using direct measures of muscle performance to further test Hill-type models, whether traditional or more complex, remains critical for establishing their accuracy and essential for verifying their applicability to scientific and clinical studies of musculoskeletal function. PMID:24928073

Firefighter exercise protocols conducted in an environmental chamber: developing a laboratory-based simulated firefighting protocol.

PubMed

Ensari, Ipek; Motl, Robert W; Klaren, Rachel E; Fernhall, Bo; Smith, Denise L; Horn, Gavin P

2017-05-01

A standard exercise protocol that allows comparisons across various ergonomic studies would be of great value for researchers investigating the physical and physiological strains of firefighting and possible interventions for reducing the demands. We compared the pattern of cardiorespiratory changes from 21 firefighters during simulated firefighting activities using a newly developed firefighting activity station (FAS) and treadmill walking both performed within an identical laboratory setting. Data on cardiorespiratory parameters and core temperature were collected continuously using a portable metabolic unit and a wireless ingestible temperature probe. Repeated measures ANOVA indicated distinct patterns of change in cardiorespiratory parameters and heart rate between conditions. The pattern consisted of alternating periods of peaks and nadirs in the FAS that were qualitatively and quantitatively similar to live fire activities, whereas the same parameters increased logarithmically in the treadmill condition. Core temperature increased in a similarly for both conditions, although more rapidly in the FAS. Practitioner Summary: The firefighting activity station (FAS) yields a pattern of cardiorespiratory responses qualitatively and quantitatively similar to live fire activities, significantly different than treadmill walking. The FAS can be performed in a laboratory/clinic, providing a potentially standardised protocol for testing interventions to improve health and safety and conducting return to duty decisions.

Understanding Our Environment: Planet.

ERIC Educational Resources Information Center

Callister, Jeffrey C.; And Others

Part of the Understanding Our Environment project that is designed to engage students in investigating specific environmental problems through concrete activities and direct experience, this unit places Earth in the context of its environment-the Universe-then focuses on Earth as seen from satellites. Students analyze patterns formed by the…

A global comparison of the cost of patented cancer drugs in relation to global differences in wealth.

PubMed

Goldstein, Daniel A; Clark, Jonathon; Tu, Yifan; Zhang, Jie; Fang, Fenqi; Goldstein, Robert; Stemmer, Salomon M; Rosenbaum, Eli

2017-09-22

There are major differences in cancer drug prices around the world. However, the patterns of affordability of these drugs are poorly understood. The objective of this study was to compare patterns of affordability of cancer drugs in Australia, China, India, Israel, South Africa, the United Kingdom, and the United States. Cancer drug prices are highest in the United States. Cancer drugs are the least affordable in India by a large margin. Despite lower prices than in the USA, cancer drugs are less affordable in middle-income countries than in high-income countries. We obtained the prices of a basket of cancer drugs in all 7 countries, and converted the prices to US$ using both foreign exchange rates and purchasing power parity. We assessed international differences in wealth by collecting values for gross domestic product (GDP) per capita in addition to average salaries. We compared patterns of affordability of cancer drugs by dividing the drug prices by the markers of wealth. Cancer drugs are less affordable in middle-income countries than in high-income countries. Differential pricing may be an acceptable policy to ensure global affordability and access to highly active anti-cancer therapies.

Common drive to the upper airway muscle genioglossus during inspiratory loading

PubMed Central

Woods, Michael J.; Nicholas, Christian L.; Semmler, John G.; Chan, Julia K. M.; Jordan, Amy S.

2015-01-01

Common drive is thought to constitute a central mechanism by which the efficiency of a motor neuron pool is increased. This study tested the hypothesis that common drive to the upper airway muscle genioglossus (GG) would increase with increased respiratory drive in response to an inspiratory load. Respiration, GG electromyographic (EMG) activity, single-motor unit activity, and coherence in the 0–5 Hz range between pairs of GG motor units were assessed for the 30 s before an inspiratory load, the first and second 30 s of the load, and the 30 s after the load. Twelve of twenty young, healthy male subjects provided usable data, yielding 77 pairs of motor units: 2 Inspiratory Phasic, 39 Inspiratory Tonic, 15 Expiratory Tonic, and 21 Tonic. Respiratory and GG inspiratory activity significantly increased during the loads and returned to preload levels during the postload periods (all showed significant quadratic functions over load trials, P < 0.05). As hypothesized, common drive increased during the load in inspiratory modulated motor units to a greater extent than in expiratory/tonic motor units (significant load × discharge pattern interaction, P < 0.05). Furthermore, this effect persisted during the postload period. In conclusion, common drive to inspiratory modulated motor units was elevated in response to increased respiratory drive. The postload elevation in common drive was suggestive of a poststimulus activation effect. PMID:26378207

Physiological recruitment of motor units by high-frequency electrical stimulation of afferent pathways.

PubMed

Dideriksen, Jakob L; Muceli, Silvia; Dosen, Strahinja; Laine, Christopher M; Farina, Dario

2015-02-01

Neuromuscular electrical stimulation (NMES) is commonly used in rehabilitation, but electrically evoked muscle activation is in several ways different from voluntary muscle contractions. These differences lead to challenges in the use of NMES for restoring muscle function. We investigated the use of low-current, high-frequency nerve stimulation to activate the muscle via the spinal motoneuron (MN) pool to achieve more natural activation patterns. Using a novel stimulation protocol, the H-reflex responses to individual stimuli in a train of stimulation pulses at 100 Hz were reliably estimated with surface EMG during low-level contractions. Furthermore, single motor unit recruitment by afferent stimulation was analyzed with intramuscular EMG. The results showed that substantially elevated H-reflex responses were obtained during 100-Hz stimulation with respect to a lower stimulation frequency. Furthermore, motor unit recruitment using 100-Hz stimulation was not fully synchronized, as it occurs in classic NMES, and the discharge rates differed among motor units because each unit was activated only after a specific number of stimuli. The most likely mechanism behind these observations is the temporal summation of subthreshold excitatory postsynaptic potentials from Ia fibers to the MNs. These findings and their interpretation were also verified by a realistic simulation model of afferent stimulation of a MN population. These results suggest that the proposed stimulation strategy may allow generation of considerable levels of muscle activation by motor unit recruitment that resembles the physiological conditions. Copyright © 2015 the American Physiological Society.

Task-dependent output of human parasternal intercostal motor units across spinal levels.

PubMed

Hudson, Anna L; Gandevia, Simon C; Butler, Jane E

2017-12-01

During breathing, there is differential activity in the human parasternal intercostal muscles and the activity is tightly coupled to the known mechanical advantages for inspiration of the same regions of muscles. It is not known whether differential activity is preserved for the non-respiratory task of ipsilateral trunk rotation. In the present study, we compared single motor units during resting breathing and axial rotation of the trunk during apnoea. We not only confirmed non-uniform recruitment of motor units across parasternal intercostal muscles in breathing, but also demonstrated that the same motor units show an altered pattern of recruitment in the non-respiratory task of trunk rotation. The output of parasternal intercostal motoneurones is modulated differently across spinal levels depending on the task and these results help us understand the mechanisms that may govern task-dependent differences in motoneurone output. During inspiration, there is differential activity in the human parasternal intercostal muscles across interspaces. We investigated whether the earlier recruitment of motor units in the rostral interspaces compared to more caudal spaces during inspiration is preserved for the non-respiratory task of ipsilateral trunk rotation. Single motor unit activity (SMU) was recorded from the first, second and fourth parasternal interspaces on the right side in five participants in two tasks: resting breathing and 'isometric' axial rotation of the trunk during apnoea. Recruitment of the same SMUs was compared between tasks (n = 123). During resting breathing, differential activity was indicated by earlier recruitment of SMUs in the first and second interspaces compared to the fourth space in inspiration (P < 0.01). By contrast, during trunk rotation, the same motor units showed an altered pattern of recruitment because SMUs in the first interspace were recruited later and at a higher rotation torque than those in the second and fourth interspaces (P < 0.05). Tested for a subset of SMUs, the reliability of the breathing and rotation tasks, as well as the SMU recruitment measures, was good-excellent [intraclass correlation (2,1): 0.69-0.91]. Thus, the output of parasternal intercostal motoneurones is modulated differently across spinal levels depending on the task. Given that the differential inspiratory output of parasternal intercostal muscles is linked to their relative mechanical effectiveness for inspiration and also that this output is altered in trunk rotation, we speculate that a mechanism matching neural drive to muscle mechanics underlies the task-dependent differences in output of axial motoneurone pools. © 2017 The Authors. The Journal of Physiology © 2017 The Physiological Society.

Self-patterning Gd nano-fibers in Mg-Gd alloys

DOE PAGES

Li, Yangxin; Wang, Jian; Chen, Kaiguo; ...

2016-12-07

Manipulating the shape and distribution of strengthening units, e.g. particles, fibers, and precipitates, in a bulk metal, has been a widely applied strategy of tailoring their mechanical properties. Here, we report self-assembled patterns of Gd nano-fibers in Mg-Gd alloys for the purpose of improving their strength and deformability. 1-nm Gd nano-fibers, with amore » $$\\langle$$c$$\\rangle$$ -rod shape, are formed and hexagonally patterned in association with Gd segregations along dislocations that nucleated during hot extrusion. Such Gd-fiber patterns are able to regulate the relative activities of slips and twinning, as a result, overcome the inherent limitations in strength and ductility of Mg alloys. Finally, this nano-fiber patterning approach could be an effective method to engineer hexagonal metals.« less

Self-patterning Gd nano-fibers in Mg-Gd alloys

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

Li, Yangxin; Wang, Jian; Chen, Kaiguo

Manipulating the shape and distribution of strengthening units, e.g. particles, fibers, and precipitates, in a bulk metal, has been a widely applied strategy of tailoring their mechanical properties. Here, we report self-assembled patterns of Gd nano-fibers in Mg-Gd alloys for the purpose of improving their strength and deformability. 1-nm Gd nano-fibers, with amore » $$\\langle$$c$$\\rangle$$ -rod shape, are formed and hexagonally patterned in association with Gd segregations along dislocations that nucleated during hot extrusion. Such Gd-fiber patterns are able to regulate the relative activities of slips and twinning, as a result, overcome the inherent limitations in strength and ductility of Mg alloys. Finally, this nano-fiber patterning approach could be an effective method to engineer hexagonal metals.« less

A software package for interactive motor unit potential classification using fuzzy k-NN classifier.

PubMed

Rasheed, Sarbast; Stashuk, Daniel; Kamel, Mohamed

2008-01-01

We present an interactive software package for implementing the supervised classification task during electromyographic (EMG) signal decomposition process using a fuzzy k-NN classifier and utilizing the MATLAB high-level programming language and its interactive environment. The method employs an assertion-based classification that takes into account a combination of motor unit potential (MUP) shapes and two modes of use of motor unit firing pattern information: the passive and the active modes. The developed package consists of several graphical user interfaces used to detect individual MUP waveforms from a raw EMG signal, extract relevant features, and classify the MUPs into motor unit potential trains (MUPTs) using assertion-based classifiers.

Muscle synergies evoked by microstimulation are preferentially encoded during behavior

PubMed Central

Overduin, Simon A.; d'Avella, Andrea; Carmena, Jose M.; Bizzi, Emilio

2014-01-01

Electrical microstimulation studies provide some of the most direct evidence for the neural representation of muscle synergies. These synergies, i.e., coordinated activations of groups of muscles, have been proposed as building blocks for the construction of motor behaviors by the nervous system. Intraspinal or intracortical microstimulation (ICMS) has been shown to evoke muscle patterns that can be resolved into a small set of synergies similar to those seen in natural behavior. However, questions remain about the validity of microstimulation as a probe of neural function, particularly given the relatively long trains of supratheshold stimuli used in these studies. Here, we examined whether muscle synergies evoked during ICMS in two rhesus macaques were similarly encoded by nearby motor cortical units during a purely voluntary behavior involving object reach, grasp, and carry movements. At each microstimulation site we identified the synergy most strongly evoked among those extracted from muscle patterns evoked over all microstimulation sites. For each cortical unit recorded at the same microstimulation site, we then identified the synergy most strongly encoded among those extracted from muscle patterns recorded during the voluntary behavior. We found that the synergy most strongly evoked at an ICMS site matched the synergy most strongly encoded by proximal units more often than expected by chance. These results suggest a common neural substrate for microstimulation-evoked motor responses and for the generation of muscle patterns during natural behaviors. PMID:24634652

The United States Marine Corps Reserve: Reorganization for an Integrated Force

DTIC Science & Technology

2015-04-28

ForceHeadquartersGroup/MarineCorpsI ndividualReserveSupportActivity/Definitions.aspx 23 MCRAMM,1-3 24 Edgar H . Schein , Organizational Culture and...COMMAND AND STAFF COLL QUANTICO VA, 2012. Schein , Edgar H . Organizational Culture and Leadership. The Jossey-Bass Business & Management Series. 3rd...Significant differences exist in culture among the reservists and the active duty members. Schein defines culture as “A pattern of shared basic

Behçet syndrome manifestations and activity in the United States versus Turkey -- a cross-sectional cohort comparison.

PubMed

Sibley, Cailin; Yazici, Yusuf; Tascilar, Koray; Khan, Nafiz; Bata, Yasmin; Yazici, Hasan; Goldbach-Mansky, Raphaela; Hatemi, Gulen

2014-07-01

To compare clinical manifestations and activity of Behçet syndrome (BS) in the United States versus Turkey using validated outcome measures. Consecutive patients with BS from the US National Institutes of Health (NIH), New York University, and the University of Istanbul were evaluated. Disease activity was measured using the Behçet's Syndrome Activity Scale (BSAS) and the Behçet's Disease Current Activity Form (BDCAF) with quality of life measured by the Behçet Disease Quality of Life (BDQOL) form. One-way ANOVA, t-tests, and multivariate regression analyses were performed. Mean age did not differ between sites; however, more women were seen in the United States versus in Turkey (p < 0.001), and disease duration was longer in the United States (p = 0.02). Organ manifestations were similar for oral and genital ulcers, skin disease, arthralgia, eye disease, and thrombosis. However, more gastrointestinal (p < 0.001) and neurologic disease (p = 0.003) was seen in the United States. BSAS and BDCAF scores were worse in the United States compared to Turkey (p = 0.013 and < 0.001, respectively). Worse mean BDQOL scores were observed at the NIH compared to Istanbul (not significant). Multivariable regression models showed worse scores in ethnically atypical patients for BSAS and BDCAF (p = 0.04 and p = 0.001), American patients for BDCAF (p = 0.01), older age for BDCAF (p = 0.005), and women for BDQOL (p = 0.01). Demographic and clinical manifestations of BS differ between sites with higher disease activity in the United States compared to Turkey. Referral patterns, age, sex, ethnicity, and country of origin may be important in these differences. These observations raise the question of whether pathogenic mechanisms differ in Turkish and American patients.

Affinity communities in United Nations voting: Implications for democracy, cooperation, and conflict

NASA Astrophysics Data System (ADS)

Pauls, Scott D.; Cranmer, Skyler J.

2017-10-01

A network oriented examination of the co-voting network of the United Nations (UN) provides powerful insights into the international alignment of states, as well as normatively important processes such as democracy, defensive cooperation, and armed conflict. Here, we investigate the UN co-voting network using the tools of community detection and inductively identify "affinity communities" in which states articulate similar policy preferences through their voting patterns. Analysis of these communities reveals that there is more information contained in UN voting and co-voting patterns than has previously been thought. Affinity communities have complex relationships with some of the most normatively important international outcomes: they reflect transitions to democracy, have a feedback loop with the formation of defensive alliances, and actively help states avoid armed conflict.

Hands-on Science: Wildcatters.

ERIC Educational Resources Information Center

Markle, Sandra

1988-01-01

A science unit illustrates the concept of scientific predictions by using how geologists predict where to drill for oil as an example. In a related exercise, everyday items such as bricks, sand, and marbles introduce permeability. Other activities demonstrate how to base predictions on established patterns. A reproducible page is provided. (JL)

Gay-Straight Alliances in High Schools: Social Predictors of Early Adoption

ERIC Educational Resources Information Center

Fetner, Tina; Kush, Kristin

2008-01-01

This article examines the patterns of emergence of gay-straight alliances (GSAs) in public high schools in the United States. These extracurricular student groups offer safe spaces, social support, and opportunities for activism to lesbian, gay, bisexual, transgender, queer, and straight students. Combining data on various characteristics of…

Engineering Manpower and Education: Foundation for Future Competitiveness.

ERIC Educational Resources Information Center

Business-Higher Education Forum, Washington, DC.

Important issues, approaches, and options pertaining to supply and utilization of engineering manpower in the United States are outlined. An overview is presented of ongoing engineering manpower surveys, projections, and patterns, with particular emphasis on activities and trends of the past 2 years. Attention is also directed to manpower…

The Living Room Celebration of the Olympic Games.

ERIC Educational Resources Information Center

Rothenbuhler, Eric W.

1988-01-01

Evaluates the pattern of celebratory activities in United States homes that accompanied television viewing of the 1984 Summer Olympic Games. Finds that those watching the Olympics were more likely to be in a group, to have visitors, to plan their viewing, and to pay close attention to the television. (MS)

Process Evaluation of Healthy Bodies, Healthy Souls: A Church-Based Health Intervention Program in Baltimore City

ERIC Educational Resources Information Center

Wang, H. Echo; Lee, Matthew; Hart, Adante; Summers, Amber C.; Steeves, Elizabeth Anderson; Gittelsohn, Joel

2013-01-01

Soaring obesity rates in the United States demand comprehensive health intervention strategies that simultaneously address dietary patterns, physical activity, psychosocial factors and the food environment. Healthy Bodies, Healthy Souls (HBHS) is a church-based, community-participatory, cluster-randomized health intervention trial conducted in…

76 FR 70451 - Agency Information Collection Activities; Proposed Collection; Comment Request; Extension

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-14

... commodities to keep records that substantiate ``cents off,'' ``introductory offer,'' and/or ``economy size... United States, 2010, U.S. Department of Labor, U.S. Bureau of Labor Statistics (May 2011) (``BLS National... information such as costs, sales statistics, inventories, formulas, patterns devices, manufacturing processes...

An investigation of short haul air transportation in the southeastern United States

NASA Technical Reports Server (NTRS)

Kanafani, A.; Yuan, H. S.

1977-01-01

The specific objectives of this stage of the study are numerous. First, an attempt is made to characterize the travel patterns in the study region, both in terms of origin destination patterns, and connecting and through trip patterns. Second, the structure of the air service in the region is characterized in an attempt to develop an understanding of the evolution of the short haul air transportation network. Finally, a look is taken at the socioeconomic environment of Atlanta and the region in order to seek an explanation for the historic evolution of short haul air travel activities and the rather high growth rates experienced in recent years.

How Escherichia coli lands and forms cell clusters on a surface: a new role of surface topography

PubMed Central

Gu, Huan; Chen, Aaron; Song, Xinran; Brasch, Megan E.; Henderson, James H.; Ren, Dacheng

2016-01-01

Bacterial response to surface topography during biofilm formation was studied using 5 μm tall line patterns of poly (dimethylsiloxane) (PDMS). Escherichia coli cells attached on top of protruding line patterns were found to align more perpendicularly to the orientation of line patterns when the pattern narrowed. Consistently, cell cluster formation per unit area on 5 μm wide line patterns was reduced by 14-fold compared to flat PDMS. Contrasting the reduced colony formation, cells attached on narrow patterns were longer and had higher transcriptional activities, suggesting that such unfavorable topography may present a stress to attached cells. Results of mutant studies indicate that flagellar motility is involved in the observed preference in cell orientation on narrow patterns, which was corroborated by the changes in cell rotation pattern before settling on different surface topographies. These findings led to a set of new design principles for creating antifouling topographies, which was validated using 10 μm tall hexagonal patterns. PMID:27412365

Task-specific recruitment of motor units for vibration damping.

PubMed

Wakeling, James M; Liphardt, Anna-Maria

2006-01-01

Vibrations occur within the soft tissues of the lower extremities due to the heel-strike impact during walking. Increases in muscle activity in the lower extremities result in increased damping to reduce this vibration. The myoelectric intensity spectra were compared using principal component analysis from the tibialis anterior and lateral gastrocnemius of 40 subjects walking with different shoe conditions. The soft insert condition resulted in a significant, simultaneous increase in muscle activity with a shift to higher myoelectric frequencies in the period 0-60 ms after heel-strike which is the period when the greater vibration damping occurred. These increases in myoelectric frequency match the spectral patterns which indicate increases in recruitment of faster motor units. It is concluded that fast motor units are recruited during the task of damping the soft-tissue resonance that occurs following heel-strike.

Enzymatic production of defined chitosan oligomers with a specific pattern of acetylation using a combination of chitin oligosaccharide deacetylases

NASA Astrophysics Data System (ADS)

Hamer, Stefanie Nicole; Cord-Landwehr, Stefan; Biarnés, Xevi; Planas, Antoni; Waegeman, Hendrik; Moerschbacher, Bruno Maria; Kolkenbrock, Stephan

2015-03-01

Chitin and chitosan oligomers have diverse biological activities with potentially valuable applications in fields like medicine, cosmetics, or agriculture. These properties may depend not only on the degrees of polymerization and acetylation, but also on a specific pattern of acetylation (PA) that cannot be controlled when the oligomers are produced by chemical hydrolysis. To determine the influence of the PA on the biological activities, defined chitosan oligomers in sufficient amounts are needed. Chitosan oligomers with specific PA can be produced by enzymatic deacetylation of chitin oligomers, but the diversity is limited by the low number of chitin deacetylases available. We have produced specific chitosan oligomers which are deacetylated at the first two units starting from the non-reducing end by the combined use of two different chitin deacetylases, namely NodB from Rhizobium sp. GRH2 that deacetylates the first unit and COD from Vibrio cholerae that deacetylates the second unit starting from the non-reducing end. Both chitin deacetylases accept the product of each other resulting in production of chitosan oligomers with a novel and defined PA. When extended to further chitin deacetylases, this approach has the potential to yield a large range of novel chitosan oligomers with a fully defined architecture.

Uncovering the role of the East Asian jet stream and heterogeneities in atmospheric rivers affecting the western United States.

PubMed

Zhang, Wei; Villarini, Gabriele

2018-01-30

Atmospheric rivers (ARs) exert major socioeconomic repercussions along the US West Coast by inducing heavy rainfall, flooding, strong winds, and storm surge. Despite the significant societal and economic repercussions of these storms, our understanding of the physical drivers responsible for their interannual variability is limited, with different climate modes identified as possible mechanisms. Here we show that the Pacific-Japan (PJ) teleconnections/patterns and the East Asian subtropical jet (EASJ) exhibit a strong linkage with the total frequency of ARs making landfall over the western United States, much stronger than the other potential climate modes previously considered. While our findings indicate that the PJ pattern and EASJ are the most relevant climate modes driving the overall AR activity, we also uncover heterogeneities in AR tracks. Specifically, we show that not all ARs making landfall along the West Coast come from a single population, but rather that it is possible to stratify these storms into three clusters. While the PJ pattern and EASJ are major drivers of AR activity for two clusters, the cluster that primarily affects the US Southwest is largely driven by other climate modes [El Niño Southern Oscillation (ENSO), the Atlantic meridional mode (AMM), the Pacific-North America (PNA) teleconnection pattern, and the North Pacific Gyre Oscillation (NPGO)]. Therefore, important regional differences exist and this information can substantially enhance our ability to predict and prepare for these storms and their impacts.

Synthesis, in vitro and in vivo antimalarial assessment of sulfide, sulfone and vinyl amide-substituted 1,2,4-trioxanes prepared via thiol-olefin co-oxygenation (TOCO) of allylic alcohols.

PubMed

Amewu, Richard; Gibbons, Peter; Mukhtar, Amira; Stachulski, Andrew V; Ward, Stephen A; Hall, Charlotte; Rimmer, Karen; Davies, Jill; Vivas, Livia; Bacsa, John; Mercer, Amy E; Nixon, Gemma; Stocks, Paul A; O'Neill, Paul M

2010-05-07

Thiol-Olefin Co-Oxygenation (TOCO) methodology has been applied to the synthesis of a small library of weak base and polar 1,2,4-trioxanes. The 1,2,4-trioxane units synthesised exhibit remarkable stability as they survive base catalysed hydrolysis and mixed anhydride/amine coupling reactions. This unique stability feature has enabled a range of novel substitution patterns to be incorporated within the spiro 1,2,4-trioxane unit. Selected analogues express potent in vitro nM antimalarial activity, low cytotoxicity and oral activity in the Plasmodium berghei mouse model of malaria.

An artificial neural network model for periodic trajectory generation

NASA Astrophysics Data System (ADS)

Shankar, S.; Gander, R. E.; Wood, H. C.

A neural network model based on biological systems was developed for potential robotic application. The model consists of three interconnected layers of artificial neurons or units: an input layer subdivided into state and plan units, an output layer, and a hidden layer between the two outer layers which serves to implement nonlinear mappings between the input and output activation vectors. Weighted connections are created between the three layers, and learning is effected by modifying these weights. Feedback connections between the output and the input state serve to make the network operate as a finite state machine. The activation vector of the plan units of the input layer emulates the supraspinal commands in biological central pattern generators in that different plan activation vectors correspond to different sequences or trajectories being recalled, even with different frequencies. Three trajectories were chosen for implementation, and learning was accomplished in 10,000 trials. The fault tolerant behavior, adaptiveness, and phase maintenance of the implemented network are discussed.

Patterning of sympathetic nerve activity in response to vestibular stimulation

NASA Technical Reports Server (NTRS)

Kerman, I. A.; McAllen, R. M.; Yates, B. J.

2000-01-01

Growing evidence suggests a role for the vestibular system in regulation of autonomic outflow during postural adjustments. In the present paper we review evidence for the patterning of sympathetic nerve activity elicited by vestibular stimulation. In response to electrical activation of vestibular afferents, firing of sympathetic nerves located throughout the body is altered. However, activity of the renal nerve is most sensitive to vestibular inputs. In contrast, high-intensity simultaneous activation of cutaneous and muscle inputs elicits equivalent changes in firing of the renal, superior mesenteric and lumbar colonic nerves. Responses of muscle vasoconstrictor (MVC) efferents to vestibular stimulation are either inhibitory (Type I) or are comprised of a combination of excitation and inhibition (Type II). Interestingly, single MVC units located in the hindlimb exhibited predominantly Type I responses while those located in the forelimb and face exhibited Type II responses. Furthermore, brachial and femoral arterial blood flows were dissociated in response to vestibular stimulation, such that brachial vascular resistance increased while femoral resistance decreased. These studies demonstrate that vestibulosympathetic reflexes are patterned according to both the anatomical location and innervation target of a particular sympathetic nerve, and can lead to distinct changes in local blood flow.

Prevalence of myofascial trigger points in fibromyalgia: the overlap of two common problems.

PubMed

Ge, Hong-You

2010-10-01

With the objective evidence of their existence, myofascial trigger points (MTrPs) contribute to an increasing number of chronic regional and widespread pain conditions. The widespread spontaneous pain pattern in fibromyalgia (FM) is a summation of multiple regional pains due to active MTrPs. A regional pain in FM is from local active MTrPs and/or referred from remote active MTrPs. Positive tender points specified in FM are MTrPs, either active or latent. Manual stimulation of active MTrPs located in the muscles in different body regions completely reproduced overall spontaneous FM pain pattern. Active MTrPs as tonic peripheral nociceptive input contribute tremendously to the initiation and maintenance of central sensitization, to the impairment of descending inhibition, to the increased excitability of motor units, and to the induction of sympathetic hyperactivity observed in FM. The considerable overlap of MTrPs and FM in pain characteristics and pathophysiology suggests that FM pain is largely due to MTrPs.

Modeling white-tailed deer activity patterns across forested landscapes

Treesearch

Linda S. Gribko; Michael E. Hohn; William M. Ford

2000-01-01

White-tailed deer (Odocoileus virginianus) herbivory has been identified as a major impediment to the survival and growth of forest regeneration in the northeastern United States. As a supplement to direct control of deer densities through hunting, it may be possible for land managers to manipulate habitat and browsing pressure through carefully...

A CURRICULUM FOR ENGLISH, GRADE 3, UNITS 23-33.

ERIC Educational Resources Information Center

Nebraska Univ., Lincoln. Curriculum Development Center.

THE NEBRASKA ENGLISH CURRICULUM FOR GRADE THREE CONTINUES TO CENTER ON THE READING OF LITERATURE, WITH RELATED LANGUAGE AND COMPOSITION ACTIVITIES. TO STRENGTHEN CHILDREN'S AWARENESS OF THE ORAL AND REPETITIVE PATTERNS IN FOLK LITERATURE AND OF THE LITERARY PURPOSES OF THESE DEVICES, SEVERAL GRIMM FAIRY TALES ARE READ AND THEN COMPARED WITH MODERN…

Southern United States climate, land use, and forest conditions

Treesearch

David N. Wear; Thomas L. Mote; J. Marshall Shepherd; K. C. Benita; Christopher W. Strother

2014-01-01

The Intergovernmental Panel on Climate Change (IPCC) has concluded, with 90% certainty, that human or "anthropogenic" activities (emissions of greenhouse gases, aerosols and pollution, landuse/land-cover change) have altered global temperature patterns over the past 100-150 years (IPCC 2007a). Such temperature changes have a set of cascading, and sometimes...

The stability and slow dynamics of spot patterns in the 2D Brusselator model: The effect of open systems and heterogeneities

NASA Astrophysics Data System (ADS)

Tzou, J. C.; Ward, M. J.

2018-06-01

Spot patterns, whereby the activator field becomes spatially localized near certain dynamically-evolving discrete spatial locations in a bounded multi-dimensional domain, is a common occurrence for two-component reaction-diffusion (RD) systems in the singular limit of a large diffusivity ratio. In previous studies of 2-D localized spot patterns for various specific well-known RD systems, the domain boundary was assumed to be impermeable to both the activator and inhibitor, and the reaction-kinetics were assumed to be spatially uniform. As an extension of this previous theory, we use formal asymptotic methods to study the existence, stability, and slow dynamics of localized spot patterns for the singularly perturbed 2-D Brusselator RD model when the domain boundary is only partially impermeable, as modeled by an inhomogeneous Robin boundary condition, or when there is an influx of inhibitor across the domain boundary. In our analysis, we will also allow for the effect of a spatially variable bulk feed term in the reaction kinetics. By applying our extended theory to the special case of one-spot patterns and ring patterns of spots inside the unit disk, we provide a detailed analysis of the effect on spot patterns of these three different sources of heterogeneity. In particular, when there is an influx of inhibitor across the boundary of the unit disk, a ring pattern of spots can become pinned to a ring-radius closer to the domain boundary. Under a Robin condition, a quasi-equilibrium ring pattern of spots is shown to exhibit a novel saddle-node bifurcation behavior in terms of either the inhibitor diffusivity, the Robin constant, or the ambient background concentration. A spatially variable bulk feed term, with a concentrated source of "fuel" inside the domain, is shown to yield a saddle-node bifurcation structure of spot equilibria, which leads to qualitatively new spot-pinning behavior. Results from our asymptotic theory are validated from full numerical simulations of the Brusselator model.

Using radar to advance migratory bird management: An interagency collaboration

USGS Publications Warehouse

Sojda, R.; Ruth, J.M.; Barrow, W.C.; Dawson, D.K.; Diehl, R.H.; Manville, A.; Green, M.T.; Krueper, D.J.; Johnston, S.

2005-01-01

Migratory birds face many changes to the landscapes they traverse and the habitats they use. Wind turbines and communications towers, which pose hazards to birds and bats in flight, are being erected across the United States and offshore. Human activities can also destroy or threaten habitats critical to birds during migratory passage, and climate change appears to be altering migratory patterns. The U.S. Fish and Wildlife Service (USFWS) and other agencies are under increasing pressure to identify and evaluate movement patterns and habitats used during migration and other times.

Reciprocal links between metabolic and ionic events in islet cells. Their relevance to the rhythmics of insulin release.

PubMed

Malaisse, W J

1998-02-01

The notion of reciprocal links between metabolic and ionic events in islet cells and the rhythmics of insulin release is based on (i) the rhythmic pattern of hormonal release from isolated perfused rat pancreas, which supports the concept of an intrapancreatic pacemaker; (ii) the assumption that this phasic pattern is due to the integration of secretory activity in distinct functional units, e.g. distinct islets; and (iii) the fact that reciprocal coupling between metabolic and ionic events is operative in the secretory sequence.

Accelerometer-Derived Pattern of Sedentary and Physical Activity Time in Persons with Mobility Disability: National Health and Nutrition Examination Survey 2003 to 2006.

PubMed

Manns, Patricia; Ezeugwu, Victor; Armijo-Olivo, Susan; Vallance, Jeff; Healy, Genevieve N

2015-07-01

To describe objectively determined sedentary and activity outcomes (volume and pattern) and their associations with cardiometabolic risk biomarkers in individuals with and without mobility disability. Cross-sectional. Population based. Community-dwelling older adults (≥60) living in the United States who were participants in the 2003 to 2004 or 2005 to 2006 National Health and Nutrition Examination Survey. Participants were classified as with or without mobility disability according to responses to self-reported questions about ability to walk, climb stairs, and/or use of ambulatory aids. Accelerometer-derived sedentary and activity variables for volume (time in sedentary (<100 counts per minute (cpm)), very light- (100-759 cpm), light- (760-1,951 cpm), and moderate- to vigorous- (≥1,952 cpm) intensity activity and pattern (number of breaks from sedentary time, duration of sedentary bouts, duration of activity bouts). Survey-weighted regression models, adjusted for age, sex, ethnicity, education, and smoking, were used to examine the associations between pattern of activity and cardiometabolic health risk factors (blood pressure, waist circumference, high-density lipoprotein cholesterol). Of the 2,017 participants, 547 were classified as having a mobility disability. Participants with mobility disability had more sedentary time and less active time than those without. Sedentary bouts were longer and active bouts shorter in those with disability. The total number of sedentary breaks (transitions from sedentary to nonsedentary) differed between groups after adjustment for total sedentary time. Fewer breaks, longer sedentary bouts, and shorter activity bouts were associated with higher average waist circumference regardless of disability status. This study provides rationale for the development and testing of interventions to change the pattern of activity (e.g., include more breaks and longer activity bout durations) in older adults with mobility disability. © 2015, Copyright the Authors Journal compilation © 2015, The American Geriatrics Society.

A global comparison of the cost of patented cancer drugs in relation to global differences in wealth

PubMed Central

Goldstein, Daniel A.; Clark, Jonathon; Tu, Yifan; Zhang, Jie; Fang, Fenqi; Goldstein, Robert

2017-01-01

Introduction There are major differences in cancer drug prices around the world. However, the patterns of affordability of these drugs are poorly understood. The objective of this study was to compare patterns of affordability of cancer drugs in Australia, China, India, Israel, South Africa, the United Kingdom, and the United States. Results Cancer drug prices are highest in the United States. Cancer drugs are the least affordable in India by a large margin. Despite lower prices than in the USA, cancer drugs are less affordable in middle-income countries than in high-income countries. Materials and Methods We obtained the prices of a basket of cancer drugs in all 7 countries, and converted the prices to US$ using both foreign exchange rates and purchasing power parity. We assessed international differences in wealth by collecting values for gross domestic product (GDP) per capita in addition to average salaries. We compared patterns of affordability of cancer drugs by dividing the drug prices by the markers of wealth. Conclusions Cancer drugs are less affordable in middle-income countries than in high-income countries. Differential pricing may be an acceptable policy to ensure global affordability and access to highly active anti-cancer therapies. PMID:29069727

Cooperative Security in the Pacific Basin. The 1988 Pacific Symposium,

DTIC Science & Technology

1990-01-01

show the same pattern which Taiwan established and Singapore is following closely. Among the four Asian NICs Hong Kong led the pattern early, followed...government, have become a driving force for the tri- angular trade pattern among the United States, Japan, and the East Asian countries. JAPANESE DIRECT...Division of roles between the United States and Japan in East Asia has unintentionally effected a triangular trade pattern among the United States, Japan

Productive engagement among older Americans: prevalence, patterns, and implications for public policy.

PubMed

Hinterlong, James E

2008-01-01

This study estimates the prevalence of productive engagement among adults aged 60 and over residing in the United States over a nine-year period. We analyze three waves of data from the Americans' Changing Lives Study, which allows the findings to describe the non-institutionalized older American population. Focusing upon five activities--formal paid employment, irregular paid work, unpaid volunteerism, caregiving, and informal assistance to others--we identify changes in the engagement rates, examine the extent to which engagement occurs through single or multiple concurrent activities, and document intra-individual patterns of engagement within and across forms of productive activity, including the continuity, initiation, and cessation of involvement. The findings reveal that late-life productive engagement is widespread, with the majority of older individuals involved in multiple forms of activity concurrently. Non-market-based activities such as caregiving, informal assistance, and volunteering are most prevalent. Initiation and cessation of activities are common and yield more complex patterns and lower rates of non-participation than are revealed in cross-sectional analyses. Time spent in productive engagement is highly variable and exhibits an overall decline across time. We conclude by highlighting policy strategies to increase the availability and quality of opportunities for productive engagement and promote planning for engagement in late life.

Spatial and Temporal Patterns in Carbon Emissions to the Atmosphere

NASA Astrophysics Data System (ADS)

Broniak, C. T.; Blasing, T. J.; Marland, G.

2003-12-01

Data on global fossil-fuel emissions of CO2 to the atmosphere for year 2000 show that the range of national average per capita emissions, in metric tons of carbon per person, includes values of 5.40 for the United States, 2.61 for Germany, 0.29 for India and 0.04 for Liberia. This range is more than two orders of magnitude. Similar data on national fossil-fuel emissions for the United States vary by more than an order of magnitude, from 34.18 metric tons of carbon per person for Wyoming to 2.70 for California. The state data also show differing patterns of change over time. The Kyoto Protocol would require ratifying developed countries to reduce greenhouse gas emissions to quantified negotiated targets. The concept of contraction and convergence (C&C) has been widely touted as a possible basis for ultimate, more strict limits on greenhouse gas emissions. The idea of C&C is that per-capita emissions of CO2 for all countries would converge toward some common value that is consistent with stabilization of global climate. The U.S., on the other hand, has proposed intensity-based emissions targets whereby goals would be defined in terms of emissions per unit of gross domestic product, or perhaps emissions per unit of output for specific activities. This paper describes the data set on U.S. CO2 emissions by state, and begins to explore the patterns between states and over time.

Pallidal neuronal discharge in Huntington's disease: support for selective loss of striatal cells originating the indirect pathway.

PubMed

Starr, Philip A; Kang, Gail A; Heath, Susan; Shimamoto, Shoichi; Turner, Robert S

2008-05-01

Chorea is the predominant motor manifestation in the early symptomatic phase of adult onset Huntington's disease (HD). Pathologically, this stage is marked by differential loss of striatal neurons contributing to the indirect pathway. This pattern of neuronal loss predicts decreased neuronal firing rates in GPi and increased firing rates in GPe, the opposite of the changes in firing rate known to occur in Parkinson's disease (PD). We present single-unit discharge characteristics (33 neurons) observed in an awake patient with HD (41 CAG repeats) undergoing microelectrode guided surgery for pallidal deep brain stimulation. Pallidal single-unit activity at "rest" and during voluntary movement was discriminated off line by principal component analysis and evaluated with respect to discharge rate, bursting, and oscillatory activity in the 0-200 Hz range. 24 GPi and 9 GPe units were studied, and compared with 132 GPi and 50 GPe units from 14 patients with PD. The mean (+/-SEM) spontaneous discharge rate for HD was 58+/-4 for GPi and 73+/-5 for GPe. This contrasted with discharge rates in PD of 95+/-2 for GPi and 57+/-3 for GPe. HD GPi units showed more bursting than PD GPi units but much less oscillatory activity in the 2-35 Hz frequency range at rest. These findings are consistent with selective early loss of striatal cells originating the indirect pathway.

Human and biophysical influences on fire occurrence in the United States

USGS Publications Warehouse

Hawbaker, Todd J.; Radeloff, Volker C.; Stewart, Susan I.; Hammer, Roger B.; Keuler, Nicholas S.; Clayton, Murray K.

2013-01-01

National-scale analyses of fire occurrence are needed to prioritize fire policy and management activities across the United States. However, the drivers of national-scale patterns of fire occurrence are not well understood, and how the relative importance of human or biophysical factors varies across the country is unclear. Our research goal was to model the drivers of fire occurrence within ecoregions across the conterminous United States. We used generalized linear models to compare the relative influence of human, vegetation, climate, and topographic variables on fire occurrence in the United States, as measured by MODIS active fire detections collected between 2000 and 2006. We constructed models for all fires and for large fires only and generated predictive maps to quantify fire occurrence probabilities. Areas with high fire occurrence probabilities were widespread in the Southeast, and localized in the Mountain West, particularly in southern California, Arizona, and New Mexico. Probabilities for large-fire occurrence were generally lower, but hot spots existed in the western and south-central United States The probability of fire occurrence is a critical component of fire risk assessments, in addition to vegetation type, fire behavior, and the values at risk. Many of the hot spots we identified have extensive development in the wildland–urban interface and are near large metropolitan areas. Our results demonstrated that human variables were important predictors of both all fires and large fires and frequently exhibited nonlinear relationships. However, vegetation, climate, and topography were also significant variables in most ecoregions. If recent housing growth trends and fire occurrence patterns continue, these areas will continue to challenge policies and management efforts seeking to balance the risks generated by wildfires with the ecological benefits of fire.

National patterns in environmental injustice and inequality: outdoor NO2 air pollution in the United States.

PubMed

Clark, Lara P; Millet, Dylan B; Marshall, Julian D

2014-01-01

We describe spatial patterns in environmental injustice and inequality for residential outdoor nitrogen dioxide (NO2) concentrations in the contiguous United States. Our approach employs Census demographic data and a recently published high-resolution dataset of outdoor NO2 concentrations. Nationally, population-weighted mean NO2 concentrations are 4.6 ppb (38%, p<0.01) higher for nonwhites than for whites. The environmental health implications of that concentration disparity are compelling. For example, we estimate that reducing nonwhites' NO2 concentrations to levels experienced by whites would reduce Ischemic Heart Disease (IHD) mortality by ∼7,000 deaths per year, which is equivalent to 16 million people increasing their physical activity level from inactive (0 hours/week of physical activity) to sufficiently active (>2.5 hours/week of physical activity). Inequality for NO2 concentration is greater than inequality for income (Atkinson Index: 0.11 versus 0.08). Low-income nonwhite young children and elderly people are disproportionately exposed to residential outdoor NO2. Our findings establish a national context for previous work that has documented air pollution environmental injustice and inequality within individual US metropolitan areas and regions. Results given here can aid policy-makers in identifying locations with high environmental injustice and inequality. For example, states with both high injustice and high inequality (top quintile) for outdoor residential NO2 include New York, Michigan, and Wisconsin.

Unique and Highly Selective Anticytomegalovirus Activities of Artemisinin-Derived Dimer Diphenyl Phosphate Stem from Combination of Dimer Unit and a Diphenyl Phosphate Moiety

PubMed Central

He, Ran; Forman, Michael; Mott, Bryan T.; Venkatadri, Rajkumar; Posner, Gary H.

2013-01-01

We report that the artemisinin-derived dimer diphenyl phosphate (DPP; dimer 838) is the most selective inhibitor of human cytomegalovirus (CMV) replication among a series of artemisinin-derived monomers and dimers. Dimer 838 was also unique in being an irreversible CMV inhibitor. The peroxide unit within artemisinins' chemical structures is critical to their activities, and its absence results in loss of anti-CMV activities. Surprisingly, the deoxy dimer of 838 retained modest anti-CMV activity, suggesting that the DPP moiety of dimer 838 contributes to its anti-CMV activities. DPP alone did not inhibit CMV replication, but triphenyl phosphate (TPP) had modest CMV inhibition, although its selectivity index was low. Artemisinin DPP derivatives dimer 838 and monomer diphenyl phosphate (compound 558) showed stronger CMV inhibition and a higher selectivity index than their analogs lacking the DPP unit. An add-on and removal assay revealed that removing DPP derivatives (compounds 558 and 838) but not the non-DPP backbones (artesunate and compound 606) at 24 h postinfection (hpi) already resulted in dominant CMV inhibition. CMV inhibition was fully irreversible with 838 and partially irreversible with 558, while non-DPP artemisinins were reversible inhibitors. While all artemisinin derivatives and TPP reduced the expression of the CMV immediate early 2 (IE2), UL44, and pp65 proteins at or after 48 hpi, only TPP inhibited the expression of both IE1 and IE2. Combination of a non-DPP dimer (compound 606) with TPP was synergistic in CMV inhibition, while ganciclovir and TPP were additive. Although TPP shared structural similarity with monomer DPP (compound 558) and dimer DPP (compound 838), its pattern of CMV inhibition was significantly different from the patterns of the artemisinins. These findings demonstrate that the DPP group contributes to the unique activities of compound 838. PMID:23774439

Influence of light exposure at nighttime on sleep development and body growth of preterm infants

PubMed Central

Kaneshi, Yosuke; Ohta, Hidenobu; Morioka, Keita; Hayasaka, Itaru; Uzuki, Yutaka; Akimoto, Takuma; Moriichi, Akinori; Nakagawa, Machiko; Oishi, Yoshihisa; Wakamatsu, Hisanori; Honma, Naoki; Suma, Hiroki; Sakashita, Ryuichi; Tsujimura, Sei-ichi; Higuchi, Shigekazu; Shimokawara, Miyuki; Cho, Kazutoshi; Minakami, Hisanori

2016-01-01

Previous studies have demonstrated that a light-dark cycle has promoted better sleep development and weight gain in preterm infants than constant light or constant darkness. However, it was unknown whether brief light exposure at night for medical treatment and nursing care would compromise the benefits brought about by such a light-dark cycle. To examine such possibility, we developed a special red LED light with a wavelength of >675 nm which preterm infants cannot perceive. Preterm infants born at <36 weeks’ gestational age were randomly assigned for periodic exposure to either white or red LED light at night in a light-dark cycle after transfer from the Neonatal Intensive Care Unit to the Growing Care Unit, used for supporting infants as they mature. Activity, nighttime crying and body weight were continuously monitored from enrolment until discharge. No significant difference in rest-activity patterns, nighttime crying, or weight gain was observed between control and experimental groups. The data indicate that nursing care conducted at 3 to 4-hour intervals exposing infants to light for <15 minutes does not prevent the infants from developing circadian rest-activity patterns, or proper body growth as long as the infants are exposed to regular light-dark cycles. PMID:26877166

Altered motor unit discharge patterns in paretic muscles of stroke survivors assessed using surface electromyography.

PubMed

Hu, Xiaogang; Suresh, Aneesha K; Rymer, William Z; Suresh, Nina L

2016-08-01

Hemispheric stroke survivors often show impairments in voluntary muscle activation. One potential source of these impairments could come from altered control of muscle, via disrupted motor unit (MU) firing patterns. In this study, we sought to determine whether MU firing patterns are modified on the affected side of stroke survivors, as compared with the analogous contralateral muscle. Using a novel surface electromyogram (EMG) sensor array, coupled with advanced template recognition software (dEMG) we recorded surface EMG signals over the first dorsal interosseous (FDI) muscle on both paretic and contralateral sides. Recordings were made as stroke survivors produced isometric index finger abductions over a large force range (20%-60% of maximum). Utilizing the dEMG algorithm, MU firing rates, recruitment thresholds, and action potential amplitudes were estimated for concurrently active MUs in each trial. Our results reveal significant changes in the firing rate patterns in paretic FDI muscle, in that the discharge rates, characterized in relation to recruitment force threshold and to MU size, were less clearly correlated with recruitment force than in contralateral FDI muscles. Firing rates in the affected muscle also did not modulate systematically with the level of voluntary muscle contraction, as would be expected in intact muscles. These disturbances in firing properties also correlated closely with the impairment of muscle force generation. Our results provide strong evidence of disruptions in MU firing behavior in paretic muscles after a hemispheric stroke, suggesting that modified control of the spinal motoneuron pool could be a contributing factor to muscular weakness in stroke survivors.

Altered motor unit discharge patterns in paretic muscles of stroke survivors assessed using surface electromyography

NASA Astrophysics Data System (ADS)

Hu, Xiaogang; Suresh, Aneesha K.; Rymer, William Z.; Suresh, Nina L.

2016-08-01

Objective. Hemispheric stroke survivors often show impairments in voluntary muscle activation. One potential source of these impairments could come from altered control of muscle, via disrupted motor unit (MU) firing patterns. In this study, we sought to determine whether MU firing patterns are modified on the affected side of stroke survivors, as compared with the analogous contralateral muscle. Approach. Using a novel surface electromyogram (EMG) sensor array, coupled with advanced template recognition software (dEMG) we recorded surface EMG signals over the first dorsal interosseous (FDI) muscle on both paretic and contralateral sides. Recordings were made as stroke survivors produced isometric index finger abductions over a large force range (20%-60% of maximum). Utilizing the dEMG algorithm, MU firing rates, recruitment thresholds, and action potential amplitudes were estimated for concurrently active MUs in each trial. Main results. Our results reveal significant changes in the firing rate patterns in paretic FDI muscle, in that the discharge rates, characterized in relation to recruitment force threshold and to MU size, were less clearly correlated with recruitment force than in contralateral FDI muscles. Firing rates in the affected muscle also did not modulate systematically with the level of voluntary muscle contraction, as would be expected in intact muscles. These disturbances in firing properties also correlated closely with the impairment of muscle force generation. Significance. Our results provide strong evidence of disruptions in MU firing behavior in paretic muscles after a hemispheric stroke, suggesting that modified control of the spinal motoneuron pool could be a contributing factor to muscular weakness in stroke survivors.

Permits To Operate: Doing What We Do with the Proper Authority--USA Context.

ERIC Educational Resources Information Center

Jackson, Stefan J.

This paper discusses how outdoor recreation and education personnel can work with the laws, regulations, patterns, and vagaries of educational and institutional permitting on public lands in the United States. The difference between a permit and a management plan is defined: a permit authorizes a specific activity with restrictions of amount,…

Improving Parental Involvement in an Inner-City School

ERIC Educational Resources Information Center

Marion, Veronica D.

2017-01-01

A pattern of low parental involvement exists at in an inner-city school in the northeast region of the United States, where 90% of the students are students of color and fewer than 10% of parents attend school-based activities. Low parental involvement at the local school may lead to decreased student achievement and limited access to needed…

Diurnal patterns in flight activity and effects of light on host finding behavior of the Asian citrus psyllid

USDA-ARS?s Scientific Manuscript database

The Asian citrus psyllid (ACP), Diaphorina citri (Hemiptera: Psyllidae), is an invasive pest of citrus in the United States. The psyllid feeds and reproduces primarily on new flush growth of citrus and other rutaceous plants. Because it vectors the bacterial causal agents of the deadly citrus green...

75 FR 38976 - Proposed Information Collection; Comment Request; Precanvass Operation for the 2012 Economic...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-07

... multimodal, system-wide data on the volume and pattern of goods movement in the United States. The Commodity... Census Bureau will mail a one- page questionnaire to manufacturing, mining, and wholesale establishments... used to improve the mailing and follow-up activities for the 2012 Commodity Flow Survey. III. Data OMB...

Modelling of sequential groundwater treatment with zero valent iron and granular activated carbon.

PubMed

Bayer, Peter; Finkel, Michael

2005-06-01

Multiple contaminant mixtures in groundwater may not efficiently be treated by a single technology if contaminants possess rather different properties with respect to sorptivity, solubility, and degradation potential. An obvious choice is to use sequenced units of the generally accepted treatment materials zero valent iron (ZVI) and granular activated carbon (GAC). However, as the results of this modelling study suggest, the required dimensions of both reactor units may strongly differ from those expected on the grounds of a contaminant-specific design. This is revealed by performing an analysis for a broad spectrum of design alternatives through numerical experiments for selected patterns of contaminant mixtures consisting of monochlorobenzene, tetrachloroethylene, trichloroethylene (TCE), cis-1,2-dichloroethylene (cis-DCE), and vinyl chloride (VC). It is shown that efficient treatment can be achieved only if competitive sorption effects in the GAC unit as well as the formation of intermediate products in the ZVI unit are carefully taken into account. Cost-optimal designs turned out to vary extremely depending on the prevailing conditions concerning contaminant concentrations, branching ratios, and unit costs of both reactor materials. Where VC is the critical contaminant, due to high initial concentration or extensive production as an intermediate, two options are cost-effective: an oversized ZVI unit with an oversized GAC unit or a pure GAC reactor.

Motor control by precisely timed spike patterns

PubMed Central

Srivastava, Kyle H.; Holmes, Caroline M.; Vellema, Michiel; Pack, Andrea R.; Elemans, Coen P. H.; Nemenman, Ilya; Sober, Samuel J.

2017-01-01

A fundamental problem in neuroscience is understanding how sequences of action potentials (“spikes”) encode information about sensory signals and motor outputs. Although traditional theories assume that this information is conveyed by the total number of spikes fired within a specified time interval (spike rate), recent studies have shown that additional information is carried by the millisecond-scale timing patterns of action potentials (spike timing). However, it is unknown whether or how subtle differences in spike timing drive differences in perception or behavior, leaving it unclear whether the information in spike timing actually plays a role in brain function. By examining the activity of individual motor units (the muscle fibers innervated by a single motor neuron) and manipulating patterns of activation of these neurons, we provide both correlative and causal evidence that the nervous system uses millisecond-scale variations in the timing of spikes within multispike patterns to control a vertebrate behavior—namely, respiration in the Bengalese finch, a songbird. These findings suggest that a fundamental assumption of current theories of motor coding requires revision. PMID:28100491

Chapter4 - Drought patterns in the conterminous United States and Hawaii.

Treesearch

Frank H. Koch; William D. Smith; John W. Coulston

2014-01-01

Droughts are common in virtually all U.S. forests, but their frequency and intensity vary widely both between and within forest ecosystems (Hanson and Weltzin 2000). Forests in the Western United States generally exhibit a pattern of annual seasonal droughts. Forests in the Eastern United States tend to exhibit one of two prevailing patterns: random occasional droughts...

Associative memory of phase-coded spatiotemporal patterns in leaky Integrate and Fire networks.

PubMed

Scarpetta, Silvia; Giacco, Ferdinando

2013-04-01

We study the collective dynamics of a Leaky Integrate and Fire network in which precise relative phase relationship of spikes among neurons are stored, as attractors of the dynamics, and selectively replayed at different time scales. Using an STDP-based learning process, we store in the connectivity several phase-coded spike patterns, and we find that, depending on the excitability of the network, different working regimes are possible, with transient or persistent replay activity induced by a brief signal. We introduce an order parameter to evaluate the similarity between stored and recalled phase-coded pattern, and measure the storage capacity. Modulation of spiking thresholds during replay changes the frequency of the collective oscillation or the number of spikes per cycle, keeping preserved the phases relationship. This allows a coding scheme in which phase, rate and frequency are dissociable. Robustness with respect to noise and heterogeneity of neurons parameters is studied, showing that, since dynamics is a retrieval process, neurons preserve stable precise phase relationship among units, keeping a unique frequency of oscillation, even in noisy conditions and with heterogeneity of internal parameters of the units.

Evolution-Based Functional Decomposition of Proteins

PubMed Central

Rivoire, Olivier; Reynolds, Kimberly A.; Ranganathan, Rama

2016-01-01

The essential biological properties of proteins—folding, biochemical activities, and the capacity to adapt—arise from the global pattern of interactions between amino acid residues. The statistical coupling analysis (SCA) is an approach to defining this pattern that involves the study of amino acid coevolution in an ensemble of sequences comprising a protein family. This approach indicates a functional architecture within proteins in which the basic units are coupled networks of amino acids termed sectors. This evolution-based decomposition has potential for new understandings of the structural basis for protein function. To facilitate its usage, we present here the principles and practice of the SCA and introduce new methods for sector analysis in a python-based software package (pySCA). We show that the pattern of amino acid interactions within sectors is linked to the divergence of functional lineages in a multiple sequence alignment—a model for how sector properties might be differentially tuned in members of a protein family. This work provides new tools for studying proteins and for generally testing the concept of sectors as the principal units of function and adaptive variation. PMID:27254668

Crew Activity Analyzer

NASA Technical Reports Server (NTRS)

Murray, James; Kirillov, Alexander

2008-01-01

The crew activity analyzer (CAA) is a system of electronic hardware and software for automatically identifying patterns of group activity among crew members working together in an office, cockpit, workshop, laboratory, or other enclosed space. The CAA synchronously records multiple streams of data from digital video cameras, wireless microphones, and position sensors, then plays back and processes the data to identify activity patterns specified by human analysts. The processing greatly reduces the amount of time that the analysts must spend in examining large amounts of data, enabling the analysts to concentrate on subsets of data that represent activities of interest. The CAA has potential for use in a variety of governmental and commercial applications, including planning for crews for future long space flights, designing facilities wherein humans must work in proximity for long times, improving crew training and measuring crew performance in military settings, human-factors and safety assessment, development of team procedures, and behavioral and ethnographic research. The data-acquisition hardware of the CAA (see figure) includes two video cameras: an overhead one aimed upward at a paraboloidal mirror on the ceiling and one mounted on a wall aimed in a downward slant toward the crew area. As many as four wireless microphones can be worn by crew members. The audio signals received from the microphones are digitized, then compressed in preparation for storage. Approximate locations of as many as four crew members are measured by use of a Cricket indoor location system. [The Cricket indoor location system includes ultrasonic/radio beacon and listener units. A Cricket beacon (in this case, worn by a crew member) simultaneously transmits a pulse of ultrasound and a radio signal that contains identifying information. Each Cricket listener unit measures the difference between the times of reception of the ultrasound and radio signals from an identified beacon. Assuming essentially instantaneous propagation of the radio signal, the distance between that beacon and the listener unit is estimated from this time difference and the speed of sound in air.] In this system, six Cricket listener units are mounted in various positions on the ceiling, and as many as four Cricket beacons are attached to crew members. The three-dimensional position of each Cricket beacon can be estimated from the time-difference readings of that beacon from at least three Cricket listener units

Nursing Unit Design, Nursing Staff Communication Networks, and Patient Falls: Are They Related?

PubMed

Brewer, Barbara B; Carley, Kathleen M; Benham-Hutchins, Marge; Effken, Judith A; Reminga, Jeffrey

2018-01-01

The purpose of this research is to (1) investigate the impact of nursing unit design on nursing staff communication patterns and, ultimately, on patient falls in acute care nursing units; and (2) evaluate whether differences in fall rates, if found, were associated with the nursing unit physical structure (shape) or size. Nursing staff communication and nursing unit design are frequently linked to patient safety outcomes, yet little is known about the impact of specific nursing unit designs on nursing communication patterns that might affect patient falls. An exploratory longitudinal correlational design was used to measure nursing unit communication structures using social network analysis techniques. Data were collected 4 times over a 7-month period. Floor plans were used to determine nursing unit design. Fall rates were provided by hospital coordinators. An analysis of covariance controlling for hospitals resulted in a statistically significant interaction of unit shape and size (number of beds). The interaction occurred when medium- and large-sized racetrack-shaped units intersected with medium- and large-sized cross-shaped units. The results suggest that nursing unit design shape impacts nursing communication patterns, and the interaction of shape and size may impact patient falls. How those communication patterns affect patient falls should be considered when planning hospital construction of nursing care units.

Behçet Syndrome Manifestations and Activity in the United States versus Turkey — A Cross-sectional Cohort Comparison

PubMed Central

Sibley, Cailin; Yazici, Yusuf; Tascilar, Koray; Khan, Nafiz; Bata, Yasmin; Yazici, Hasan; Goldbach-Mansky, Raphaela; Hatemi, Gulen

2015-01-01

Objective To compare clinical manifestations and activity of Behçet syndrome (BS) in the United States versus Turkey using validated outcome measures. Methods Consecutive patients with BS from the US National Institutes of Health (NIH), New York University, and the University of Istanbul were evaluated. Disease activity was measured using the Behçet’s Syndrome Activity Scale (BSAS) and the Behçet’s Disease Current Activity Form (BDCAF) with quality of life measured by the Behçet Disease Quality of Life (BDQOL) form. One-way ANOVA, t-tests, and multivariate regression analyses were performed. Results Mean age did not differ between sites; however, more women were seen in the United States versus in Turkey (p < 0.001), and disease duration was longer in the United States (p = 0.02). Organ manifestations were similar for oral and genital ulcers, skin disease, arthralgia, eye disease, and thrombosis. However, more gastrointestinal (p < 0.001) and neurologic disease (p = 0.003) was seen in the United States. BSAS and BDCAF scores were worse in the United States compared to Turkey (p = 0.013 and < 0.001, respectively). Worse mean BDQOL scores were observed at the NIH compared to Istanbul (not significant). Multivariable regression models showed worse scores in ethnically atypical patients for BSAS and BDCAF (p = 0.04 and p = 0.001), American patients for BDCAF (p = 0.01), older age for BDCAF (p = 0.005), and women for BDQOL (p = 0.01). Conclusion Demographic and clinical manifestations of BS differ between sites with higher disease activity in the United States compared to Turkey. Referral patterns, age, sex, ethnicity, and country of origin may be important in these differences. These observations raise the question of whether pathogenic mechanisms differ in Turkish and American patients. PMID:24931953

Prognostic EEG patterns in patients resuscitated from cardiac arrest with particular focus on Generalized Periodic Epileptiform Discharges (GPEDs).

PubMed

Milani, P; Malissin, I; Tran-Dinh, Y R; Deye, N; Baud, F; Lévy, B I; Kubis, N

2014-04-01

We assessed clinical and early electrophysiological characteristics, in particular Generalized Periodic Epileptiform Discharges (GPEDs) patterns, of consecutive patients during a 1-year period, hospitalized in the Intensive Care Unit (ICU) after resuscitation following cardiac arrest (CA). Consecutive patients resuscitated from cardiac arrest (CA) with first EEG recordings within 48hours were included. Clinical data were collected from hospital records, in particular therapeutic hypothermia. Electroencephalograms (EEGs) were re-analyzed retrospectively. Sixty-two patients were included. Forty-two patients (68%) were treated with therapeutic hypothermia according to international guidelines. Global mortality was 74% but not significantly different between patients who benefited from therapeutic hypothermia compared to those who did not. All the patients who did not have an initial background activity (36/62; 58%) died. By contrast, initial background activity was present in 26/62 (42%) and among these patients, 16/26 (61%) survived. Electroencephalography demonstrated GPEDs patterns in 5 patients, all treated by therapeutic hypothermia and antiepileptic drugs. One of these survived and showed persistent background activity with responsiveness to benzodiazepine intravenous injection. Patients presenting suppressed background activity, even when treated by hypothermia, have a high probability of poor outcome. Thorough analysis of EEG patterns might help to identify patients with a better chance of survival. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

On a phase diagram for random neural networks with embedded spike timing dependent plasticity.

PubMed

Turova, Tatyana S; Villa, Alessandro E P

2007-01-01

This paper presents an original mathematical framework based on graph theory which is a first attempt to investigate the dynamics of a model of neural networks with embedded spike timing dependent plasticity. The neurons correspond to integrate-and-fire units located at the vertices of a finite subset of 2D lattice. There are two types of vertices, corresponding to the inhibitory and the excitatory neurons. The edges are directed and labelled by the discrete values of the synaptic strength. We assume that there is an initial firing pattern corresponding to a subset of units that generate a spike. The number of activated externally vertices is a small fraction of the entire network. The model presented here describes how such pattern propagates throughout the network as a random walk on graph. Several results are compared with computational simulations and new data are presented for identifying critical parameters of the model.

The effect of vegetation patterns on wind-blown mass transport at the regional scale: A wind tunnel experiment

NASA Astrophysics Data System (ADS)

Youssef, Feras; Visser, Saskia M.; Karssenberg, Derek; Erpul, Gunay; Cornelis, Wim M.; Gabriels, Donald; Poortinga, Ate

2012-07-01

Wind erosion is a global environmental problem. Re-vegetating land is a commonly used method to reduce the negative effects of wind erosion. However, there is limited knowledge on the effect of vegetation pattern on wind-blown mass transport. The objective of this study was to investigate the effect of vegetation pattern on this phenomenon within a land unit and at the border between land units. Wind tunnel experiments were conducted with artificial shrubs representing Atriplex halimus. Wind runs at a speed of 11 m s- 1 were conducted and sand translocation was measured after 200-230 s using a graph paper prepared for this purpose. This research showed that: 1) the transport within a land unit is affected by the neighboring land units and by the vegetation pattern within both the unit itself and the neighboring land units; 2) re-vegetation plans for degraded land can take into account the 'streets' effect (zones of erosion areas similar to streets); 3) the effect of neighboring land units includes sheltering effect and the regulation of sediment passing from one land unit to the neighboring land units and 4) in addition to investigation of the general effect of vegetation pattern on erosion and deposition within the region, it is important to investigate the redistribution of sediment at smaller scales depending on the scope of the project.

Tephra Blanket Record of a Violent Strombolian Eruption, Sunset Crater, Arizona

NASA Astrophysics Data System (ADS)

Wagner, K. D.; Ort, M. H.

2015-12-01

New fieldwork provides a detailed description of the widespread tephra of the ~1085 CE Sunset Crater eruption in the San Francisco Volcanic Field, Arizona, and refines interpretation of the eruptive sequence. The basal fine-lapilli tephra-fall-units I-IV are considered in detail. Units I and II are massive, with Unit I composed of angular to spiny clasts and II composed of more equant, oxidized clasts. Units III and IV have inversely graded bases and massive tops and are composed of angular to spiny iridescent and mixed iridescent and oxidized angular clasts, respectively. Xenoliths are rare in all units (<0.1%): sedimentary xenoliths are consistent with the known shallow country rock (Moenkopi and Kaibab Fms); magmatic xenoliths are pumiceous rhyolite mingled with basalt. Unit II is less sideromelane rich (20%) than Units I, III, and IV (60-80%). Above these units are at least two more coarse tephra-fall units. Variably preserved ash and fine-lapilli laminae cap the tephra blanket. This deposit is highly susceptible to reworking, and likely experienced both syn- and post-eruptive aeolian redistribution. It appears as either well sorted, alternating planar-parallel beds of ash and fine lapilli with rare wavy beds, or as cross- or planar-bedded ash. The tephra blanket as a whole is stratigraphically underlain by a fissure-fed lava flow and lapilli-fall units are intercalated with two larger flows. Mean grain size is coarsest in Unit I but coarsens in Units II-IV. Units I, III, and IV are moderately to poorly sorted with no skew. Unit II is better sorted and more coarse-skewed. Units I and III are slightly more platykurtic than II and IV. Without considering possible spatial effects introduced by dispersion patterns, bootstrap ANOVA confidence intervals suggest at least Unit II sorting and skewness are from distinct populations. Isopachs indicate Units I and II were associated with a 10-km-long fissure source. After or during Unit II's deposition, activity localized to Sunset Crater. Units III and IV were emplaced with waxing to sustained activity, and followed by at least two more sustained episodes. Two lava flows began effusing from the cone during this period and remained active after explosive activity ceased. Primary tephra deposition ended with a period of small discrete explosions.

Rock magnetic stratigraphy of a mafic layered sill: A key to the Karoo volcanics plumbing system

NASA Astrophysics Data System (ADS)

Maes, S. M.; Ferré, E. C.; Tikoff, B.; Brown, P. E.; Marsh, J. S.

2008-05-01

The Insizwa sill is an ~ 1 km-thick subhorizontal layered mafic intrusion and part of the Karoo Large Igneous Province in South Africa. This well-exposed intrusion consists of several superimposed petrologically and geochemically distinct units. Magnetic methods were used to study the intrusion in order to constrain the physical processes active in these types of bodies during crystallization. Rock magnetism studies indicate that within different petrologic units bulk susceptibility is controlled by primary magnetite (with minor pyrrhotite) and/or paramagnetic minerals (olivine, pyroxene). New magnetic data based on 659 specimens obtained from 3 vertical borehole cores, each spaced 5 km apart, confirm the prominent vertical zonation in low field magnetic susceptibility ( Klf), degree of anisotropy ( Pj) and orientation of the anisotropy of magnetic susceptibility (AMS) axes. The magnetic susceptibility correlates very well with petrographic units and the lateral continuity of magnetic units between boreholes is very consistent. Petrologic units with high, but variable, Klf, also show moderate anisotropy and dominantly vertical foliations. We interpret these patterns to result from inverse fabrics from single domain magnetite. The degree of anisotropy is low in petrologic units with low Klf, which also show shallowly dipping magnetic foliations. We interpret that the magnetic properties of these units are dominated by the paramagnetic minerals. These low Klf petrologic units also show no systematic increase in Klf, suggesting that only minor differentiation is occurring in these units. The dataset derived from 2 surface sampling traverses are consistent with borehole core AMS data, showing a pattern of dominantly steep magnetic foliation and variably plunging magnetic lineation with a NW-SE trend.

Energy cost and lower leg muscle activities during erect bipedal locomotion under hyperoxia.

PubMed

Abe, Daijiro; Fukuoka, Yoshiyuki; Maeda, Takafumi; Horiuchi, Masahiro

2018-06-19

Energy cost of transport per unit distance (CoT) against speed shows U-shaped fashion in walking and linear fashion in running, indicating that there exists a specific walking speed minimizing the CoT, being defined as economical speed (ES). Another specific gait speed is the intersection speed between both fashions, being called energetically optimal transition speed (EOTS). We measured the ES, EOTS, and muscle activities during walking and running at the EOTS under hyperoxia (40% fraction of inspired oxygen) on the level and uphill gradients (+ 5%). Oxygen consumption [Formula: see text] and carbon dioxide output [Formula: see text] were measured to calculate the CoT values at eight walking speeds (2.4-7.3 km h -1 ) and four running speeds (7.3-9.4 km h - 1 ) in 17 young males. Electromyography was recorded from gastrocnemius medialis, gastrocnemius lateralis (GL), and tibialis anterior (TA) to evaluate muscle activities. Mean power frequency (MPF) was obtained to compare motor unit recruitment patterns between walking and running. [Formula: see text], [Formula: see text], and CoT values were lower under hyperoxia than normoxia at faster walking speeds and any running speeds. A faster ES on the uphill gradient and slower EOTS on both gradients were observed under hyperoxia than normoxia. GL and TA activities became lower when switching from walking to running at the EOTS under both FiO 2 conditions on both gradients, so did the MPF in the TA. ES and EOTS were influenced by reduced metabolic demands induced by hyperoxia. GL and TA activities in association with a lower shift of motor unit recruitment patterns in the TA would be related to the gait selection when walking or running at the EOTS. UMIN000017690 ( R000020501 ). Registered May 26, 2015, before the first trial.

Socioeconomic impacts of climate change on rural communities in the United States

Treesearch

Pankaj Lal; Janaki Alavalapati; D Evan Mercer

2011-01-01

Climate change refers to any distinct change in measures of climate such as temperature, rainfall, snow, or wind patterns lasting for decades or longer (USEPA 2009). In the last decade, there has been a clear consensus among scientists that the world is experiencing a rapid global climate change, much of it attributable to anthropogenic activities. The extent of...

Measurements of AAFE RADSCAT antenna characteristics

NASA Technical Reports Server (NTRS)

Cross, A. E.; Jones, W. L., Jr.; Jones, A. L.

1977-01-01

Antenna characteristics (active and passive) for a modified AAFE-RADSCAT parabolic dish antenna are documented for a variety of antenna configurations. The modified antenna was a replacement for the original unit which was damaged in January 1975. Pattern measurements made at Langley Research Center and Johnson Space Center are presented, with an analysis of the results. Antenna loss measurements are also presented and summarized.

Enzyme activity and expression pattern of intra- and extracellular chitinase and β-1,3-glucanase of Wickerhamomyces anomalus EG2 using glycol chitin and glucan-containing high polymer complex.

PubMed

Hong, Sin-Hyoung; Song, Yong-Su; Seo, Dong-Jun; Kim, Kil-Yong; Jung, Woo-Jin

2017-12-01

We investigated cell growth and activity of intra- and extracellular chitinase, β-1,3-glucanase, and chitin deacetylase with SDS-PAGE by incubating W. anomalus EG2 in PDB and YPD media for 24h in presence of different concentrations (0%, 0.1%, 0.3%, and 0.5%) of colloidal chitin. Maximum cell growth was observed in both PDB and YPD media without colloidal chitin. In the absence of colloidal chitin, maximum extracellular β-1,3-glucanase activity of 32.96 and 47.28 units/mL was reported at 18h in PDB medium and 6h in YPD medium, respectively. In addition, extracellular chitinase was unaffected by various concentrations of carboxymethyl chitin in both PDB and YPD media. In the absence of colloidal chitin, maximum intracellular chitinase activity was indicated to be 9.82 and 9.86 units/mg protein in PDB and YPD media, respectively. Maximum intracellular β-1,3-glucanase activity reported was 17.34 units/mg protein in PDB medium containing 0.5% colloidal chitin and 15.0 units/mg protein in YPD medium containing 0.3% colloidal chitin. Five major isozymes, GN1, GN2, GN3, GN4, and GN5, of intracellular β-1,3-glucanase were detected with glucan-containing high polymer complex as a substrate with or without colloidal chitin. Copyright © 2017 Elsevier B.V. All rights reserved.

Nursing staff work patterns in a residential aged care home: a time-motion study.

PubMed

Qian, Siyu; Yu, Ping; Hailey, David

2016-11-01

Objective Residential aged care services are challenged by an increasing number of residents and a shortage of nursing staff. Developing strategies to overcome this challenge requires an understanding of nursing staff work patterns. The aim of the present study was to investigate the work processes followed by nursing staff and how nursing time is allocated in a residential aged care home. Methods An observational time-motion study was conducted at two aged care units for 12 morning shifts. Seven nurses were observed, one per shift. Results In all, there were 91h of observation. The results showed that there was a common work process followed by all nurse participants. Medication administration, documentation and verbal communication were the most time-consuming activities and were conducted most frequently. No significant difference between the two units was found in any category of activities. The average duration of most activities was less than 1min. There was no difference in time utilisation between the endorsed enrolled nurses and the personal carers in providing nursing care. Conclusion Medication administration, documentation and verbal communication were the major tasks in morning shifts in a residential aged care home. Future research can investigate how verbal communication supports nursing care. What is known about the topic? The aging population will substantially increase the demand for residential aged care services. There is a lack of research on nurses' work patterns in residential aged care homes. What does this paper add? The present study provides a comprehensive understanding of nurses' work patterns in a residential aged care home. There is a common work process followed by nurses in providing nursing care. Medication administration, verbal communication and documentation are the most time-consuming activities and they are frequently conducted in the same period of time. Wound care, physical review and documentation on desktop computers are arranged flexibly by the nurses. What are the implications for practitioners? When developing a task reallocation strategy to improve work efficiency, effort can be put into tasks that can be arranged more flexibly.

Response of cat cerebellar vermis induced by sound. I. Influence of drugs on responses of single units.

PubMed

Jastreboff, P J; Tarnecki, R

1975-01-01

Experiments were done on the cats under Chloralose and/or Nembutal anesthesia. A click was used as a standard acoustic stimulus. The type of responses of single units from cerebellar vermis lobuli V-VII were analyzed. At least four different types of single unit reactions were observed and one of these - oscillatory - was produced by the presence of Flaxedil simultaneously with Chloralose. The system that controls the activity of the middle-ear-muscles can be suspected as the source of the oscillatory pattern of the cerebellar response. Latencies were found to be constant, independent of anesthesia, but it was necessary to have a low level of Nembutal anesthesia because of the overriding inhibitory influence of Nembutal.

Using Organization Risk Analyzer (ORA) to Explore the Relationship of Nursing Unit Communication to Patient Safety and Quality Outcomes

PubMed Central

Effken, Judith A.; Carley, Kathleen M.; Gephart, Sheila; Verran, Joyce A.; Bianchi, Denise; Reminga, Jeff; Brewer, Barbara

2011-01-01

Purpose We used Organization Risk Analyzer (ORA), a dynamic network analysis tool, to identify patient care unit communication patterns associated with patient safety and quality outcomes. Although ORA had previously had limited use in healthcare, we felt it could effectively model communication on patient care units. Methods Using a survey methodology, we collected communication network data from nursing staff on seven patient care units on two different days. Patient outcome data were collected via a separate survey. Results of the staff survey were used to represent the communication networks for each unit in ORA. We then used ORA's analysis capability to generate communication metrics for each unit. ORA's visualization capability was used to better understand the metrics. Results We identified communication patterns that correlated with two safety (falls and medication errors) and five quality (e.g., symptom management, complex self care, and patient satisfaction) outcome measures. Communication patterns differed substantially by shift. Conclusion The results demonstrate the utility of ORA for healthcare research and the relationship of nursing unit communication patterns to patient safety and quality outcomes. PMID:21536492

Geologic and anthropogenic factors influencing karst development in the Frederick region of Maryland

USGS Publications Warehouse

Brezinski, D.K.

2007-01-01

Karst features pervade the outcrop belts of Triassic, Ordovician, and Cambrian rocks in the Frederick Valley region of Maryland's western Piedmont. Detailed stratigraphic analysis and geologic and karst mapping demonstrate that individual stratigraphic units have differing susceptibilities of karst feature creation. Although the Triassic Leesburg Member of the Bull Run Formation and Rocky Springs Station Member of the Cambrian Frederick Formation have many surface depressions within their outcrop belts, the Lime Kiln Member of the Frederick Formation and the Ceresville, Fountain Rock, and Woodsboro members of the Ordovician Grove Formation have the greatest potential for development of catastrophic collapse sinkholes. Although these four members have the highest relative susceptibility, human activity can increase the potential for sinkhole activation in all units. Rerouting of surface drainage patterns, unlined drainage, and storm-water management areas and removal of significant overburden deposits significantly increase sinkhole development, but mainly, these units are inherently more susceptible to begin with. Copyright ?? 2007. The American Association of Petroleum Geologists/Division of Environmental Geosciences. All rights reserved.

Imaging of American football injuries in children.

PubMed

Podberesky, Daniel J; Unsell, Bryan J; Anton, Christopher G

2009-12-01

It is estimated that 3.2 million children ages 6 to 14 years participated in organized youth football in the United States in 2007. Approximately 240,000 children play football in the nation's largest youth football organization, with tackle divisions starting at age 5 years. The number of children playing unsupervised football is much higher, and the overall number of children participating in American football is increasing. Sports are the leading cause of injury-related emergency room visits for teenagers, and football is a leading precipitating athletic activity for these visits. Football is also the most hazardous organized sports in the United States. Though most pediatric football-related injuries are minor, such as abrasions, sprains, and strains of the extremities, football accounts for more major and catastrophic injuries than any other sport. Given football's popularity with children in the United States, combined with the high rate of injury associated with participation in this activity, radiologists should be familiar with the imaging features and injury patterns seen in this patient population.

Task and fatigue effects on low-threshold motor units in human hand muscle.

PubMed

Enoka, R M; Robinson, G A; Kossev, A R

1989-12-01

1. The activity of single motor units was recorded in the first dorsal interosseus muscle of human subjects while they performed an isometric ramp-and-hold maneuver. Motor-unit activity was characterized before and after fatigue by the use of a branched bipolar electrode that was positioned subcutaneously over the test muscle. Activity was characterized in terms of the forces of recruitment and derecruitment and the discharge pattern. The purpose was to determine, before and after fatigue, whether motor-unit activity was affected by the direction in which the force was exerted. 2. Regardless of the task during prefatigue trials, interimpulse intervals were 1) more variable during increases or decreases in force than when force was held constant at the target value (4-6% above the recruitment force), and 2) more clustered around an arbitrary central value than would be expected with a normal (Gaussian) distribution. Both effects were seen during the flexion and abduction tasks. The behavior of low-threshold motor units in first dorsal interosseus is thus largely unaffected by the direction of the force exerted by the index finger. The absence of a task (i.e., a direction of force) effect suggests that the resultant force vector about the metacarpophalangeal joint of the index finger is not coded in terms of discrete populations of motor units, but, rather, it is based on the net muscle activity about the joint. 3. Motor-unit behavior during and after fatigue showed that the relatively homogeneous behavior seen before fatigue could be severely disrupted. The fatiguing protocol involved the continuous repetition, to the endurance limit, of a 15-s ramp-and-hold maneuver in which the abduction target force was 50% of maximum and was held for 10-s epochs (ramps up and down were approximately 2 s each). Motor-unit threshold was assessed by the forces of recruitment and derecruitment associated with each cycle of the fatigue test. Changes in recruitment force during the protocol were either minimal or, when present, not systematic. In contrast, the derecruitment force of all units exhibited a marked and progressive increase over the course of the test. 4. After the fatigue test, when the initial threshold tasks were repeated, the behavior of most motor units changed. These changes included the derecruitment of previously active motor units, the recruitment of additional motor units, and an increased discharge variability of units that remained recruited. The variation in recruitment order seemed to be much greater than that reported previously for nonfatiguing conditions.(ABSTRACT TRUNCATED AT 400 WORDS)

Synchronization of presynaptic input to motor units of tongue, inspiratory intercostal, and diaphragm muscles.

PubMed

Rice, Amber; Fuglevand, Andrew J; Laine, Christopher M; Fregosi, Ralph F

2011-05-01

The respiratory central pattern generator distributes rhythmic excitatory input to phrenic, intercostal, and hypoglossal premotor neurons. The degree to which this input shapes motor neuron activity can vary across respiratory muscles and motor neuron pools. We evaluated the extent to which respiratory drive synchronizes the activation of motor unit pairs in tongue (genioglossus, hyoglossus) and chest-wall (diaphragm, external intercostals) muscles using coherence analysis. This is a frequency domain technique, which characterizes the frequency and relative strength of neural inputs that are common to each of the recorded motor units. We also examined coherence across the two tongue muscles, as our previous work shows that, despite being antagonists, they are strongly coactivated during the inspiratory phase, suggesting that excitatory input from the premotor neurons is distributed broadly throughout the hypoglossal motoneuron pool. All motor unit pairs showed highly correlated activity in the low-frequency range (1-8 Hz), reflecting the fundamental respiratory frequency and its harmonics. Coherence of motor unit pairs recorded either within or across the tongue muscles was similar, consistent with broadly distributed premotor input to the hypoglossal motoneuron pool. Interestingly, motor units from diaphragm and external intercostal muscles showed significantly higher coherence across the 10-20-Hz bandwidth than tongue-muscle units. We propose that the lower coherence in tongue-muscle motor units over this range reflects a larger constellation of presynaptic inputs, which collectively lead to a reduction in the coherence between hypoglossal motoneurons in this frequency band. This, in turn, may reflect the relative simplicity of the respiratory drive to the diaphragm and intercostal muscles, compared with the greater diversity of functions fulfilled by muscles of the tongue.

Pattern Informatics Approach to Earthquake Forecasting in 3D

NASA Astrophysics Data System (ADS)

Toya, Y.; Tiampo, K. F.; Rundle, J. B.; Chen, C.; Li, H.; Klein, W.

2009-05-01

Natural seismicity is correlated across multiple spatial and temporal scales, but correlations in seismicity prior to a large earthquake are locally subtle (e.g. seismic quiescence) and often prominent in broad scale (e.g., seismic activation), resulting in local and regional seismicity patterns, e.g. a Mogi's donut. Recognizing that patterns in seismicity rate are reflecting the regional dynamics of the directly unobservable crustal stresses, the Pattern Informatics (PI) approach was introduced by Tiampo et al. in 2002 [Europhys. Lett., 60 (3), 481-487,] Rundle et al., 2002 [PNAS 99, suppl. 1, 2514-2521.] In this study, we expand the PI approach to forecasting earthquakes into the third, or vertical dimension, and illustrate its further improvement in the forecasting performance through case studies of both natural and synthetic data. The PI characterizes rapidly evolving spatio-temporal seismicity patterns as angular drifts of a unit state vector in a high dimensional correlation space, and systematically identifies anomalous shifts in seismic activity with respect to the regional background. 3D PI analysis is particularly advantageous over 2D analysis in resolving vertically overlapped seismicity anomalies in a highly complex tectonic environment. Case studies will help to illustrate some important properties of the PI forecasting tool. [Submitted to: Concurrency and Computation: Practice and Experience, Wiley, Special Issue: ACES2008.

Obesity, Physical Activity and Sedentary Behavior Amongst British and Saudi Youth: A Cross-Cultural Study

PubMed Central

Al-Nakeeb, Yahya; Lyons, Mark; Collins, Peter; Al-Nuaim, Anwar; Al-Hazzaa, Hazzaa; Duncan, Michael J.; Nevill, Alan

2012-01-01

This study explores differences in weight status, obesity and patterns of physical activity (PA) in relation to gender and age of youth from two culturally, environmentally and geographically diverse countries, the United Kingdom (UK) and Saudi Arabia (SA). A total of 2,290 males and females (15–17 years) volunteered to participate in this study. Participants completed a validated self-report questionnaire that contained 47 items relating to patterns of PA, sedentary activity and eating habits. The questionnaire allows the calculation of total energy expenditure in metabolic equivalent (MET-min) values per week. Significant differences in percentage of overweight/obese and levels of PA were evident between the youth from the two countries, with males being generally more physically active than females. Additionally, there were significant associations between Body Mass Index (BMI), PA and sedentary behaviors; the youth with higher BMI reported lower levels of PA and higher amounts of sedentary time. These findings highlight the diverse nature of lifestyle of youth living in different geographical areas of the world and the need for further research to explore the socio-cultural factors that impact on the prevalence of obesity and patterns of PA of youth in different populations. PMID:22690207

Gut carbohydrases from the New Zealand marine herbivorous fishes Kyphosus sydneyanus (Kyphosidae), Aplodactylus arctidens (Aplodactylidae) and Odax pullus (Labridae).

PubMed

Skea, G L; Mountfort, D O; Clements, K D

2005-02-01

Carbohydrase activities were examined in Odax pullus (Labridae), Kyphosus sydneyanus (Kyphosidae) and Aplodactylus arctidens (Aplodactylidae) collected from subtidal reefs in northeastern New Zealand. Enzyme extracts were prepared using two methods from gut wall, gut fluid and microbial pellet samples taken serially along the gut, and assayed against the substrates starch, laminarin, carrageenan, alginate and agarose. In all three fish species, starch degradation activity was substantially higher than for any other substrate tested. Activities of 500, 1294 and 3326 units g tissue(-1) were measured in anterior gut wall extracts of O. pullus, K. sydneyanus and A. arctidens, respectively. Starch degrading activity in gut fluid declined from 37, 313 and 284 units ml(-1) in anterior gut sections of O. pullus, K. sydneyanus and A. arctidens, respectively, to less than 50 units ml(-1) in terminal gut section of each species. Activity against structural polysaccharides was much lower than against starch and was detected mainly in posterior gut sections. The two methods of sample preparation differed little in enzyme activities; however, method of sample preparation did affect isoform patterns as displayed by zymogram analysis. Results suggest that these fish species fall on a continuum from maximizing throughput and digesting easily hydrolysed substrates in the foregut in A. arctidens to relying more heavily on microbial fermentation in the hindgut in K. sydneyanus.

The secret life of ground squirrels: accelerometry reveals sex-dependent plasticity in above-ground activity

PubMed Central

Wilsterman, Kathryn; Zhang, Victor; Moore, Jeanette; Barnes, Brian M.; Buck, C. Loren

2016-01-01

The sexes differ in how and when they allocate energy towards reproduction, but how this influences phenotypic plasticity in daily activity patterns is unclear. Here, we use collar-mounted light loggers and triaxial accelerometers to examine factors that affect time spent above ground and overall dynamic body acceleration (ODBA), an index of activity-specific energy expenditure, across the active season of free-living, semi-fossorial arctic ground squirrels (Urocitellus parryii). We found high day-to-day variability in time spent above ground and ODBA with most of the variance explained by environmental conditions known to affect thermal exchange. In both years, females spent more time below ground compared with males during parturition and early lactation; however, this difference was fourfold larger in the second year, possibly, because females were in better body condition. Daily ODBA positively correlated with time spent above ground in both sexes, but females were more active per unit time above ground. Consequently, daily ODBA did not differ between the sexes when females were early in lactation, even though females were above ground three to six fewer hours each day. Further, on top of having the additional burden of milk production, ODBA data indicate females also had fragmented rest patterns and were more active during late lactation. Our results indicate that sex differences in reproductive requirements can have a substantial influence on activity patterns, but the size of this effect may be dependent on capital resources accrued during gestation. PMID:27703706

Differential activation of motor units in the wrist extensor muscles during the tonic vibration reflex in man.

PubMed Central

Romaiguère, P; Vedel, J P; Azulay, J P; Pagni, S

1991-01-01

1. Single motor unit activity was recorded in the extensor carpi radialis longus and extensor carpi radialis brevis muscles of five healthy human subjects, using metal microelectrodes. 2. Motor units were characterized on the basis of their twitch contraction times and their force recruitment thresholds during voluntary imposed-ramp contractions. 3. The discharge patterns of forty-three motor units were studied during tonic vibration reflex elicited by prolonged (150 s) trains of vibration (30 Hz) applied to the distal tendons of the muscles. The temporal relationships between the individual small tendon taps of the vibratory stimulus and the motor unit impulses were analysed on dot raster displays and post-stimulus time histograms. 4. After tendon taps, the impulses of motor units with long twitch contraction times (mean +/- S.D., 47.2 +/- 10.7 ms) and low recruitment thresholds (0.88 +/- 0.6 N) formed a single narrow peak (P1) with a latency (22.7 +/- 1.4 ms) which was comparable to that of the tendon jerk in the extensor carpi radialis muscles. These motor units were named 'P1 units'. On the other hand, the response of motor units with shorter twitch contraction times (31.1 +/- 3.3 ms) and higher recruitment thresholds (3.21 +/- 1.3 N) showed two peaks: a short latency (23.4 +/- 1.3 ms) P1 peak similar to the previous one and a P2 peak occurring 9.4 +/- 1.2 ms later. These motor units were named 'P1-P2 units'. 5. When the reflex contraction increased slowly, the P1 peaks of 'P1-P2 units' were clearly predominant at the beginning of the contraction, during the rising phase of the motor unit discharge frequency, while the P2 peaks became predominant when the units had reached their maximal discharge frequency. 6. Increasing the tendon vibration frequency (35, 55, 75, 95 Hz) did not modify the 'P1 unit' discharge pattern. Due to interference between vibration period and peak latencies, increasing the vibration frequency caused the P1 and P2 peaks of 'P1-P2 units' to overlap. 7. Superficial cutaneous stimulation of the dorsal side of the forearm during tendon vibration noticeably decreased the P1 peaks in both types of motor units. In the P2 peaks it could result in either a decrease or an increase but the average effect was a slight increase. 8. When applied 10 s before tendon vibration, cutaneous stimulation considerably suppressed the tonic vibration reflex.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:1822565

Prediction limits of mobile phone activity modelling

NASA Astrophysics Data System (ADS)

Kondor, Dániel; Grauwin, Sebastian; Kallus, Zsófia; Gódor, István; Sobolevsky, Stanislav; Ratti, Carlo

2017-02-01

Thanks to their widespread usage, mobile devices have become one of the main sensors of human behaviour and digital traces left behind can be used as a proxy to study urban environments. Exploring the nature of the spatio-temporal patterns of mobile phone activity could thus be a crucial step towards understanding the full spectrum of human activities. Using 10 months of mobile phone records from Greater London resolved in both space and time, we investigate the regularity of human telecommunication activity on urban scales. We evaluate several options for decomposing activity timelines into typical and residual patterns, accounting for the strong periodic and seasonal components. We carry out our analysis on various spatial scales, showing that regularity increases as we look at aggregated activity in larger spatial units with more activity in them. We examine the statistical properties of the residuals and show that it can be explained by noise and specific outliers. Also, we look at sources of deviations from the general trends, which we find to be explainable based on knowledge of the city structure and places of attractions. We show examples how some of the outliers can be related to external factors such as specific social events.

Prediction limits of mobile phone activity modelling.

PubMed

Kondor, Dániel; Grauwin, Sebastian; Kallus, Zsófia; Gódor, István; Sobolevsky, Stanislav; Ratti, Carlo

2017-02-01

Thanks to their widespread usage, mobile devices have become one of the main sensors of human behaviour and digital traces left behind can be used as a proxy to study urban environments. Exploring the nature of the spatio-temporal patterns of mobile phone activity could thus be a crucial step towards understanding the full spectrum of human activities. Using 10 months of mobile phone records from Greater London resolved in both space and time, we investigate the regularity of human telecommunication activity on urban scales. We evaluate several options for decomposing activity timelines into typical and residual patterns, accounting for the strong periodic and seasonal components. We carry out our analysis on various spatial scales, showing that regularity increases as we look at aggregated activity in larger spatial units with more activity in them. We examine the statistical properties of the residuals and show that it can be explained by noise and specific outliers. Also, we look at sources of deviations from the general trends, which we find to be explainable based on knowledge of the city structure and places of attractions. We show examples how some of the outliers can be related to external factors such as specific social events.

Longitudinal Analysis of Adolescent Girls' Activity Patterns: Understanding the Influence of the Transition to Licensure

PubMed Central

McDonald, Noreen C.; Merlin, Louis; Hu, Haoting; Shih, Joshu; Cohen, Deborah A.; Evenson, Kelly R.; McKenzie, Thomas L.; Rodriguez, Daniel A.

2016-01-01

The proportion of teens and young adults with driver's licenses has declined sharply in many industrialized countries including the United States. Explanations for this decline have ranged from the introduction of graduated driver licensing programs to the increase in online social interaction. We used a longitudinal cohort study of teenage girls in San Diego and Minneapolis to evaluate factors associated with licensure and whether teens' travel patterns become more independent as they aged. We found that licensure depended not only on age, but on race and ethnicity as well as variables that correlate with household income. Results also showed evidence that teen travel became more independent as teen's age, and that acquiring a license is an important part of this increased independence. However, we found limited evidence that teen's travel-activity patterns changed as a result of acquiring a driver's license. Rather, teen independence resulted in less parental chauffeuring, but little shift in travel patterns. For the larger debate on declining Millennial mobility, our results suggest the need for more nuanced attention to variation across demographic groups and consideration of the equity implications if declines in travel and licensure are concentrated in low-income and minority populations. PMID:28458769

Developing Signal-Pattern-Recognition Programs

NASA Technical Reports Server (NTRS)

Shelton, Robert O.; Hammen, David

2006-01-01

Pattern Interpretation and Recognition Application Toolkit Environment (PIRATE) is a block-oriented software system that aids the development of application programs that analyze signals in real time in order to recognize signal patterns that are indicative of conditions or events of interest. PIRATE was originally intended for use in writing application programs to recognize patterns in space-shuttle telemetry signals received at Johnson Space Center's Mission Control Center: application programs were sought to (1) monitor electric currents on shuttle ac power busses to recognize activations of specific power-consuming devices, (2) monitor various pressures and infer the states of affected systems by applying a Kalman filter to the pressure signals, (3) determine fuel-leak rates from sensor data, (4) detect faults in gyroscopes through analysis of system measurements in the frequency domain, and (5) determine drift rates in inertial measurement units by regressing measurements against time. PIRATE can also be used to develop signal-pattern-recognition software for different purposes -- for example, to monitor and control manufacturing processes.

Paradox of pattern separation and adult neurogenesis: A dual role for new neurons balancing memory resolution and robustness.

PubMed

Johnston, Stephen T; Shtrahman, Matthew; Parylak, Sarah; Gonçalves, J Tiago; Gage, Fred H

2016-03-01

Hippocampal adult neurogenesis is thought to subserve pattern separation, the process by which similar patterns of neuronal inputs are transformed into distinct neuronal representations, permitting the discrimination of highly similar stimuli in hippocampus-dependent tasks. However, the mechanism by which immature adult-born dentate granule neurons cells (abDGCs) perform this function remains unknown. Two theories of abDGC function, one by which abDGCs modulate and sparsify activity in the dentate gyrus and one by which abDGCs act as autonomous coding units, are generally suggested to be mutually exclusive. This review suggests that these two mechanisms work in tandem to dynamically regulate memory resolution while avoiding memory interference and maintaining memory robustness. Copyright © 2015 Elsevier Inc. All rights reserved.

Recruitment of faster motor units is associated with greater rates of fascicle strain and rapid changes in muscle force during locomotion.

PubMed

Lee, Sabrina S M; de Boef Miara, Maria; Arnold, Allison S; Biewener, Andrew A; Wakeling, James M

2013-01-15

Animals modulate the power output needed for different locomotor tasks by changing muscle forces and fascicle strain rates. To generate the necessary forces, appropriate motor units must be recruited. Faster motor units have faster activation-deactivation rates than slower motor units, and they contract at higher strain rates; therefore, recruitment of faster motor units may be advantageous for tasks that involve rapid movements or high rates of work. This study identified motor unit recruitment patterns in the gastrocnemii muscles of goats and examined whether faster motor units are recruited when locomotor speed is increased. The study also examined whether locomotor tasks that elicit faster (or slower) motor units are associated with increased (or decreased) in vivo tendon forces, force rise and relaxation rates, fascicle strains and/or strain rates. Electromyography (EMG), sonomicrometry and muscle-tendon force data were collected from the lateral and medial gastrocnemius muscles of goats during level walking, trotting and galloping and during inclined walking and trotting. EMG signals were analyzed using wavelet and principal component analyses to quantify changes in the EMG frequency spectra across the different locomotor conditions. Fascicle strain and strain rate were calculated from the sonomicrometric data, and force rise and relaxation rates were determined from the tendon force data. The results of this study showed that faster motor units were recruited as goats increased their locomotor speeds from level walking to galloping. Slow inclined walking elicited EMG intensities similar to those of fast level galloping but different EMG frequency spectra, indicating that recruitment of the different motor unit types depended, in part, on characteristics of the task. For the locomotor tasks and muscles analyzed here, recruitment patterns were generally associated with in vivo fascicle strain rates, EMG intensity and tendon force. Together, these data provide new evidence that changes in motor unit recruitment have an underlying mechanical basis, at least for certain locomotor tasks.

Chapter 2 - Large-scale patterns of insect and disease activity in the conterminous United States, Alaska, and Hawaii from the national Insect and Disease Survey, 2016

Treesearch

Kevin M. Potter; Jeanne L. Paschke; Mark O. Zweifler

2018-01-01

Insects and diseases cause changes in forest structure and function, species succession, and biodiversity, which may be considered negative or positive depending on management objectives (Edmonds and others 2011). An important task for forest managers, pathologists, and entomologists is recognizing and distinguishing between natural and excessive mortality, a task

Patterns of soil calcium and aluminum across the conterminous United States (Chapter 9)

Treesearch

Charles H. Perry; Michael C. Amacher

2012-01-01

The health and growth of forests depends upon soil nutrients. Calcium (Ca) is a cation - positive ion - used by plants to build cell walls (Marschner 1986). It is also involved in root and leaf development and the activation of plant enzymes (Potash and Phosphate Institute 1995). Soils that develop in areas with low rainfall tend to have greater Ca supplies than soils...

Retrospective analysis of EAB spread: understanding the effect of landscape pattern on invasion and propagation

Treesearch

Susan J. Crocker; Greg C. Liknes; Dacia M. Meneguzzo

2011-01-01

Spread of emerald ash borer (Agrilus planipennis Fairmaire, EAB) in the United States has been rapid and extensive. Nearly 10 years after its initial detection near Detroit, Michigan, EAB is now found in 15 states spanning a radius greater than 500 miles. While human activity has been central to facilitating the spread of EAB over long distances, the...

Framing the future in the Southern United States climate, land use, and forest conditions

Treesearch

David N. Wear; Thomas L. Mote; J. Marshall Shepherd; K.C. Binita; Christopher W. Strother

2014-01-01

The Intergovernmental Panel on Climate Change (IPCC) has concluded, with 90% certainty, that human or “anthropogenic” activities (emissions of greenhouse gases, aerosols and pollution, landuse/ land-cover change) have altered global temperature patterns over the past 100-150 years (IPCC 2007a). Such temperature changes have a set of cascading, and sometimes amplifying...

Positional error and time-activity patterns in near-highway proximity studies: an exposure misclassification analysis

PubMed Central

2013-01-01

Background The growing interest in research on the health effects of near-highway air pollutants requires an assessment of potential sources of error in exposure assignment techniques that rely on residential proximity to roadways. Methods We compared the amount of positional error in the geocoding process for three different data sources (parcels, TIGER and StreetMap USA) to a “gold standard” residential geocoding process that used ortho-photos, large multi-building parcel layouts or large multi-unit building floor plans. The potential effect of positional error for each geocoding method was assessed as part of a proximity to highway epidemiological study in the Boston area, using all participants with complete address information (N = 703). Hourly time-activity data for the most recent workday/weekday and non-workday/weekend were collected to examine time spent in five different micro-environments (inside of home, outside of home, school/work, travel on highway, and other). Analysis included examination of whether time-activity patterns were differentially distributed either by proximity to highway or across demographic groups. Results Median positional error was significantly higher in street network geocoding (StreetMap USA = 23 m; TIGER = 22 m) than parcel geocoding (8 m). When restricted to multi-building parcels and large multi-unit building parcels, all three geocoding methods had substantial positional error (parcels = 24 m; StreetMap USA = 28 m; TIGER = 37 m). Street network geocoding also differentially introduced greater amounts of positional error in the proximity to highway study in the 0–50 m proximity category. Time spent inside home on workdays/weekdays differed significantly by demographic variables (age, employment status, educational attainment, income and race). Time-activity patterns were also significantly different when stratified by proximity to highway, with those participants residing in the 0–50 m proximity category reporting significantly more time in the school/work micro-environment on workdays/weekdays than all other distance groups. Conclusions These findings indicate the potential for both differential and non-differential exposure misclassification due to geocoding error and time-activity patterns in studies of highway proximity. We also propose a multi-stage manual correction process to minimize positional error. Additional research is needed in other populations and geographic settings. PMID:24010639

Positional error and time-activity patterns in near-highway proximity studies: an exposure misclassification analysis.

PubMed

Lane, Kevin J; Kangsen Scammell, Madeleine; Levy, Jonathan I; Fuller, Christina H; Parambi, Ron; Zamore, Wig; Mwamburi, Mkaya; Brugge, Doug

2013-09-08

The growing interest in research on the health effects of near-highway air pollutants requires an assessment of potential sources of error in exposure assignment techniques that rely on residential proximity to roadways. We compared the amount of positional error in the geocoding process for three different data sources (parcels, TIGER and StreetMap USA) to a "gold standard" residential geocoding process that used ortho-photos, large multi-building parcel layouts or large multi-unit building floor plans. The potential effect of positional error for each geocoding method was assessed as part of a proximity to highway epidemiological study in the Boston area, using all participants with complete address information (N = 703). Hourly time-activity data for the most recent workday/weekday and non-workday/weekend were collected to examine time spent in five different micro-environments (inside of home, outside of home, school/work, travel on highway, and other). Analysis included examination of whether time-activity patterns were differentially distributed either by proximity to highway or across demographic groups. Median positional error was significantly higher in street network geocoding (StreetMap USA = 23 m; TIGER = 22 m) than parcel geocoding (8 m). When restricted to multi-building parcels and large multi-unit building parcels, all three geocoding methods had substantial positional error (parcels = 24 m; StreetMap USA = 28 m; TIGER = 37 m). Street network geocoding also differentially introduced greater amounts of positional error in the proximity to highway study in the 0-50 m proximity category. Time spent inside home on workdays/weekdays differed significantly by demographic variables (age, employment status, educational attainment, income and race). Time-activity patterns were also significantly different when stratified by proximity to highway, with those participants residing in the 0-50 m proximity category reporting significantly more time in the school/work micro-environment on workdays/weekdays than all other distance groups. These findings indicate the potential for both differential and non-differential exposure misclassification due to geocoding error and time-activity patterns in studies of highway proximity. We also propose a multi-stage manual correction process to minimize positional error. Additional research is needed in other populations and geographic settings.

Thyroid cancer incidence patterns in Sao Paulo, Brazil, and the U.S. SEER program, 1997-2008.

PubMed

Veiga, Lene H S; Neta, Gila; Aschebrook-Kilfoy, Briseis; Ron, Elaine; Devesa, Susan S

2013-06-01

Thyroid cancer incidence has risen steadily over the last few decades in most of the developed world, but information on incidence trends in developing countries is limited. Sao Paulo, Brazil, has one of the highest rates of thyroid cancer worldwide, higher than in the United States. We examined thyroid cancer incidence patterns using data from the Sao Paulo Cancer Registry (SPCR) in Brazil and the National Cancer Institute's Surveillance Epidemiology End Results (SEER) program in the United States. Data on thyroid cancer cases diagnosed during 1997-2008 were obtained from SPCR (n=15,892) and SEER (n=42,717). Age-adjusted and age-specific rates were calculated by sex and histology and temporal patterns were compared between the two populations. Overall incidence rates increased over time in both populations and were higher in Sao Paulo than in the United States among females (SPCR/SEER incidence rate ratio [IRR]=1.65) and males (IRR=1.23). Papillary was the most common histology in both populations, followed by follicular and medullary carcinomas. Incidence rates by histology were consistently higher in Sao Paulo than in the United States, with the greatest differences for follicular (IRR=2.44) and medullary (IRR=3.29) carcinomas among females. The overall female/male IRR was higher in Sao Paulo (IRR=4.17) than in SEER (IRR=3.10) and did not change over time. Papillary rates rose over time more rapidly in Sao Paulo (annual percentage change=10.3% among females and 9.6% among males) than in the United States (6.9% and 5.7%, respectively). Regardless of sex, rates rose faster among younger people (<50 years) in Sao Paulo, but among older people (≥50 years) in the United States. The papillary to follicular carcinoma ratio rose from <3 to >8 among both Sao Paulo males and females, in contrast to increases from 9 to 12 and from 6 to 7 among U.S.males and females, respectively. Increased diagnostic activity may be contributing to the notable rise in incidence, mainly for papillary type, in both populations, but it is not likely to be the only reason. Differences in iodine nutrition status between Sao Paulo and the U.S. SEER population might have affected the observed incidence patterns.

Thyroid Cancer Incidence Patterns in Sao Paulo, Brazil, and the U.S. SEER Program, 1997–2008

PubMed Central

Neta, Gila; Aschebrook-Kilfoy, Briseis; Ron, Elaine; Devesa, Susan S.

2013-01-01

Background Thyroid cancer incidence has risen steadily over the last few decades in most of the developed world, but information on incidence trends in developing countries is limited. Sao Paulo, Brazil, has one of the highest rates of thyroid cancer worldwide, higher than in the United States. We examined thyroid cancer incidence patterns using data from the Sao Paulo Cancer Registry (SPCR) in Brazil and the National Cancer Institute's Surveillance Epidemiology End Results (SEER) program in the United States. Methods Data on thyroid cancer cases diagnosed during 1997–2008 were obtained from SPCR (n=15,892) and SEER (n=42,717). Age-adjusted and age-specific rates were calculated by sex and histology and temporal patterns were compared between the two populations. Results Overall incidence rates increased over time in both populations and were higher in Sao Paulo than in the United States among females (SPCR/SEER incidence rate ratio [IRR]=1.65) and males (IRR=1.23). Papillary was the most common histology in both populations, followed by follicular and medullary carcinomas. Incidence rates by histology were consistently higher in Sao Paulo than in the United States, with the greatest differences for follicular (IRR=2.44) and medullary (IRR=3.29) carcinomas among females. The overall female/male IRR was higher in Sao Paulo (IRR=4.17) than in SEER (IRR=3.10) and did not change over time. Papillary rates rose over time more rapidly in Sao Paulo (annual percentage change=10.3% among females and 9.6% among males) than in the United States (6.9% and 5.7%, respectively). Regardless of sex, rates rose faster among younger people (<50 years) in Sao Paulo, but among older people (≥50 years) in the United States. The papillary to follicular carcinoma ratio rose from <3 to >8 among both Sao Paulo males and females, in contrast to increases from 9 to 12 and from 6 to 7 among U.S.males and females, respectively. Conclusions Increased diagnostic activity may be contributing to the notable rise in incidence, mainly for papillary type, in both populations, but it is not likely to be the only reason. Differences in iodine nutrition status between Sao Paulo and the U.S. SEER population might have affected the observed incidence patterns. PMID:23410185

Evaluating ecoregions for sampling and mapping land-cover patterns

Treesearch

Kurt H. Riitters; James D. Wickham; Timothy G. Wade

2006-01-01

Ecoregional stratification has been proposed for sampling and mapping land-cover composition and pattern over time. Using a wall-to-wall land-cover map of the United States, we evaluated geographic scales of variance for nine landscapelevel and eight forest pattern indices, and compared stratification by ecoregions, administrative units, and watersheds. Ecoregions...

Relationships between motor unit size and recruitment threshold in older adults: implications for size principle.

PubMed

Fling, Brett W; Knight, Christopher A; Kamen, Gary

2009-08-01

As a part of the aging process, motor unit reorganization occurs in which small motoneurons reinnervate predominantly fast-twitch muscle fibers that have lost their innervation. We examined the relationship between motor unit size and the threshold force for recruitment in two muscles to determine whether older individuals might develop an alternative pattern of motor unit activation. Young and older adults performed isometric contractions ranging from 0 to 50% of maximal voluntary contraction in both the first dorsal interosseous (FDI) and tibialis anterior (TA) muscles. Muscle fiber action potentials were recorded with an intramuscular needle electrode and motor unit size was computed using spike-triggered averaging of the global EMG signal (macro EMG), which was also obtained from the intramuscular needle electrode. As expected, older individuals exhibited larger motor units than young subjects in both the FDI and the TA. However, moderately strong correlations were obtained for the macro EMG amplitude versus recruitment threshold relationship in both the young and older adults within both muscles, suggesting that the size principle of motor unit recruitment seems to be preserved in older adults.

Using exploratory data analysis to identify and predict patterns of human Lyme disease case clustering within a multistate region, 2010-2014.

PubMed

Hendricks, Brian; Mark-Carew, Miguella

2017-02-01

Lyme disease is the most commonly reported vectorborne disease in the United States. The objective of our study was to identify patterns of Lyme disease reporting after multistate inclusion to mitigate potential border effects. County-level human Lyme disease surveillance data were obtained from Kentucky, Maryland, Ohio, Pennsylvania, Virginia, and West Virginia state health departments. Rate smoothing and Local Moran's I was performed to identify clusters of reporting activity and identify spatial outliers. A logistic generalized estimating equation was performed to identify significant associations in disease clustering over time. Resulting analyses identified statistically significant (P=0.05) clusters of high reporting activity and trends over time. High reporting activity aggregated near border counties in high incidence states, while low reporting aggregated near shared county borders in non-high incidence states. Findings highlight the need for exploratory surveillance approaches to describe the extent to which state level reporting affects accurate estimation of Lyme disease progression. Copyright © 2017 Elsevier Ltd. All rights reserved.

Remote sensing of physiographic soil units of Bennett County, South Dakota

NASA Technical Reports Server (NTRS)

Frazee, C. J.; Gropper, J. L.; Westin, F. C.

1973-01-01

A study was conducted in Bennett County, South Dakota, to establish a rangeland test site for evaluating the usefulness of ERTS data for mapping soil resources in rangeland areas. Photographic imagery obtained in October, 1970, was analyzed to determine which type of imagery is best for mapping drainage and land use patterns. Imagery of scales ranging from 1:1,000,000 to 1.20,000 was used to delineate soil-vegetative physiographic units. The photo characteristics used to define physiographic units were texture, drainage pattern, tone pattern, land use pattern and tone. These units will be used as test data for evaluating ERTS data. The physiographic units were categorized into a land classification system. The various categories which were delineated at the different scales of imagery were designed to be useful for different levels of land use planning. The land systems are adequate only for planning of large areas for general uses. The lowest category separated was the facet. The facets have a definite soil composition and represent different soil landscapes. These units are thought to be useful for providing natural resource information needed for local planning.

National youth sedentary behavior and physical activity daily patterns using latent class analysis applied to accelerometry.

PubMed

Evenson, Kelly R; Wen, Fang; Hales, Derek; Herring, Amy H

2016-05-03

Applying latent class analysis (LCA) to accelerometry can help elucidated underlying patterns. This study described the patterns of accelerometer-determined sedentary behavior and physical activity among youth by applying LCA to a nationally representative United States (US) sample. Using 2003-2006 National Health and Nutrition Examination Survey data, 3998 youths 6-17 years wore an ActiGraph 7164 accelerometer for one week, providing > =3 days of wear for > =8 h/day from 6:00 am-midnight. Cutpoints defined sedentary behavior (<100 counts/minute), light activity (100-2295 counts/minute), moderate to vigorous physical activity (MVPA; > = 2296 counts/minute), and vigorous activity (> = 4012 counts/minute). To account for wear time differences, outcomes were expressed as percent of day in a given intensity. LCA was used to classify daily (Monday through Sunday) patterns of average counts/minute, sedentary behavior, light activity, MVPA, and vigorous activity separately. The latent classes were explored overall and by age (6-11, 12-14, 15-17 years), gender, and whether or not youth attended school during measurement. Estimates were weighted to account for the sampling frame. For average counts/minute/day, four classes emerged from least to most active: 40.9% of population (mean 323.5 counts/minute/day), 40.3% (559.6 counts/minute/day), 16.5% (810.0 counts/minute/day), and 2.3% (1132.9 counts/minute/day). For percent of sedentary behavior, four classes emerged: 13.5% of population (mean 544.6 min/day), 30.1% (455.1 min/day), 38.5% (357.7 min/day), and 18.0% (259.2 min/day). For percent of light activity, four classes emerged: 12.3% of population (mean 222.6 min/day), 29.3% (301.7 min/day), 41.8% (384.0 min/day), and 16.6% (455.5 min/day). For percent of MVPA, four classes emerged: 59.9% of population (mean 25.0 min/day), 33.3% (60.9 min/day), 3.1% (89.0 min/day), and 3.6% (109.3 min/day). For percent of vigorous activity, three classes emerged: 76.8% of population (mean 7.1 min/day), 18.5% (23.9 min/day), and 4.7% (47.4 min/day). Classes were developed by age, gender, and school attendance since some patterns differed when stratifying by these factors. The models supported patterns for average intensity, sedentary behavior, light activity, MVPA, and vigorous activity. These latent class derived patterns can be used in other youth studies to explore correlates or outcomes and to target sedentary behavior or physical activity interventions.

Specific sulfation and glycosylation—a structural combination for the anticoagulation of marine carbohydrates

PubMed Central

Pomin, Vitor H.; Mourão, Paulo A. S.

2014-01-01

Based on considered achievements of the last 25 years, specific combinations of sulfation patterns and glycosylation types have been proved to be key structural players for the anticoagulant activity of certain marine glycans. These conclusions were obtained from comparative and systematic analyses on the structure-anticoagulation relationships of chemically well-defined sulfated polysaccharides of marine invertebrates and red algae. These sulfated polysaccharides are known as sulfated fucans (SFs), sulfated galactans (SGs) and glycosaminoglycans (GAGs). The structural combinations necessary for the anticoagulant activities are the 2-sulfation in α-L-SGs, the 2,4-di-sulfation in α-L-fucopyranosyl units found as composing units of certain sea-urchin and sea-cucumber linear SFs, or as branching units of the fucosylated chondroitin sulfate, a unique GAG from sea-cucumbers. Another unique GAG type from marine organisms is the dermatan sulfate isolated from ascidians. The high levels of 4-sulfation at the galactosamine units combined with certain levels of 2-sulfation at the iduronic acid units is the anticoagulant structural requirements of these GAGs. When the backbones of red algal SGs are homogeneous, the anticoagulation is proportionally dependent of their sulfation content. Finally, 4-sulfation was observed to be the structural motif required to enhance the inhibition of thrombin via heparin cofactor-II by invertebrate SFs. PMID:24639954

Aging in the Americas: Disability-free Life Expectancy Among Adults Aged 65 and Older in the United States, Costa Rica, Mexico, and Puerto Rico.

PubMed

Payne, Collin F

2018-01-11

To estimate and compare disability-free life expectancy (DFLE) and current age patterns of disability onset and recovery from disability between the United States and countries in Latin America and the Caribbean. Disability is measured using the activities of daily living scale. Data come from longitudinal surveys of older adult populations in Costa Rica, Mexico, Puerto Rico, and the United States. Age patterns of transitions in and out of disability are modeled with a discrete-time logistic hazard model, and a microsimulation approach is used to estimate DFLE. Overall life expectancy for women aged 65 is 20.11 years in Costa Rica, 19.2 years in Mexico, 20.4 years in Puerto Rico, and 20.5 years in the United States. For men, these figures are 19.0 years in Costa Rica, 18.4 years in Mexico, 18.1 years in Puerto Rico, and 18.1 years in the United States. Proportion of remaining life spent free of disability for women at age 65 is comparable between Mexico, Puerto Rico, and the United States, with Costa Rica trailing slightly. Male estimates of DFLE are similar across the four populations. Though the older adult population of Latin America and the Caribbean lived many years exposed to poor epidemiological and public health conditions, their functional health in later life is comparable with the older adult population of the United States. © The Author(s) 2015. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Dynamic neural network models of the premotoneuronal circuitry controlling wrist movements in primates.

PubMed

Maier, M A; Shupe, L E; Fetz, E E

2005-10-01

Dynamic recurrent neural networks were derived to simulate neuronal populations generating bidirectional wrist movements in the monkey. The models incorporate anatomical connections of cortical and rubral neurons, muscle afferents, segmental interneurons and motoneurons; they also incorporate the response profiles of four populations of neurons observed in behaving monkeys. The networks were derived by gradient descent algorithms to generate the eight characteristic patterns of motor unit activations observed during alternating flexion-extension wrist movements. The resulting model generated the appropriate input-output transforms and developed connection strengths resembling those in physiological pathways. We found that this network could be further trained to simulate additional tasks, such as experimentally observed reflex responses to limb perturbations that stretched or shortened the active muscles, and scaling of response amplitudes in proportion to inputs. In the final comprehensive network, motor units are driven by the combined activity of cortical, rubral, spinal and afferent units during step tracking and perturbations. The model displayed many emergent properties corresponding to physiological characteristics. The resulting neural network provides a working model of premotoneuronal circuitry and elucidates the neural mechanisms controlling motoneuron activity. It also predicts several features to be experimentally tested, for example the consequences of eliminating inhibitory connections in cortex and red nucleus. It also reveals that co-contraction can be achieved by simultaneous activation of the flexor and extensor circuits without invoking features specific to co-contraction.

Brain State Is a Major Factor in Preseizure Hippocampal Network Activity and Influences Success of Seizure Intervention

PubMed Central

Ewell, Laura A.; Liang, Liang; Armstrong, Caren; Soltész, Ivan; Leutgeb, Stefan

2015-01-01

Neural dynamics preceding seizures are of interest because they may shed light on mechanisms of seizure generation and could be predictive. In healthy animals, hippocampal network activity is shaped by behavioral brain state and, in epilepsy, seizures selectively emerge during specific brain states. To determine the degree to which changes in network dynamics before seizure are pathological or reflect ongoing fluctuations in brain state, dorsal hippocampal neurons were recorded during spontaneous seizures in a rat model of temporal lobe epilepsy. Seizures emerged from all brain states, but with a greater likelihood after REM sleep, potentially due to an observed increase in baseline excitability during periods of REM compared with other brains states also characterized by sustained theta oscillations. When comparing the firing patterns of the same neurons across brain states associated with and without seizures, activity dynamics before seizures followed patterns typical of the ongoing brain state, or brain state transitions, and did not differ until the onset of the electrographic seizure. Next, we tested whether disparate activity patterns during distinct brain states would influence the effectiveness of optogenetic curtailment of hippocampal seizures in a mouse model of temporal lobe epilepsy. Optogenetic curtailment was significantly more effective for seizures preceded by non-theta states compared with seizures that emerged from theta states. Our results indicate that consideration of behavioral brain state preceding a seizure is important for the appropriate interpretation of network dynamics leading up to a seizure and for designing effective seizure intervention. SIGNIFICANCE STATEMENT Hippocampal single-unit activity is strongly shaped by behavioral brain state, yet this relationship has been largely ignored when studying activity dynamics before spontaneous seizures in medial temporal lobe epilepsy. In light of the increased attention on using single-unit activity for the prediction of seizure onset and closed-loop seizure intervention, we show a need for monitoring brain state to interpret correctly whether changes in neural activity before seizure onset is pathological or normal. Moreover, we also find that the brain state preceding a seizure determines the success of therapeutic interventions to curtail seizure duration. Together, these findings suggest that seizure prediction and intervention will be more successful if tailored for the specific brain states from which seizures emerge. PMID:26609157

Short-Term Space-Use Patterns of Translocated Mojave Desert Tortoise in Southern California

PubMed Central

Farnsworth, Matthew L.; Dickson, Brett G.; Zachmann, Luke J.; Hegeman, Ericka E.; Cangelosi, Amanda R.; Jackson, Thomas G.; Scheib, Amanda F.

2015-01-01

Increasingly, renewable energy comprises a larger share of global energy production. Across the western United States, public lands are being developed to support renewable energy production. Where there are conflicts with threatened or endangered species, translocation can be used in an attempt to mitigate negative effects. For the threatened Mojave desert tortoise (Gopherus agassizii), we sought to compare habitat- and space-use patterns between short-distance translocated, resident, and control groups. We tested for differences in home range size based on utilization distributions and used linear mixed-effects models to compare space-use intensity, while controlling for demographic and environmental variables. In addition, we examined mean movement distances as well as home range overlap between years and for male and female tortoises in each study group. During the first active season post-translocation, home range size was greater and space-use intensity was lower for translocated tortoises than resident and control groups. These patterns were not present in the second season. In both years, there was no difference in home range size or space-use intensity between control and resident groups. Translocation typically resulted in one active season of questing followed by a second active season characterized by space-use patterns that were indistinguishable from control tortoises. Across both years, the number of times a tortoise was found in a burrow was positively related to greater space-use intensity. Minimizing the time required for translocated tortoises to exhibit patterns similar to non-translocated individuals may have strong implications for conservation by reducing exposure to adverse environmental conditions and predation. With ongoing development, our results can be used to guide future efforts aimed at understanding how translocation strategies influence patterns of animal space use. PMID:26352691

Short-Term Space-Use Patterns of Translocated Mojave Desert Tortoise in Southern California.

PubMed

Farnsworth, Matthew L; Dickson, Brett G; Zachmann, Luke J; Hegeman, Ericka E; Cangelosi, Amanda R; Jackson, Thomas G; Scheib, Amanda F

2015-01-01

Increasingly, renewable energy comprises a larger share of global energy production. Across the western United States, public lands are being developed to support renewable energy production. Where there are conflicts with threatened or endangered species, translocation can be used in an attempt to mitigate negative effects. For the threatened Mojave desert tortoise (Gopherus agassizii), we sought to compare habitat- and space-use patterns between short-distance translocated, resident, and control groups. We tested for differences in home range size based on utilization distributions and used linear mixed-effects models to compare space-use intensity, while controlling for demographic and environmental variables. In addition, we examined mean movement distances as well as home range overlap between years and for male and female tortoises in each study group. During the first active season post-translocation, home range size was greater and space-use intensity was lower for translocated tortoises than resident and control groups. These patterns were not present in the second season. In both years, there was no difference in home range size or space-use intensity between control and resident groups. Translocation typically resulted in one active season of questing followed by a second active season characterized by space-use patterns that were indistinguishable from control tortoises. Across both years, the number of times a tortoise was found in a burrow was positively related to greater space-use intensity. Minimizing the time required for translocated tortoises to exhibit patterns similar to non-translocated individuals may have strong implications for conservation by reducing exposure to adverse environmental conditions and predation. With ongoing development, our results can be used to guide future efforts aimed at understanding how translocation strategies influence patterns of animal space use.

Muscle fibre recruitment can respond to the mechanics of the muscle contraction.

PubMed

Wakeling, James M; Uehli, Katrin; Rozitis, Antra I

2006-08-22

This study investigates the motor unit recruitment patterns between and within muscles of the triceps surae during cycling on a stationary ergometer at a range of pedal speeds and resistances. Muscle activity was measured from the soleus (SOL), medial gastrocnemius (MG) and lateral gastrocnemius (LG) using surface electromyography (EMG) and quantified using wavelet and principal component analysis. Muscle fascicle strain rates were quantified using ultrasonography, and the muscle-tendon unit lengths were calculated from the segmental kinematics. The EMG intensities showed that the body uses the SOL relatively more for the higher-force, lower-velocity contractions than the MG and LG. The EMG spectra showed a shift to higher frequencies at faster muscle fascicle strain rates for MG: these shifts were independent of the level of muscle activity, the locomotor load and the muscle fascicle strain. These results indicated that a selective recruitment of the faster motor units occurred within the MG muscle in response to the increasing muscle fascicle strain rates. This preferential recruitment of the faster fibres for the faster tasks indicates that in some circumstances motor unit recruitment during locomotion can match the contractile properties of the muscle fibres to the mechanical demands of the contraction.

Pattern recognition with "materials that compute".

PubMed

Fang, Yan; Yashin, Victor V; Levitan, Steven P; Balazs, Anna C

2016-09-01

Driven by advances in materials and computer science, researchers are attempting to design systems where the computer and material are one and the same entity. Using theoretical and computational modeling, we design a hybrid material system that can autonomously transduce chemical, mechanical, and electrical energy to perform a computational task in a self-organized manner, without the need for external electrical power sources. Each unit in this system integrates a self-oscillating gel, which undergoes the Belousov-Zhabotinsky (BZ) reaction, with an overlaying piezoelectric (PZ) cantilever. The chemomechanical oscillations of the BZ gels deflect the PZ layer, which consequently generates a voltage across the material. When these BZ-PZ units are connected in series by electrical wires, the oscillations of these units become synchronized across the network, where the mode of synchronization depends on the polarity of the PZ. We show that the network of coupled, synchronizing BZ-PZ oscillators can perform pattern recognition. The "stored" patterns are set of polarities of the individual BZ-PZ units, and the "input" patterns are coded through the initial phase of the oscillations imposed on these units. The results of the modeling show that the input pattern closest to the stored pattern exhibits the fastest convergence time to stable synchronization behavior. In this way, networks of coupled BZ-PZ oscillators achieve pattern recognition. Further, we show that the convergence time to stable synchronization provides a robust measure of the degree of match between the input and stored patterns. Through these studies, we establish experimentally realizable design rules for creating "materials that compute."

Pattern recognition with “materials that compute”

PubMed Central

Fang, Yan; Yashin, Victor V.; Levitan, Steven P.; Balazs, Anna C.

2016-01-01

Driven by advances in materials and computer science, researchers are attempting to design systems where the computer and material are one and the same entity. Using theoretical and computational modeling, we design a hybrid material system that can autonomously transduce chemical, mechanical, and electrical energy to perform a computational task in a self-organized manner, without the need for external electrical power sources. Each unit in this system integrates a self-oscillating gel, which undergoes the Belousov-Zhabotinsky (BZ) reaction, with an overlaying piezoelectric (PZ) cantilever. The chemomechanical oscillations of the BZ gels deflect the PZ layer, which consequently generates a voltage across the material. When these BZ-PZ units are connected in series by electrical wires, the oscillations of these units become synchronized across the network, where the mode of synchronization depends on the polarity of the PZ. We show that the network of coupled, synchronizing BZ-PZ oscillators can perform pattern recognition. The “stored” patterns are set of polarities of the individual BZ-PZ units, and the “input” patterns are coded through the initial phase of the oscillations imposed on these units. The results of the modeling show that the input pattern closest to the stored pattern exhibits the fastest convergence time to stable synchronization behavior. In this way, networks of coupled BZ-PZ oscillators achieve pattern recognition. Further, we show that the convergence time to stable synchronization provides a robust measure of the degree of match between the input and stored patterns. Through these studies, we establish experimentally realizable design rules for creating “materials that compute.” PMID:27617290

Cross-boundary rotational working for neonatal nurses.

PubMed

Kane, Tina

2007-05-01

Neonatal services in England and Wales are undergoing significant changes as a result of technological advances as well as the development of new networks. These changes have had a dramatic effect on the neonatal workforce. The skills of the available staff govern the level of activity of neonatal units: many units have had to re-evaluate the services they can safely deliver with the available workforce. This has resulted in the re-configuration of some neonatal units and changes in the dependency levels of many. Units have had to undertake reviews of the patterns of working of their staff to ensure that a skilled and competent workforce is available to provide the level of care each neonatal service requires. Shortages in some areas have meant that units have had to find new ways to retain and update skilled staff. This article describes a rotational programme developed with the aim of providing a continued clinical development pathway for neonatal nursing staff. The programme incorporates competency assessments of emergency skills and clinical and technological advances in neonatal care.

[Characteristics of temporal-spatial differentiation in landscape pattern vulnerability in Nansihu Lake wetland, China.

PubMed

Liang, Jia Xin; Li, Xin Ju

2018-02-01

With remote sensing images from 1985, 2000 Lantsat 5 TM and 2015 Lantsat 8 OLI as data sources, we tried to select the suitable research scale and examine the temporal-spatial diffe-rentiation with such scale in the Nansihu Lake wetland by using landscape pattern vulnerability index constructed by sensitivity index and adaptability index, and combined with space statistics such as semivariogram and spatial autocorrelation. The results showed that 1 km × 1 km equidistant grid was the suitable research scale, which could eliminate the influence of spatial heterogeneity induced by random factors. From 1985 to 2015, the landscape pattern vulnerability in the Nansihu Lake wetland deteriorated gradually. The high-risk area of landscape pattern vulnerability dramatically expanded with time. The spatial heterogeneity of landscape pattern vulnerability increased, and the influence of non-structural factors on landscape pattern vulnerability strengthened. Spatial variability affected by spatial autocorrelation slightly weakened. Landscape pattern vulnerability had strong general spatial positive correlation, with the significant form of spatial agglomeration. The positive spatial autocorrelation continued to increase and the phenomenon of spatial concentration was more and more obvious over time. The local autocorrelation mainly based on high-high accumulation zone and low-low accumulation zone had stronger spatial autocorrelation among neighboring space units. The high-high accumulation areas showed the strongest level of significance, and the significant level of low-low accumulation zone increased with time. Natural factors, such as temperature and precipitation, affected water-level and landscape distribution, and thus changed the landscape patterns vulnerability of Nansihu Lake wetland. The dominant driver for the deterioration of landscape patterns vulnerability was human activities, including social economy activity and policy system.

Effects of nursing unit spatial layout on nursing team communication patterns, quality of care, and patient safety.

PubMed

Hua, Ying; Becker, Franklin; Wurmser, Teri; Bliss-Holtz, Jane; Hedges, Christine

2012-01-01

Studies investigating factors contributing to improved quality of care have found that effective team member communication is among the most critical and influential aspects in the delivery of quality care. Relatively little research has examined the role of the physical design of nursing units on communication patterns among care providers. Although the concept of decentralized unit design is intended to increase patient safety, reduce nurse fatigue, and control the noisy, chaotic, and crowded space associated with centralized nursing stations, until recently little attention has been paid to how such nursing unit designs affected communication patterns or other medical and organizational outcomes. Using a pre/post research design comparing more centralized or decentralized unit designs with a new multi-hub design, the aim of this study was to describe the relationship between the clinical spatial environment and its effect on communication patterns, nurse satisfaction, distance walked, organizational outcomes, patient safety, and patient satisfaction. Hospital institutional data indicated that patient satisfaction increased substantially. Few significant changes were found in communication patterns; no significant changes were found in nurse job satisfaction, patient falls, pressure ulcers, or organizational outcomes such as average length of stay or patient census.

Environmental factors influencing biological rhythms in newborns: From neonatal intensive care units to home.

PubMed

Bueno, Clarissa; Menna-Barreto, Luiz

2016-01-01

Photic and non-photic environmental factors are suggested to modulate the development of circadian rhythms in infants. Our aim is to evaluate the development of biological rhythms (circadian or ultradian) in newborns in transition from Neonatal Intensive Care Units (NICU) to home and along the first 6 months of life, to identify masking and entraining environment factors along development. Ten newborns were evaluated in their last week inside the NICU and in the first week after being delivered home; 6 babies were also followed until 6 months of corrected age. Activity, recorded with actimeters, wrist temperature and observed sleep and feeding behavior were recorded continuously along their last week inside the NICU and in the first week at home and also until 6 months of corrected age for the subjects who remained in the study. Sleep/wake and activity/rest cycle showed ultradian patterns and the sleep/wake was strongly influenced by the 3 h feeding schedule inside the NICU, while wrist temperature showed a circadian pattern that seemed no to be affected by environmental cycles. A circadian rhythm emerges for sleep/wake behavior in the first week at home, whereas the 3 h period vanishes. Both activity/rest and wrist temperature presented a sudden increase in the contribution of the circadian component immediately after babies were delivered home, also suggesting a masking effect of the NICU environment. We found a positive correlation of postconceptional age and the increase in the daily component of activity and temperature along the following 6 months, while feeding behavior became arrhythmic.

Acute effects of 3,4-methylenedioxymethamphetamine on striatal single-unit activity and behavior in freely moving rats: differential involvement of dopamine D(1) and D(2) receptors.

PubMed

Ball, Kevin T; Budreau, Daniel; Rebec, George V

2003-12-24

3,4-Methylenedioxymethamphetamine (MDMA) is a widely abused amphetamine derivative that increases dopamine (DA) and serotonin release via a reverse transport mechanism. Changes in the activity of striatal neurons in response to increased DA transmission may shape the behavioral patterns associated with amphetamine-like stimulants. To determine how the striatum participates in MDMA-induced locomotor activation, we recorded the activity of >100 single units in the striatum of freely moving rats in response to a dose that increased motor activation (5.0 mg/kg). MDMA had a predominantly excitatory effect on neuronal activity that was positively correlated with the magnitude of locomotor activation. Categorizing neurons according to baseline locomotor responsiveness revealed that MDMA excited significantly more neurons showing movement-related increases in activity compared to units that were non-movement-related or associated with movement-related decreases in activity. Further analysis revealed that the drug-induced striatal activation was not simply secondary to the behavioral change, indicating a primary action of MDMA on striatal motor circuits. Prior administration of SCH-23390 (0.2 mg/kg), a D(1) antagonist, resulted in a late onset of MDMA-induced locomotion, which correlated positively with delayed neuronal excitations. Conversely, prior administration of eticlopride (0.2 mg/kg), a D(2) antagonist, completely abolished MDMA-induced locomotion, which paralleled its blockade of MDMA-induced excitatory neuronal responses. Our results highlight the importance of striatal neuronal activity in shaping the behavioral response to MDMA, and suggest that DA D(1) and D(2) receptors have distinct functional roles in the expression of MDMA-induced striatal and locomotor activation.

GEMINI-TITAN (GT)-11 - MISC. - EXPERIMENT D-16 - KNEE TETHER - MSC

NASA Image and Video Library

1966-01-28

S66-00933 (28 Jan. 1966) --- Gemini-11 Experiment D-16 Knee Tether, sponsored by the Department of Defense and the United States Air Force. The astronaut tightens and loosens bolts in a prescribed pattern during his extravehicular activity, once with his body held to the spacecraft by a nine-inch tether looped around his knee and through the handrail, and once without the tether. Photo credit: NASA

A Hybrid Neuromechanical Ambulatory Assist System

DTIC Science & Technology

2016-08-01

provide real- time closed-loop control using brace mounted sensors to deliver the stimulation needed to stand up and walk while coordinating exoskeletal...target PC during real- time implementation. The muscle stimulator unit delivered the NES to target paralyzed muscles to drive limb motion. The activity...manual adjustment of thresholds used in the GED and stimulation pattern lengths (Figure 26b). The time for a right or left step could be decreased

Health sector reform and trends in the United Kingdom hospital workforce.

PubMed

Buchan, J; Hancock, C; Rafferty, A M

1997-10-01

The authors examine changing trends in the profile and patterns of employment of the workforce in hospitals in the National Health Service (NHS) in the United Kingdom. The effect of the implementation of the NHS reforms is considered, with particular reference to the changing composition of the nursing workforce. The authors note that there are problems with establishing trend data because of altered information requirements as a result of the NHS reforms. Analysis and review of data from secondary sources and research publications. Although hospital activity rates have grown, patient length of hospital stays decreased, and patient activity levels increased, there has not been a linked growth in the size of the nursing workforce. The main changes in the profile of the nursing workforce highlighted are a marked reduction in the numbers of nursing students and alterations in the skill mix between first- and second-level qualified nurses. The authors also note a large increase in the number of managerial and administrative staff employed and growth in medical staff numbers. Changes in working patterns and increases in contracting for support services and in the use of temporary staff also are discussed. There have been pronounced changes in the profile of the hospital workforce but little evaluation of the impact of these changes on outcomes of care.

Development of rotation sample designs for the estimation of crop acreages

NASA Technical Reports Server (NTRS)

Lycthuan-Lee, T. G. (Principal Investigator)

1981-01-01

The idea behind the use of rotation sample designs is that the variation of the crop acreage of a particular sample unit from year to year is usually less than the variation of crop acreage between units within a particular year. The estimation theory is based on an additive mixed analysis of variance model with years as fixed effects, (a sub t), and sample units as a variable factor. The rotation patterns are decided upon according to: (1) the number of sample units in the design each year; (2) the number of units retained in the following years; and (3) the number of years to complete the rotation pattern. Different analytic formulae for the variance of (a sub t) and the variance comparisons in using a complete survey of the rotation patterns.

Seizures and Sleep in the Thalamus: Focal Limbic Seizures Show Divergent Activity Patterns in Different Thalamic Nuclei.

PubMed

Feng, Li; Motelow, Joshua E; Ma, Chanthia; Biche, William; McCafferty, Cian; Smith, Nicholas; Liu, Mengran; Zhan, Qiong; Jia, Ruonan; Xiao, Bo; Duque, Alvaro; Blumenfeld, Hal

2017-11-22

The thalamus plays diverse roles in cortical-subcortical brain activity patterns. Recent work suggests that focal temporal lobe seizures depress subcortical arousal systems and convert cortical activity into a pattern resembling slow-wave sleep. The potential simultaneous and paradoxical role of the thalamus in both limbic seizure propagation, and in sleep-like cortical rhythms has not been investigated. We recorded neuronal activity from the central lateral (CL), anterior (ANT), and ventral posteromedial (VPM) nuclei of the thalamus in an established female rat model of focal limbic seizures. We found that population firing of neurons in CL decreased during seizures while the cortex exhibited slow waves. In contrast, ANT showed a trend toward increased neuronal firing compatible with polyspike seizure discharges seen in the hippocampus. Meanwhile, VPM exhibited a remarkable increase in sleep spindles during focal seizures. Single-unit juxtacellular recordings from CL demonstrated reduced overall firing rates, but a switch in firing pattern from single spikes to burst firing during seizures. These findings suggest that different thalamic nuclei play very different roles in focal limbic seizures. While limbic nuclei, such as ANT, appear to participate directly in seizure propagation, arousal nuclei, such as CL, may contribute to depressed cortical function, whereas sleep spindles in relay nuclei, such as VPM, may interrupt thalamocortical information flow. These combined effects could be critical for controlling both seizure severity and impairment of consciousness. Further understanding of differential effects of seizures on different thalamocortical networks may lead to improved treatments directly targeting these modes of impaired function. SIGNIFICANCE STATEMENT Temporal lobe epilepsy has a major negative impact on quality of life. Previous work suggests that the thalamus plays a critical role in thalamocortical network modulation and subcortical arousal maintenance, but its precise seizure-associated functions are not known. We recorded neuronal activity in three different thalamic regions and found divergent activity patterns, which may respectively participate in seizure propagation, impaired level of conscious arousal, and altered relay of information to the cortex during focal limbic seizures. These very different activity patterns within the thalamus may help explain why focal temporal lobe seizures often disrupt widespread network function, and can help guide future treatments aimed at restoring normal thalamocortical network activity and cognition. Copyright © 2017 the authors 0270-6474/17/3711441-14$15.00/0.

Seizures and Sleep in the Thalamus: Focal Limbic Seizures Show Divergent Activity Patterns in Different Thalamic Nuclei

PubMed Central

Feng, Li; Motelow, Joshua E.; Ma, Chanthia; Liu, Mengran; Zhan, Qiong; Jia, Ruonan; Xiao, Bo; Duque, Alvaro

2017-01-01

The thalamus plays diverse roles in cortical-subcortical brain activity patterns. Recent work suggests that focal temporal lobe seizures depress subcortical arousal systems and convert cortical activity into a pattern resembling slow-wave sleep. The potential simultaneous and paradoxical role of the thalamus in both limbic seizure propagation, and in sleep-like cortical rhythms has not been investigated. We recorded neuronal activity from the central lateral (CL), anterior (ANT), and ventral posteromedial (VPM) nuclei of the thalamus in an established female rat model of focal limbic seizures. We found that population firing of neurons in CL decreased during seizures while the cortex exhibited slow waves. In contrast, ANT showed a trend toward increased neuronal firing compatible with polyspike seizure discharges seen in the hippocampus. Meanwhile, VPM exhibited a remarkable increase in sleep spindles during focal seizures. Single-unit juxtacellular recordings from CL demonstrated reduced overall firing rates, but a switch in firing pattern from single spikes to burst firing during seizures. These findings suggest that different thalamic nuclei play very different roles in focal limbic seizures. While limbic nuclei, such as ANT, appear to participate directly in seizure propagation, arousal nuclei, such as CL, may contribute to depressed cortical function, whereas sleep spindles in relay nuclei, such as VPM, may interrupt thalamocortical information flow. These combined effects could be critical for controlling both seizure severity and impairment of consciousness. Further understanding of differential effects of seizures on different thalamocortical networks may lead to improved treatments directly targeting these modes of impaired function. SIGNIFICANCE STATEMENT Temporal lobe epilepsy has a major negative impact on quality of life. Previous work suggests that the thalamus plays a critical role in thalamocortical network modulation and subcortical arousal maintenance, but its precise seizure-associated functions are not known. We recorded neuronal activity in three different thalamic regions and found divergent activity patterns, which may respectively participate in seizure propagation, impaired level of conscious arousal, and altered relay of information to the cortex during focal limbic seizures. These very different activity patterns within the thalamus may help explain why focal temporal lobe seizures often disrupt widespread network function, and can help guide future treatments aimed at restoring normal thalamocortical network activity and cognition. PMID:29066556

Recent drought conditions in the Conterminous United States

Treesearch

Frank H. Koch; William D. Smith; John W. Coulston

2013-01-01

Droughts are common in virtually all U.S. forests, but their frequency and intensity vary widely both between and within forest ecosystems (Hanson and Weltzin 2000). Forests in the Western United States generally exhibit a pattern of annual seasonal droughts. Forests in the Eastern United States tend to exhibit one of two prevailing patterns: random occasional droughts...

Meaning in Cross-Cultural Situations: An Application of Vygotsky's Unit of Analysis to Ethnolinguistics.

ERIC Educational Resources Information Center

Cadart-Ricard, Odette

The problem of meaning in cross-cultural situations, resulting from differing patterns of thought, requires comprehension of the basic rules or patterns of these thought systems. This comprehension can be sought through Vygotsky's unit of analysis, a unit being a product of analysis which, unlike elements, retains all the basic properties of the…

U.S. Army noncombat munitions injuries.

PubMed

Kopchinski, B; Lein, B

2001-02-01

The object of this study was to determine the types of noncombat injuries secondary to munitions sustained by U.S. Army soldiers. A retrospective review of all noncombat munitions injuries reported to the U.S. Army Safety Center from August 1989 to September 1996 was conducted. There were 742 incidents reported, resulting in 894 injured soldiers. The most common types of injuries were thermal burns, puncture wounds, and lacerations. The extremities were the most common anatomical location injured. The most common activities associated with injuries were combat training exercises, munitions firing, and rendering munitions safe. This study demonstrates a distinctive injury pattern for each category of munitions. Military readiness will be improved if we train all personnel to be familiar with the injury patterns and the most common situations associated with injury. By informing unit commanders which activities are associated with increased risk of injury, they may better prepare preventive measures to decrease the number of noncombat injuries.

Effective deep brain stimulation suppresses low-frequency network oscillations in the basal ganglia by regularizing neural firing patterns.

PubMed

McConnell, George C; So, Rosa Q; Hilliard, Justin D; Lopomo, Paola; Grill, Warren M

2012-11-07

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is an effective treatment for the motor symptoms of Parkinson's disease (PD). The effects of DBS depend strongly on stimulation frequency: high frequencies (>90 Hz) improve motor symptoms, while low frequencies (<50 Hz) are either ineffective or exacerbate symptoms. The neuronal basis for these frequency-dependent effects of DBS is unclear. The effects of different frequencies of STN-DBS on behavior and single-unit neuronal activity in the basal ganglia were studied in the unilateral 6-hydroxydopamine lesioned rat model of PD. Only high-frequency DBS reversed motor symptoms, and the effectiveness of DBS depended strongly on stimulation frequency in a manner reminiscent of its clinical effects in persons with PD. Quantification of single-unit activity in the globus pallidus externa (GPe) and substantia nigra reticulata (SNr) revealed that high-frequency DBS, but not low-frequency DBS, reduced pathological low-frequency oscillations (∼9 Hz) and entrained neurons to fire at the stimulation frequency. Similarly, the coherence between simultaneously recorded pairs of neurons within and across GPe and SNr shifted from the pathological low-frequency band to the stimulation frequency during high-frequency DBS, but not during low-frequency DBS. The changes in firing patterns in basal ganglia neurons were not correlated with changes in firing rate. These results indicate that high-frequency DBS is more effective than low-frequency DBS, not as a result of changes in firing rate, but rather due to its ability to replace pathological low-frequency network oscillations with a regularized pattern of neuronal firing.

Effective deep brain stimulation suppresses low frequency network oscillations in the basal ganglia by regularizing neural firing patterns

PubMed Central

McConnell, George C.; So, Rosa Q.; Hilliard, Justin D; Lopomo, Paola; Grill, Warren M.

2012-01-01

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is an effective treatment for the motor symptoms of Parkinson’s disease (PD). The effects of DBS depend strongly on stimulation frequency: high frequencies (>90Hz) improve motor symptoms, while low frequencies (<50Hz) are either ineffective or exacerbate symptoms. The neuronal basis for these frequency-dependent effects of DBS is unclear. The effects of different frequencies of STN-DBS on behavior and single-unit neuronal activity in the basal ganglia were studied in the unilateral 6-hydroxydopamine lesioned rat model of PD. Only high frequency DBS reversed motor symptoms and the effectiveness of DBS depended strongly on stimulation frequency in a manner reminiscent of its clinical effects in persons with PD. Quantification of single-unit activity in the globus pallidus externa (GPe) and substantia nigra reticulata (SNr) revealed that high frequency DBS, but not low frequency DBS, reduced pathological low frequency oscillations (~9Hz) and entrained neurons to fire at the stimulation frequency. Similarly, the coherence between simultaneously recorded pairs of neurons within and across GPe and SNr shifted from the pathological low frequency band to the stimulation frequency during high frequency DBS, but not during low frequency DBS. The changes in firing patterns in basal ganglia neurons were not correlated with changes in firing rate. These results indicate that high frequency DBS is more effective than low frequency DBS, not as a result of changes in firing rate, but rather due to its ability to replace pathological low frequency network oscillations with a regularized pattern of neuronal firing. PMID:23136407

Beyond the central pattern generator: amine modulation of decision-making neural pathways descending from the brain of the medicinal leech.

PubMed

Crisp, Kevin M; Mesce, Karen A

2006-05-01

The biological mechanisms of behavioral selection, as it relates to locomotion, are far from understood, even in relatively simple invertebrate animals. In the medicinal leech, Hirudo medicinalis, the decision to swim is distributed across populations of swim-activating and swim-inactivating neurons descending from the subesophageal ganglion of the compound cephalic ganglion, i.e. the brain. In the present study, we demonstrate that the serotonergic LL and Retzius cells in the brain are excited by swim-initiating stimuli and during spontaneous swim episodes. This activity likely influences or resets the neuromodulatory state of neural circuits involved in the activation or subsequent termination of locomotion. When serotonin (5-HT) was perfused over the brain, multi-unit recordings from descending brain neurons revealed rapid and substantial alterations. Subsequent intracellular recordings from identified command-like brain interneurons demonstrated that 5-HT, especially in combination with octopamine, inhibited swim-triggering neuron Tr1, as well as swim-inactivating neurons Tr2 and SIN1. Although 5-HT inhibited elements of the swim-inactivation pathway, rather than promoting them, the indirect and net effect of the amine was a reliable and sustained reduction in the firing of the segmental swim-gating neuron 204. This modulation caused cell 204 to relinquish its excitatory drive to the swim central pattern generator. The activation pattern of serotonergic brain neurons that we observed during swimming and the 5-HT-immunoreactive staining pattern obtained, suggest that within the head brain 5-HT secretion is massive. Over time, 5-HT secretion may provide a homeostatic feedback mechanism to limit swimming activity at the level of the head brain.

An examination of factors influencing the spatial distribution of foraging bats in pine stands in the southeastern United States.

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

Menzel, Michael, A., Jr.

Menzel, M.A. 2003. An examination of factors influencing the spatial distribution of foraging bats in pine stands in the Southeastern United States. Ph.D Dissertation. Davis College of Agriculture, Forestry and Consumer Sciences at West Virginia University, Morgantown, West Virginia. 336 pp. The general objective of this dissertation was to determine the effect of changes in forest structure on bat activity patterns in southern pine stands. Four sub studies are included in the dissertation: (1) An examination of the homerange size, habitat use and diet of four reproductively active male Rafinesque's big eared bats (Corynorhimus rafinesquii); (2) An examination of themore » diet of 5 reproductively active male Rafinesque's big eared bats; (3) A comparison of bat activity levels in the Coastal Plain of South Carolina among 5 vegetational community types: forested riparian areas, clearcuts, young pine plantations, mature plantations, and pine savannahs; (4) A summarization of information concerning the natural history of all bat species common in the SPR.« less

Modeling complexity in pathologist workload measurement: the Automatable Activity-Based Approach to Complexity Unit Scoring (AABACUS).

PubMed

Cheung, Carol C; Torlakovic, Emina E; Chow, Hung; Snover, Dale C; Asa, Sylvia L

2015-03-01

Pathologists provide diagnoses relevant to the disease state of the patient and identify specific tissue characteristics relevant to response to therapy and prognosis. As personalized medicine evolves, there is a trend for increased demand of tissue-derived parameters. Pathologists perform increasingly complex analyses on the same 'cases'. Traditional methods of workload assessment and reimbursement, based on number of cases sometimes with a modifier (eg, the relative value unit (RVU) system used in the United States), often grossly underestimate the amount of work needed for complex cases and may overvalue simple, small biopsy cases. We describe a new approach to pathologist workload measurement that aligns with this new practice paradigm. Our multisite institution with geographically diverse partner institutions has developed the Automatable Activity-Based Approach to Complexity Unit Scoring (AABACUS) model that captures pathologists' clinical activities from parameters documented in departmental laboratory information systems (LISs). The model's algorithm includes: 'capture', 'export', 'identify', 'count', 'score', 'attribute', 'filter', and 'assess filtered results'. Captured data include specimen acquisition, handling, analysis, and reporting activities. Activities were counted and complexity units (CUs) generated using a complexity factor for each activity. CUs were compared between institutions, practice groups, and practice types and evaluated over a 5-year period (2008-2012). The annual load of a clinical service pathologist, irrespective of subspecialty, was ∼40,000 CUs using relative benchmarking. The model detected changing practice patterns and was appropriate for monitoring clinical workload for anatomical pathology, neuropathology, and hematopathology in academic and community settings, and encompassing subspecialty and generalist practices. AABACUS is objective, can be integrated with an LIS and automated, is reproducible, backwards compatible, and future adaptable. It can be applied as a robust decision support tool for the assessment of overall and targeted staffing needs as well as utilization analyses for resource allocation.

Computational advances towards linking BOLD and behavior.

PubMed

Serences, John T; Saproo, Sameer

2012-03-01

Traditionally, fMRI studies have focused on analyzing the mean response amplitude within a cortical area. However, the mean response is blind to many important patterns of cortical modulation, which severely limits the formulation and evaluation of linking hypotheses between neural activity, BOLD responses, and behavior. More recently, multivariate pattern classification analysis (MVPA) has been applied to fMRI data to evaluate the information content of spatially distributed activation patterns. This approach has been remarkably successful at detecting the presence of specific information in targeted brain regions, and provides an extremely flexible means of extracting that information without a precise generative model for the underlying neural activity. However, this flexibility comes at a cost: since MVPA relies on pooling information across voxels that are selective for many different stimulus attributes, it is difficult to infer how specific sub-sets of tuned neurons are modulated by an experimental manipulation. In contrast, recently developed encoding models can produce more precise estimates of feature-selective tuning functions, and can support the creation of explicit linking hypotheses between neural activity and behavior. Although these encoding models depend on strong - and often untested - assumptions about the response properties of underlying neural generators, they also provide a unique opportunity to evaluate population-level computational theories of perception and cognition that have previously been difficult to assess using either single-unit recording or conventional neuroimaging techniques. Copyright © 2011. Published by Elsevier Ltd.

Active modulation of laser coded systems using near infrared video projection system based on digital micromirror device (DMD)

NASA Astrophysics Data System (ADS)

Khalifa, Aly A.; Aly, Hussein A.; El-Sherif, Ashraf F.

2016-02-01

Near infrared (NIR) dynamic scene projection systems are used to perform hardware in-the-loop (HWIL) testing of a unit under test operating in the NIR band. The common and complex requirement of a class of these units is a dynamic scene that is spatio-temporal variant. In this paper we apply and investigate active external modulation of NIR laser in different ranges of temporal frequencies. We use digital micromirror devices (DMDs) integrated as the core of a NIR projection system to generate these dynamic scenes. We deploy the spatial pattern to the DMD controller to simultaneously yield the required amplitude by pulse width modulation (PWM) of the mirror elements as well as the spatio-temporal pattern. Desired modulation and coding of high stable, high power visible (Red laser at 640 nm) and NIR (Diode laser at 976 nm) using the combination of different optical masks based on DMD were achieved. These spatial versatile active coding strategies for both low and high frequencies in the range of kHz for irradiance of different targets were generated by our system and recorded using VIS-NIR fast cameras. The temporally-modulated laser pulse traces were measured using array of fast response photodetectors. Finally using a high resolution spectrometer, we evaluated the NIR dynamic scene projection system response in terms of preserving the wavelength and band spread of the NIR source after projection.

A Multi-Scale Comparative Study of Shape and Sprawl in Metropolitan Regions of the United States

ERIC Educational Resources Information Center

Kugler, Tracy A.

2012-01-01

This dissertation constitutes a multi-scale quantitative and qualitative investigation of patterns of urban development in metropolitan regions of the United States. This work has generated a comprehensive data set on spatial patterns of metropolitan development in the U.S. and an approach to the study of such patterns that can be used to further…

Probabilistic models for neural populations that naturally capture global coupling and criticality

PubMed Central

2017-01-01

Advances in multi-unit recordings pave the way for statistical modeling of activity patterns in large neural populations. Recent studies have shown that the summed activity of all neurons strongly shapes the population response. A separate recent finding has been that neural populations also exhibit criticality, an anomalously large dynamic range for the probabilities of different population activity patterns. Motivated by these two observations, we introduce a class of probabilistic models which takes into account the prior knowledge that the neural population could be globally coupled and close to critical. These models consist of an energy function which parametrizes interactions between small groups of neurons, and an arbitrary positive, strictly increasing, and twice differentiable function which maps the energy of a population pattern to its probability. We show that: 1) augmenting a pairwise Ising model with a nonlinearity yields an accurate description of the activity of retinal ganglion cells which outperforms previous models based on the summed activity of neurons; 2) prior knowledge that the population is critical translates to prior expectations about the shape of the nonlinearity; 3) the nonlinearity admits an interpretation in terms of a continuous latent variable globally coupling the system whose distribution we can infer from data. Our method is independent of the underlying system’s state space; hence, it can be applied to other systems such as natural scenes or amino acid sequences of proteins which are also known to exhibit criticality. PMID:28926564

Empirical Studies of Behavioural Patterns at the United Nations. Peace Research Reviews, Vol. VII, No. 4, May 1978 [And] Vol. VII, No. 5, May 1978.

ERIC Educational Resources Information Center

Newcombe, Alan G., Ed.; Newcombe, Hanna, Ed.

These volumes present the findings of four studies of behavioral patterns of delegates at the United Nations (UN). UN voting records, delegate questionnaires, and national, political, social, and geographic variables were analyzed. The first study, "Exploring Delegate Attitudes at the United Nations," reports delegates' reactions to…

Regional assessments of the Nation's water quality—Improved understanding of stream nutrient sources through enhanced modeling capabilities

USGS Publications Warehouse

Preston, Stephen D.; Alexander, Richard B.; Woodside, Michael D.

2011-01-01

The U.S. Geological Survey (USGS) recently completed assessments of stream nutrients in six major regions extending over much of the conterminous United States. SPARROW (SPAtially Referenced Regressions On Watershed attributes) models were developed for each region to explain spatial patterns in monitored stream nutrient loads in relation to human activities and natural resources and processes. The model information, reported by stream reach and catchment, provides contrasting views of the spatial patterns of nutrient source contributions, including those from urban (wastewater effluent and diffuse runoff from developed land), agricultural (farm fertilizers and animal manure), and specific background sources (atmospheric nitrogen deposition, soil phosphorus, forest nitrogen fixation, and channel erosion).

Condensed tannins from mangrove species Kandelia candel and Rhizophora mangle and their antioxidant activity.

PubMed

Zhang, Liang-Liang; Lin, Yi-Ming; Zhou, Hai-Chao; Wei, Shu-Dong; Chen, Jia-Hong

2010-01-20

The structures of condensed tannins isolated from two mangrove species, Kandelia candel and Rhizophora mangle, were characterized by 13C nuclear magnetic resonance (NMR) spectroscopy and matrix assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) analyses. Results demonstrate that large heterogeneity occurs in degree of polymerization, pattern of hydroxylation, and substitution with monosaccharides in the structures of the condensed tannins. Condensed tannin oligomers from K. candel and R. mangle were shown to be heterogeneous mixtures consisting of procyanidin and prodelphinidin structural units with the former dominating. The MALDI-TOF mass spectra contained masses corresponding to a distinct oligomeric series of glycosylated heteropoly flavan units. In addition, condensed tannins from two mangrove plants were screened for their potential antioxidant activities using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) model systems.

Tropical Cyclones and Climate Controls in the Western Atlantic Basin during the First Half of the Nineteenth Century

NASA Astrophysics Data System (ADS)

Mock, C. J.; Dodds, S. F.; Rodgers, M. D.; Patwardhan, A.

2008-12-01

This study describes new comprehensive reconstructions of individual Western Atlantic Basin tropical cyclones for each year of the first half of the nineteenth century in the Western Atlantic Basin that are directly compatible and supplement the National Hurricane Center's HURDAT (Atlantic basin hurricane database). Data used for reconstructing tropical cyclones come from ship logbooks, ship protests, diaries, newspapers, and early instrumental records from more than 50 different archival repositories in the United States and the United Kingdom. Tropical cyclone strength was discriminated among tropical storms, hurricanes, major hurricanes, and non-tropical lows at least at tropical storm strength. The results detail the characteristics of several hundred storms, many of them being newly documented, and tracks for all storms were mapped. Overall, prominent active periods of tropical cyclones are evident along the western Atlantic Ocean in the 1830s but Caribbean and Gulf coasts exhibit active periods as being more evident in the 1810s and 1820s. Differences in decadal variations were even more pronounced when examining time series of activity at the statewide scale. High resolution paleoclimate and historical instrumental records of the AMO, NAO, ENSO, Atlantic SSTs, West African rainfall, and volcanic activity explain how different modes in these forcing mechanisms may explain some of the multidecadal and interannual variations. The early nineteenth century active hurricane activity appears to be particularly unique in corresponding with a low (negative index) AMO period, and as they relate to particular synoptic-scale patterns in the latter part of the Little Ice Age. Model simulations offer some hypotheses on such patterns, perhaps suggesting increased baroclinic-related storms and a slight later possible shift in the seasonal peak of tropical cyclones for some areas at times. Some years, such as 1806, 1837, 1838, 1842, and 1846 have particularly very active seasons, and we critically examined the synoptic-scale circulation responsible and also related some of the storms as they relate to potential modern analogs.

United States Military Retirement Migration: Patterns and Processes.

DTIC Science & Technology

1984-03-27

active duty force e) Number of heating degree days tA 23 f) Number of physicians per 1000 population g) Recreation acres per 1000 population h...Eva Mueller. 1967. The Geographic Mobility of Labor. Ann Arbor : University of Michigan. Institute for Social Research, Survey Research Center. Law, C.M... Chicken or Egg?. Southern Economic Journal. 37:295-306. Muth, J.F. 1961. Rational Expectations and the Theory of Price Movements. Econometrics. 29:315

United States Air Force Guide to Operational Surveillance of Medically Important Vectors and Pests Operational Entomology

DTIC Science & Technology

2006-08-15

Programs Section 3. Sampling Equipment Sampling Equipment Solid-State Army Miniature (SSAM) trap ABC style trap Encephalitis Vector Survey Trap CDC...Baseline Survey - these are conducted to determine the types of vectors and pests occurring in the area of operations, their respective breeding sites...or source habitat, and seasonal activity patterns. Operational Survey - data collected in an operational survey are used specifically to aid pest

Electrical stimulation of transplanted motoneurons improves motor unit formation

PubMed Central

Liu, Yang; Grumbles, Robert M.

2014-01-01

Motoneurons die following spinal cord trauma and with neurological disease. Intact axons reinnervate nearby muscle fibers to compensate for the death of motoneurons, but when an entire motoneuron pool dies, there is complete denervation. To reduce denervation atrophy, we have reinnervated muscles in Fisher rats from local transplants of embryonic motoneurons in peripheral nerve. Since growth of axons from embryonic neurons is activity dependent, our aim was to test whether brief electrical stimulation of the neurons immediately after transplantation altered motor unit numbers and muscle properties 10 wk later. All surgical procedures and recordings were done in anesthetized animals. The muscle consequences of motoneuron death were mimicked by unilateral sciatic nerve section. One week later, 200,000 embryonic day 14 and 15 ventral spinal cord cells, purified for motoneurons, were injected into the tibial nerve 10–15 mm from the gastrocnemii muscles as the only neuron source for muscle reinnervation. The cells were stimulated immediately after transplantation for up to 1 h using protocols designed to examine differential effects due to pulse number, stimulation frequency, pattern, and duration. Electrical stimulation that included short rests and lasted for 1 h resulted in higher motor unit counts. Muscles with higher motor unit counts had more reinnervated fibers and were stronger. Denervated muscles had to be stimulated directly to evoke contractions. These results show that brief electrical stimulation of embryonic neurons, in vivo, has long-term effects on motor unit formation and muscle force. This muscle reinnervation provides the opportunity to use patterned electrical stimulation to produce functional movements. PMID:24848463

Painting Patterns with Pixels.

ERIC Educational Resources Information Center

Yoerg, Kim

2002-01-01

Describes an art unit for middle school students where they created their own original pattern through the use of "ClarisWorks Paint." Discusses the procedure for the project and the evaluation used at the end of the unit. Emphasizes the importance of learning about computers. (CMK)

Structural and tectonic setting of the Charleston, South Carolina, region: Evidence from the Tertiary stratigraphic record

USGS Publications Warehouse

Weems, R.E.; Lewis, W.C.

2002-01-01

Eleven upper Eocene through Pliocene stratigraphic units occur in the subsurface of the region surrounding Charleston, South Carolina. These units contain a wealth of information concerning the long-term tectonic and structural setting of that area. These stratigraphic units have a mosaic pattern of distribution, rather than a simple layered pattern, because deposition, erosion, and tectonic warping have interacted in a complex manner through time. By generating separate structure-contour maps for the base of each stratigraphic unit, an estimate of the original basal surface of each unit can be reconstructed over wide areas. Changes in sea level over geologic time generate patterns of deposition and erosion that are geographically unique for the time of each transgression. Such patterns fail to persist when compared sequentially over time. In some areas, however, there has been persistent, repetitive net downward of upward movement over the past 34 m.y. These repetitive patterns of persistent motion are most readily attributable to tectonism. The spatial pattern of these high and low areas is complex, but it appears to correlate well with known tectonic features of the region. This correlation suggests that the tectonic setting of the Charleston region is controlled by scissors-like compression on a crustal block located between the north-trending Adams Run fault and the northwest-trending Charleston fault. Tectonism is localized in the Charleston region because it lies within a discrete hinge zone that accommodates structural movement between the Cape Fear arch and the Southeast Georgia embayment.

Effects of salinity and sea salt type on egg activation, fertilization, buoyancy and early embryology of European eel, Anguilla anguilla.

PubMed

Sørensen, Sune Riis; Butts, Ian Anthony Ernest; Munk, Peter; Tomkiewicz, Jonna

2016-02-01

Improper activation and swelling of in vitro produced eggs of European eel, Anguilla anguilla, has been shown to negatively affect embryonic development and hatching. We investigated this phenomenon by examining the effects of salinity and sea salt type on egg dimensions, cell cleavage patterns and egg buoyancy. Egg diameter after activation, using natural seawater adjusted to different salinities, varied among female eels, but no consistent pattern emerged. Activation salinities between 30-40 practical salinity unit (psu) produced higher quality eggs and generally larger egg diameters. Chorion diameters reached maximal values of 1642 ± 8 μm at 35 psu. A positive relationship was found between egg neutral buoyancy and activation salinity. Nine salt types were investigated as activation and incubation media. Five of these types induced a substantial perivitelline space (PVS), leading to large egg sizes, while the remaining four salt types resulted in smaller eggs. All salt types except NaCl treatments led to high fertilization rates and had no effect on fertilization success as well as egg neutral buoyancies at 7 h post-fertilization. The study points to the importance of considering ionic composition of the media when rearing fish eggs and further studies are encouraged.

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

PubMed Central

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

2015-01-01

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

Benchmarking organ procurement organizations: a national study.

PubMed Central

Ozcan, Y A; Begun, J W; McKinney, M M

1999-01-01

OBJECTIVE: An exploratory examination of the technical efficiency of organ procurement organizations (OPOs) relative to optimal patterns of production in the population of OPOs in the United States. DATA SOURCES: A composite data set with the OPO as the unit of analysis, constructed from a 1995 national survey of OPOs (n = 64), plus secondary data from the Association of Organ Procurement Organizations and the United Network for Organ Sharing. STUDY DESIGN: The study uses data envelopment analysis (DEA) to evaluate the technical efficiency of all OPOs. PRINCIPAL FINDINGS: Overall, six of the 22 larger OPOs (27 percent) are classified as inefficient, while 23 of the 42 smaller OPOs (55 percent) are classified as inefficient. Efficient OPOs recover significantly more kidneys and extrarenal organs; have higher operating expenses; and have more referrals, donors, extrarenal transplants, and kidney transplants. The quantities of hospital development personnel and other personnel, and formalization of hospital development activities in both small and large OPOs, do not significantly differ. CONCLUSIONS: Indications that larger OPOs are able to operate more efficiently relative to their peers suggest that smaller OPOs are more likely to benefit from technical assistance. More detailed information on the activities of OPO staff would help pinpoint activities that can increase OPO efficiency and referrals, and potentially improve outcomes for large numbers of patients awaiting transplants. PMID:10536974

Ambulatory activity classification with dendogram-based support vector machine: Application in lower-limb active exoskeleton.

PubMed

Mazumder, Oishee; Kundu, Ananda Sankar; Lenka, Prasanna Kumar; Bhaumik, Subhasis

2016-10-01

Ambulatory activity classification is an active area of research for controlling and monitoring state initiation, termination, and transition in mobility assistive devices such as lower-limb exoskeletons. State transition of lower-limb exoskeletons reported thus far are achieved mostly through the use of manual switches or state machine-based logic. In this paper, we propose a postural activity classifier using a 'dendogram-based support vector machine' (DSVM) which can be used to control a lower-limb exoskeleton. A pressure sensor-based wearable insole and two six-axis inertial measurement units (IMU) have been used for recognising two static and seven dynamic postural activities: sit, stand, and sit-to-stand, stand-to-sit, level walk, fast walk, slope walk, stair ascent and stair descent. Most of the ambulatory activities are periodic in nature and have unique patterns of response. The proposed classification algorithm involves the recognition of activity patterns on the basis of the periodic shape of trajectories. Polynomial coefficients extracted from the hip angle trajectory and the centre-of-pressure (CoP) trajectory during an activity cycle are used as features to classify dynamic activities. The novelty of this paper lies in finding suitable instrumentation, developing post-processing techniques, and selecting shape-based features for ambulatory activity classification. The proposed activity classifier is used to identify the activity states of a lower-limb exoskeleton. The DSVM classifier algorithm achieved an overall classification accuracy of 95.2%. Copyright © 2016 Elsevier B.V. All rights reserved.

Emergence of multicellular organisms with dynamic differentiation and spatial pattern.

PubMed

Furusawa, C; Kaneko, K

1998-01-01

The origin of multicellular organisms and the mechanism of development in cell societies are studied by choosing a model with intracellular biochemical dynamics allowing for oscillations, cell-cell interaction through diffusive chemicals on a two-dimensional grid, and state-dependent cell adhesion. Cells differentiate due to a dynamical instability, as described by our "isologous diversification" theory. A fixed spatial pattern of differentiated cells emerges, where spatial information is sustained by cell-cell interactions. This pattern is robust against perturbations. With an adequate cell adhesion force, active cells are release that form the seed of a new generation of multicellular organisms, accompanied by death of the original multicellular unit as a halting state. It is shown that the emergence of multicellular organisms with differentiation, regulation, and life cycle is not an accidental event, but a natural consequence in a system of replicating cells with growth.

Effect of ADAMTS13 activity turnaround time on plasma utilization for suspected thrombotic thrombocytopenic purpura.

PubMed

Connell, Nathan T; Cheves, Tracey; Sweeney, Joseph D

2016-02-01

Thrombotic thrombocytopenic purpura (TTP) due to deficiency of the von Willebrand-cleaving protease ADAMTS13 is a hematologic emergency that requires prompt initiation of therapeutic plasma exchange (TPE). Long turnaround times (TATs) have precluded the use of pre-TPE measurement of ADAMTS13 activity for the initial diagnosis in most institutions. An in-house rapid TAT (r-TAT) assay for ADAMTS13 activity was implemented after 18 months of validation. In a quasi-experimental design using interrupted time series analysis, patterns of plasma utilization in patients with suspected TTP were assessed after implementation of this assay for ADAMTS13 activity and compared to utilization patterns for patients who received plasma exchange before r-TAT assay implementation designated the standard TAT period. In the 18 months after implementation of the r-TAT ADAMTS13 assay, there was a significant reduction in plasma utilization per patient suspected of having TTP (mean, 144.5 units vs. 63.3 units of plasma per patients suspected of having TTP; p = 0.002). The mean number of exchanges per patient and mean number of exchanges after achieving a platelet count of at least 150 × 10(9) /L were lower in the r-TAT cohort (p < 0.001 for both). There was no significant difference in 30-day mortality. Implementation of a rapid turnaround assay for ADAMTS13 resulted in a significant reduction in plasma utilization for patients with suspected TTP, without an increase in mortality. This study demonstrates that these data, provided in a timely fashion, can avoid unnecessary plasma exchange in patients who do not have TTP. © 2015 AABB.

eHealth Search Patterns: A Comparison of Private and Public Health Care Markets Using Online Panel Data

PubMed Central

2017-01-01

Background Patient and consumer access to eHealth information is of crucial importance because of its role in patient-centered medicine and to improve knowledge about general aspects of health and medical topics. Objectives The objectives were to analyze and compare eHealth search patterns in a private (United States) and a public (United Kingdom) health care market. Methods A new taxonomy of eHealth websites is proposed to organize the largest eHealth websites. An online measurement framework is developed that provides a precise and detailed measurement system. Online panel data are used to accurately track and analyze detailed search behavior across 100 of the largest eHealth websites in the US and UK health care markets. Results The health, medical, and lifestyle categories account for approximately 90% of online activity, and e-pharmacies, social media, and professional categories account for the remaining 10% of online activity. Overall search penetration of eHealth websites is significantly higher in the private (United States) than the public market (United Kingdom). Almost twice the number of eHealth users in the private market have adopted online search in the health and lifestyle categories and also spend more time per website than those in the public market. The use of medical websites for specific conditions is almost identical in both markets. The allocation of search effort across categories is similar in both the markets. For all categories, the vast majority of eHealth users only access one website within each category. Those that conduct a search of two or more websites display very narrow search patterns. All users spend relatively little time on eHealth, that is, 3-7 minutes per website. Conclusions The proposed online measurement framework exploits online panel data to provide a powerful and objective method of analyzing and exploring eHealth behavior. The private health care system does appear to have an influence on eHealth search behavior in terms of search penetration and time spent per website in the health and lifestyle categories. Two explanations are offered: (1) the personal incentive of medical costs in the private market incentivizes users to conduct online search; and (2) health care information is more easily accessible through health care professionals in the United Kingdom compared with the United States. However, the use of medical websites is almost identical, suggesting that patients interested in a specific condition have a motivation to search and evaluate health information, irrespective of the health care market. The relatively low level of search in terms of the number of websites accessed and the average time per website raise important questions about the actual level of patient informedness in both the markets. Areas for future research are outlined. PMID:28408362

Genes on a Wire: The Nucleoid-Associated Protein HU Insulates Transcription Units in Escherichia coli

PubMed Central

Berger, Michael; Gerganova, Veneta; Berger, Petya; Rapiteanu, Radu; Lisicovas, Viktoras; Dobrindt, Ulrich

2016-01-01

The extent to which chromosomal gene position in prokaryotes affects local gene expression remains an open question. Several studies have shown that chromosomal re-positioning of bacterial transcription units does not alter their expression pattern, except for a general decrease in gene expression levels from chromosomal origin to terminus proximal positions, which is believed to result from gene dosage effects. Surprisingly, the question as to whether this chromosomal context independence is a cis encoded property of a bacterial transcription unit, or if position independence is a property conferred by factors acting in trans, has not been addressed so far. For this purpose, we established a genetic test system assessing the chromosomal positioning effects by means of identical promoter-fluorescent reporter gene fusions inserted equidistantly from OriC into both chromosomal replichores of Escherichia coli K-12. Our investigations of the reporter activities in mutant cells lacking the conserved nucleoid associated protein HU uncovered various drastic chromosomal positional effects on gene transcription. In addition we present evidence that these positional effects are caused by transcriptional activity nearby the insertion site of our reporter modules. We therefore suggest that the nucleoid-associated protein HU is functionally insulating transcription units, most likely by constraining transcription induced DNA supercoiling. PMID:27545593

Dirac Sea and its Evolution

NASA Astrophysics Data System (ADS)

Volfson, Boris

2013-09-01

The hypothesis of transition from a chaotic Dirac Sea, via highly unstable positronium, into a Simhony Model of stable face-centered cubic lattice structure of electrons and positrons securely bound in vacuum space, is considered. 13.75 Billion years ago, the new lattice, which, unlike a Dirac Sea, is permeable by photons and phonons, made the Universe detectable. Many electrons and positrons ended up annihilating each other producing energy quanta and neutrino-antineutrino pairs. The weak force of the electron-positron crystal lattice, bombarded by the chirality-changing neutrinos, may have started capturing these neutrinos thus transforming from cubic crystals into a quasicrystal lattice. Unlike cubic crystal lattice, clusters of quasicrystals are "slippery" allowing the formation of centers of local torsion, where gravity condenses matter into galaxies, stars and planets. In the presence of quanta, in a quasicrystal lattice, the Majorana neutrinos' rotation flips to the opposite direction causing natural transformations in a category comprised of three components; two others being positron and electron. In other words, each particle-antiparticle pair "e-" and "e+", in an individual crystal unit, could become either a quasi- component "e- ve e+", or a quasi- component "e+ - ve e-". Five-to-six six billion years ago, a continuous stimulation of the quasicrystal aetherial lattice by the same, similar, or different, astronomical events, could have triggered Hebbian and anti-Hebbian learning processes. The Universe may have started writing script into its own aether in a code most appropriate for the quasicrystal aether "hardware": Eight three-dimensional "alphabet" characters, each corresponding to the individual quasi-crystal unit shape. They could be expressed as quantum Turing machine qubits, or, alternatively, in a binary code. The code numerals could contain terminal and nonterminal symbols of the Chomsky's hierarchy, wherein, the showers of quanta, forming the cosmic microwave background radiation, may re-script a quasi-component "e- ve e+" (in the binary code case, same as numeral "0") into a quasi-component "e+ -ve e-" (numeral "1"), or vice versa. According to both, the Chomsky"s logic, and the rules applicable to Majorana particles, terminals "e-" and "e+" cannot be changed using the rules of grammar, while nonterminals "ve" and "-ve" can. Under "quantum" showers, the quasi- unit cells re-shape, resulting in re-combination of the clusters that they form, with the affected pattern become same as, similar to, or different from, other pattern(s). The process of self-learning may have occurred as a natural response to various astronomical events and cosmic cataclysms: The same astronomical activity in two different areas resulted in the emission of the same energy forming the same secondary quasicrystal pattern. Different but similar astronomical activity resulted in the emission of a similar amount of energy forming a similar secondary quasicrystal pattern. Different astronomical activity resulted in the emission of a different amount of energy forming a different secondary quasicrystal pattern. Since quasicrystals conduct energy in one direction and don't conduct energy in the other, the control over quanta flows allows aether to scribe a script onto itself through changing its own quasi- patterns. The paper, as published below, is a lecture summary. The full text is published on website: www.borisvolfson.org

Representational Similarity Analysis – Connecting the Branches of Systems Neuroscience

PubMed Central

Kriegeskorte, Nikolaus; Mur, Marieke; Bandettini, Peter

2008-01-01

A fundamental challenge for systems neuroscience is to quantitatively relate its three major branches of research: brain-activity measurement, behavioral measurement, and computational modeling. Using measured brain-activity patterns to evaluate computational network models is complicated by the need to define the correspondency between the units of the model and the channels of the brain-activity data, e.g., single-cell recordings or voxels from functional magnetic resonance imaging (fMRI). Similar correspondency problems complicate relating activity patterns between different modalities of brain-activity measurement (e.g., fMRI and invasive or scalp electrophysiology), and between subjects and species. In order to bridge these divides, we suggest abstracting from the activity patterns themselves and computing representational dissimilarity matrices (RDMs), which characterize the information carried by a given representation in a brain or model. Building on a rich psychological and mathematical literature on similarity analysis, we propose a new experimental and data-analytical framework called representational similarity analysis (RSA), in which multi-channel measures of neural activity are quantitatively related to each other and to computational theory and behavior by comparing RDMs. We demonstrate RSA by relating representations of visual objects as measured with fMRI in early visual cortex and the fusiform face area to computational models spanning a wide range of complexities. The RDMs are simultaneously related via second-level application of multidimensional scaling and tested using randomization and bootstrap techniques. We discuss the broad potential of RSA, including novel approaches to experimental design, and argue that these ideas, which have deep roots in psychology and neuroscience, will allow the integrated quantitative analysis of data from all three branches, thus contributing to a more unified systems neuroscience. PMID:19104670

Changing Patterns of Blood Borne Sepsis in Special Care Baby Unit, Khoula Hospital

PubMed Central

Gupta, Bhaskar; El Amin, Eisa

2010-01-01

Objectives Infection is a frequent and important cause of morbidity and mortality in neonatal units all over the world. Over the years, there has been a shift in the microorganisms responsible for neonatal septicemia. This study aims to analyze the changing patterns of blood borne organisms in the neonatal unit. Methods This retrospective study was undertaken at the neonatal intensive care unit of Khoula Hospital in Muscat, Sultanate of Oman to analyze the incidence of blood borne sepsis and its changing pattern from 1997-2000. Results Out of a total 2181 admissions to the neonatal intensive care unit, 71 (3.25%) babies had positive blood culture. A reduction in the incidence of blood borne sepsis with changing patterns of organisms was seen over the period of four years with incidence of Group B Streptococcus declining from 34% in 1997-1998 to 17.8% in 1999-2000 and the incidence of CONS (Staphylococcus epidermidis) increasing from 20% in 1997-1998 to 35% in 1999-2000. Conclusion Overall, due to survival and prolonged hospitalization of extremely low birth weight babies who need frequent invasive procedures, and the use of powerful antibiotics, the incidence of Staphylococcus epidermidis which was previously thought to be non pathogenic has increased over the years in neonatal intensive care units. PMID:22125709

Ideological and organizational components of differing public health strategies for addressing the social determinants of health.

PubMed

Raphael, Dennis; Brassolotto, Julia; Baldeo, Navindra

2015-12-01

Despite a history of conceptual contributions to reducing health inequalities by addressing the social determinants of health (SDH), Canadian governmental authorities have struggled to put these concepts into action. Ontario's-Canada's most populous province-public health scene shows a similar pattern. In statements and reports, governmental ministries, professional associations and local public health units (PHUs) recognize the importance of these issues, yet there has been varying implementation of these concepts into public health activity. The purpose of this study was to gain insight into the key features responsible for differences in SDH-related activities among local PHUs. We interviewed Medical Officers of Health (MOH) and key staff members from nine local PHUs in Ontario varying in SDH activity as to their understandings of the SDH, public health's role in addressing the SDH, and their units' SDH-related activities. We also reviewed their unit's documents and their organizational structures in relation to acting on the SDH. Three clusters of PHUs are identified based on their SDH-related activities: service-delivery-oriented; intersectoral and community-based; and public policy/public education-focused. The two key factors that differentiate PHUs are specific ideological commitments held by MOHs and staff and the organizational structures established to carry out SDH-related activities. The ideological commitments and the organizational structures of the most active PHUs showed congruence with frameworks adopted by national jurisdictions known for addressing health inequalities. These include a structural analysis of the SDH and a centralized organizational structure that coordinates SDH-related activities. © The Author (2014). Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Detection rates of the MODIS active fire product in the United States

USGS Publications Warehouse

Hawbaker, T.J.; Radeloff, V.C.; Syphard, A.D.; Zhu, Z.; Stewart, S.I.

2008-01-01

MODIS active fire data offer new information about global fire patterns. However, uncertainties in detection rates can render satellite-derived fire statistics difficult to interpret. We evaluated the MODIS 1??km daily active fire product to quantify detection rates for both Terra and Aqua MODIS sensors, examined how cloud cover and fire size affected detection rates, and estimated how detection rates varied across the United States. MODIS active fire detections were compared to 361 reference fires (??? 18??ha) that had been delineated using pre- and post-fire Landsat imagery. Reference fires were considered detected if at least one MODIS active fire pixel occurred within 1??km of the edge of the fire. When active fire data from both Aqua and Terra were combined, 82% of all reference fires were found, but detection rates were less for Aqua and Terra individually (73% and 66% respectively). Fires not detected generally had more cloudy days, but not when the Aqua data were considered exclusively. MODIS detection rates decreased with fire size, and the size at which 50% of all fires were detected was 105??ha when combining Aqua and Terra (195??ha for Aqua and 334??ha for Terra alone). Across the United States, detection rates were greatest in the West, lower in the Great Plains, and lowest in the East. The MODIS active fire product captures large fires in the U.S. well, but may under-represent fires in areas with frequent cloud cover or rapidly burning, small, and low-intensity fires. We recommend that users of the MODIS active fire data perform individual validations to ensure that all relevant fires are included. ?? 2008 Elsevier Inc. All rights reserved.

A case study examination of structure and function in a state health department chronic disease unit.

PubMed

Alongi, Jeanne

2015-04-01

I explored the structural and operational practices of the chronic disease prevention and control unit of a state health department and proposed a conceptual model of structure, function, and effectiveness for future study. My exploratory case study examined 7 elements of organizational structure and practice. My interviews with staff and external stakeholders of a single chronic disease unit yielded quantitative and qualitative data that I coded by perspective, process, relationship, and activity. I analyzed these for patterns and emerging themes. Chi-square analysis revealed significant correlations among collaboration with goal ambiguity, political support, and responsiveness, and evidence-based decisions with goal ambiguity and responsiveness. Although my study design did not permit conclusions about causality, my findings suggested that some elements of the model might facilitate effectiveness for chronic disease units and should be studied further. My findings might have important implications for identifying levers around which capacity can be built that may strengthen effectiveness.

Radon removal using point-of-entry water-treatment techniques. Final report, October 1988-June 1990

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

Kinner, N.E.; Malley, J.P.; Clement, J.A.

1990-10-01

The purpose of the EPA Cooperative Agreement was to evaluate the performance of POE granular activated carbon (GAC), and diffused bubble and bubble place aeration systems treating a ground water supply containing radon (35,620 + or - 6,717 pCi/L). The pattern of loading to the units was designed to simulate daily demand in a household. Each of the systems was evaluated with respect to three primary factors: radon removal efficiency, potential problems, and economics. The radon removal efficiencies of the POE GAC units gradually deteriorated over time from 99.7% to 79% for the GAC without pretreatment and 99.7% to 85%more » for the units preceded by ion exchange. The bubble plate and diffused bubble POE units were very efficient (99%) at removing radon from the water. The resilience is primarly due to the high air to water ratios supplied by the aeration blowers. One major problem associated with the aeration techniques is iron oxidation/precipitation.« less

A Case Study Examination of Structure and Function in a State Health Department Chronic Disease Unit

PubMed Central

2015-01-01

Objectives. I explored the structural and operational practices of the chronic disease prevention and control unit of a state health department and proposed a conceptual model of structure, function, and effectiveness for future study. Methods. My exploratory case study examined 7 elements of organizational structure and practice. My interviews with staff and external stakeholders of a single chronic disease unit yielded quantitative and qualitative data that I coded by perspective, process, relationship, and activity. I analyzed these for patterns and emerging themes. Results. Chi-square analysis revealed significant correlations among collaboration with goal ambiguity, political support, and responsiveness, and evidence-based decisions with goal ambiguity and responsiveness. Conclusions. Although my study design did not permit conclusions about causality, my findings suggested that some elements of the model might facilitate effectiveness for chronic disease units and should be studied further. My findings might have important implications for identifying levers around which capacity can be built that may strengthen effectiveness. PMID:25689211

Region-specific network plasticity in simulated and living cortical networks: comparison of the center of activity trajectory (CAT) with other statistics

NASA Astrophysics Data System (ADS)

Chao, Zenas C.; Bakkum, Douglas J.; Potter, Steve M.

2007-09-01

Electrically interfaced cortical networks cultured in vitro can be used as a model for studying the network mechanisms of learning and memory. Lasting changes in functional connectivity have been difficult to detect with extracellular multi-electrode arrays using standard firing rate statistics. We used both simulated and living networks to compare the ability of various statistics to quantify functional plasticity at the network level. Using a simulated integrate-and-fire neural network, we compared five established statistical methods to one of our own design, called center of activity trajectory (CAT). CAT, which depicts dynamics of the location-weighted average of spatiotemporal patterns of action potentials across the physical space of the neuronal circuitry, was the most sensitive statistic for detecting tetanus-induced plasticity in both simulated and living networks. By reducing the dimensionality of multi-unit data while still including spatial information, CAT allows efficient real-time computation of spatiotemporal activity patterns. Thus, CAT will be useful for studies in vivo or in vitro in which the locations of recording sites on multi-electrode probes are important.

Protein Tyrosine Phosphatase-PEST and β8 Integrin Regulate Spatiotemporal Patterns of RhoGDI1 Activation in Migrating Cells

PubMed Central

Lee, Hye Shin; Cheerathodi, Mujeeburahiman; Chaki, Sankar P.; Reyes, Steve B.; Zheng, Yanhua; Lu, Zhimin; Paidassi, Helena; DerMardirossian, Celine; Lacy-Hulbert, Adam; Rivera, Gonzalo M.

2015-01-01

Directional cell motility is essential for normal development and physiology, although how motile cells spatiotemporally activate signaling events remains largely unknown. Here, we have characterized an adhesion and signaling unit comprised of protein tyrosine phosphatase (PTP)-PEST and the extracellular matrix (ECM) adhesion receptor β8 integrin that plays essential roles in directional cell motility. β8 integrin and PTP-PEST form protein complexes at the leading edge of migrating cells and balance patterns of Rac1 and Cdc42 signaling by controlling the subcellular localization and phosphorylation status of Rho GDP dissociation inhibitor 1 (RhoGDI1). Translocation of Src-phosphorylated RhoGDI1 to the cell's leading edge promotes local activation of Rac1 and Cdc42, whereas dephosphorylation of RhoGDI1 by integrin-bound PTP-PEST promotes RhoGDI1 release from the membrane and sequestration of inactive Rac1/Cdc42 in the cytoplasm. Collectively, these data reveal a finely tuned regulatory mechanism for controlling signaling events at the leading edge of directionally migrating cells. PMID:25666508

Utilization of robotic "remote presence" technology within North American intensive care units.

PubMed

Reynolds, Eliza M; Grujovski, Andre; Wright, Tim; Foster, Michael; Reynolds, H Neal

2012-09-01

To describe remote presence robotic utilization and examine perceived physician impact upon care in the intensive care unit (ICU). Data were obtained from academic, university, community, and rural medical facilities in North America with remote presence robots used in ICUs. Objective utilization data were extracted from a continuous monitoring system. Physician data were obtained via an Internet-based survey. As of 2010, 56 remote presence robots were deployed in 25 North American ICUs. Of 10,872 robot activations recorded, 10,065 were evaluated. Three distinct utilization patterns were discovered. Combining all programs revealed a pattern that closely reflects diurnal ICU activity. The physician survey revealed staff are senior (75% >40 years old, 60% with >16 years of clinical practice), trained in and dedicated to critical care. Programs are mature (70% >3 years old) and operate in a decentralized system, originating from cities with >50,000 population and provided to cities >50,000 (80%). Of the robots, 46.6% are in academic facilities. Most physicians (80%) provide on-site and remote ICU care, with 60% and 73% providing routine or scheduled rounds, respectively. All respondents (100%) believed patient care and patient/family satisfaction were improved. Sixty-six percent perceived the technology was a "blessing," while 100% intend to continue using the technology. Remote presence robotic technology is deployed in ICUs with various patterns of utilization that, in toto, simulate normal ICU work flow. There is a high rate of deployment in academic ICUs, suggesting the intensivists shortage also affects large facilities. Physicians using the technology are generally senior, experienced, and dedicated to critical care and highly support the technology.

A dynamic population model to investigate effects of climate and climate-independent factors on the lifecycle of the tick Amblyomma americanum (Acari: Ixodidae)

USGS Publications Warehouse

Ludwig, Antoinette; Ginsberg, Howard; Hickling, Graham J.; Ogden, Nicholas H.

2016-01-01

The lone star tick, Amblyomma americanum, is a disease vector of significance for human and animal health throughout much of the eastern United States. To model the potential effects of climate change on this tick, a better understanding is needed of the relative roles of temperature-dependent and temperature-independent (day-length-dependent behavioral or morphogenetic diapause) processes acting on the tick lifecycle. In this study, we explored the roles of these processes by simulating seasonal activity patterns using models with site-specific temperature and day-length-dependent processes. We first modeled the transitions from engorged larvae to feeding nymphs, engorged nymphs to feeding adults, and engorged adult females to feeding larvae. The simulated seasonal patterns were compared against field observations at three locations in United States. Simulations suggested that 1) during the larva-to-nymph transition, some larvae undergo no diapause while others undergo morphogenetic diapause of engorged larvae; 2) molted adults undergo behavioral diapause during the transition from nymph-to-adult; and 3) there is no diapause during the adult-to-larva transition. A model constructed to simulate the full lifecycle of A. americanum successfully predicted observed tick activity at the three U.S. study locations. Some differences between observed and simulated seasonality patterns were observed, however, identifying the need for research to refine some model parameters. In simulations run using temperature data for Montreal, deterministic die-out of A. americanum populations did not occur, suggesting the possibility that current climate in parts of southern Canada is suitable for survival and reproduction of this tick.

A Dynamic Population Model to Investigate Effects of Climate and Climate-Independent Factors on the Lifecycle of Amblyomma americanum (Acari: Ixodidae).

PubMed

Ludwig, Antoinette; Ginsberg, Howard S; Hickling, Graham J; Ogden, Nicholas H

2016-01-01

The lone star tick, Amblyomma americanum, is a disease vector of significance for human and animal health throughout much of the eastern United States. To model the potential effects of climate change on this tick, a better understanding is needed of the relative roles of temperature-dependent and temperature-independent (day-length-dependent behavioral or morphogenetic diapause) processes acting on the tick lifecycle. In this study, we explored the roles of these processes by simulating seasonal activity patterns using models with site-specific temperature and day-length-dependent processes. We first modeled the transitions from engorged larvae to feeding nymphs, engorged nymphs to feeding adults, and engorged adult females to feeding larvae. The simulated seasonal patterns were compared against field observations at three locations in United States. Simulations suggested that 1) during the larva-to-nymph transition, some larvae undergo no diapause while others undergo morphogenetic diapause of engorged larvae; 2) molted adults undergo behavioral diapause during the transition from nymph-to-adult; and 3) there is no diapause during the adult-to-larva transition. A model constructed to simulate the full lifecycle of A. americanum successfully predicted observed tick activity at the three U.S. study locations. Some differences between observed and simulated seasonality patterns were observed, however, identifying the need for research to refine some model parameters. In simulations run using temperature data for Montreal, deterministic die-out of A. americanum populations did not occur, suggesting the possibility that current climate in parts of southern Canada is suitable for survival and reproduction of this tick. © Crown copyright 2015.

Terrestrial Vegetation Dynamics, Global Climate Controls, and Extreme Events

NASA Astrophysics Data System (ADS)

Klooster, S.; Potter, C.; Boriah, S.; Steinbach, M.; Kumar, V.

2006-12-01

Monthly greenness data from the Moderate Resolution Imaging Spectroradiometer (MODIS) was used to reconstruct vegetation dynamics in response to climate patterns over the period 2000-2005. Results suggest that plant growth over extensive land areas of southern Africa and Central Asia were the most closely coupled of any major land area to El Niño-Southern Oscillation (ENSO) effects on regional climate. Others land areas strongly tied to recent ENSO climate effects were in northern Canada, Alaska, western United States, northern Mexico, northern Argentina, and Australia. Localized variations in precipitation were the most common controllers of monthly values for the fraction absorbed of photosynthetically active radiation (FPAR) over these regions. In addition to the areas cited above, seasonal FPAR values were closely coupled to rainfall patterns in grassland and cropland areas of the northern and central United States. Historical associations between global vegetation FPAR and atmospheric carbon dioxide anomalies suggest that the terrestrial biosphere can contribute major fluxes of carbon dioxide during major drought events, such as those triggered by the 1997-98 El Niño event.

Chapter 2 - Large-scale patterns of insect and disease activity in the conterminous United States and Alaska from the National Insect and Disease Survey, 2011

Treesearch

Kevin M. Potter; Jeanine L. Paschke

2014-01-01

The impacts of insects and pathogens on forests vary from natural thinning to extraordinary levels of tree mortality, but the fact that insects and diseases kill trees does not necessarily make them enemies of the forest (Teale and Castello 2011). If disturbances, pests, and diseases are viewed in their full ecological context, then some amount can be considered “...

Functional autonomy of distant-acting human enhancers

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

Visel, Axel; Akiyama, Jennifer A.; Shoukry, Malak

2009-02-19

Many human genes are associated with dispersed arrays of transcriptional enhancers that regulate their expression in time and space. Studies in invertebrate model systems have suggested that these elements function as discrete and independent regulatory units, but the in vivo combinatorial properties of vertebrate enhancers remain poorly understood. To explore the modularity and regulatory autonomy of human developmental enhancers, we experimentally concatenated up to four enhancers from different genes and used a transgenic mouse assay to compare the in vivo activity of these compound elements with that of the single modules. In all of the six different combinations of elementsmore » tested, the reporter gene activity patterns were additive without signs of interference between the individual modules, indicating that regulatory specificity was maintained despite the presence of closely-positioned heterologous enhancers. Even in cases where two elements drove expression in close anatomical proximity, such as within neighboring subregions of the developing limb bud, the compound patterns did not show signs of cross-inhibition between individual elements or novel expression sites. These data indicate that human developmental enhancers are highly modular and functionally autonomous and suggest that genomic enhancer shuffling may have contributed to the evolution of complex gene expression patterns in vertebrates« less

Analysis of the project synthesis goal cluster orientation and inquiry emphasis of elementary science textbooks

NASA Astrophysics Data System (ADS)

Staver, John R.; Bay, Mary

The purpose of this descriptive study was to examine selected units of commonly used elementary science texts, using the Project Synthesis goal clusters as a framework for part of the examination. An inquiry classification scheme was used for the remaining segment. Four questions were answered: (1) To what extent do elementary science textbooks focus on each Project Synthesis goal cluster? (2) In which part of the text is such information found? (3) To what extent are the activities and experiments merely verifications of information already introduced in the text? (4) If inquiry is present in an activity, then what is the level of such inquiry?Eleven science textbook series, which comprise approximately 90 percent of the national market, were selected for analysis. Two units, one primary (K-3) and one intermediate (4-6), were selected for analysis by first identifying units common to most series, then randomly selecting one primary and one intermediate unit for analysis.Each randomly selected unit was carefully read, using the sentence as the unit of analysis. Each declarative and interrogative sentence in the body of the text was classified as: (1) academic; (2) personal; (3) career; or (4) societal in its focus. Each illustration, except those used in evaluation items, was similarly classified. Each activity/experiment and each miscellaneous sentence in end-of-chapter segments labelled review, summary, evaluation, etc., were similarly classified. Finally, each activity/experiment, as a whole, was categorized according to a four-category inquiry scheme (confirmation, structured inquiry, guided inquiry, open inquiry).In general, results of the analysis are: (1) most text prose focuses on academic science; (2) most remaining text prose focuses on the personal goal cluster; (3) the career and societal goal clusters receive only minor attention; (4) text illustrations exhibit a pattern similar to text prose; (5) text activities/experiments are academic in orientation, almost to the exclusion of other goal clusters; (6) end-of-chapter sentences are largely academic; (7) inquiry is absent or present only in limited forms in text activities/experiments; and (8) texts allocate only a minor portion of space to activities/experiments. Detailed findings are given as numeral, percentage, and decimal values. Discussion focuses on the implications of the results and a comparison of NSTA recommendations with the results of this analysis.

Muscle activation patterns and motor anatomy of Anna's hummingbirds Calypte anna and zebra finches Taeniopygia guttata.

PubMed

Donovan, Edward R; Keeney, Brooke K; Kung, Eric; Makan, Sirish; Wild, J Martin; Altshuler, Douglas L

2013-01-01

Flying animals exhibit profound transformations in anatomy, physiology, and neural architecture. Although much is known about adaptations in the avian skeleton and musculature, less is known about neuroanatomy and motor unit integration for bird flight. Hummingbirds are among the most maneuverable and specialized of vertebrate fliers, and two unusual neuromuscular features have been previously reported: (1) the pectoralis major has a unique distribution pattern of motor end plates (MEPs) compared with all other birds and (2) electromyograms (EMGs) from the hummingbird's pectoral muscles, the pectoralis major and the supracoracoideus, show activation bursts composed of one or a few spikes that appear to have a very consistent pattern. Here, we place these findings in a broader context by comparing the MEPs, EMGs, and organization of the spinal motor neuron pools of flight muscles of Anna's hummingbird Calypte anna, zebra finches Taeniopygia guttata, and, for MEPs, several other species. The previously shown MEP pattern of the hummingbird pectoralis major is not shared with its closest taxonomic relative, the swift, and appears to be unique to hummingbirds. MEP arrangements in previously undocumented wing muscles show patterns that differ somewhat from other avian muscles. In the parallel-fibered strap muscles of the shoulder, MEP patterns appear to relate to muscle length, with the smallest muscles having fibers that span the entire muscle. MEP patterns in pennate distal wing muscles were the same regardless of size, with tightly clustered bands in the middle portion of the muscle, not evenly distributed bands over the muscle's entire length. Muscle activations were examined during slow forward flight in both species, during hovering in hummingbirds, and during slow ascents in zebra finches. The EMG bursts of a wing muscle, the pronator superficialis, were highly variable in peak number, size, and distribution across wingbeats for both species. In the pectoralis major, although the individual EMG bursts were much shorter in duration in hummingbirds relative to zebra finches, the variables describing the normalized amplitude and area of the activation bursts were otherwise indistinguishable between taxa during these flight modes. However, the degree of variation in the time intervals between EMG peaks was much lower in hummingbirds, which is a plausible explanation for the "patterned" EMG signals reported previously.

Personal customizing exercise with a wearable measurement and control unit.

PubMed

Wang, Zhihui; Kiryu, Tohru; Tamura, Naoki

2005-06-28

Recently, wearable technology has been used in various health-related fields to develop advanced monitoring solutions. However, the monitoring function alone cannot meet all the requirements of customizing machine-based exercise on an individual basis by relying on biosignal-based controls. We propose a new wearable unit design equipped with measurement and control functions to support the customization process. The wearable unit can measure the heart rate and electromyogram signals during exercise performance and output workload control commands to the exercise machines. The workload is continuously tracked with exercise programs set according to personally customized workload patterns and estimation results from the measured biosignals by a fuzzy control method. Exercise programs are adapted by relying on a computer workstation, which communicates with the wearable unit via wireless connections. A prototype of the wearable unit was tested together with an Internet-based cycle ergometer system to demonstrate that it is possible to customize exercise on an individual basis. We tested the wearable unit in nine people to assess its suitability to control cycle ergometer exercise. The results confirmed that the unit could successfully control the ergometer workload and continuously support gradual changes in physical activities. The design of wearable units equipped with measurement and control functions is an important step towards establishing a convenient and continuously supported wellness environment.

Practice variation in the treatment of rheumatoid arthritis among German rheumatologists.

PubMed

Zink, A; Listing, J; Ziemer, S; Zeidler, H

2001-10-01

To describe practice variation in the treatment of rheumatoid arthritis (RA) among German rheumatologists with regard to drug and non-drug therapy. We used data of 7,326 patients with RA registered in a national German rheumatological database in 1998. In the database, every patient with an inflammatory rheumatic disease seen at one of the German Collaborative Arthritis Centres is registered once a year with a standard clinical data form and a patient questionnaire. We compared health care provided by 29 rheumatological outpatient units. For drug and non-drug treatment unit prescription rates, ranges and outliers were calculated. Logistic regression analysis was used for case mix adjustment and for the identification of practice patterns. We observed variation concerning the frequency of use of single disease modifying antirheumatic drugs (DMARD). The median of the prescription rates in the 29 units for methotrexate (MTX) was 55% in 1998 (1st quartile: 51%, 3rd quartile: 63%); sulfasalazine had a median of 15% (quartiles: 10%/19%), antimalarials a median of 8% (quartiles: 5%/21%). Combination DMARD therapy was used in 11% (quartiles: 6%/18%). Prescriptions of low dose steroids (< or = 7.5 mg) had a median of 45% (quartiles: 35%/55%), and nonsteroidal antiinflammatory drugs (NSAID) had a median prescription rate of 58% (quartiles: 50%/70%). High variation was also found concerning active physiotherapy (median: 41%; quartiles 34%/55%) and passive physical measures (median 14%, quartiles 9%/37%). Differences in case mix (age, sex, rheumatoid factor, disease duration, severity, disability) only explained a small proportion of the total variation. When the units were grouped according to the frequency of prescription of DMARD combination therapy, treatment patterns could be identified. Units with higher rates of DMARD combination therapy used more drugs for the prevention and treatment of osteoporosis, more active physiotherapy but fewer NSAID and fewer passive physical therapies. Variation in drug and non-drug treatment indicates significant differences in health care provision. Trends in the drug management of RA are adopted differentially by the members of the rheumatology community. The large variability in non-drug therapies may, apart from differences in availability, suggest a lack of agreement on therapeutic effectiveness.

Gravitational salt tectonics above a rising basement plateau offshore Algeria

NASA Astrophysics Data System (ADS)

Gaullier, Virginie; Vendeville, Bruno C.; Besème, Grégoire; Legoux, Gaetan; Déverchère, Jacques; Lymer, Gaël

2017-04-01

Seismic data (survey "MARADJA 1", 2003) offshore the Algerian coast have imaged an unexpected deformation pattern of the Messinian salt (Mobile Unit; MU) and its sedimentary overburden (Messinian Upper Unit and Plio-Quaternary) above an actively rising plateau in the subsalt basement. From a geodynamic point of view, the region is undergoing crustal convergence, as attested by the Boumerdes earthquake (2003, magnitude 6.8). The rise of this plateau, forming a 3D promontory restricted to the area offshore Algiers, is associated with that geodynamic setting. The seismic profiles show several subsalt thrusts (Domzig et al. 2006). The data provided additional information on the deformation of the Messinian mobile evaporitic unit and its Plio-Quaternary overburden. Margin-perpendicular profiles show mostly compressional features (anticlines and synclines) that had little activity during Messinian times, then grew more during Plio-Quaternary times. A few normal faults are also present, but are not accompanied by salt rise. By contrast, margin-parallel profiles clearly show that extensional, reactive salt diapiric ridges (symptomatic with their triangular shape in cross section) formed early, as early as the time of deposition of the Messinian Upper Unit, as recorded by fan-shaped strata. These ridges have recorded E-W, thin-skinned gravity gliding above the Messinian salt, as a response to the rise of the basement plateau. We tested this hypothesis using two analogue models, one where we assumed that the rise of the plateau started after Messinian times (initially tabular salt across the entire region), the second model assumed that the plateau had already risen partially as the Messininan Mobile Unit was deposited (salt initially thinner above the plateau than in the adjacent regions). In both experiments, the rise of the plateau generated preferential E-W extension above the salt, combined with N-S shortening. Extension was caused by gravity gliding of the salt from above the rising basement toward the deeper adjacent basins. So far, the deformation pattern of the salt and overburden on the plateau did not allow us to use it as a clear indicator of whether the plateau's rise started before or during Messinian times.

Observations and interpretation of fundamental mode Rayleigh wavefields recorded by the Transportable Array (USArray)

USGS Publications Warehouse

Pollitz, F.F.

2008-01-01

Broadband recordings of the dense Transportable Array (TA) in the western United States provide unparalleled detailed images of long-period seismic surface wavefields. With 400 stations spanning most of the western United States, wavefronts of fundamental mode Rayleigh waves may be visualized coherently across the array at periods ???40 s. In order to constrain the Rayleigh wave phase velocity structure in the western United States, I assemble a data set of vertical component seismograms from 53 teleseismic events recorded by the TA from April 2006 to October 2007. Complex amplitude spectra from these recordings at peni ods 27-100 s are interpreted using the multiplane wave tomographic method of Friederich and Wielandt (1995) and Pollitz (1999). This analysis yields detailed surface wave phase velocity and three-dimensional shear wave velocity patterns across the North American plate boundary zone, elucidating the active processes in the highly heterogeneous western U.S. upper mantle.

Anticoagulant and antithrombotic evaluation of native fucosylated chondroitin sulfates and their derivatives as selective inhibitors of intrinsic factor Xase.

PubMed

Wu, Mingyi; Wen, Dandan; Gao, Na; Xiao, Chuang; Yang, Lian; Xu, Li; Lian, Wu; Peng, Wenlie; Jiang, Jianmin; Zhao, Jinhua

2015-03-06

Fucosylated chondroitin sulfate (FCS), a structurally unusual glycosaminoglycan, has distinct anticoagulant properties, and is an especially strong inhibitor of the intrinsic factor Xase (anti-Xase). To obtain a highly selective inhibitor of human Xase, we purified six native FCSs with various sulfation patterns, prepared a series of FCS derivatives, and then elucidated the relationship between the structures and the anticoagulant activities of FCSs. FCSs 1-3 containing higher Fuc2S4S exhibit stronger AT-dependent anti-IIa activities, whereas 4-6 containing more Fuc3S4S produce potent HCII-dependent anti-IIa activities. Saccharides containing a minimum of 6-8 trisaccharide units, free carboxyl groups, and full fucosylation of GlcA may be required for potent anti-Xase activity, and approximately six trisaccharide units and partial fucosylation of GlcA may contribute to potent HCII-dependent activity. Decreasing of the molecular weights markedly reduces their AT-dependent anti-IIa activities, and even eliminates human platelet and factor XII activation. Furthermore, in vitro and in vivo studies suggested that fractions of 6-12 kDa may be very promising compounds as putative selective intrinsic Xase inhibitors with antithrombotic action, but without the consequences of major bleeding and factor XII activation. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Spacecraft Reed-Solomon downlink module

NASA Technical Reports Server (NTRS)

Luong, Huy H. (Inventor); Donaldson, James A. (Inventor); Wood, Steven H. (Inventor)

1998-01-01

Apparatus and method for providing downlink frames to be transmitted from a spacecraft to a ground station. Each downlink frame includes a synchronization pattern and a transfer frame. The apparatus may comprise a monolithic Reed-Solomon downlink (RSDL) encoding chip coupled to data buffers for storing transfer frames. The RSKL chip includes a timing device, a bus interface, a timing and control unit, a synchronization pattern unit, and a Reed-Solomon encoding unit, and a bus arbiter.

Spatial patterns of ecosystem carbon residence time and NPP-driven carbon uptake in the conterminous United States

NASA Astrophysics Data System (ADS)

Zhou, Tao; Luo, Yiqi

2008-09-01

Ecosystem carbon (C) uptake is determined largely by C residence times and increases in net primary production (NPP). Therefore, evaluation of C uptake at a regional scale requires knowledge on spatial patterns of both residence times and NPP increases. In this study, we first applied an inverse modeling method to estimate spatial patterns of C residence times in the conterminous United States. Then we combined the spatial patterns of estimated residence times with a NPP change trend to assess the spatial patterns of regional C uptake in the United States. The inverse analysis was done by using the genetic algorithm and was based on 12 observed data sets of C pools and fluxes. Residence times were estimated by minimizing the total deviation between modeled and observed values. Our results showed that the estimated C residence times were highly heterogeneous over the conterminous United States, with most of the regions having values between 15 and 65 years; and the averaged C residence time was 46 years. The estimated C uptake for the whole conterminous United States was 0.15 P g C a-1. Large portions of the taken C were stored in soil for grassland and cropland (47-70%) but in plant pools for forests and woodlands (73-82%). The proportion of C uptake in soil was found to be determined primarily by C residence times and be independent of the magnitude of NPP increase. Therefore, accurate estimation of spatial patterns of C residence times is crucial for the evaluation of terrestrial ecosystem C uptake.

Methylation Pattern of Radish (Raphanus sativus) Nuclear Ribosomal RNA Genes 1

PubMed Central

Delseny, Michel; Laroche, Monique; Penon, Paul

1984-01-01

The methylation pattern of radish Raphanus sativus nuclear rDNA has been investigated using the Hpa II, Msp I, and Hha I restriction enzymes. The presence of numerous target sites for these enzymes has been shown using cloned rDNA fragments. A large fraction of the numerous rDNA units are heavily methylated, being completely resistant to Hpa II and Hpa I. However, specific sites are constantly available in another fraction of the units and are therefore unmethylated. The use of different probes allowed us to demonstrate that hypomethylated sites are present in different regions. Major hypomethylated Hha I sites have been mapped in the 5′ portion of 25S rRNA coding sequence. Among the hypomethylated fraction, different methylation patterns coexist. It has been possible to demonstrate that methylation patterns are specific for particular units. The Hha I pattern of rDNA in tissues of different developmental stages was analyzed. Evidence for possible tissue specific differences in the methylation pattern is reported. Images Fig. 2 Fig. 3 Fig. 5 PMID:16663896

Computer Vision for Artificially Intelligent Robotic Systems

NASA Astrophysics Data System (ADS)

Ma, Chialo; Ma, Yung-Lung

1987-04-01

In this paper An Acoustic Imaging Recognition System (AIRS) will be introduced which is installed on an Intelligent Robotic System and can recognize different type of Hand tools' by Dynamic pattern recognition. The dynamic pattern recognition is approached by look up table method in this case, the method can save a lot of calculation time and it is practicable. The Acoustic Imaging Recognition System (AIRS) is consist of four parts -- position control unit, pulse-echo signal processing unit, pattern recognition unit and main control unit. The position control of AIRS can rotate an angle of ±5 degree Horizental and Vertical seperately, the purpose of rotation is to find the maximum reflection intensity area, from the distance, angles and intensity of the target we can decide the characteristic of this target, of course all the decision is target, of course all the decision is processed bye the main control unit. In Pulse-Echo Signal Process Unit, we ultilize the correlation method, to overcome the limitation of short burst of ultrasonic, because the Correlation system can transmit large time bandwidth signals and obtain their resolution and increased intensity through pulse compression in the correlation receiver. The output of correlator is sampled and transfer into digital data by u law coding method, and this data together with delay time T, angle information OH, eV will be sent into main control unit for further analysis. The recognition process in this paper, we use dynamic look up table method, in this method at first we shall set up serval recognition pattern table and then the new pattern scanned by Transducer array will be devided into serval stages and compare with the sampling table. The comparison is implemented by dynamic programing and Markovian process. All the hardware control signals, such as optimum delay time for correlator receiver, horizental and vertical rotation angle for transducer plate, are controlled by the Main Control Unit, the Main Control Unit also handles the pattern recognition process. The distance from the target to the transducer plate is limitted by the power and beam angle of transducer elements, in this AIRS Model, we use a narrow beam transducer and it's input voltage is 50V p-p. A RobOt equipped with AIRS can not only measure the distance from the target but also recognize a three dimensional image of target from the image lab of Robot memory. Indexitems, Accoustic System, Supersonic transducer, Dynamic programming, Look-up-table, Image process, pattern Recognition, Quad Tree, Quadappoach.

Improved Performance Characteristics For Indium Antimonide Photovoltaic Detector Arrays Using A FET-Switched Multiplexing Technique

NASA Astrophysics Data System (ADS)

Ma, Yung-Lung; Ma, Chialo

1987-03-01

In this paper An Acoustic Imaging Recognition System (AIRS) will be introduced which is installed on an Intelligent Robotic System and can recognize different type of Hand tools' by Dynamic pattern recognition. The dynamic pattern recognition is approached by look up table method in this case, the method can save a lot of calculation time and it is practicable. The Acoustic Imaging Recognition System (AIRS) is consist of four parts _ position control unit, pulse-echo signal processing unit, pattern recognition unit and main control unit. The position control of AIRS can rotate an angle of ±5 degree Horizental and Vertical seperately, the purpose of rotation is to find the maximum reflection intensity area, from the distance, angles and intensity of the target we can decide the characteristic of this target, of course all the decision is target, of course all the decision is processed by the main control unit. In Pulse-Echo Signal Process Unit, we utilize the correlation method, to overcome the limitation of short burst of ultrasonic, because the Correlation system can transmit large time bandwidth signals and obtain their resolution and increased intensity through pulse compression in the correlation receiver. The output of correlator is sampled and transfer into digital data by p law coding method, and this data together with delay time T, angle information eH, eV will be sent into main control unit for further analysis. The recognition process in this paper, we use dynamic look up table method, in this method at first we shall set up serval recognition pattern table and then the new pattern scanned by Transducer array will be devided into serval stages and compare with the sampling table. The comparison is implemented by dynamic programing and Markovian process. All the hardware control signals, such as optimum delay time for correlator receiver, horizental and vertical rotation angle for transducer plate, are controlled by the Main Control Unit, the Main Control Unit also handles the pattern recognition process. The distance from the target to the transducer plate is limitted by the power and beam angle of transducer elements, in this AIRS Models, we use a narrow beam transducer and it's input voltage is 50V p-p. A Robot equipped with AIRS can not only measure the distance from the target but also recognize a three dimensional image of target from the image lab of Robot memory. Indexitems, Accoustic System, Supersonic transducer, Dynamic programming, Look-up-table, Image process, pattern Recognition, Quad Tree, Quadappoach.

Regional Patterns of Communication in the United States: A Theoretical Perspective.

ERIC Educational Resources Information Center

Andersen, Peter A.; And Others

1987-01-01

Provides the rationale for a systematic study of regional patterns of communication in the United States. Conceptualizes regionalism, appraises regional influences on communication, and establishes their significance. Describes regional development of the U.S. and proposes a program of regional research on U.S. communication. Examines deficiencies…

Orienteering: Growth Patterns in the United States.

ERIC Educational Resources Information Center

Jeffery, Charles F.

The history of orienteering in the United States includes both military and civilian interest, with the period of greatest growth between 1970 and 1980. To investigate growth patterns in orienteering, questionnaires were mailed to 42 civilian orienteering clubs and 286 universities supporting senior Reserve Office Training Corps (ROTC)…

Profiles of Acculturative Adjustment Patterns among Chinese International Students

ERIC Educational Resources Information Center

Wang, Kenneth T.; Heppner, Puncky Paul; Fu, Chu-Chun; Zhao, Ran; Li, Feihan; Chuang, Chih-Chun

2012-01-01

This is the first study to empirically identify distinct acculturative adjustment patterns of new international students over their first 3 semesters in the United States. The sample consisted of 507 Chinese international students studying in the United States. Using psychological distress as an indicator of acculturative adjustment, measured over…

Geographic patterns of industry in the United States. An aid to the study of occupational disease.

PubMed

Stone, B J; Blot, W J; Fraumeni, J F

1978-07-01

The geographic location of 18 major manufacturing industries within the United States is illustrated by a series of computer-generated county maps. The metal and machinery industries, the two largest employers, an the transportation and rubber industries are concentrated in the northeastern quadrant of the United States, while most counties with textile, apparel, tobacco, and furniture manufacturing are in the South. Other industries had different patterns. The counties where industry was concentrated tended to be more urban and to have higher levels of income and education. The maps and associated demographic data on industrial counties may prove a useful adjunct to county maps illustrating mortality patterns for cancer and other diseases. Despite obvious limitations, the visual patterns and correlation analyses may help to generate and formulate hypothese concerning occupationally induced diease.

Muscle activity pattern dependent pain development and alleviation.

PubMed

Sjøgaard, Gisela; Søgaard, Karen

2014-12-01

Muscle activity is for decades considered to provide health benefits irrespectively of the muscle activity pattern performed and whether it is during e.g. sports, transportation, or occupational work tasks. Accordingly, the international recommendations for public health-promoting physical activity do not distinguish between occupational and leisure time physical activity. However, in this body of literature, attention has not been paid to the extensive documentation on occupational physical activity imposing a risk of impairment of health - in particular musculoskeletal health in terms of muscle pain. Focusing on muscle activity patterns and musculoskeletal health it is pertinent to elucidate the more specific aspects regarding exposure profiles and body regional pain. Static sustained muscle contraction for prolonged periods often occurs in the neck/shoulder area during occupational tasks and may underlie muscle pain development in spite of rather low relative muscle load. Causal mechanisms include a stereotype recruitment of low threshold motor units (activating type 1 muscle fibers) characterized by a lack of temporal as well as spatial variation in recruitment. In contrast during physical activities at leisure and sport the motor recruitment patterns are more dynamic including regularly relatively high muscle forces - also activating type 2 muscles fibers - as well as periods of full relaxation even of the type 1 muscle fibers. Such activity is unrelated to muscle pain development if adequate recovery is granted. However, delayed muscle soreness may develop following intensive eccentric muscle activity (e.g. down-hill skiing) with peak pain levels in thigh muscles 1-2 days after the exercise bout and a total recovery within 1 week. This acute pain profile is in contrast to the chronic muscle pain profile related to repetitive monotonous work tasks. The painful muscles show adverse functional, morphological, hormonal, as well as metabolic characteristics. Of note is that intensive muscle strength training actually may rehabilitate painful muscles, which has recently been repeatedly proven in randomized controlled trials. With training the maximal muscle activation and strength can be shown to recover, and consequently allow for decreased relative muscle load during occupational repetitive work tasks. Exercise training induces adaptation of metabolic and stress-related mRNA and protein responses in the painful muscles, which is in contrast to the responses evoked during repetitive work tasks per se. Copyright © 2014 Elsevier Ltd. All rights reserved.

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

PubMed Central

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

2015-01-01

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

Virus diseases of the salmonidae in the western United States. III. Immunopathological aspects

USGS Publications Warehouse

Klontz, George W.; Yasutake, William T.; Parisot, T.J.

1965-01-01

The immune response among fish, from a phylogenetic standpoint, presents a progressive pattern of increasing development. The cyclostomes have been shown to have only feeble immunologic responsiveness. One of their number, the hagfish, appeared to be totally lacking in the ability to actively acquire antibodies.Among the elasmobranchs, the sharks have received the most study immunologically. This group demonstrated a variable response to antigenic stimulationOf the teleosts, the salmonids and the cyprinids have been the more frequent recipients of experimentally introduced antigens. These fishes, as well as other species of teleosts, are quite active and quite consistent in their response to various antigens.

Fragmented patterns of flood change across the United States

PubMed Central

Hirsch, R. M.; Viglione, A.; Blöschl, G.

2016-01-01

Abstract Trends in the peak magnitude, frequency, duration, and volume of frequent floods (floods occurring at an average of two events per year relative to a base period) across the United States show large changes; however, few trends are found to be statistically significant. The multidimensional behavior of flood change across the United States can be described by four distinct groups, with streamgages experiencing (1) minimal change, (2) increasing frequency, (3) decreasing frequency, or (4) increases in all flood properties. Yet group membership shows only weak geographic cohesion. Lack of geographic cohesion is further demonstrated by weak correlations between the temporal patterns of flood change and large‐scale climate indices. These findings reveal a complex, fragmented pattern of flood change that, therefore, clouds the ability to make meaningful generalizations about flood change across the United States. PMID:27917010

Fragmented patterns of flood change across the United States

USGS Publications Warehouse

Archfield, Stacey A.; Hirsch, Robert M.; Viglione, A.; Blöschl, G.

2016-01-01

Trends in the peak magnitude, frequency, duration, and volume of frequent floods (floods occurring at an average of two events per year relative to a base period) across the United States show large changes; however, few trends are found to be statistically significant. The multidimensional behavior of flood change across the United States can be described by four distinct groups, with streamgages experiencing (1) minimal change, (2) increasing frequency, (3) decreasing frequency, or (4) increases in all flood properties. Yet group membership shows only weak geographic cohesion. Lack of geographic cohesion is further demonstrated by weak correlations between the temporal patterns of flood change and large-scale climate indices. These findings reveal a complex, fragmented pattern of flood change that, therefore, clouds the ability to make meaningful generalizations about flood change across the United States.

Spatio-Temporal Characteristics of Resident Trip Based on Poi and OD Data of Float CAR in Beijing

NASA Astrophysics Data System (ADS)

Mou, N.; Li, J.; Zhang, L.; Liu, W.; Xu, Y.

2017-09-01

Due to the influence of the urban inherent regional functional distribution, the daily activities of the residents presented some spatio-temporal patterns (periodic patterns, gathering patterns, etc.). In order to further understand the spatial and temporal characteristics of urban residents, this paper research takes the taxi trajectory data of Beijing as a sample data and studies the spatio-temporal characteristics of the residents' activities on the weekdays. At first, according to the characteristics of the taxi trajectory data distributed along the road network, it takes the Voronoi generated by the road nodes as the research unit. This paper proposes a hybrid clustering method - based on grid density, which is used to cluster the OD (origin and destination) data of taxi at different times. Then combining with the POI data of Beijing, this research calculated the density of the POI data in the clustering results, and analyzed the relationship between the activities of residents in different periods and the functional types of the region. The final results showed that the residents were mainly commuting on weekdays. And it found that the distribution of travel density showed a concentric circle of the characteristics, focusing on residential areas and work areas. The results of cluster analysis and POI analysis showed that the residents' travel had experienced the process of "spatial relative dispersion - spatial aggregation - spatial relative dispersion" in one day.

Decoding visual object categories from temporal correlations of ECoG signals.

PubMed

Majima, Kei; Matsuo, Takeshi; Kawasaki, Keisuke; Kawai, Kensuke; Saito, Nobuhito; Hasegawa, Isao; Kamitani, Yukiyasu

2014-04-15

How visual object categories are represented in the brain is one of the key questions in neuroscience. Studies on low-level visual features have shown that relative timings or phases of neural activity between multiple brain locations encode information. However, whether such temporal patterns of neural activity are used in the representation of visual objects is unknown. Here, we examined whether and how visual object categories could be predicted (or decoded) from temporal patterns of electrocorticographic (ECoG) signals from the temporal cortex in five patients with epilepsy. We used temporal correlations between electrodes as input features, and compared the decoding performance with features defined by spectral power and phase from individual electrodes. While using power or phase alone, the decoding accuracy was significantly better than chance, correlations alone or those combined with power outperformed other features. Decoding performance with correlations was degraded by shuffling the order of trials of the same category in each electrode, indicating that the relative time series between electrodes in each trial is critical. Analysis using a sliding time window revealed that decoding performance with correlations began to rise earlier than that with power. This earlier increase in performance was replicated by a model using phase differences to encode categories. These results suggest that activity patterns arising from interactions between multiple neuronal units carry additional information on visual object categories. Copyright © 2013 Elsevier Inc. All rights reserved.

No Evidence of Reciprocal Associations between Daily Sleep and Physical Activity.

PubMed

Mitchell, Jonathan A; Godbole, Suneeta; Moran, Kevin; Murray, Kate; James, Peter; Laden, Francine; Hipp, J Aaron; Kerr, Jacqueline; Glanz, Karen

2016-10-01

This study aimed to determine whether physical activity patterns are associated with sleep later at night and if nighttime sleep is associated with physical activity patterns the next day among adult women. Women (N = 353) living throughout the United States wore a wrist and a hip accelerometer for 7 d. Total sleep time (TST, hours per night) and sleep efficiency (SE, %) were estimated from the wrist accelerometer, and moderate to vigorous physical activity (MVPA, >1040 counts per minute, h·d) and sedentary behavior (SB, <100 counts per minute, h·d) were estimated from the hip accelerometer. Mixed-effects models adjusted for age, race, body mass index, education, employment, marital status, health status, and hip accelerometer wear time were used to analyze the data. Follow-up analyses using quantile regression were used to investigate associations among women with below average TST and MVPA and above average SB. The average age of our sample was 55.5 yr (SD = 10.2 yr). The majority of participants were White (79%) and married (72%), and half were employed full time (49%). The participants spent on average 8.9 and 1.1 h·d in SB and MVPA, respectively, and 6.8 h per night asleep. No associations were observed between MVPA and SB with nighttime TST or SE. There were no associations between nighttime TST and SE with MVPA or SB the next day. The findings were the same in the quantile regression analyses. In free-living adult women, accelerometry-estimated nighttime sleep and physical activity patterns were not associated with one another. On the basis of our observational study involving a sample of adult women, higher physical activity will not necessarily improve sleep at night on a day-to-day basis (and vice versa).

Feasibility of Obtaining Measures of Lifestyle From a Smartphone App: The MyHeart Counts Cardiovascular Health Study.

PubMed

McConnell, Michael V; Shcherbina, Anna; Pavlovic, Aleksandra; Homburger, Julian R; Goldfeder, Rachel L; Waggot, Daryl; Cho, Mildred K; Rosenberger, Mary E; Haskell, William L; Myers, Jonathan; Champagne, Mary Ann; Mignot, Emmanuel; Landray, Martin; Tarassenko, Lionel; Harrington, Robert A; Yeung, Alan C; Ashley, Euan A

2017-01-01

Studies have established the importance of physical activity and fitness, yet limited data exist on the associations between objective, real-world physical activity patterns, fitness, sleep, and cardiovascular health. To assess the feasibility of obtaining measures of physical activity, fitness, and sleep from smartphones and to gain insights into activity patterns associated with life satisfaction and self-reported disease. The MyHeart Counts smartphone app was made available in March 2015, and prospective participants downloaded the free app between March and October 2015. In this smartphone-based study of cardiovascular health, participants recorded physical activity, filled out health questionnaires, and completed a 6-minute walk test. The app was available to download within the United States. The feasibility of consent and data collection entirely on a smartphone, the use of machine learning to cluster participants, and the associations between activity patterns, life satisfaction, and self-reported disease. From the launch to the time of the data freeze for this study (March to October 2015), the number of individuals (self-selected) who consented to participate was 48 968, representing all 50 states and the District of Columbia. Their median age was 36 years (interquartile range, 27-50 years), and 82.2% (30 338 male, 6556 female, 10 other, and 3115 unknown) were male. In total, 40 017 (81.7% of those who consented) uploaded data. Among those who consented, 20 345 individuals (41.5%) completed 4 of the 7 days of motion data collection, and 4552 individuals (9.3%) completed all 7 days. Among those who consented, 40 017 (81.7%) filled out some portion of the questionnaires, and 4990 (10.2%) completed the 6-minute walk test, made available only at the end of 7 days. The Heart Age Questionnaire, also available after 7 days, required entering lipid values and age 40 to 79 years (among 17 245 individuals, 43.1% of participants). Consequently, 1334 (2.7%) of those who consented completed all fields needed to compute heart age and a 10-year risk score. Physical activity was detected for a mean (SD) of 14.5% (8.0%) of individuals' total recorded time. Physical activity patterns were identified by cluster analysis. A pattern of lower overall activity but more frequent transitions between active and inactive states was associated with equivalent self-reported cardiovascular disease as a pattern of higher overall activity with fewer transitions. Individuals' perception of their activity and risk bore little relation to sensor-estimated activity or calculated cardiovascular risk. A smartphone-based study of cardiovascular health is feasible, and improvements in participant diversity and engagement will maximize yield from consented participants. Large-scale, real-world assessment of physical activity, fitness, and sleep using mobile devices may be a useful addition to future population health studies.

Effect of oxygen minimum zone formation on communities of marine protists

PubMed Central

Orsi, William; Song, Young C; Hallam, Steven; Edgcomb, Virginia

2012-01-01

Changes in ocean temperature and circulation patterns compounded by human activities are leading to oxygen minimum zone (OMZ) expansion with concomitant alteration in nutrient and climate active trace gas cycling. Here, we report the response of microbial eukaryote populations to seasonal changes in water column oxygen-deficiency using Saanich Inlet, a seasonally anoxic fjord on the coast of Vancouver Island British Columbia, as a model ecosystem. We combine small subunit ribosomal RNA gene sequencing approaches with multivariate statistical methods to reveal shifts in operational taxonomic units during successive stages of seasonal stratification and renewal. A meta-analysis is used to identify common and unique patterns of community composition between Saanich Inlet and the anoxic/sulfidic Cariaco Basin (Venezuela) and Framvaren Fjord (Norway) to show shared and unique responses of microbial eukaryotes to oxygen and sulfide in these three environments. Our analyses also reveal temporal fluctuations in rare populations of microbial eukaryotes, particularly anaerobic ciliates, that may be of significant importance to the biogeochemical cycling of methane in OMZs. PMID:22402396

Alpine ski and snowboarding traumatic injuries: incidence, injury patterns, and risk factors for 10 years.

PubMed

McBeth, Paul B; Ball, Chad G; Mulloy, Robert H; Kirkpatrick, Andrew W

2009-05-01

Alpine skiing and snowboarding are popular winter sports in Canada. Every year participation in these activities results in traumatic injury. The purpose of this study was to identify the incidence and injury patterns, as well as risk factors associated with ski and snowboarding injuries. A comprehensive 10-year retrospective review of Alpine ski and snowboarding injuries from 1996 to 2006 was conducted. The Alberta Trauma Registry was used as the primary source of data. A total of 196 patients (56.6% skiers, 43.4% snowboarders) were identified as having major traumatic injuries (Injury Severity Score, >or=12). Forty-three patients required intensive care unit support. The majority of injuries were related to falls and collisions with natural objects. Head injuries were most common, followed by chest, spinal, and extremity trauma. Seventy-nine patients required emergency surgery. Skiing and snowboarding represent activities with high potential for traumatic injury. Safety initiatives should be developed to target this population.

Tests of Si(111)-7 × 7 structural models by comparison with transmission electron diffraction patterns

NASA Astrophysics Data System (ADS)

McRae, E. G.; Petroff, P. M.

1984-11-01

Several structural models of the Si(111)-7 × 7 surface are tested by comparing calculated and observed transmission electron diffraction (TED) patterns. The models comprise "adatom" models where the unit mesh contains 12 adatoms or atom clusters in a locally (2 × 2) arrangement, and "triangle-dimer" models where the unit mesh contains 9 dimers or pairs of dimers bordering a triangular subunit of the unit mesh. The distribution of diffraction intensity among fractional-order spots is calculated kinematically and compared with TED patterns observed by Petroff and Wilson and others. No agreement is found for adatom models. Good but not perfect agreement is found for one triangle-dimer model.

Structure and anticoagulant activity of a sulfated galactan from the red alga, Gelidium crinale. Is there a specific structural requirement for the anticoagulant action?

PubMed

Pereira, Maria G; Benevides, Norma M B; Melo, Marcia R S; Valente, Ana Paula; Melo, Fábio R; Mourão, Paulo A S

2005-09-05

Marine red algae are an abundant source of sulfated galactans with potent anticoagulant activity. However, the specific structural motifs that confer biological activity remain to be elucidated. We have now isolated and purified a sulfated galactan from the marine red alga, Gellidium crinale. The structure of this polysaccharide was determined using NMR spectroscopy. It is composed of the repeating structure -4-alpha-Galp-(1-->3)-beta-Galp1--> but with a variable sulfation pattern. Clearly 15% of the total alpha-units are 2,3-di-sulfated and another 55% are 2-sulfated. No evidence for the occurrence of 3,6-anhydro alpha-galactose units was observed in the NMR spectra. We also compared the anticoagulant activity of this sulfated galactan with a polysaccharide from the species, Botryocladia occidentalis, with a similar saccharide chain but with higher amounts of 2,3-di-sulfated alpha-units. The sulfated galactan from G. crinale has a lower anticoagulant activity on a clotting assay when compared with the polysaccharide from B. occidentalis. When tested in assays using specific proteases and coagulation inhibitors, these two galactans showed significant differences in their activity. They do not differ in thrombin inhibition mediated by antithrombin, but in assays where heparin cofactor II replaces antithrombin, the sulfated galactan from G. crinale requires a significantly higher concentration to achieve the same inhibitory effect as the polysaccharide from B. occidentalis. In contrast, when factor Xa instead of thrombin is used as the target protease, the sulfated galactan from G. crinale is a more potent anticoagulant. These observations suggest that the proportion and/or the distribution of 2,3-di-sulfated alpha-units along the galactan chain may be a critical structural motif to promote the interaction of the protease with specific protease and coagulation inhibitors.

Depressed Frank-Starling mechanism in the left ventricular muscle of the knock-in mouse model of dilated cardiomyopathy with troponin T deletion mutation ΔK210.

PubMed

Inoue, Takahiro; Kobirumaki-Shimozawa, Fuyu; Kagemoto, Tatsuya; Fujii, Teruyuki; Terui, Takako; Kusakari, Yoichiro; Hongo, Kenichi; Morimoto, Sachio; Ohtsuki, Iwao; Hashimoto, Kazuhiro; Fukuda, Norio

2013-10-01

It has been reported that the Frank-Starling mechanism is coordinately regulated in cardiac muscle via thin filament "on-off" equilibrium and titin-based lattice spacing changes. In the present study, we tested the hypothesis that the deletion mutation ΔK210 in the cardiac troponin T gene shifts the equilibrium toward the "off" state and accordingly attenuate the sarcomere length (SL) dependence of active force production, via reduced cross-bridge formation. Confocal imaging in isolated hearts revealed that the cardiomyocytes were enlarged, especially in the longitudinal direction, in ΔK210 hearts, with striation patterns similar to those in wild type (WT) hearts, suggesting that the number of sarcomeres is increased in cardiomyocytes but the sarcomere length remains unaltered. For analysis of the SL dependence of active force, skinned muscle preparations were obtained from the left ventricle of WT and knock-in (ΔK210) mice. An increase in SL from 1.90 to 2.20μm shifted the mid-point (pCa50) of the force-pCa curve leftward by ~0.21pCa units in WT preparations. In ΔK210 muscles, Ca(2+) sensitivity was lower by ~0.37pCa units, and the SL-dependent shift of pCa50, i.e., ΔpCa50, was less pronounced (~0.11pCa units), with and without protein kinase A treatment. The rate of active force redevelopment was lower in ΔK210 preparations than in WT preparations, showing blunted thin filament cooperative activation. An increase in thin filament cooperative activation upon an increase in the fraction of strongly bound cross-bridges by MgADP increased ΔpCa50 to ~0.21pCa units. The depressed Frank-Starling mechanism in ΔK210 hearts is the result of a reduction in thin filament cooperative activation. © 2013.

Is Spending More Time Associated With Less Missed Care?: A Comparison of Time Use and Missed Care Across 15 Nursing Units at 2 Hospitals.

PubMed

McNair, Norma; Baird, Jennifer; Grogan, Tristan R; Walsh, Catherine M; Liang, Li-Jung; Worobel-Luk, Pamela; Needleman, Jack; Nuckols, Teryl K

2016-09-01

The aim of this study is to examine the relationship between nursing time use and perceptions of missed care. Recent literature has highlighted the problem of missed nursing care, but little is known about how nurses' time use patterns are associated with reports of missed care. In 15 nursing units at 2 hospitals, we assessed registered nurse (RN) perceptions of missed care, observed time use by RNs, and examined the relationship between time spent and degree of missed care at the nursing unit level. Patterns of time use were similar across hospitals, with 25% of time spent on documentation. For 6 different categories of nursing tasks, no association was detected between time use, including time spent on documentation, and the degree of missed care at the nursing unit level. Nursing time use cannot fully explain variation in missed care across nursing units. Further work is needed to account for patterns of missed care.

Tracing retail cannabis in the United States: geographic origin and cultivation patterns.

PubMed

Hurley, Janet M; West, Jason B; Ehleringer, James R

2010-05-01

Although cannabis is the most readily available and widely used illicit drug in the United States, there remains significant uncertainty about the importance of different production regions and trafficking patterns. We analysed 628 "retail" cannabis seizures from over 50 municipalities across the United States for hydrogen and carbon isotope ratios to predict their growth locations and environments. Results are presented for 22 consolidated retail locations across the United States. Evaluation of specimens from within these retail areas suggested that cannabis seizures had region-dependent origins, often from both domestic and foreign sources, and although indoor growth was common in many areas, there was also regional dependence in the proportions cultivated under indoor versus outdoor conditions. Street-available cannabis exhibits region-specific trafficking patterns, both Mexican- and Canadian-grown cannabis are apparently widely available, and indoor-grown cannabis appears to be cultivated and trafficked in both warm and cool weather localities throughout the United States. Copyright 2009 Elsevier B.V. All rights reserved.

Tectolinear interpretation of a 1:5,000,000 Landsat-1 mosaic compared with the structure of central and eastern United States

USGS Publications Warehouse

Kutina, Jan; Carter, William D.

1978-01-01

The pattern of lineaments and curvilinear features interpreted from a 1:5,000,000 mosaic of satellite images (Landsat-1 was superimposed on a simplified version of the Geological Map of the United States, 1:2,500,000 scale, showing the structural scheme of Central and Eastern United States. A comparison of the above two patterns, shown in Fig. 1, is presented in this paper.

The teacher's role in the establishment of whole-class dialogue in a fifth grade science classroom using argument-based inquiry

NASA Astrophysics Data System (ADS)

Benus, Matthew J.

The purpose of this study was to examine the patterns of dialogue that were established and emerged in one experienced fifth-grade science teacher's classroom that used the argument-based inquiry (ABI) and the ways in which these patterns of dialogue and consensus-making were used toward the establishment of a grasp of science practice. Most current studies on ABI agree that it does not come naturally and is only acquired through practice. Additionally, the quality of dialogue is also understood to be an important link in support of student learning. Few studies have examined the ways in which a teacher develops whole-class dialogue over time and the ways in which patterns of dialogue shift over time. The research questions that guided this study were: (1) What were the initial whole-class dialogue patterns established by a fifth-grade science teacher who engaged in ABI? (2) How did the science teacher help to refine whole-class dialogue to support the agreeability of ideas constructed over time? This eighteen week study that took place in a small city of less than 15,000 in Midwestern United States was grounded in interactive constructivism, and utilized a qualitative design method to identify the ways in which an experienced fifth-grade science teacher developed whole-class dialogue and used consensus-making activities to develop the practice of ABI with his students. The teacher in this study used the Science Writing Heuristic (SWH) approach to ABI with twenty-one students who had no previous experience engaging in ABI. This teacher with 10 of years teaching experience was purposefully selected because he was proficient and experienced in practicing ABI. Multiple sources of data were collected, including classroom video with transcriptions, semi-structured interviews, after lesson conversations, and researcher's field notes. Data analysis used a basic qualitative approach. The results showed (1) that the teacher principally engaged in three forms of whole-class dialogue with students; talking to, talking with, and thinking through ideas with students. As time went on, the teacher's interactions in whole-class dialogue became increasingly focused on thinking through ideas with students, while at the same time students also dialogued more as each unit progressed. (2) This teacher persistently engaged with students in consensus-making activities during whole-class dialogue.These efforts toward consensus-making over time became part of the students' own as each unit progressed. (3) The classroom did not engage in critique and construction of knowledge necessarily like the community of science but rather used agreeing and disagreeing and explaining why through purposeful dialogic interactions to construct a grasp of science classroom practice. The findings have informed theory and practice about science argumentation, the practice of whole-class dialogue, and grasp of science practice along four aspects: (1) patterns of dialogue within a unit of instruction and across units of instruction, (2) the teacher's ability to follow and develop students' ideas, (3) the role of early and persistent opportunities to engage novice students in consensus-making, and (4) the meaning of grasp of science practice in classroom. This study provides insight into the importance of prolonged and persistent engagement with ABI in classroom practice.

Parental Involvement in a School-Based Child Physical Activity and Nutrition Program in Southeastern United States: A Qualitative Analysis of Parenting Capacities.

PubMed

Ickes, Scott; Mahoney, Emily; Roberts, Alison; Dolan, Carrie

2016-03-01

Parent involvement varies widely in school-based programs designed to promote physical activity and healthy nutrition, yet the underlying factors that may limit parent's participation and support of learned behaviors at home are not well understood. We conducted a qualitative study that consisted of one focus group (n = 5) and 52 in-depth interviews among parents whose children participated in a school-based physical activity and nutrition (PAN) promotion program in Williamsburg, Virginia, United States. We sought to identify factors that enabled or constrained parent's support of and involvement in children's programs and to understand the underlying factors that contribute to family success in making dietary and physical activity changes at home. Parents identified their physical and mental health, self-confidence, time, and decision making as underlying "capacities" in the family health pattern. When strengthened, these capacities encourage healthful family behavior and support of school-based PAN programs. Families that succeeded in adopting lessons learned from school-based PAN programs identified four primary strategies for success: shared goals, meal planning, modeling of good behaviors, and collective activities. Interventions that aim to improve child nutrition and physical activity and the broader family health environment should consider underlying capacities of parents and the importance of joint goals and activities. © 2016 Society for Public Health Education.

Is atmospheric phosphorus pollution altering global alpine Lake stoichiometry?

NASA Astrophysics Data System (ADS)

Brahney, Janice; Mahowald, Natalie; Ward, Daniel S.; Ballantyne, Ashley P.; Neff, Jason C.

2015-09-01

Anthropogenic activities have significantly altered atmospheric chemistry and changed the global mobility of key macronutrients. Here we show that contemporary global patterns in nitrogen (N) and phosphorus (P) emissions drive large hemispheric variation in precipitation chemistry. These global patterns of nutrient emission and deposition (N:P) are in turn closely reflected in the water chemistry of naturally oligotrophic lakes (r2 = 0.81, p < 0.0001). Observed increases in anthropogenic N deposition play a role in nutrient concentrations (r2 = 0.20, p < 0.05) however, atmospheric deposition of P appears to be major contributor to this pattern (r2 = 0.65, p < 0.0001). Atmospheric simulations indicate a global increase in P deposition by 1.4 times the preindustrial rate largely due to increased dust and biomass burning emissions. Although changes in the mass flux of global P deposition are smaller than for N, the impacts on primary productivity may be greater because, on average, one unit of increased P deposition has 16 times the influence of one unit of N deposition. These stoichiometric considerations, combined with the evidence presented here, suggest that increases in P deposition may be a major driver of alpine Lake trophic status, particularly in the Southern Hemisphere. These results underscore the need for the broader scientific community to consider the impact of atmospheric phosphorus deposition on the water quality of naturally oligotrophic lakes.

Stripe rust epidemiological regions, virulence dynamics, pathogen reproduction modes, yield losses, forecasting models, and management in the United States

USDA-ARS?s Scientific Manuscript database

Stripe rust of wheat, caused by Puccinia striiformis f. sp. tritici (Pst), is one of the most important diseases in the United States. Epidemiological regions were determined based on epidemic patterns, cropping systems, geographic barriers, weather patterns, and inoculum exchanges. Areas where Ps...

Asymmetric top-down modulation of ascending visual pathways in pigeons.

PubMed

Freund, Nadja; Valencia-Alfonso, Carlos E; Kirsch, Janina; Brodmann, Katja; Manns, Martina; Güntürkün, Onur

2016-03-01

Cerebral asymmetries are a ubiquitous phenomenon evident in many species, incl. humans, and they display some similarities in their organization across vertebrates. In many species the left hemisphere is associated with the ability to categorize objects based on abstract or experience-based behaviors. Using the asymmetrically organized visual system of pigeons as an animal model, we show that descending forebrain pathways asymmetrically modulate visually evoked responses of single thalamic units. Activity patterns of neurons within the nucleus rotundus, the largest thalamic visual relay structure in birds, were differently modulated by left and right hemispheric descending systems. Thus, visual information ascending towards the left hemisphere was modulated by forebrain top-down systems at thalamic level, while right thalamic units were strikingly less modulated. This asymmetry of top-down control could promote experience-based processes within the left hemisphere, while biasing the right side towards stimulus-bound response patterns. In a subsequent behavioral task we tested the possible functional impact of this asymmetry. Under monocular conditions, pigeons learned to discriminate color pairs, so that each hemisphere was trained on one specific discrimination. Afterwards the animals were presented with stimuli that put the hemispheres in conflict. Response patterns on the conflicting stimuli revealed a clear dominance of the left hemisphere. Transient inactivation of left hemispheric top-down control reduced this dominance while inactivation of right hemispheric top-down control had no effect on response patterns. Functional asymmetries of descending systems that modify visual ascending pathways seem to play an important role in the superiority of the left hemisphere in experience-based visual tasks. Copyright © 2015. Published by Elsevier Ltd.

Dynamic stereotypic responses of Basal Ganglia neurons to subthalamic nucleus high-frequency stimulation in the parkinsonian primate.

PubMed

Moran, Anan; Stein, Edward; Tischler, Hadass; Belelovsky, Katya; Bar-Gad, Izhar

2011-01-01

Deep brain stimulation (DBS) in the subthalamic nucleus (STN) is a well-established therapy for patients with severe Parkinson's disease (PD); however, its mechanism of action is still unclear. In this study we explored static and dynamic activation patterns in the basal ganglia (BG) during high-frequency macro-stimulation of the STN. Extracellular multi-electrode recordings were performed in primates rendered parkinsonian using 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine. Recordings were preformed simultaneously in the STN and the globus pallidus externus and internus. Single units were recorded preceding and during the stimulation. During the stimulation, STN mean firing rate dropped significantly, while pallidal mean firing rates did not change significantly. The vast majority of neurons across all three nuclei displayed stimulation driven modulations, which were stereotypic within each nucleus but differed across nuclei. The predominant response pattern of STN neurons was somatic inhibition. However, most pallidal neurons demonstrated synaptic activation patterns. A minority of neurons across all nuclei displayed axonal activation. Temporal dynamics were observed in the response to stimulation over the first 10 seconds in the STN and over the first 30 seconds in the pallidum. In both pallidal segments, the synaptic activation response patterns underwent delay and decay of the magnitude of the peak response due to short term synaptic depression. We suggest that during STN macro-stimulation the STN goes through a functional ablation as its upper bound on information transmission drops significantly. This notion is further supported by the evident dissociation between the stimulation driven pre-synaptic STN somatic inhibition and the post-synaptic axonal activation of its downstream targets. Thus, BG output maintains its firing rate while losing the deleterious effect of the STN. This may be a part of the mechanism leading to the beneficial effect of DBS in PD.

Kokkos: Enabling manycore performance portability through polymorphic memory access patterns

DOE PAGES

Carter Edwards, H.; Trott, Christian R.; Sunderland, Daniel

2014-07-22

The manycore revolution can be characterized by increasing thread counts, decreasing memory per thread, and diversity of continually evolving manycore architectures. High performance computing (HPC) applications and libraries must exploit increasingly finer levels of parallelism within their codes to sustain scalability on these devices. We found that a major obstacle to performance portability is the diverse and conflicting set of constraints on memory access patterns across devices. Contemporary portable programming models address manycore parallelism (e.g., OpenMP, OpenACC, OpenCL) but fail to address memory access patterns. The Kokkos C++ library enables applications and domain libraries to achieve performance portability on diversemore » manycore architectures by unifying abstractions for both fine-grain data parallelism and memory access patterns. In this paper we describe Kokkos’ abstractions, summarize its application programmer interface (API), present performance results for unit-test kernels and mini-applications, and outline an incremental strategy for migrating legacy C++ codes to Kokkos. Furthermore, the Kokkos library is under active research and development to incorporate capabilities from new generations of manycore architectures, and to address a growing list of applications and domain libraries.« less

Patterns of antibacterials use in intensive care units.

PubMed

Santos, Edilson Floriano Dos; Lauria-Pires, Liana

2010-06-01

To know and compare the patterns of antimicrobials use in intensive care units (ICUs) based on the Anatomical Therapeutic Chemical/Defined Daily Dose (ATC/DDD) system. a prospective cohort study was conducted in three medical-surgical intensive care units, two of them in public hospitals and one in a private hospital. Simple random, independent samples of patients admitted from 10/2004 to 09/2005 to the selected intensive care units were used. The antibiotics use was assessed using the ATC/DDD system. The amount of antibacterials used in each intensive care unit, in grams, was transformed in daily defined dose (DDD). The number of DDDs was divided by the number of patient-days, multiplied by one thousand, to obtain the average density of consumption (DC) per thousand patient-days (DDD1000). 1,728 patients-days and 2,918.6 DDDs were examined in the three intensive care units, corresponding to an average density of consumption of 1,689.0 DDD1000. The median number of DDDs of antibiotics use in the public hospitals’ intensive care units was significantly higher (p=0.002) versus the private hospital’s intensive care unit. The consumption of antibiotics in the private hospital’s intensive care unit (DC=2,191.7 DDD1000) was significantly higher (p<0.001) versus the intensive care units of public hospitals (1,499.5 DDD1000). The most used antibiotics groups in the three intensive care units were 3rd generation cephalosporins, penicillins/betalactamases inhibitors, carbapenems and fluorquinolones. The pattern of antibiotics use in the three examined intensive care units was not uniform. The private hospital’s intensive care unit used a significantly larger amount versus the public hospitals’ intensive care units. Nevertheless, the most used antibiotics groups were similar in the three intensive care units.

Joint Facial Action Unit Detection and Feature Fusion: A Multi-conditional Learning Approach.

PubMed

Eleftheriadis, Stefanos; Rudovic, Ognjen; Pantic, Maja

2016-10-05

Automated analysis of facial expressions can benefit many domains, from marketing to clinical diagnosis of neurodevelopmental disorders. Facial expressions are typically encoded as a combination of facial muscle activations, i.e., action units. Depending on context, these action units co-occur in specific patterns, and rarely in isolation. Yet, most existing methods for automatic action unit detection fail to exploit dependencies among them, and the corresponding facial features. To address this, we propose a novel multi-conditional latent variable model for simultaneous fusion of facial features and joint action unit detection. Specifically, the proposed model performs feature fusion in a generative fashion via a low-dimensional shared subspace, while simultaneously performing action unit detection using a discriminative classification approach. We show that by combining the merits of both approaches, the proposed methodology outperforms existing purely discriminative/generative methods for the target task. To reduce the number of parameters, and avoid overfitting, a novel Bayesian learning approach based on Monte Carlo sampling is proposed, to integrate out the shared subspace. We validate the proposed method on posed and spontaneous data from three publicly available datasets (CK+, DISFA and Shoulder-pain), and show that both feature fusion and joint learning of action units leads to improved performance compared to the state-of-the-art methods for the task.

Chemical structure and anticoagulant activity of highly pyruvylated sulfated galactans from tropical green seaweeds of the order Bryopsidales.

PubMed

Arata, Paula X; Quintana, Irene; Canelón, Dilsia J; Vera, Beatriz E; Compagnone, Reinaldo S; Ciancia, Marina

2015-05-20

Sulfated and pyruvylated galactans were isolated from three tropical species of the Bryopsidales, Penicillus capitatus, Udotea flabellum, and Halimeda opuntia. They represent the only important sulfated polysaccharides present in the cell walls of these highly calcified seaweeds of the suborder Halimedineae. Their structural features were studied by chemical analyses and NMR spectroscopy. Their backbone comprises 3-, 6-, and 3,6-linkages, constituted by major amounts of 3-linked 4,6-O-(1'-carboxy)ethylidene-d-galactopyranose units in part sulfated on C-2. Sulfation on C-2 was not found in galactans from other seaweeds of this order. In addition, a complex sulfation pattern, comprising also 4-, 6-, and 4,6-disulfated galactose units was found. A fraction from P. capitatus, F1, showed a moderate anticoagulant activity, evaluated by general coagulation tests and also kinetics of fibrin formation was assayed. Besides, preliminary results suggest that one of the possible mechanisms involved is direct thrombin inhibition. Copyright © 2014 Elsevier Ltd. All rights reserved.

Psychophysical estimation of 3D virtual depth of united, synthesized and mixed type stereograms by means of simultaneous observation

NASA Astrophysics Data System (ADS)

Iizuka, Masayuki; Ookuma, Yoshio; Nakashima, Yoshio; Takamatsu, Mamoru

2007-02-01

Recently, many types of computer-generated stereograms (CGSs), i.e. various works of art produced by using computer are published for hobby and entertainment. It is said that activation of brain, improvement of visual eye sight, decrease of mental stress, effect of healing, etc. are expected when properly appreciating a kind of CGS as the stereoscopic view. There is a lot of information on the internet web site concerning all aspects of stereogram history, science, social organization, various types of stereograms, and free software for generating CGS. Generally, the CGS is classified into nine types: (1) stereo pair type, (2) anaglyph type, (3) repeated pattern type, (4) embedded type, (5) random dot stereogram (RDS), (6) single image stereogram (SIS), (7) united stereogram, (8) synthesized stereogram, and (9) mixed or multiple type stereogram. Each stereogram has advantages and disadvantages when viewing directly the stereogram with two eyes by training with a little patience. In this study, the characteristics of united, synthesized and mixed type stereograms, the role and composition of depth map image (DMI) called hidden image or picture, and the effect of irregular shift of texture pattern image called wall paper are discussed from the viewpoint of psychophysical estimation of 3D virtual depth and visual quality of virtual image by means of simultaneous observation in the case of the parallel viewing method.

Smart materials systems through mesoscale patterning

NASA Astrophysics Data System (ADS)

Aksay, Ilhan A.; Groves, John T.; Gruner, Sol M.; Lee, P. C. Y.; Prud'homme, Robert K.; Shih, Wei-Heng; Torquato, Salvatore; Whitesides, George M.

1996-02-01

We report work on the fabrication of smart materials with two unique strategies: (1) self- assembly and (2) laser stereolithography. Both methods are akin to the processes used by biological systems. The first one is ideal for pattern development and the fabrication of miniaturized units in the submicron range and the second one in the 10 micrometer to 1 mm size range. By using these miniaturized units as building blocks, one can also produce smart material systems that can be used at larger length scales such as smart structural components. We have chosen to focus on two novel piezoceramic systems: (1) high-displacement piezoelectric actuators, and (2) piezoceramic hydrophone composites possessing negative Poisson ratio matrices. High-displacement actuators are essential in such applications as linear motors, pumps, switches, loud speakers, variable-focus mirrors, and laser deflectors. Arrays of such units can potentially be used for active vibration control of helicopter rotors as well as the fabrication of adaptive rotors. In the case of piezoceramic hydrophone composites, we utilize matrices having a negative Poisson's ratio in order to produce highly sensitive, miniaturized sensors. We envision such devices having promising new application areas such as the implantation of hydrophones in small blood vessels to monitor blood pressure. Negative Poisson ratio materials have promise as robust shock absorbers, air filters, and fasteners, and hence, can be used in aircraft and land vehicles.

No evidence for an epidemiological transition in sleep patterns among children: a 12-country study.

PubMed

Manyanga, Taru; Barnes, Joel D; Tremblay, Mark S; Katzmarzyk, Peter T; Broyles, Stephanie T; Barreira, Tiago V; Fogelholm, Mikael; Hu, Gang; Maher, Carol; Maia, Jose; Olds, Timothy; Sarmiento, Olga L; Standage, Martyn; Tudor-Locke, Catrine; Chaput, Jean-Philippe

2018-02-01

To examine the relationships between socioeconomic status (SES; household income and parental education) and objectively measured sleep patterns (sleep duration, sleep efficiency, and bedtime) among children from around the world and explore how the relationships differ across country levels of human development. Multinational, cross-sectional study from sites in Australia, Brazil, Canada, China, Colombia, Finland, India, Kenya, Portugal, South Africa, the United Kingdom, and the United States. The International Study of Childhood Obesity, Lifestyle and the Environment. A total of 6040 children aged 9-11 years. Sleep duration, sleep efficiency, and bedtime were monitored over 7 consecutive days using waist-worn accelerometers. Multilevel models were used to examine the relationships between sleep patterns and SES. In country-specific analyses, there were no significant linear trends for sleep duration and sleep efficiency based on income and education levels. There were significant linear trends in 4 countries for bedtime (Australia, United States, United Kingdom, and India), generally showing that children in the lowest income group had later bedtimes. Later bedtimes were associated with lowest level of parental education in only 2 countries (United Kingdom and India). Patterns of associations between sleep characteristics and SES were not different between boys and girls. Sleep patterns of children (especially sleep duration and efficiency) appear unrelated to SES in each of the 12 countries, with no differences across country levels of human development. The lack of evidence for an epidemiological transition in sleep patterns suggests that efforts to improve sleep hygiene of children should not be limited to any specific SES level. Copyright © 2017 National Sleep Foundation. Published by Elsevier Inc. All rights reserved.

Young people's time use and maternal employment in the UK.

PubMed

Mullan, Killian

2009-12-01

This paper analyses the relationship between young people's time use and maternal employment in the United Kingdom (UK). Two dimensions of young people's time use are important for understanding the impact of maternal employment. The first of these is family context. This concerns the time young people are near their parents or not. The second relates to young people's activity patterns. Combining information from both dimensions is necessary to provide a comprehensive overview of the impact of maternal employment on young people's time use. The paper demonstrates that young people's time use is associated with maternal employment both in terms of activity patterns and family context. Young people with employed mothers spend more time alone with a father, and more time with neither parent. More specifically, young people with mothers employed full time (FT) spend significantly more time watching TV than those whose mothers are not employed, especially when they are not near any parents. There is a negative association between FT maternal employment and the time young people spend in achievement-related activities, concentrated in time when alone with a mother. Unlike time in leisure activities or time watching TV, time in achievement-related activities when in the presence of a father does not increase to compensate for the loss in time spent in achievement-related activities when alone with a mother.

Changing the texture of footwear can alter gait patterns.

PubMed

Nurse, Matthew A; Hulliger, Manuel; Wakeling, James M; Nigg, Benno M; Stefanyshyn, Darren J

2005-10-01

The foot provides an important source of afferent feedback for balance and locomotion. Sensory feedback from the feet can be altered by standing or walking on different surfaces. The purpose was to determine the effects of textured footwear on lower extremity muscle activity, limb kinematics, and joint kinetics while walking. Three-dimensional kinematics and kinetics, as well as muscle EMG, were collected as subjects walked with a smooth and textured shoe insert. Muscle activity was analyzed using a wavelet technique. The textured shoe insert caused a significant reduction in both soleus and tibialis anterior intensity during periods when these muscles are most active. Furthermore, the changes in muscle activity were only seen in the low frequency content of the EMG signal. The foot was significantly more plantar flexed at heel strike with the textured inserts. Small changes were also seen in vertical ground reaction forces and joint moments. It was assumed that the changes in gait patterns were due to a change in sensory feedback caused by the textured shoe insert. The possibilities of altered sensory feedback with footwear are discussed. Sensory feedback from the feet may affect specific motor unit pools during different activities. Changing the texture, without changing the geometry, of a shoe insert can alter muscle activity during walking. This may be useful in the prescription of footwear interventions and suggests that footwear may have sensory as well as mechanical effects.

From mobsters to managers. RIC0 (Racketeer Influenced and Corrupt Organizations Act) extends its reach beyond the underworld.

PubMed

Scott, J S

1989-10-01

The federal Racketeer influenced and Corrupt Organizations Act (RICO) was enacted in 1970 to combat the infiltration of organized crime into legitimate businesses operating in interstate commerce. During the first 10 years of its existence, the statute was applied almost exclusively in charges requiring criminal penalties. Section 1964 of RICO, however, allows civil remedies for injuries resulting from certain defined criminal activities. These civil remedies authorize treble damages and a reasonable attorney's fee. The Supreme Court has upheld the extension of this law to apply to general business activities, including hospitals. Hospitals risk involvement in civil RICO litigation as they become increasingly active in alternative healthcare businesses--medical supply operations real estate ventures, etc.--that involve public participation and the sale of securities, partnership units, and other equity interests. A disgruntled investor in a failed venture may initiate litigation. Other areas where hospitals are vulnerable to RICO claims include medical staff grievances, involvement in health maintenance organizations, and profile protest activities. The RICO civil provisions contain five basic elements: injury, person, enterprise, pattern of racketeering activity, and interstate or foreign commerce. Basically, this means that any person injured by the unlawful conduct of a person who is employed by or associated with any enterprise that engages in a pattern of activity which affects interstate commerce is entitled to civil RICO damages.

Exercise and limitations in physical activity levels among new dialysis patients in the United States: an epidemiologic study.

PubMed

Stack, Austin G; Murthy, Bhamidipati

2008-12-01

Epidemiologic studies of physical activity among patients with end-stage renal disease (ESRD) are lacking. The aim of this study was to describe the patterns of physical activity among new dialysis patients in the United States. Multivariate logistic regression analyses examined associations of self-reported limitations in physical activity and exercise frequency with sociodemographic and clinical variables in 2,264 patients from Wave 2 of the Dialysis Morbidity and Mortality Study. Overall, 56% of patients exercised less than once a week, 75% reported severe limitations in vigorous activities, whereas 42% had severe limitations in moderate physical activities. Fewer limitations in moderate or vigorous activities correlated positively with male gender (odds-ratio [OR] = 1.61), black race OR =1.49), Hispanic ethnicity (OR = 2.39), serum albumin (OR = 1.69 per 1 g/L higher), positive affect (OR = 2.33), peritoneal dialysis (OR = 1.90), and negatively with age (OR = 0.67), heart failure (OR = 0.75), peripheral vascular disease (OR = 0.69), malnutrition (OR = 0.67), and depression (OR = 0.39). Patients reporting fewer limitations in moderate or vigorous activities (OR = 1.35 and 1.28, respectively), or frequent visits with a dietitian (2 to 3 times per week vs. less) (OR = 1.21) in the pre-ESRD period exercised more frequently. Limitations in physical activity are common among new ESRD patients and these, in part, are related to pre-existing cardiovascular disease, malnutrition, and mental health.

Winter behavior of bats and the progression of white-nose syndrome in the southeastern United States.

PubMed

Bernard, Riley F; McCracken, Gary F

2017-03-01

Understanding the winter behavior of bats in temperate North America can provide insight into how bats react to perturbations caused by natural disturbances such as weather, human-induced disturbances, or the introduction of disease. This study measured the activity patterns of bats outside of their hibernaculum and asked how this winter activity varied by time, temperature, bat species, body condition, and WNS status. Over the course of three winters (2011-2013), we collected acoustic data and captured bats outside of five hibernacula in Tennessee, United States. During this time, Pseudogymnoascus destructans, the causative agent of white-nose syndrome, became established in hibernacula throughout the region, allowing us to track disease-related changes in the winter behavior of ten bat species. We determined that bats in the southeastern United States were active during winter regardless of disease. We recorded activity outside of hibernacula at temperatures as low as -13°C. Although bat activity was best determined by a combination of variables, the strongest factor was mean daily temperature ( R 2  = .2879, F 1,1450  = 586.2, p  < .0001). Bats that left the hibernacula earlier in evening had lower body condition than those that left 2-4 hr after sunset ( F 7,932  = 7.225, p  < .0001, Tukey HSD, p  < .05). The number of daytime emergences from hibernacula, as determined via acoustic detection, increased the longer a site was P. destructans positive ( F 3,17 808  = 124.48, p  < .0001, Tukey HSD, p  < .05). Through the use of passive acoustic monitoring and monthly captures, we determined that winter activity was driven by both ambient temperature and the presence of P. destructans .

FDG-PET detects nonuniform muscle activity in the lower body during human gait.

PubMed

Kindred, John H; Ketelhut, Nathaniel B; Benson, John-Michael; Rudroff, Thorsten

2016-11-01

Nonuniform muscle activity has been partially explained by anatomically defined neuromuscular compartments. The purpose of this study was to investigate the uniformity of skeletal muscle activity during walking. Eight participants walked at a self-selected speed, and muscle activity was quantified using [ 18 F]-fluorodeoxyglucose positron emission tomography imaging. Seventeen muscles were divided into 10 equal length sections, and within muscle activity was compared. Nonuniform activity was detected in 12 of 17 muscles (ƒ > 4.074; P < 0.046), which included both uni- and multi-articular muscles. Greater proximal activity was detected in 6 muscles (P < 0.049), and greater distal versus medial activity was found in the iliopsoas (P < 0.042). Nonuniform muscle activity is likely related to recruitment of motor units located within separate neuromuscular compartments. These findings indicate that neuromuscular compartments are recruited selectively to allow for efficient energy transfer, and these patterns may be task-dependent. Muscle Nerve 54: 959-966, 2016. © 2016 Wiley Periodicals, Inc.

Rootless tephra stratigraphy and emplacement processes

NASA Astrophysics Data System (ADS)

Hamilton, Christopher W.; Fitch, Erin P.; Fagents, Sarah A.; Thordarson, Thorvaldur

2017-01-01

Volcanic rootless cones are the products of thermohydraulic explosions involving rapid heat transfer from active lava (fuel) to external sources of water (coolant). Rootless eruptions are attributed to molten fuel-coolant interactions (MFCIs), but previous studies have not performed systematic investigations of rootless tephrostratigraphy and grain-size distributions to establish a baseline for evaluating relationships between environmental factors, MFCI efficiency, fragmentation, and patterns of tephra dispersal. This study examines a 13.55-m-thick vertical section through an archetypal rootless tephra sequence, which includes a rhythmic succession of 28 bed pairs. Each bed pair is interpreted to be the result of a discrete explosion cycle, with fine-grained basal material emplaced dominantly as tephra fall during an energetic opening phase, followed by the deposition of coarser-grained material mainly as ballistic ejecta during a weaker coda phase. Nine additional layers are interleaved throughout the stratigraphy and are interpreted to be dilute pyroclastic density current (PDC) deposits. Overall, the stratigraphy divides into four units: unit 1 contains the largest number of sediment-rich PDC deposits, units 2 and 3 are dominated by a rhythmic succession of bed pairs, and unit 4 includes welded layers. This pattern is consistent with a general decrease in MFCI efficiency due to the depletion of locally available coolant (i.e., groundwater or wet sediments). Changing conduit/vent geometries, mixing conditions, coolant and melt temperatures, and/or coolant impurities may also have affected MFCI efficiency, but the rhythmic nature of the bed pairs implies a periodic explosion process, which can be explained by temporary increases in the water-to-lava mass ratio during cycles of groundwater recharge.

[Study on molecular characteristics regarding DNA genotype of Mycobacterium tuberculosis clinical strains in Shandong].

PubMed

Deng, Yun-feng; Zhang, Yan-an; Zheng, Jian-li; Jing, Hui; Wang, Yan; Wang, Hai-ying; Ma, Xin; Liu, Zhi-min

2010-03-01

To establish the molecular characteristics of Mycobacterium tuberculosis and on factors influencing the recent transmission of drug resistant isolates in Shandong. Mycobacterium tuberculosis isolated from active pulmonary tuberculosis patients of 13 counties were genotyped by mycobacterial interspersed repetitive units (MIRU) methods. 12 loci of MIRU were detected in 558 isolates and a total of 143 MIRU patterns were confirmed. 66 isolates had distinct patterns, and 481 (86.2%) strains were in clusters. Shandong cluster included 177 strains with 74.6% of the isolates belonged to Beijing family. The recent transmission index of multi-drug resistance strains was in lower level, comparing to the susceptible strains. Our results showed that the Shandong cluster isolates had capacities of facilitating person-to-person transmission and high level of drug resistance.

University Enrollment Patterns in England and the United States.

ERIC Educational Resources Information Center

Fairweather, Malcolm

Factors that influence college choice and enrollment patterns in both the United States and England were identified, based on a comparative literature review. It was found that the reasons given by students for attending universities in the two countries are very similar, in spite of the fact that the systems of higher education in these countries…

Patterns of Enquiry: Textual Analysis of a Classroom Discussion Unit on Bee Feeding Behaviour.

ERIC Educational Resources Information Center

Binns, Richard W.

This paper constitutes an analysis of "Honey Bee Communication: An Enquiry into Two Concepts of Animal Behavior," a unit of classroom discussion modules developed by the Patterns of Enquiry Project at the Ontario Institute for Studies in Education. The conceptual framework of the analysis consists of four major items: (1) descriptive…

Spatial scaling of non-native fish richness across the United States

Treesearch

Qinfeng Guo; Julian D. Olden

2014-01-01

A major goal and challenge of invasion ecology is to describe and interpret spatial and temporal patterns of species invasions. Here, we examined fish invasion patterns at four spatially structured and hierarchically nested scales across the contiguous United States (i.e., from large to small: region, basin, watershed, and sub-watershed). All spatial relationships in...

Epiphytic cryptogams as a source of bioaerosols and trace gases

NASA Astrophysics Data System (ADS)

Ruckteschler, Nina; Hrabe de Angelis, Isabella; Zartman, Charles E.; Araùjo, Alessandro; Pöschl, Ulrich; Manzi, Antonio O.; Andreae, Meinrat O.; Pöhlker, Christopher; Weber, Bettina

2016-04-01

Cryptogamic covers comprise (cyano-)bacteria, algae, lichens, bryophytes, fungi, and archaea in varying proportions. These organisms do not form flowers, but reproduce by spores or cell cleavage with these reproductive units being dispersed via the atmosphere. As so-called poikilohydric organisms they are unable to regulate their water content, and their physiological activity pattern mainly follows the external water conditions. We hypothesize, that both spore dispersal and the release of trace gases are governed by the moisture patterns of these organisms and thus they could have a greater impact on the atmosphere than previously thought. In order to test this hypothesis, we initiated experiments at the study site Amazonian Tall Tower Observatory (ATTO) in September 2014. We installed microclimate sensors in epiphytic cryptogams at four different heights of a tree to monitor the activity patterns of these organisms. Self-developed moisture probes are used to analyze the water status of the organisms accompanied by light and temperature sensors. The continuously logged data are linked to ongoing measurements of trace gases and particulate bioaerosols to analyze these for the relevance of cryptogams. Here, we are particularly interested in diurnal cycles of coarse mode particles and the atmospheric abundance of fine potassium-rich particles from a currently unknown biogenic source. Based upon the results of this field study we also investigate the bioaerosol and trace gas release patterns of cryptogamic covers under controlled conditions. With this combined approach of field and laboratory experiments we aim to disclose the role of cryptogamic covers in bioaerosol and trace gas release patterns in the Amazonian rainforest.

Dynamic labelling of neural connections in multiple colours by trans-synaptic fluorescence complementation

PubMed Central

Macpherson, Lindsey J.; Zaharieva, Emanuela E.; Kearney, Patrick J.; Alpert, Michael H.; Lin, Tzu-Yang; Turan, Zeynep; Lee, Chi-Hon; Gallio, Marco

2015-01-01

Determining the pattern of activity of individual connections within a neural circuit could provide insights into the computational processes that underlie brain function. Here, we develop new strategies to label active synapses by trans-synaptic fluorescence complementation in Drosophila. First, we demonstrate that a synaptobrevin-GRASP chimera functions as a powerful activity-dependent marker for synapses in vivo. Next, we create cyan and yellow variants, achieving activity-dependent, multi-colour fluorescence reconstitution across synapses (X-RASP). Our system allows for the first time retrospective labelling of synapses (rather than whole neurons) based on their activity, in multiple colours, in the same animal. As individual synapses often act as computational units in the brain, our method will promote the design of experiments that are not possible using existing techniques. Moreover, our strategies are easily adaptable to circuit mapping in any genetic system. PMID:26635273

Movement-Related Discharge in the Macaque Globus Pallidus during High-Frequency Stimulation of the Subthalamic Nucleus

PubMed Central

Zimnik, Andrew J.; Nora, Gerald J.; Desmurget, Michel

2015-01-01

Deep brain stimulation (DBS) of the subthalamic nucleus (STN-DBS) has largely replaced ablative therapies for Parkinson's disease. Because of the similar efficacies of the two treatments, it has been proposed that DBS acts by creating an “informational lesion,” whereby pathologic neuronal firing patterns are replaced by low-entropy, stimulus-entrained firing patterns. The informational lesion hypothesis, in its current form, states that DBS blocks the transmission of all information from the basal ganglia, including both pathologic firing patterns and normal, task-related modulations in activity. We tested this prediction in two healthy rhesus macaques by recording single-unit spiking activity from the globus pallidus (232 neurons) while the animals completed choice reaction time reaching movements with and without STN-DBS. Despite strong effects of DBS on the activity of most pallidal cells, reach-related modulations in firing rate were equally prevalent in the DBS-on and DBS-off states. This remained true even when the analysis was restricted to cells affected significantly by DBS. In addition, the overall form and timing of perimovement modulations in firing rate were preserved between DBS-on and DBS-off states in the majority of neurons (66%). Active movement and DBS had largely additive effects on the firing rate of most neurons, indicating an orthogonal relationship in which both inputs contribute independently to the overall firing rate of pallidal neurons. These findings suggest that STN-DBS does not act as an indiscriminate informational lesion but rather as a filter that permits task-related modulations in activity while, presumably, eliminating the pathological firing associated with parkinsonism. PMID:25740526

eHealth Search Patterns: A Comparison of Private and Public Health Care Markets Using Online Panel Data.

PubMed

Schneider, Janina Anne; Holland, Christopher Patrick

2017-04-13

Patient and consumer access to eHealth information is of crucial importance because of its role in patient-centered medicine and to improve knowledge about general aspects of health and medical topics. The objectives were to analyze and compare eHealth search patterns in a private (United States) and a public (United Kingdom) health care market. A new taxonomy of eHealth websites is proposed to organize the largest eHealth websites. An online measurement framework is developed that provides a precise and detailed measurement system. Online panel data are used to accurately track and analyze detailed search behavior across 100 of the largest eHealth websites in the US and UK health care markets. The health, medical, and lifestyle categories account for approximately 90% of online activity, and e-pharmacies, social media, and professional categories account for the remaining 10% of online activity. Overall search penetration of eHealth websites is significantly higher in the private (United States) than the public market (United Kingdom). Almost twice the number of eHealth users in the private market have adopted online search in the health and lifestyle categories and also spend more time per website than those in the public market. The use of medical websites for specific conditions is almost identical in both markets. The allocation of search effort across categories is similar in both the markets. For all categories, the vast majority of eHealth users only access one website within each category. Those that conduct a search of two or more websites display very narrow search patterns. All users spend relatively little time on eHealth, that is, 3-7 minutes per website. The proposed online measurement framework exploits online panel data to provide a powerful and objective method of analyzing and exploring eHealth behavior. The private health care system does appear to have an influence on eHealth search behavior in terms of search penetration and time spent per website in the health and lifestyle categories. Two explanations are offered: (1) the personal incentive of medical costs in the private market incentivizes users to conduct online search; and (2) health care information is more easily accessible through health care professionals in the United Kingdom compared with the United States. However, the use of medical websites is almost identical, suggesting that patients interested in a specific condition have a motivation to search and evaluate health information, irrespective of the health care market. The relatively low level of search in terms of the number of websites accessed and the average time per website raise important questions about the actual level of patient informedness in both the markets. Areas for future research are outlined. ©Janina Anne Schneider, Christopher Patrick Holland. Originally published in the Journal of Medical Internet Research (http://www.jmir.org), 13.04.2017.

Personal customizing exercise with a wearable measurement and control unit

PubMed Central

Wang, Zhihui; Kiryu, Tohru; Tamura, Naoki

2005-01-01

Background Recently, wearable technology has been used in various health-related fields to develop advanced monitoring solutions. However, the monitoring function alone cannot meet all the requirements of customizing machine-based exercise on an individual basis by relying on biosignal-based controls. We propose a new wearable unit design equipped with measurement and control functions to support the customization process. Methods The wearable unit can measure the heart rate and electromyogram signals during exercise performance and output workload control commands to the exercise machines. The workload is continuously tracked with exercise programs set according to personally customized workload patterns and estimation results from the measured biosignals by a fuzzy control method. Exercise programs are adapted by relying on a computer workstation, which communicates with the wearable unit via wireless connections. A prototype of the wearable unit was tested together with an Internet-based cycle ergometer system to demonstrate that it is possible to customize exercise on an individual basis. Results We tested the wearable unit in nine people to assess its suitability to control cycle ergometer exercise. The results confirmed that the unit could successfully control the ergometer workload and continuously support gradual changes in physical activities. Conclusion The design of wearable units equipped with measurement and control functions is an important step towards establishing a convenient and continuously supported wellness environment. PMID:15982425

Synergy between publication and promotion: comparing adoption of new evidence in Canada and the United States.

PubMed

Majumdar, Sumit R; McAlister, Finlay A; Soumerai, Stephen B

2003-10-15

Few studies have examined the effect of new evidence from clinical trials on physician practice. We took advantage of differences in promotional activity in Canada and the United States for the Heart Outcomes Prevention and Evaluation (HOPE) study and the Randomized Aldactone Evaluation Study (RALES) to determine if publication of new evidence changes practice, and the extent to which promotion influences adoption of new evidence. We used longitudinal dispensing data, collected from 1998 to 2001, to examine changes in prescribing patterns for ramipril and other angiotensin-converting enzyme (ACE) inhibitors before and after the HOPE study. We also obtained estimates for promotional expenditures. We stratified analyses by country, to isolate the effect of promotion, and used interrupted time series methods to adjust for pre-existing prescribing trends. Similar analyses were conducted for spironolactone use before and after RALES. Publication of the HOPE study results was associated with rapid increases in the use of ramipril. After adjusting for pre-existing prescribing trends, ramipril prescribing increased by 12% per month (P = 0.001) in Canada versus 5% per month (P = 0.001) in the United States after the study results were presented and published. One year later, ramipril accounted for 30% of the ACE inhibitor market in Canada versus 6% in the United States. The year before publication of these results, expenditures for detailing increased by 20% in Canada (to 18 US dollars per physician) but decreased by 7% in the United States (to 13 US dollars per physician); the year after publication, spending increased to 27 US dollars per physician in Canada versus 23 US dollars per physician in the United States. In the absence of promotional activity for RALES in either country, publication of results was associated with more modest but similar increases of 2% per month (P = 0.001) in spironolactone use in both countries. Publication of new evidence is associated with modest changes in practice. Promotional activity appears to increase the adoption of evidence. Rather than relying on the publication of articles and creation of guidelines, those wishing to accelerate the adoption of new evidence may need to undertake more active promotion.

Search query data to monitor interest in behavior change: application for public health.

PubMed

Carr, Lucas J; Dunsiger, Shira I

2012-01-01

There is a need for effective interventions and policies that target the leading preventable causes of death in the U.S. (e.g., smoking, overweight/obesity, physical inactivity). Such efforts could be aided by the use of publicly available, real-time search query data that illustrate times and locations of high and low public interest in behaviors related to preventable causes of death. This study explored patterns of search query activity for the terms 'weight', 'diet', 'fitness', and 'smoking' using Google Insights for Search. Search activity for 'weight', 'diet', 'fitness', and 'smoking' conducted within the United States via Google between January 4(th), 2004 (first date data was available) and November 28(th), 2011 (date of data download and analysis) were analyzed. Using a generalized linear model, we explored the effects of time (month) on mean relative search volume for all four terms. Models suggest a significant effect of month on mean search volume for all four terms. Search activity for all four terms was highest in January with observable declines throughout the remainder of the year. These findings demonstrate discernable temporal patterns of search activity for four areas of behavior change. These findings could be used to inform the timing, location and messaging of interventions, campaigns and policies targeting these behaviors.

Trends in physical activity, sedentary behavior, diet, and BMI among US adolescents, 2001-2009.

PubMed

Iannotti, Ronald J; Wang, Jing

2013-10-01

The high prevalence of adolescent obesity in the United States has been attributed to population changes in physical activity (PA), sedentary behaviors, and dietary behaviors. This study examines 8-year trends in these behaviors in US adolescents ages 11 to 16. Nationally representative samples of US students in grades 6 to 10 were recruited during the 2001-2002 (N = 14607), 2005-2006 (N = 9150), and 2009-2010 (N = 10848) school years by using multistage stratified designs, with census regions and grades as strata, and school districts as the primary sampling units. African-American and Hispanic students were oversampled to obtain better estimates for those groups. Using the Health Behavior in School-aged Children quadrennial surveys, identical questions assessed BMI, PA, and sedentary and dietary behaviors at each school year. Logistic and linear regression analyses were conducted taking into account the sampling design and controlling for age, gender, race/ethnicity, and family affluence. Across the quadrennial surveys, significant increases were identified in number of days with at least 60 minutes of PA, daily consumption of fruits and vegetables, eating breakfast on weekdays and weekends, and BMI. Television viewing and consumption of sweets and sweetened beverages decreased across this same period. These same patterns were seen in all racial/ethnic groups. These patterns suggest that public health efforts to improve the obesity-related behaviors of US adolescents may be having some success. However, alternative explanations for the increase in BMI over the same period need to be considered.

Trace element mobility in dolomitic argillites of the Mesoproterozoic Belt-Purcell Supergroup, Western North America

NASA Astrophysics Data System (ADS)

González-Álvarez, Ignacio; Kerrich, Robert

2011-04-01

The Belt-Purcell Supergroup comprises dolomite-rich stratigraphic units in a dominantly siliciclastic succession, where sedimentation spans 1400-1470 Ma. Dolomitic units are variable mixtures of co-sedimented argillite and primary carbonate post-depositionally converted to secondary dolomite. Based on rare earth element (REE) relationships three distinct REE patterns are identified in the dolomite-rich units: Type 1 (T1d; d = dolomitic sample) with REE patterns parallel to post-Archean Upper Continental Crust (PA-UCC), albeit at lower absolute abundances due to dilution by carbonate content; Type 2 (T2d) with Heavy REE (HREE) enrichment but Light REE (LREE) depletion relative to T1d; and Type 3 (T3d) with enrichment in LREE and HREE relative to T1d, but erratic Middle REE (MREE) patterns. There is a progressive increase of ΣREE from T1d through T2d to T3d, whereas for ΣLREE/ΣHREE T2d < T1d < T3d. T1d-T2d and T3d represent three different "snapshots" of a continuous process. In terms of timing, dolomitization of calcite primary sediment in all samples likely took place broadly during burial diagenesis, as inferred for most Proterozoic dolomites. T1d is easily explained by provenance: however, T2d and T3d cannot be related to provenance, weathering or sedimentary sorting processes to explain higher concentrations of HREE referenced to PA-UCC and consequently developed in the sediment from a T1d precursor. The same three REE signatures have been described in previous studies in counterpart siliciclastic counterparts throughout the Belt-Purcell Supergroup at three different locations. Mobility of normally stable REE is accompanied by mobility of normally isochemical high field strength elements (HFSE) in T2d and T3d to give REE/REE, HFSE/HFSE, REE/HFSE and Y/HREE fractionations. No specific REE-HFSE signatures are apparent in the carbonate-rich units as compared to their non-dolomitic siliciclastic counterparts. This unusual mobility of REE and HFSE reflected in T2d and T3d is attributed to alkaline oxidizing post-depositional brines. Salinity was derived from seawater-sediment reactions, dissolution of evaporite minerals, and the smectite-illite transformation, whereas alkaline oxidizing conditions were promoted by groundwater interaction with mafic units in the basin, CO 2 introduced into the system during episodic rifting with mantle degassing, and interaction of syn-sedimentary mafic intrusions with carbonate units at early stages of BPS deposition. Intermittent brine activity, inducing T2d and T3d patterns, spanned >1 Ga as recorded by secondary monazite grains with age distributions that correspond to large scale tectono-thermal events in Laurentia. Post-depositional processes and redistribution of carbonate can have an impact on transitional stratigraphic contacts between dolomitic and siliciclastic units which may have been incorrectly described as primary due to sedimentary environment changes.

Electropalatography in home training of retracted articulation in a Swedish child with cleft palate: effect on articulation pattern and speech.

PubMed

Lohmander, Anette; Henriksson, Cecilia; Havstam, Christina

2010-12-01

The aim was to evaluate the effectiveness of electropalatography (EPG) in home training of persistent articulation errors in an 11-year-old Swedish girl born with isolated cleft palate. The /t/ and /s/ sounds were trained in a single subject design across behaviours during an eight month period using a portable training unit (PTU). Both EPG analysis and perceptual analysis showed an improvement in the production of /t/ and /s/ in words and sentences after therapy. Analysis of tongue-contact patterns showed that the participant had more normal articulatory patterns of /t/ and /s/ after just 2 months (after approximately 8 hours of training) respectively. No statistically significant transfer by means of intelligibility in connected speech was found. The present results show that EPG home training can be a sufficient method for treating persistent speech disorders associated with cleft palate. Methods for transfer from function (articulation) to activity (intelligibility) need to be explored.

Regulation of ventral surface chemoreceptors by the central respiratory pattern generator.

PubMed

Guyenet, Patrice G; Mulkey, Daniel K; Stornetta, Ruth L; Bayliss, Douglas A

2005-09-28

The rat retrotrapezoid nucleus (RTN) contains neurons described as central chemoreceptors in the adult and respiratory rhythm-generating pacemakers in neonates [parafacial respiratory group (pfRG)]. Here we test the hypothesis that both RTN and pfRG neurons are intrinsically chemosensitive and tonically firing neurons whose respiratory rhythmicity is caused by a synaptic feedback from the central respiratory pattern generator (CPG). In halothane-anesthetized adults, RTN neurons were silent below 4.5% end-expiratory (e-exp) CO2. Their activity increased linearly (3.2 Hz/1% CO2) up to 6.5% (CPG threshold) and then more slowly to peak approximately 10 Hz at 10% CO2. Respiratory modulation of RTN neurons was absent below CPG threshold, gradually stronger beyond, and, like pfRG neurons, typically (42%) characterized by twin periods of reduced activity near phrenic inspiration. After CPG inactivation with kynurenate (KYN), RTN neurons discharged linearly as a function of e-exp CO2 (slope, +1.7 Hz/1% CO2) and arterial pH (threshold, 7.48; slope, 39 Hz/pH unit). In coronal brain slices (postnatal days 7-12), RTN chemosensitive neurons were silent at pH 7.55. Their activity increased linearly with acidification up to pH 7.2 (17 Hz/pH unit at 35 degrees C) and was always tonic. In conclusion, consistent with their postulated central chemoreceptor role, RTN/pfRG neurons encode pH linearly and discharge tonically when disconnected from the rest of the respiratory centers in vivo (KYN treatment) and in vitro. In vivo, RTN neurons receive respiratory synchronous inhibitory inputs that may serve as feedback and impart these neurons with their characteristic respiratory modulation.

Aedes albopictus in the United States: ten-year presence and public health implications.

PubMed Central

Moore, C. G.; Mitchell, C. J.

1997-01-01

Since its discovery in Houston, Texas, in 1987, the Asian "tiger mosquito" Aedes albopictus has spread to 678 counties in 25 states. This species, which readily colonizes container habitats in the peridomestic environment, was probably introduced into the continental United States in shipments of scrap tires from northern Asia. The early pattern of dispersal followed the interstate highway system, which suggests further dispersal by human activities. The Public Health Service Act of 1988 requires shipments of used tires from countries with Ae. albopictus to be treated to prevent further importations. Given the extensive spread of the mosquito in the United States, it is questionable whether such a requirement is still justified. Ae. albopictus, a major biting pest throughout much of its range, is a competent laboratory vector of at least 22 arboviruses, including many viruses of public health importance. Cache Valley and eastern equine encephalomyelitis viruses are the only human pathogens isolated from U.S. populations of Ae. albopictus. There is no evidence that this mosquito is the vector of human disease in the United States. PMID:9284377

Earthquakes in the Central United States, 1699-2010

USGS Publications Warehouse

Dart, Richard L.; Volpi, Christina M.

2010-01-01

This publication is an update of an earlier report, U.S. Geological Survey (USGS) Geologic Investigation I-2812 by Wheeler and others (2003), titled ?Earthquakes in the Central United States-1699-2002.? Like the original poster, the center of the updated poster is a map showing the pattern of earthquake locations in the most seismically active part of the central United States. Arrayed around the map are short explanatory texts and graphics, which describe the distribution of historical earthquakes and the effects of the most notable of them. The updated poster contains additional, post 2002, earthquake data. These are 38 earthquakes covering the time interval from January 2003 to June 2010, including the Mount Carmel, Illinois, earthquake of 2008. The USGS Preliminary Determination of Epicenters (PDE) was the source of these additional data. Like the I-2812 poster, this poster was prepared for a nontechnical audience and designed to inform the general public as to the widespread occurrence of felt and damaging earthquakes in the Central United States. Accordingly, the poster should not be used to assess earthquake hazard in small areas or at individual locations.

Kinetics of fast short-term depression are matched to spike train statistics to reduce noise.

PubMed

Khanbabaie, Reza; Nesse, William H; Longtin, Andre; Maler, Leonard

2010-06-01

Short-term depression (STD) is observed at many synapses of the CNS and is important for diverse computations. We have discovered a form of fast STD (FSTD) in the synaptic responses of pyramidal cells evoked by stimulation of their electrosensory afferent fibers (P-units). The dynamics of the FSTD are matched to the mean and variance of natural P-unit discharge. FSTD exhibits switch-like behavior in that it is immediately activated with stimulus intervals near the mean interspike interval (ISI) of P-units (approximately 5 ms) and recovers immediately after stimulation with the slightly longer intervals (>7.5 ms) that also occur during P-unit natural and evoked discharge patterns. Remarkably, the magnitude of evoked excitatory postsynaptic potentials appear to depend only on the duration of the previous ISI. Our theoretical analysis suggests that FSTD can serve as a mechanism for noise reduction. Because the kinetics of depression are as fast as the natural spike statistics, this role is distinct from previously ascribed functional roles of STD in gain modulation, synchrony detection or as a temporal filter.

Source-to-sink cycling of aeolian sediment in the north polar region of Mars

NASA Astrophysics Data System (ADS)

Ewing, R. C.; Kocurek, G.

2012-12-01

Aeolian sand dunes are prominent features on the landscapes of Earth, Mars, Venus and Titan and sedimentary deposits interpreted as aeolian in origin are found in the rock records of Earth and Mars. The widespread occurrence of aeolian dunes on the surface of these worlds and within their deep-time depositional records suggests that aeolian systems are and likely have been a default depositional environment for the Solar System. Within an aeolian source-to-sink context, we hypothesize that planet-specific boundary conditions strongly impact production, transport, accumulation and preservation of aeolian sediment, whereas dunes and dune-field patterns remain largely similar. This hypothesis is explored within the north polar region of Mars, which hosts the most extensive aeolian dune fields and aeolian sedimentary deposits yet recognized on Mars and appears to be a region of dynamic source-to-sink cycling of aeolian sediments. The Planum Boreum Cavi Unit rests beneath north polar ice cap of Mars and is composed of several hundred meters of niveo-aeolian dune cross-stratification. The overall architecture of the unit consists of sets of preserved dune topography with an upward increase in the abundance of ice. Dune sets are defined by stabilized, polygonally fractured bounding surfaces, erosional bounding surfaces and typical internal lee foresets made of sediment and ice. The accumulation of the Cavi Unit is interpreted as occurring through freezing and serves as an example of a cold temperature boundary condition on aeolian sediment accumulation. Preservation of the Cavi Unit arises because of deposition of the overlying ice cap and contrasts with preservation of aeolian sediment on Earth, which is largely driven by eustasy and tectonics. The Cavi Unit is thought to be one source of sediment for the north polar Olympia Undae Dune Field. The region of Olympia Undae near the Cavi Unit shows a reticulate dune field pattern composed of two sets of nearly orthogonal dune crestlines, with slipfaces on the primary crests, wind ripples, coarse-grained ripples and deflated interdune areas with exposed dune stratigraphy. Wind transport directions interpreted from wind ripple orientations show that the interaction between dune topography and wind flow on Mars are largely the same as on Earth giving rise to basic types of lee-slope processes - grain flow, grain fall and wind ripples. Using wind flow reconstruction and pattern analysis the pattern is interpreted as complex in which a younger pattern superposes a larger, older pattern. The younger pattern may have emerged with the development of the retreat of the Cavi reentrant into the Cavi Unit and ice cap, which acted to channel katabatic winds and inject a new sediment source into Olympia Undae. The similarity of the Olympia Undae dune-field pattern to dune-field patterns on other planets shows the robustness of pattern formation across different planetary boundary conditions and the applicability of pattern-analysis methods for paleoenvironmental reconstruction. The aeolian source-to-sink system of Mars' north polar region demonstrates how the stratigraphic and geomorphic principles of aeolian systems may differ because of different planetary boundary conditions and provides a framework for analysis of aeolian systems on other worlds.

Inflammatory and vascular placental lesions are associated with neonatal amplitude integrated EEG recording in early premature neonates

PubMed Central

Goshen, Sharon; Richardson, Justin; Drunov, VIadimir; Staretz Chacham, Orna; Shany, Eilon

2017-01-01

Introduction Placental histologic examination can assist in revealing the mechanism leading to preterm birth. Accumulating evidence suggests an association between intrauterine pathological processes, morbidity and mortality of premature infants, and their long term outcome. Neonatal brain activity is increasingly monitored in neonatal intensive care units by amplitude integrated EEG (aEEG) and indices of background activity and sleep cycling patterns were correlated with long term outcome. We hypothesized an association between types of placental lesions and abnormal neonatal aEEG patterns. Objective To determine the association between the placental lesions observed in extreme preterm deliveries, and their neonatal aEEG patterns and survival. Patients and methods This prospective cohort study included extreme premature infants, who were born ≤ 28 weeks of gestation, their placentas were available for histologic examination, and had a continues aEEG, soon after birth)n = 34). Infants and maternal clinical data were collected. aEEG data was assessed for percentage of depressed daily activity in the first 3 days of life and for sleep cycling. Associations of placental histology with clinical findings and aEEG activity were explored using parametric and non-parametric statistics. Results Twenty two out of the 34 newborns survived to discharge. Preterm prelabor rupture of membranes (PPROM) or chorioamnionitis were associated with placental lesions consistent with fetal amniotic fluid infection (AFI) or maternal under perfusion (MUP) (P < 0.05). Lesions consistent with fetal response to AFI were associated with absence of SWC pattern during the 1st day of life. Fetal-vascular-thrombo-occlusive lesions of inflammatory type were negatively associated with depressed cerebral activity during the 1st day of life, and with aEEG cycling during the 2nd day of life (P<0.05). Placental lesions associated with MUP were associated with depressed neonatal cerebral activity during the first 3 days of life (P = 0.007). Conclusions Depressed neonatal aEEG patterns are associated with placental lesions consistent with maternal under perfusion, and amniotic fluid infection of fetal type, but not with fetal thrombo-oclusive vascular disease of inflammatory type. Our findings highlight the association between the intrauterine mechanisms leading to preterm parturition and subsequent depressed neonatal cerebral function early after birth, which eventually may put premature infants at risk for abnormal neurodevelopmental outcome. PMID:28644831

Are kids too busy?: early adolescents' perceptions of discretionary activities, overscheduling, and stress.

PubMed

Brown, Stephen L; Nobiling, Brandye D; Teufel, James; Birch, David A

2011-09-01

The activity patterns of children, especially after-school patterns, are receiving more professional attention. However, evidence regarding the value of various activities in children's lives is contradictory. The purpose of this study was to assess perceptions of discretionary activities, overscheduling, and levels of stress from adolescents' perspective. A sample of 882 children, ages 9 to 13, recruited at 9 health education centers in the United States was selected for this study. Children answered questionnaires using remote, handheld devices. Data were analyzed using descriptive statistics and multivariate logistic regression. The outcomes of interest were activity-based stress and desire for more free time. The primary predictor for the desire for more free time was hours of screen time (television, computer, video games): those who reported 3 or more hours were nearly 3 times more likely to desire more free time. Further, children who chose their own activities experienced more activity-related stress than those who shared decisions with parents. The single greatest predictor of activity-related stress was the reported number of hours spent on homework. Students who averaged at least 2 hours on homework per night were nearly twice as likely to report frequent activity-related stress. Parents of school-aged children should assess activity-related stress and the degree to which children perceive they are busy. Teachers, school counselors, and school administrators should be aware of these perceptions as they are making decisions regarding school schedules and should teach personal skills such as time management and stress control. © 2011, American School Health Association.

SPARROW MODELING - Enhancing Understanding of the Nation's Water Quality

USGS Publications Warehouse

Preston, Stephen D.; Alexander, Richard B.; Woodside, Michael D.; Hamilton, Pixie A.

2009-01-01

The information provided here is intended to assist water-resources managers with interpretation of the U.S. Geological Survey (USGS) SPARROW model and its products. SPARROW models can be used to explain spatial patterns in monitored stream-water quality in relation to human activities and natural processes as defined by detailed geospatial information. Previous SPARROW applications have identified the sources and transport of nutrients in the Mississippi River basin, Chesapeake Bay watershed, and other major drainages of the United States. New SPARROW models with improved accuracy and interpretability are now being developed by the USGS National Water Quality Assessment (NAWQA) Program for six major regions of the conterminous United States. These new SPARROW models are based on updated geospatial data and stream-monitoring records from local, State, and other federal agencies.

Analysis of humpback whale sounds in shallow waters of the Southeastern Arabian Sea: An indication of breeding habitat.

PubMed

Mahanty, Madan M; Latha, G; Thirunavukkarasu, A

2015-06-01

The primary objective of this work was to present the acoustical identification of humpback whales, detected by using an autonomous ambient noise measurement system, deployed in the shallow waters of the Southeastern Arabian Sea (SEAS) during the period January to May 2011. Seven types of sounds were detected. These were characteristically upsweeps and downsweeps along with harmonics. Sounds produced repeatedly in a specific pattern were referred to as phrases (PQRS and ABC). Repeated phrases in a particular pattern were referred to as themes, and from the spectrographic analysis, two themes (I and II) were identified. The variation in the acoustic characteristics such as fundamental frequency, range, duration of the sound unit, and the structure of the phrases and themes are discussed. Sound units were recorded from mid-January to mid-March, with a peak in February, when the mean SST is approx. 28 degree C, and no presence was recorded after mid-March. The temporal and thematic structures strongly determine the functions of the humpback whale song form. Given the use of song in the SEAS, this area is possibly used as an active breeding habitat by humpback whales during the winter season.

Frequency analyses for recent regional floods in the United States

USGS Publications Warehouse

Melcher, Nick B.; Martinez, Patsy G.; ,

1996-01-01

During 1993-95, significant floods that resulted in record-high river stages, loss of life, and significant property damage occurred in the United States. The floods were caused by unique global weather patterns that produced large amounts of rain over large areas. Standard methods for flood-frequency analyses may not adequately consider the probability of recurrence of these global weather patterns.

The Effects of Exercise on the Firing Patterns of Single Motor Units.

ERIC Educational Resources Information Center

Cracraft, Joe D.

In this study, the training effects of static and dynamic exercise programs on the firing patterns of 450 single motor units (SMU) in the human tibialis anterior muscle were investigated. In a six week program, the static group (N=5) participated in daily high intensity, short duration, isometric exercises while the dynamic group (N=5)…

Associations of forest bird species richness with housing and landscape pattern across the United States

Treesearch

A. M. Pidgeon; V. C. Radeloff; C. H. Flather; C. A. Lepczyk; M. K. Clayton; T. J. Hawbaker; R. B. Hammer

2007-01-01

In the United States, housing density has substantially increased in and adjacent to forests. Our goal in this study was to identify how housing density and human populations are associated with avian diversity. We compared these associations to those between landscape pattern and avian diversity, and we examined how these associations vary across the conterminous...

Patterns, Functions, and Algebra: Wired for Space. NASA Connect: Program 3 in the 2000-2001 Series.

ERIC Educational Resources Information Center

National Aeronautics and Space Administration, Hampton, VA. Langley Research Center.

This teaching unit is designed to help students in grades 5 to 8 explore the concepts of patterns, functions, and algebra in the context of propelling spacecraft. The units in the series have been developed to enhance and enrich mathematics, science, and technology education and to accommodate different teaching and learning styles. Each unit…

Laser-assisted chemical vapor deposition setup for fast synthesis of graphene patterns

NASA Astrophysics Data System (ADS)

Zhang, Chentao; Zhang, Jianhuan; Lin, Kun; Huang, Yuanqing

2017-05-01

An automatic setup based on the laser-assisted chemical vapor deposition method has been developed for the rapid synthesis of graphene patterns. The key components of this setup include a laser beam control and focusing unit, a laser spot monitoring unit, and a vacuum and flow control unit. A laser beam with precision control of laser power is focused on the surface of a nickel foil substrate by the laser beam control and focusing unit for localized heating. A rapid heating and cooling process at the localized region is induced by the relative movement between the focalized laser spot and the nickel foil substrate, which causes the decomposing of gaseous hydrocarbon and the out-diffusing of excess carbon atoms to form graphene patterns on the laser scanning path. All the fabrication parameters that affect the quality and number of graphene layers, such as laser power, laser spot size, laser scanning speed, pressure of vacuum chamber, and flow rates of gases, can be precisely controlled and monitored during the preparation of graphene patterns. A simulation of temperature distribution was carried out via the finite element method, providing a scientific guidance for the regulation of temperature distribution during experiments. A multi-layer graphene ribbon with few defects was synthesized to verify its performance of the rapid growth of high-quality graphene patterns. Furthermore, this setup has potential applications in other laser-based graphene synthesis and processing.

Detrended cross-correlations between returns, volatility, trading activity, and volume traded for the stock market companies

NASA Astrophysics Data System (ADS)

Rak, Rafał; Drożdż, Stanisław; Kwapień, Jarosław; Oświȩcimka, Paweł

2015-11-01

We consider a few quantities that characterize trading on a stock market in a fixed time interval: logarithmic returns, volatility, trading activity (i.e., the number of transactions), and volume traded. We search for the power-law cross-correlations among these quantities aggregated over different time units from 1 min to 10 min. Our study is based on empirical data from the American stock market consisting of tick-by-tick recordings of 31 stocks listed in Dow Jones Industrial Average during the years 2008-2011. Since all the considered quantities except the returns show strong daily patterns related to the variable trading activity in different parts of a day, which are the most evident in the autocorrelation function, we remove these patterns by detrending before we proceed further with our study. We apply the multifractal detrended cross-correlation analysis with sign preserving (MFCCA) and show that the strongest power-law cross-correlations exist between trading activity and volume traded, while the weakest ones exist (or even do not exist) between the returns and the remaining quantities. We also show that the strongest cross-correlations are carried by those parts of the signals that are characterized by large and medium variance. Our observation that the most convincing power-law cross-correlations occur between trading activity and volume traded reveals the existence of strong fractal-like coupling between these quantities.

Automatic classification of background EEG activity in healthy and sick neonates

NASA Astrophysics Data System (ADS)

Löfhede, Johan; Thordstein, Magnus; Löfgren, Nils; Flisberg, Anders; Rosa-Zurera, Manuel; Kjellmer, Ingemar; Lindecrantz, Kaj

2010-02-01

The overall aim of our research is to develop methods for a monitoring system to be used at neonatal intensive care units. When monitoring a baby, a range of different types of background activity needs to be considered. In this work, we have developed a scheme for automatic classification of background EEG activity in newborn babies. EEG from six full-term babies who were displaying a burst suppression pattern while suffering from the after-effects of asphyxia during birth was included along with EEG from 20 full-term healthy newborn babies. The signals from the healthy babies were divided into four behavioural states: active awake, quiet awake, active sleep and quiet sleep. By using a number of features extracted from the EEG together with Fisher's linear discriminant classifier we have managed to achieve 100% correct classification when separating burst suppression EEG from all four healthy EEG types and 93% true positive classification when separating quiet sleep from the other types. The other three sleep stages could not be classified. When the pathological burst suppression pattern was detected, the analysis was taken one step further and the signal was segmented into burst and suppression, allowing clinically relevant parameters such as suppression length and burst suppression ratio to be calculated. The segmentation of the burst suppression EEG works well, with a probability of error around 4%.

Guided participation in cultural activity by toddlers and caregivers.

PubMed

Rogoff, B; Mistry, J; Göncü, A; Mosier, C

1993-01-01

In this Monograph, we examine how toddlers and their caregivers from four cultural communities collaborate in shared activities. We focus both on similarities across communities in processes of guided participation--structuring children's participation and bridging between their understanding and that of their caregivers--and on differences in how guided participation occurs. We examine the idea that a key cultural difference entails who is responsible for learning--whether adults take this responsibility by structuring teaching situations or whether children take responsibility for learning through observation and through participating in adult activities with caregivers' support. We speculate that these two patterns relate to cultural variation in the segregation of children from adult activities of their community and in emphasis on formal schooling. The four communities of our study vary along these lines as well as in other ways: a Mayan Indian town in Guatemala, a middle-class urban group in the United States, a tribal village in India, and a middle-class urban neighborhood in Turkey. In each community, we visited the families of 14 toddlers (aged 12-24 months) for an interview that was focused on child-rearing practices, which included observations of caregivers helping the toddlers operate novel objects spontaneously during adult activities. Results are based on systematic analysis of patterns of communication and attention in each family in each community, combining the tools of ethnographic description, graphic analysis, and statistics.(ABSTRACT TRUNCATED AT 250 WORDS)

Large-scale variation in subsurface stream biofilms: a cross-regional comparison of metabolic function and community similarity.

PubMed

Findlay, S; Sinsabaugh, R L

2006-10-01

We examined bacterial metabolic activity and community similarity in shallow subsurface stream sediments distributed across three regions of the eastern United States to assess whether there were parallel changes in functional and structural attributes at this large scale. Bacterial growth, oxygen consumption, and a suite of extracellular enzyme activities were assayed to describe functional variability. Community similarity was assessed using randomly amplified polymorphic DNA (RAPD) patterns. There were significant differences in streamwater chemistry, metabolic activity, and bacterial growth among regions with, for instance, twofold higher bacterial production in streams near Baltimore, MD, compared to Hubbard Brook, NH. Five of eight extracellular enzymes showed significant differences among regions. Cluster analyses of individual streams by metabolic variables showed clear groups with significant differences in representation of sites from different regions among groups. Clustering of sites based on randomly amplified polymorphic DNA banding resulted in groups with generally less internal similarity although there were still differences in distribution of regional sites. There was a marginally significant (p = 0.09) association between patterns based on functional and structural variables. There were statistically significant but weak (r2 approximately 30%) associations between landcover and measures of both structure and function. These patterns imply a large-scale organization of biofilm communities and this structure may be imposed by factor(s) such as landcover and covariates such as nutrient concentrations, which are known to also cause differences in macrobiota of stream ecosystems.

Diversity patterns and activity of uncultured marine heterotrophic flagellates unveiled with pyrosequencing

PubMed Central

Logares, Ramiro; Audic, Stephane; Santini, Sebastien; Pernice, Massimo C; de Vargas, Colomban; Massana, Ramon

2012-01-01

Flagellated heterotrophic microeukaryotes have key roles for the functioning of marine ecosystems as they channel large amounts of organic carbon to the upper trophic levels and control the population sizes of bacteria and archaea. Still, we know very little on the diversity patterns of most groups constituting this evolutionary heterogeneous assemblage. Here, we investigate 11 groups of uncultured flagellates known as MArine STramenopiles (MASTs). MASTs are ecologically very important and branch at the base of stramenopiles. We explored the diversity patterns of MASTs using pyrosequencing (18S rDNA) in coastal European waters. We found that MAST groups range from highly to lowly diversified. Pyrosequencing (hereafter ‘454') allowed us to approach to the limits of taxonomic diversity for all MAST groups, which varied in one order of magnitude (tens to hundreds) in terms of operational taxonomic units (98% similarity). We did not evidence large differences in activity, as indicated by ratios of DNA:RNA-reads. Most groups were strictly planktonic, although we found some groups that were active in sediments and even in anoxic waters. The proportion of reads per size fraction indicated that most groups were composed of very small cells (∼2–5 μm). In addition, phylogenetically different assemblages appeared to be present in different size fractions, depths and geographic zones. Thus, MAST diversity seems to be highly partitioned in spatial scales. Altogether, our results shed light on these ecologically very important but poorly known groups of uncultured marine flagellates. PMID:22534609

Variations in the sales and sales patterns of veterinary antimicrobial agents in 25 European countries.

PubMed

Grave, Kari; Torren-Edo, Jordi; Muller, Arno; Greko, Christina; Moulin, Gerard; Mackay, David

2014-08-01

To describe sales and sales patterns of veterinary antimicrobial agents in 25 European Union (EU)/European Economic Area (EEA) countries for 2011. Data on the sales of veterinary antimicrobial agents from 25 EU member states and EEA countries for 2011 were collected at package level (name, formulation, strength, pack size, number of packages sold) according to a standardized protocol and template and presented in a harmonized manner. These data were calculated to express amounts sold, in metric tonnes, of active ingredient of each package. A population correction unit (PCU) was applied as a proxy for the animal biomass potentially treated with antimicrobial agents. The indicator used to express sales was milligrams of active substance per PCU. Substantial variations in the sales patterns and in the magnitude of sales of veterinary antimicrobial agents, expressed as mg/PCU, between the countries were observed. The proportion of sales, in mg/PCU, of products applicable for treatment of groups or herds of animals (premixes, oral powders and oral solution) varied considerably between the countries. Some countries reported much lower sales of veterinary antimicrobial agents than others, when expressed as mg/PCU. Sales patterns varied between countries, particularly with respect to pharmaceutical forms. Further studies are needed to understand the factors that explain the observed differences. © The Author 2014. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Modified Mediterranean Diet Score and Cardiovascular Risk in a North American Working Population

PubMed Central

Yang, Justin; Farioli, Andrea; Korre, Maria; Kales, Stefanos N.

2014-01-01

Introduction Greater adherence to a Mediterranean diet is linked to lower risk for cardiovascular morbidity/mortality in studies of Mediterranean cohorts, older subjects, and/or those with existing health conditions. No studies have examined the effects of this dietary pattern in younger working populations in the United States. We investigated the effects of Mediterranean diet adherence on cardiovascular disease (CVD) biomarkers, metabolic syndrome and body composition in an occupationally active, non-Mediterranean cohort. Methods A cross-sectional study in a cohort of 780 career male firefighters, ages 18 years or older, from the United States Midwest. No dietary intervention was performed. A modified Mediterranean diet score (mMDS) was developed for assessment of adherence to a Mediterranean dietary pattern from a previously administered life-style questionnaire that examined pre-existing dietary habits. Clinical data from fire department medical examinations were extracted and analyzed. Results Obese subjects had significantly lower mMDS, and they reported greater fast/take-out food consumption (p<0.001) and intake of sweetened drinks during meals (p = 0.002). After multivariate adjustment, higher mMDS was inversely related to risk of weight gain over the past 5 years (odds ratio [OR]: 0.57, 95% confidence interval [CI]: 0.39–0.84, p for trend across score quartiles: 0.01); as well as the presence of metabolic syndrome components (OR: 0.65, 95% CI: 0.44–0.94, p for trend across score quartiles: 0.04). Higher HDL-cholesterol (p = 0.008) and lower LDL-cholesterol (p = 0.04) were observed in those with higher mMDS in linear regression after multivariate adjustment for age, BMI and physical activity. Conclusions In a cohort of young and active US adults, greater adherence to a Mediterranean-style dietary pattern had significant inverse associations with metabolic syndrome, LDL-cholesterol and reported weight gain, and was significantly and independently associated with higher HDL-cholesterol. Our results support the potential effectiveness of this diet in young, non-Mediterranean working cohorts, and justify future intervention studies. PMID:24503596

Attracting Dynamics of Frontal Cortex Ensembles during Memory-Guided Decision-Making

PubMed Central

Seamans, Jeremy K.; Durstewitz, Daniel

2011-01-01

A common theoretical view is that attractor-like properties of neuronal dynamics underlie cognitive processing. However, although often proposed theoretically, direct experimental support for the convergence of neural activity to stable population patterns as a signature of attracting states has been sparse so far, especially in higher cortical areas. Combining state space reconstruction theorems and statistical learning techniques, we were able to resolve details of anterior cingulate cortex (ACC) multiple single-unit activity (MSUA) ensemble dynamics during a higher cognitive task which were not accessible previously. The approach worked by constructing high-dimensional state spaces from delays of the original single-unit firing rate variables and the interactions among them, which were then statistically analyzed using kernel methods. We observed cognitive-epoch-specific neural ensemble states in ACC which were stable across many trials (in the sense of being predictive) and depended on behavioral performance. More interestingly, attracting properties of these cognitively defined ensemble states became apparent in high-dimensional expansions of the MSUA spaces due to a proper unfolding of the neural activity flow, with properties common across different animals. These results therefore suggest that ACC networks may process different subcomponents of higher cognitive tasks by transiting among different attracting states. PMID:21625577

The pattern of early lung parenchymal and air space injury following acute blood loss.

PubMed

Younger, J G; Taqi, A S; Jost, P F; Till, G O; Johnson, K J; Stern, S A; Hirschl, R B

1998-07-01

Acute lung injury is a frequent clinical occurrence following blood loss and trauma. The nature of this injury remains poorly understood. To examine the relative parenchymal and intra-alveolar distribution of inflammation in a rat model of hemorrhage and resuscitation. Rats were anesthetized and subjected to hemorrhage followed by resuscitation with shed blood and saline. Myeloperoxidase activity of lung homogenates and cytology of bronchoalveolar lavage fluid were used to measure total lung and intra-alveolar neutrophil invasion. Extravasation of i.v.-administered [125I]-albumin was used to determine total lung and alveolar permeability. Permeability results were analyzed using their base-10 logarithmic transformations. 86 animals were studied. Whole-lung myeloperoxidase activity was increased (control = 0.34 +/- 0.16 units, injured = 0.84 +/- 0.43 units, p < 0.01), while there was no difference in intra-alveolar leukocyte counts (injured = 1.85 +/- 1.30 x 10(5)/mL, control = 2.44 +/- 1.75 x 10(5)/mL, p = 0.40), suggesting that the cellular component of the injury was more severe in the intravascular and interstitial spaces. There was a strong trend toward increased permeability in the interstitial compartment, and a significant increase in permeability in the intra-alveolar compartment (whole-lung permeability: control = -0.27 +/- 0.19 units, injured = 0.10 +/- 0.55 units, p = 0.06; alveolar permeability: control = -2.00 +/- 0.47 units, injured = -1.32 +/- 0.49 units, p < 0.01), suggesting that the loss of integrity to macromolecules was not limited to the interstitium. Hemorrhage and resuscitation resulted in an acute lung injury characterized by extravasation of intravascular protein into both the interstitium and the intra-alveolar space. Neutrophil invasion of the lung was demonstrable only in the interstitial compartment.

Enhanced Motor Imagery-Based BCI Performance via Tactile Stimulation on Unilateral Hand.

PubMed

Shu, Xiaokang; Yao, Lin; Sheng, Xinjun; Zhang, Dingguo; Zhu, Xiangyang

2017-01-01

Brain-computer interface (BCI) has attracted great interests for its effectiveness in assisting disabled people. However, due to the poor BCI performance, this technique is still far from daily-life applications. One of critical issues confronting BCI research is how to enhance BCI performance. This study aimed at improving the motor imagery (MI) based BCI accuracy by integrating MI tasks with unilateral tactile stimulation (Uni-TS). The effects were tested on both healthy subjects and stroke patients in a controlled study. Twenty-two healthy subjects and four stroke patients were recruited and randomly divided into a control-group and an enhanced-group. In the control-group, subjects performed two blocks of conventional MI tasks (left hand vs. right hand), with 80 trials in each block. In the enhanced-group, subjects also performed two blocks of MI tasks, but constant tactile stimulation was applied on the non-dominant/paretic hand during MI tasks in the second block. We found the Uni-TS significantly enhanced the contralateral cortical activations during MI of the stimulated hand, whereas it had no influence on activation patterns during MI of the non-stimulated hand. The two-class BCI decoding accuracy was significantly increased from 72.5% (MI without Uni-TS) to 84.7% (MI with Uni-TS) in the enhanced-group ( p < 0.001, paired t -test). Moreover, stroke patients in the enhanced-group achieved an accuracy >80% during MI with Uni-TS. This novel approach complements the conventional methods for BCI enhancement without increasing source information or complexity of signal processing. This enhancement via Uni-TS may facilitate clinical applications of MI-BCI.

Patterns of health behaviour associated with active travel: a compositional data analysis.

PubMed

Foley, Louise; Dumuid, Dorothea; Atkin, Andrew J; Olds, Timothy; Ogilvie, David

2018-03-21

Active travel (walking or cycling for transport) is associated with favourable health outcomes in adults. However, little is known about the concurrent patterns of health behaviour associated with active travel. We used compositional data analysis to explore differences in how people doing some active travel used their time compared to those doing no active travel, incorporating physical activity, sedentary behaviour and sleep. We analysed cross-sectional data from the 2014/15 United Kingdom Harmonised European Time Use Survey. Participants recorded two diary days of activity, and we randomly selected one day from participants aged 16 years or over. Activities were categorised into six mutually exclusive sets, accounting for the entire 24 h: (1) sleep; (2) leisure moderate to vigorous physical activity (MVPA); (3) leisure sedentary screen time; (4) non-discretionary time (work, study, chores and caring duties); (5) travel and (6) other. This mixture of activities was defined as a time-use composition. A binary variable was created indicating whether participants reported any active travel on their selected diary day. We used compositional multivariate analysis of variance (MANOVA) to test whether mean time-use composition differed between individuals reporting some active travel and those reporting no active travel, adjusted for covariates. We then used adjusted linear regression models and bootstrap confidence intervals to identify which of the six activity sets differed between groups. 6143 participants (mean age 48 years; 53% female) provided a valid diary day. There was a statistically significant difference in time-use composition between those reporting some active travel and those reporting no active travel. Those undertaking active travel reported a relatively greater amount of time in leisure MVPA and travel, and a relatively lower amount of time in leisure sedentary screen time and sleep. Compared to those not undertaking active travel, those who did active travel reported 11 min more in leisure MVPA and 18 min less in screen time per day, and reported lower sleep. From a health perspective, higher MVPA and lower screen time is favourable, but the pattern of sleep is more complex. Overall, active travel was associated with a broadly health-promoting composition of time across multiple behavioural domains, which supports the public health case for active travel.

Phase diagram of restricted Boltzmann machines and generalized Hopfield networks with arbitrary priors.

PubMed

Barra, Adriano; Genovese, Giuseppe; Sollich, Peter; Tantari, Daniele

2018-02-01

Restricted Boltzmann machines are described by the Gibbs measure of a bipartite spin glass, which in turn can be seen as a generalized Hopfield network. This equivalence allows us to characterize the state of these systems in terms of their retrieval capabilities, both at low and high load, of pure states. We study the paramagnetic-spin glass and the spin glass-retrieval phase transitions, as the pattern (i.e., weight) distribution and spin (i.e., unit) priors vary smoothly from Gaussian real variables to Boolean discrete variables. Our analysis shows that the presence of a retrieval phase is robust and not peculiar to the standard Hopfield model with Boolean patterns. The retrieval region becomes larger when the pattern entries and retrieval units get more peaked and, conversely, when the hidden units acquire a broader prior and therefore have a stronger response to high fields. Moreover, at low load retrieval always exists below some critical temperature, for every pattern distribution ranging from the Boolean to the Gaussian case.

The activity of detoxifying enzymes in the infective juveniles of Heterorhabditis bacteriophora strains: Purification and characterization of two acetylcholinesterases.

PubMed

Mohamed, Magda A; Mahdy, El-Sayed M E; Ghazy, Abd-El-Hady M; Ibrahim, Nihal M; El-Mezayen, Hatem A; Ghanem, Manal M E

2016-02-01

The infectivity and detoxifying enzyme activities including glutathione-S-transferase (GST), acetylcholinesterase (AChE) and carboxylesterase (CaE) are investigated in the infective juveniles (IJs) of six different strains of Heterorhabditis bacteriophora as a biocontrol agent against insect pests. The specific activities ranged from 10.8-29.8 and 50-220units/mg protein for GST and AChE, respectively; and from 24.7-129 and 22.6-77.3units/mg protein for CaE as estimated by P-nitrophenyl and α-naphthyl acetates, respectively. H. bacteriophora EM2 strain has the highest infectivity and the highest enzymatic activities as well. AChE is the predominant detoxifying enzyme that might imply its major role in the detoxification of insecticide(s). The isoenzyme pattern demonstrated two major slow-moving isoforms in all EPN strains examined. Purification of two AChE isoforms, AChEAII and AChEBI, from H. bacteriophora EM2 strain is performed by ammonium sulfate precipitation, gel filtration on Sephacryl S-200 and chromatography on DEAE-Sepharose. AChEAII and AChEBII have specific activities of 1207 and 1560unit/mg protein, native molecular weights of 180 and 68kDa, and are found in dimeric and monomeric forms, respectively. Both isoforms showed optimum activity at pH8.5 and 35°C. AChEBI exhibited higher thermal stability and higher activation energy than AChEAII. The enzymatic activities of purified AChEs are completely inhibited by Hg(+2) and Ni(+2) and greatly enhanced by Mn(+2). The substrate specificity, the relative efficiency of substrates hydrolysis, substrate inhibition and inhibition by BW284C51, but not by iso-OMPA, clearly indicated that they are true AChEs; their properties are compared with those recorded for insects as target hosts for H. bacteriophora EM2. Copyright © 2015 Elsevier Inc. All rights reserved.

Dopamine activates the motor pattern for crawling in the medicinal leech.

PubMed

Puhl, Joshua G; Mesce, Karen A

2008-04-16

Locomotion in segmented animals is thought to be based on the coupling of "unit burst generators," but the biological nature of the unit burst generator has been revealed in only a few animal systems. We determined that dopamine (DA), a universal modulator of motor activity, is sufficient to activate fictive crawling in the medicinal leech, and can exert its actions within the smallest division of the animal's CNS, the segmental ganglion. In the entire isolated nerve cord or in the single ganglion, DA induced slow antiphasic bursting (approximately 15 s period) of motoneurons known to participate in the two-step elongation-contraction cycle underlying crawling behavior. During each cycle, the dorsal (DE-3) and ventral (VE-4) longitudinal excitor motoneurons fired approximately 180 degrees out of phase from the ventrolateral circular excitor motoneuron (CV), which marks the elongation phase. In many isolated whole nerve cords, DE-3 bursting progressed in an anterior to posterior direction with intersegmental phase delays appropriate for crawling. In the single ganglion, the dorsal (DI-1) and ventral (VI-2) inhibitory longitudinal motoneurons fired out of phase with each DE-3 burst, further confirming that the crawl unit burst generator exists in the single ganglion. All isolated ganglia of the CNS were competent to produce DA-induced robust fictive crawling, which typically lasted uninterrupted for 5-15 min. A quantitative analysis indicated that DA-induced crawling was not significantly different from electrically evoked or spontaneous crawling. We conclude that DA is sufficient to activate the full crawl motor program and that the kernel for crawling resides within each segmental ganglion.

The regional distribution and correlates of an entrepreneurship-prone personality profile in the United States, Germany, and the United Kingdom: a socioecological perspective.

PubMed

Obschonka, Martin; Schmitt-Rodermund, Eva; Silbereisen, Rainer K; Gosling, Samuel D; Potter, Jeff

2013-07-01

In recent years the topic of entrepreneurship has become a major focus in the social sciences, with renewed interest in the links between personality and entrepreneurship. Taking a socioecological perspective to psychology, which emphasizes the role of social habitats and their interactions with mind and behavior, we investigated regional variation in and correlates of an entrepreneurship-prone Big Five profile. Specifically, we analyzed personality data collected from over half a million U.S. residents (N = 619,397) as well as public archival data on state-level entrepreneurial activity (i.e., business-creation and self-employment rates). Results revealed that an entrepreneurship-prone personality profile is regionally clustered. This geographical distribution corresponds to the pattern that can be observed when mapping entrepreneurial activity across the United States. Indeed, the state-level correlation (N = 51) between an entrepreneurial personality structure and entrepreneurial activity was positive in direction, substantial in magnitude, and robust even when controlling for regional economic prosperity. These correlations persisted at the level of U.S. metropolitan statistical areas (N = 15) and were replicated in independent German (N = 19,842; 14 regions) and British (N = 15,617; 12 regions) samples. In contrast to these profile-based analyses, an analysis linking the individual Big Five dimensions to regional measures of entrepreneurial activity did not yield consistent findings. Discussion focuses on the implications of these findings for interdisciplinary theory development and practical applications. PsycINFO Database Record (c) 2013 APA, all rights reserved.

Interpretation of Tracer Experiments on Inverted Five-spot Well-patterns within the Western Half of the Farnsworth Unit Oil Field

DOE PAGES

White, Mark D.; Esser, R. P.; McPherson, B. P.; ...

2017-07-01

The Southwest Carbon Partnership (SWP), one of the U.S. Department of Energy (U.S. DOE) seven Regional Carbon Sequestration Partnerships, is currently working to demonstrate the utilization and storage of CO 2 in the Farnsworth Unit (FWU) Enhanced Oil Recovery (EOR) site under the final development phase of this U.S. DOE initiative. A component of the research is to use fluid tracers to understand the multifluid flow patterns that develop between injection and production wells via collected field data and supporting numerical reservoir models. The FWU, located in the Anadarko Basin, Ochiltree County, Texas, and being operated by Chaparral Energy, ismore » a mature EOR water-flood field, which is currently being converted to a CO 2 flow, with inverted 5-spot patterns transitioning from pure water to alternating CO 2 and water floods (i.e., water alternating gas (WAG)) at an approximate rate of one every 6 to 10 months. The SWP tracer program is conducting a suite of tracer injections into the active 5-spot patterns at the FWU. Tracers have been selected to be nonreactive and either principally soluble in CO 2 (gas soluble) or water (aqueous soluble). In addition to characterizing the multifluid flow behaviour within reservoir, the gas and aqueous tracers have roles in detecting any leakage from the reservoir. A total of seven unique perfluorocarbon tracer (PFT) compounds make up the suite of gas soluble tracers and eight unique naphthalene sulfonate tracer (NPT) compounds comprise the aqueous soluble tracers. Lastly, all selected tracers are significantly detectable below the parts per billion concentrations, allowing for high resolution for the inter-well tests at relatively low injection volumes.« less

Interpretation of Tracer Experiments on Inverted Five-spot Well-patterns within the Western Half of the Farnsworth Unit Oil Field

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

White, Mark D.; Esser, R. P.; McPherson, B. P.

The Southwest Carbon Partnership (SWP), one of the U.S. Department of Energy (U.S. DOE) seven Regional Carbon Sequestration Partnerships, is currently working to demonstrate the utilization and storage of CO 2 in the Farnsworth Unit (FWU) Enhanced Oil Recovery (EOR) site under the final development phase of this U.S. DOE initiative. A component of the research is to use fluid tracers to understand the multifluid flow patterns that develop between injection and production wells via collected field data and supporting numerical reservoir models. The FWU, located in the Anadarko Basin, Ochiltree County, Texas, and being operated by Chaparral Energy, ismore » a mature EOR water-flood field, which is currently being converted to a CO 2 flow, with inverted 5-spot patterns transitioning from pure water to alternating CO 2 and water floods (i.e., water alternating gas (WAG)) at an approximate rate of one every 6 to 10 months. The SWP tracer program is conducting a suite of tracer injections into the active 5-spot patterns at the FWU. Tracers have been selected to be nonreactive and either principally soluble in CO 2 (gas soluble) or water (aqueous soluble). In addition to characterizing the multifluid flow behaviour within reservoir, the gas and aqueous tracers have roles in detecting any leakage from the reservoir. A total of seven unique perfluorocarbon tracer (PFT) compounds make up the suite of gas soluble tracers and eight unique naphthalene sulfonate tracer (NPT) compounds comprise the aqueous soluble tracers. Lastly, all selected tracers are significantly detectable below the parts per billion concentrations, allowing for high resolution for the inter-well tests at relatively low injection volumes.« less

Modeled historical land use and land cover for the conterminous United States

USGS Publications Warehouse

Sohl, Terry L.; Reker, Ryan R.; Bouchard, Michelle A.; Sayler, Kristi L.; Dornbierer, Jordan; Wika, Steve; Quenzer, Robert; Friesz, Aaron M.

2016-01-01

The landscape of the conterminous United States has changed dramatically over the last 200 years, with agricultural land use, urban expansion, forestry, and other anthropogenic activities altering land cover across vast swaths of the country. While land use and land cover (LULC) models have been developed to model potential future LULC change, few efforts have focused on recreating historical landscapes. Researchers at the US Geological Survey have used a wide range of historical data sources and a spatially explicit modeling framework to model spatially explicit historical LULC change in the conterminous United States from 1992 back to 1938. Annual LULC maps were produced at 250-m resolution, with 14 LULC classes. Assessment of model results showed good agreement with trends and spatial patterns in historical data sources such as the Census of Agriculture and historical housing density data, although comparison with historical data is complicated by definitional and methodological differences. The completion of this dataset allows researchers to assess historical LULC impacts on a range of ecological processes.

EEG signatures of arm isometric exertions in preparation, planning and execution.

PubMed

Nasseroleslami, Bahman; Lakany, Heba; Conway, Bernard A

2014-04-15

The electroencephalographic (EEG) activity patterns in humans during motor behaviour provide insight into normal motor control processes and for diagnostic and rehabilitation applications. While the patterns preceding brisk voluntary movements, and especially movement execution, are well described, there are few EEG studies that address the cortical activation patterns seen in isometric exertions and their planning. In this paper, we report on time and time-frequency EEG signatures in experiments in normal subjects (n=8), using multichannel EEG during motor preparation, planning and execution of directional centre-out arm isometric exertions performed at the wrist in the horizontal plane, in response to instruction-delay visual cues. Our observations suggest that isometric force exertions are accompanied by transient and sustained event-related potentials (ERP) and event-related (de-)synchronisations (ERD/ERS), comparable to those of a movement task. Furthermore, the ERPs and ERD/ERS are also observed during preparation and planning of the isometric task. Comparison of ear-lobe-referenced and surface Laplacian ERPs indicates the contribution of superficial sources in supplementary and pre-motor (FC(z)), parietal (CP(z)) and primary motor cortical areas (C₁ and FC₁) to ERPs (primarily negative peaks in frontal and positive peaks in parietal areas), but contribution of deep sources to sustained time-domain potentials (negativity in planning and positivity in execution). Transient and sustained ERD patterns in μ and β frequency bands of ear-lobe-referenced and surface Laplacian EEG indicate the contribution of both superficial and deep sources to ERD/ERS. As no physical displacement happens during the task, we can infer that the underlying mechanisms of motor-related ERPs and ERD/ERS patterns do not only depend on change in limb coordinate or muscle-length-dependent ascending sensory information and are primary generated by motor preparation, direction-dependent planning and execution of isometric motor tasks. The results contribute to our understanding of the functions of different brain regions during voluntary motor tasks and their activity signatures in EEG can shed light on the relationships between large-scale recordings such as EEG and other recordings such as single unit activity and fMRI in this context. Copyright © 2013 Elsevier Inc. All rights reserved.

Prognostic value of electroencephalography (EEG) after out-of-hospital cardiac arrest in successfully resuscitated patients used in daily clinical practice.

PubMed

Søholm, Helle; Kjær, Troels Wesenberg; Kjaergaard, Jesper; Cronberg, Tobias; Bro-Jeppesen, John; Lippert, Freddy K; Køber, Lars; Wanscher, Michael; Hassager, Christian

2014-11-01

Out-of-hospital cardiac arrest (OHCA) is associated with a poor prognosis and predicting outcome is complex with neurophysiological testing and repeated clinical neurological examinations as key components of the assessment. In this study we examine the association between different electroencephalography (EEG) patterns and mortality in a clinical cohort of OHCA-patients. From 2002 to 2011 consecutive patients were admitted to an intensive-care-unit after resuscitation from OHCA. Utstein-criteria for pre-hospital data and review of individual patients' charts for post-resuscitation care were used. EEG reports were analysed according to the 2012 American Clinical Neurophysiology Society's guidelines. A total of 1076 patients were included, and EEG was performed in 20% (n=219) with a median of 3(IQR 2-4) days after OHCA. Rhythmic Delta Activity (RDA) was found in 71 patients (36%) and Periodic Discharges (PD) in 100 patients (45%). Background EEG frequency of Alpha+ or Theta was noted in 107 patients (49%), and change in cerebral EEG activity to stimulation (reactivity) was found in 38 patients (17%). Suppression (all activity <10 μV) was found in 26 (12%) and burst-suppression in 17 (8%) patients. A favourable EEG pattern (reactivity, favourable background frequency and RDA) was independently associated with reduced mortality with hazard ratio (HR) 0.43 (95%CI: 0.24-0.76), p=0.004 (false positive rate: 31%) and a non-favourable EEG pattern (no reactivity, unfavourable background frequency, and PD, suppressed voltage or burst-suppression) was associated with higher mortality (HR=1.62(1.09-2.41), p=0.02) after adjustment for known prognostic factors (false positive rate: 9%). EEG may be useful in work-up in prognostication of patients with OHCA. Findings such as Rhythmic Delta Activity (RDA) seem to be associated with a better prognosis, whereas suppressed voltage and burst-suppression patterns were associated with poor prognosis. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Multichannel activity propagation across an engineered axon network

NASA Astrophysics Data System (ADS)

Chen, H. Isaac; Wolf, John A.; Smith, Douglas H.

2017-04-01

Objective. Although substantial progress has been made in mapping the connections of the brain, less is known about how this organization translates into brain function. In particular, the massive interconnectivity of the brain has made it difficult to specifically examine data transmission between two nodes of the connectome, a central component of the ‘neural code.’ Here, we investigated the propagation of multiple streams of asynchronous neuronal activity across an isolated in vitro ‘connectome unit.’ Approach. We used the novel technique of axon stretch growth to create a model of a long-range cortico-cortical network, a modular system consisting of paired nodes of cortical neurons connected by axon tracts. Using optical stimulation and multi-electrode array recording techniques, we explored how input patterns are represented by cortical networks, how these representations shift as they are transmitted between cortical nodes and perturbed by external conditions, and how well the downstream node distinguishes different patterns. Main results. Stimulus representations included direct, synaptic, and multiplexed responses that grew in complexity as the distance between the stimulation source and recorded neuron increased. These representations collapsed into patterns with lower information content at higher stimulation frequencies. With internodal activity propagation, a hierarchy of network pathways, including latent circuits, was revealed using glutamatergic blockade. As stimulus channels were added, divergent, non-linear effects were observed in local versus distant network layers. Pairwise difference analysis of neuronal responses suggested that neuronal ensembles generally outperformed individual cells in discriminating input patterns. Significance. Our data illuminate the complexity of spiking activity propagation in cortical networks in vitro, which is characterized by the transformation of an input into myriad outputs over several network layers. These results provide insight into how the brain potentially processes information and generates the neural code and could guide the development of clinical therapies based on multichannel brain stimulation.

High school chemistry students' learning of the elements, structure, and periodicity of the periodic table: Contributions of inquiry-based activities and exemplary graphics

NASA Astrophysics Data System (ADS)

Roddy, Knight Phares, Jr.

The main research question of this study was: How do selected high school chemistry students' understandings of the elements, structure, and periodicity of the Periodic Table change as they participate in a unit study consisting of inquiry-based activities emphasizing construction of innovative science graphics? The research question was answered using a multiple case study/mixed model design which employed elements of both qualitative and quantitative methodologies during data collection and analyses. The unit study was conducted over a six-week period with 11th -grade students enrolled in a chemistry class. A purposive sample of six students from the class was selected to participate in interviews and concept map coconstruction (Wandersee & Abrams, 1993) periodically across the study. The progress of the selected students of the case study was compared to the progress of the class as a whole. The students of the case study were also compared to a group of high school chemistry students at a comparative school. The results show that the students from both schools left traditional instruction on the periodic table (lecture and textbook activities) with a very limited understanding of the topic. It also revealed that the inquiry-based, visual approach of the unit study helped students make significant conceptual progress in their understanding of the periodic table. The pictorial periodic table (which features photographs of the elements), used in conjunction with the graphic technique of data mapping, enhanced students understanding of the patterns of the physical properties of the elements on the periodic table. The graphic technique of compound mapping helped students learn reactivity patterns between types and groups of elements on the periodic table. The recreation of the periodic table with element cards created from the pictorial periodic table helped students progress in their understanding of periodicity and its key concepts. The Periodic Table Literacy Rubric (PTLR) proved to be a valuable tool for assessing students' conceptual progress, and helped to identify a critical juncture in the learning of periodicity. In addition, the PTLR rubric's historical-conceptual design demonstrates how the history of science can be used to inform today's science teaching.

The global spread of HIV-1 subtype B epidemic.

PubMed

Magiorkinis, Gkikas; Angelis, Konstantinos; Mamais, Ioannis; Katzourakis, Aris; Hatzakis, Angelos; Albert, Jan; Lawyer, Glenn; Hamouda, Osamah; Struck, Daniel; Vercauteren, Jurgen; Wensing, Annemarie; Alexiev, Ivailo; Åsjö, Birgitta; Balotta, Claudia; Gomes, Perpétua; Camacho, Ricardo J; Coughlan, Suzie; Griskevicius, Algirdas; Grossman, Zehava; Horban, Anders; Kostrikis, Leondios G; Lepej, Snjezana J; Liitsola, Kirsi; Linka, Marek; Nielsen, Claus; Otelea, Dan; Paredes, Roger; Poljak, Mario; Puchhammer-Stöckl, Elizabeth; Schmit, Jean Claude; Sönnerborg, Anders; Staneková, Danica; Stanojevic, Maja; Stylianou, Dora C; Boucher, Charles A B; Nikolopoulos, Georgios; Vasylyeva, Tetyana; Friedman, Samuel R; van de Vijver, David; Angarano, Gioacchino; Chaix, Marie-Laure; de Luca, Andrea; Korn, Klaus; Loveday, Clive; Soriano, Vincent; Yerly, Sabine; Zazzi, Mauricio; Vandamme, Anne-Mieke; Paraskevis, Dimitrios

2016-12-01

Human immunodeficiency virus type 1 (HIV-1) was discovered in the early 1980s when the virus had already established a pandemic. For at least three decades the epidemic in the Western World has been dominated by subtype B infections, as part of a sub-epidemic that traveled from Africa through Haiti to United States. However, the pattern of the subsequent spread still remains poorly understood. Here we analyze a large dataset of globally representative HIV-1 subtype B strains to map their spread around the world over the last 50years and describe significant spread patterns. We show that subtype B travelled from North America to Western Europe in different occasions, while Central/Eastern Europe remained isolated for the most part of the early epidemic. Looking with more detail in European countries we see that the United Kingdom, France and Switzerland exchanged viral isolates with non-European countries than with European ones. The observed pattern is likely to mirror geopolitical landmarks in the post-World War II era, namely the rise and the fall of the Iron Curtain and the European colonialism. In conclusion, HIV-1 spread through specific migration routes which are consistent with geopolitical factors that affected human activities during the last 50years, such as migration, tourism and trade. Our findings support the argument that epidemic control policies should be global and incorporate political and socioeconomic factors. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Regional variation in immature Ixodes scapularis parasitism on North American songbirds: implications for transmission of the Lyme pathogen, Borrelia burgdorferi.

PubMed

Brinkerhoff, R Jory; Folsom-O'Keefe, Corrine M; Streby, Henry M; Bent, Stephen J; Tsao, Kimberly; Diuk-Wasser, Maria A

2011-03-01

Borrelia burgdorferi, the etiological agent of Lyme disease, is transmitted among hosts by the black-legged tick, Ixodes scapularis, a species that regularly parasitizes various vertebrate hosts, including birds, in its immature stages. Lyme disease risk in the United States is highest in the Northeast and in the upper Midwest where I. scapularis ticks are most abundant. Because birds might be important to the range expansion of I. scapularis and B. burgdorferi, we explored spatial variation in patterns of I. scapularis parasitism on songbirds, as well as B. burgdorferi infection in bird-derived I. scapularis larvae. We sampled birds at 23 sites in the eastern United States to describe seasonal patterns of I. scapularis occurrence on birds, and we screened a subset of I. scapularis larvae for presence of B. burgdorferi. Timing of immature I. scapularis occurrence on birds is consistent with regional variation in host-seeking activity with a generally earlier peak in larval parasitism on birds in the Midwest. Significantly more I. scapularis larvae occurred on birds that were contemporaneously parasitized by nymphs in the Midwest than the Northeast, and the proportion of birds that yielded B. burgdorferi-infected larvae was also higher in the Midwest. We conclude that regional variation in immature I. scapularis phenology results in different temporal patterns of parasitism on birds, potentially resulting in differential importance of birds to B. burgdorferi transmission dynamics among regions.

Dominance of organic nitrogen from headwater streams to large rivers across the conterminous United States

USGS Publications Warehouse

Scott, D.; Harvey, J.; Alexander, R.; Schwarz, G.

2007-01-01

The frequency and magnitude of hypoxic areas in coastal waterbodies are increasing across the globe, partially in response to the increase in nitrogen delivery from the landscape (Diaz, 2001; Rabalais et al., 2002). Although studies of annual total nitrogen and nitrate yields have greatly improved understanding of the contaminant sources that contribute to riverine nitrogen loads (Alexander et al., 2000; Caraco and Cole, 1999), the emphasis of these studies on annual timescales and selected nitrogen forms is not sufficient to understand the factors that control the cycling, transport, and fate of reactive nitrogen. Here we use data from 850 river stations to calculate long-term mean-annual and interannual loads of organic, ammonia, and nitrate-nitrite nitrogen suitable for spatial analysis. We find that organic nitrogen is the dominant nitrogen pool within rivers across most of the United States and is significant even in basins with high anthropogenic sources of nitrogen. Downstream organic nitrogen patterns illustrate that organic nitrogen is an abundant fraction of the nitrogen loads in all regions. Although the longitudinal patterns are not consistent across regions, these patterns are suggestive of cycling between ON and NO3- on seasonal timescales influenced by land use, stream morphology, and riparian connectivity with active floodplains. Future regional studies need to incorporate multinitrogen species at intraannual timescales, as well as stream characteristics beyond channel depth, to elucidate the roles of nitrogen sources and in-stream transformations on the fate and reactivity of riverine nitrogen transported to coastal seas.

Dominance of organic nitrogen from headwater streams to large rivers across the conterminous United States

NASA Astrophysics Data System (ADS)

Scott, Durelle; Harvey, Judson; Alexander, Richard; Schwarz, Gregory

2007-03-01

The frequency and magnitude of hypoxic areas in coastal waterbodies are increasing across the globe, partially in response to the increase in nitrogen delivery from the landscape (Diaz, 2001; Rabalais et al., 2002). Although studies of annual total nitrogen and nitrate yields have greatly improved understanding of the contaminant sources that contribute to riverine nitrogen loads (Alexander et al., 2000; Caraco and Cole, 1999), the emphasis of these studies on annual timescales and selected nitrogen forms is not sufficient to understand the factors that control the cycling, transport, and fate of reactive nitrogen. Here we use data from 850 river stations to calculate long-term mean-annual and interannual loads of organic, ammonia, and nitrate-nitrite nitrogen suitable for spatial analysis. We find that organic nitrogen is the dominant nitrogen pool within rivers across most of the United States and is significant even in basins with high anthropogenic sources of nitrogen. Downstream organic nitrogen patterns illustrate that organic nitrogen is an abundant fraction of the nitrogen loads in all regions. Although the longitudinal patterns are not consistent across regions, these patterns are suggestive of cycling between ON and NO3- on seasonal timescales influenced by land use, stream morphology, and riparian connectivity with active floodplains. Future regional studies need to incorporate multinitrogen species at intraannual timescales, as well as stream characteristics beyond channel depth, to elucidate the roles of nitrogen sources and in-stream transformations on the fate and reactivity of riverine nitrogen transported to coastal seas.

Kinematic control of walking.

PubMed

Lacquaniti, F; Ivanenko, Y P; Zago, M

2002-10-01

The planar law of inter-segmental co-ordination we described may emerge from the coupling of neural oscillators between each other and with limb mechanical oscillators. Muscle contraction intervenes at variable times to re-excite the intrinsic oscillations of the system when energy is lost. The hypothesis that a law of coordinative control results from a minimal active tuning of the passive inertial and viscoelastic coupling among limb segments is congruent with the idea that movement has evolved according to minimum energy criteria (1, 8). It is known that multi-segment motion of mammals locomotion is controlled by a network of coupled oscillators (CPGs, see 18, 33, 37). Flexible combination of unit oscillators gives rise to different forms of locomotion. Inter-oscillator coupling can be modified by changing the synaptic strength (or polarity) of the relative spinal connections. As a result, unit oscillators can be coupled in phase, out of phase, or with a variable phase, giving rise to different behaviors, such as speed increments or reversal of gait direction (from forward to backward). Supra-spinal centers may drive or modulate functional sets of coordinating interneurons to generate different walking modes (or gaits). Although it is often assumed that CPGs control patterns of muscle activity, an equally plausible hypothesis is that they control patterns of limb segment motion instead (22). According to this kinematic view, each unit oscillator would directly control a limb segment, alternately generating forward and backward oscillations of the segment. Inter-segmental coordination would be achieved by coupling unit oscillators with a variable phase. Inter-segmental kinematic phase plays the role of global control variable previously postulated for the network of central oscillators. In fact, inter-segmental phase shifts systematically with increasing speed both in man (4) and cat (38). Because this phase-shift is correlated with the net mechanical power output over a gait cycle (3, 4), phase control could be used for limiting the overall energy expenditure with increasing speed (22). Adaptation to different walking conditions, such as changes in body posture, body weight unloading and backward walk, also involves inter-segmental phase tuning, as does the maturation of limb kinematics in toddlers.

Outcomes of Nulliparous Women with Spontaneous Labor Onset Admitted to Hospitals in Pre-active versus Active Labor

PubMed Central

NEAL, Jeremy L.; LAMP, Jane M.; BUCK, Jacalyn S.; LOWE, Nancy K.; GILLESPIE, Shannon L.; RYAN, Sharon L.

2014-01-01

Introduction The timing of when a woman is admitted to the hospital for labor care following spontaneous contraction onset may be among the most important decisions that labor attendants make as it can influence care patterns and birth outcomes. The aims of this study were to estimate the percentage of low-risk, nulliparous women at term who are admitted to labor units prior to active labor and to evaluate the effects of the timing of admission (i.e., pre-active versus active labor) on labor interventions and mode of birth. Methods Obstetrics data from low-risk, nulliparous women with spontaneous labor onset at term gestation (N = 216) were merged from two prospective studies conducted at three large, Midwestern hospitals. Baseline characteristics, labor interventions, and outcomes were compared between groups using Fisher’s exact and Mann-Whitney U tests, as appropriate. Likelihoods for oxytocin augmentation, amniotomy, and cesarean delivery were assessed by logistic regression. Results Of the sample of 216 low-risk nulliparous women, 114 (52.8%) were admitted in pre-active labor and 102 (47.2%) were admitted in active labor. Women admitted in pre-active labor were more likely to undergo oxytocin augmentation (84.2% and 45.1%, respectively; odds ratio (OR) 6.5, 95% confidence interval (CI) 3.43–12.27) but not amniotomy (55.3% and 61.8%, respectively; OR 0.8, 95% CI 0.44–1.32) when compared to women admitted in active labor. The likelihood of cesarean delivery was higher for women admitted before active labor onset (15.8% and 6.9%, respectively; OR 2.6, 95% CI 1.02–6.37). Discussion Many low-risk nulliparous women with regular, spontaneous uterine contractions are admitted to labor units before active labor onset, which increases their likelihood of receiving oxytocin and being delivered via cesarean section. An evidence-based, standardized approach for labor admission decision-making is recommended to decrease inadvertent admissions of women in pre-active labor. When active labor cannot be diagnosed with relative certainty, observation before admission to the birthing unit is warranted. PMID:24512265

Teaching About the People's Republic of China: A Guide for Ninth Grade Social Studies, Part 1. Whose Perception? How to Use this Guide; Looking at the Past to Better Understand the Present; The Message: the Ways It Is Conveyed.

ERIC Educational Resources Information Center

New York State Education Dept., Albany. Bureau of Secondary Curriculum Development.

This guide, part 1 of a two-part publication, contains resource units on Chinese history and culture which can be used with 9th-grade students. The materials and activities, gathered by American secondary-school teachers who visited China in 1973, are intended to provide a pattern for an elective course or supplementary material for regular social…

Afro-Caribbean and African American Students, Family Factors, and the Influence on Science Performance in the United States: The Untold Story

ERIC Educational Resources Information Center

Pinder, Patrice Juliet

2012-01-01

The primary objectives of this research were to explore achievement pattern differences and the influence of family factors on the achievement patterns of Afro-Caribbean and African American students within the United States (U.S.). The study utilized two research designs; a causal-comparative and a correlational design. A student family…

The Reproductive Context of Cohabitation in the United States: Recent Change and Variation in Contraceptive Use

ERIC Educational Resources Information Center

Sweeney, Megan M.

2010-01-01

Drawing on data from 2 waves of the National Survey of Family Growth (N = 11,065), the current research addressed 2 overarching questions about the reproductive context of cohabitation in the United States. First, did patterns of contraceptive use among cohabitors change during the last 2 decades of the 20th century? Second, did patterns of…

Characterizing dynamic spatial and temporal residential density patterns from 1940-1990 across the North Central United States

Treesearch

Roger B. Hammer; Susan I. Stewart; Richelle L. Winkler; Volker C. Radeloff; Paul R. Voss

2004-01-01

The spatial deconcentration of population during the 20th century and the resulting expansion of human settlements has been a significant cause of anthropogenic landscape change in the United States and many other countries. In the seven-state North Central Region, as in other regions of the US, changing human settlement patterns are most prominent at the outlying...

Energy Use and Carbon Emissions: Some International Comparisons

EIA Publications

1994-01-01

Presents energy use and carbon emissions patterns in a world context. The report contrasts trends in economically developed and developing areas of the world since 1970, presents a disaggregated view of the "Group of Seven" (G7) key industrialized countries (Canada, France, Germany, Italy, Japan, the United Kingdom, and the United States) and examines sectoral energy use patterns within each of the G7 countries.

Effects of historical climate change, habitat connectivity, and vicariance on genetic structure and diversity across the range of the red tree vole (Phenacomys longicaudus) in the Pacific Northwestern United States.

Treesearch

Mark P. Miller; M. Renee Bellinger; Eric D. Forsman; Susan M. Haig

2006-01-01

Phylogeographical analyses conducted in the Pacific Northwestern United States have often revealed concordant patterns of genetic diversity among taxa. These studies demonstrate distinct North/South genetic discontinuities that have been attributed to Pleistocene glaciation. We examined phylogeographical patterns of red tree voles (Phenacomys longicaudus...

Interactive Story Development for the Unit of Turks on the Silk Road in Social Sciences Course

ERIC Educational Resources Information Center

Karamete, Aysen; Topraklioglu, Kivanç

2017-01-01

With this study, creating interactive story that includes interaction factors was purposed in order to support teaching of the unit of Turks on the Silk Road in Social Sciences course of 6th grades. The research method was defined as Design and Development Research and ADDIE pattern that is one of the teaching design pattern was based while…

Using demand analysis and system status management for predicting ED attendances and rostering.

PubMed

Ong, Marcus Eng Hock; Ho, Khoy Kheng; Tan, Tiong Peng; Koh, Seoh Kwee; Almuthar, Zain; Overton, Jerry; Lim, Swee Han

2009-01-01

It has been observed that emergency department (ED) attendances are not random events but rather have definite time patterns and trends that can be observed historically. To describe the time demand patterns at the ED and apply systems status management to tailor ED manpower demand. Observational study of all patients presenting to the ED at the Singapore General Hospital during a 3-year period was conducted. We also conducted a time series analysis to determine time norms regarding physician activity for various severities of patients. The yearly ED attendances increased from 113387 (2004) to 120764 (2005) and to 125773 (2006). There was a progressive increase in severity of cases, with priority 1 (most severe) increasing from 6.7% (2004) to 9.1% (2006) and priority 2 from 33.7% (2004) to 35.1% (2006). We noticed a definite time demand pattern, with seasonal peaks in June, weekly peaks on Mondays, and daily peaks at 11 to 12 am. These patterns were consistent during the period of the study. We designed a demand-based rostering tool that matched doctor-unit-hours to patient arrivals and severity. We also noted seasonal peaks corresponding to public holidays. We found definite and consistent patterns of patient demand and designed a rostering tool to match ED manpower demand.

A spatial emergy model for Alachua County, Florida

NASA Astrophysics Data System (ADS)

Lambert, James David

A spatial model of the distribution of energy flows and storages in Alachua County, Florida, was created and used to analyze spatial patterns of energy transformation hierarchy in relation to spatial patterns of human settlement. Emergy, the available energy of one kind previously required directly or indirectly to make a product or service, was used as a measure of the quality of the different forms of energy flows and storages. Emergy provides a common unit of measure for comparing the productive contributions of natural processes with those of economic and social processes---it is an alternative to using money for measuring value. A geographic information system was used to create a spatial model and make maps that show the distribution and magnitude of different types of energy and emergy flows and storages occurring in one-hectare land units. Energy transformities were used to convert individual energy flows and storages into emergy units. Maps of transformities were created that reveal a clear spatial pattern of energy transformation hierarchy. The maps display patterns of widely-dispersed areas with lower transformity energy flows and storages, and smaller, centrally-located areas with higher transformities. Energy signature graphs and spatial unit transformities were used to characterize and compare the types and amounts of energy being consumed and stored according to land use classification, planning unit, and neighborhood categories. Emergy ratio maps and spatial unit ratios were created by dividing the values for specific emergy flows or storages by the values for other emergy flows or storages. Spatial context analysis was used to analyze the spatial distribution patterns of mean and maximum values for emergy flows and storages. The modeling method developed for this study is general and applicable to all types of landscapes and could be applied at any scale. An advantage of this general approach is that the results of other studies using this method will be directly comparable with the results of this study. The results and conclusions of this study reinforce the hypothesis that an urban landscape will develop a predictable spatial pattern that can be described in terms of a universal energy transformation hierarchy.

Patterns in Nature Forming Patterns in Minds: An Evaluation of an Introductory Physics Unit

NASA Astrophysics Data System (ADS)

Sheaffer, Christopher Ryan

Educators are increasingly focused on the process over the content. In science especially, teachers want students to understand the nature of science and investigation. The emergence of scientific inquiry and engineering design teaching methods have led to the development of new teaching and evaluation methods that concentrate on steps in a process rather than facts in a topic. Research supports the notion that an explicit focus on the scientific process can lead to student science knowledge gains. In response to new research and standards many teachers have been developing teaching methods that seem to work well in their classrooms, but lack the time and resources to test them in other classroom environments. A high school Physics teacher (Bradford Hill) has developed a unit called Patterns in Nature (PIN) with objectives relating mathematical modeling to the scientific process. Designed for use in his large public school classroom, the unit was taken and used in a charter school with small classes. This study looks at specifically whether or not the PIN unit effectively teaches students how to graph the data they gather and fit an appropriate mathematical pattern, using that model to predict future measurements. Additionally, the study looks at the students' knowledge and views about the nature of science and the process of scientific investigation as it is affected by the PIN unit. Findings show that students are able to identify and apply patterns to data, but have difficulties explaining the meaning of the math. Students' show increases in their knowledge of the process of science, and the majority develop positive views about science in general. A major goal of this study is to place this unit in the cyclical process of Design-Based Research and allow for Pattern in Nature's continuous improvement, development and evaluation. Design-Based Research (DBR) is an approach that can be applied to the implementation and evaluation of classroom materials. This method incorporates the complexities of different contexts and changing treatments into the research methods and analysis. From the use of DBR teachers can understand more about how the designed materials affect the students. Others may be able to use the development and analysis of PIN study as a guide to look at similar aspects of science units developed elsewhere.

Does Size Matter? The Multipolar International Landscape of Nanoscience

PubMed Central

Jensen, Pablo; Kreimer, Pablo

2016-01-01

How do different countries tackle nanoscience research? Are all countries similar except for a trivial size effect, as science is often assumed to be universal? Or does size dictate large differences, as large countries are able to develop activities in all directions of research, while small countries have to specialize in some specific niches? Alternatively, is size irrelevant, as all countries have followed different historical paths, leading to different patterns of specialisation? Here, we develop an original method that uses a bottom-up definition of scientific subfields to map the international structure of any scientific field. Our analysis shows that nanoscience research does not show a universal pattern of specialisation, homothetic of that of a single global leader (e.g., the United States). Instead, we find a multipolar world, with four main ways of doing nanosciences. PMID:27992439

Information flow in layered networks of non-monotonic units

NASA Astrophysics Data System (ADS)

Schittler Neves, Fabio; Martim Schubert, Benno; Erichsen, Rubem, Jr.

2015-07-01

Layered neural networks are feedforward structures that yield robust parallel and distributed pattern recognition. Even though much attention has been paid to pattern retrieval properties in such systems, many aspects of their dynamics are not yet well characterized or understood. In this work we study, at different temperatures, the memory activity and information flows through layered networks in which the elements are the simplest binary odd non-monotonic function. Our results show that, considering a standard Hebbian learning approach, the network information content has its maximum always at the monotonic limit, even though the maximum memory capacity can be found at non-monotonic values for small enough temperatures. Furthermore, we show that such systems exhibit rich macroscopic dynamics, including not only fixed point solutions of its iterative map, but also cyclic and chaotic attractors that also carry information.

Does Size Matter? The Multipolar International Landscape of Nanoscience.

PubMed

Levin, Luciano; Jensen, Pablo; Kreimer, Pablo

2016-01-01

How do different countries tackle nanoscience research? Are all countries similar except for a trivial size effect, as science is often assumed to be universal? Or does size dictate large differences, as large countries are able to develop activities in all directions of research, while small countries have to specialize in some specific niches? Alternatively, is size irrelevant, as all countries have followed different historical paths, leading to different patterns of specialisation? Here, we develop an original method that uses a bottom-up definition of scientific subfields to map the international structure of any scientific field. Our analysis shows that nanoscience research does not show a universal pattern of specialisation, homothetic of that of a single global leader (e.g., the United States). Instead, we find a multipolar world, with four main ways of doing nanosciences.

Structural deformation and sedimentation in an active Caldera, Rabaul, Papua New Guinea

USGS Publications Warehouse

Greene, H. Gary; Tiffin, D.L.; McKee, C.O.

1986-01-01

Recent seismic and tectonic activity in Rabaul Caldera, Papua New Guinea, suggests that magma is accumulating at a shallow depth beneath this partially submerged structure and that a new volcano may be developing. Changes in onshore elevation since 1971 (as much as 2 m on south Matupit Island) indicate that rapid and large-scale uplifts have occurred on the seafloor near the center of the caldera. The frequency of seismic events within the caldera has also increased during this period. Earthquake locations define an elliptical ring surrounding the center of this uplift within the caldera. A marine geophysical survey in 1982 by the U.S. Geological Survey's R/V "S.P. Lee" in Rabaul Caldera shows the development of a bulge in the seafloor near the center of the caldera. High-resolution seismic reflection profiles show that this bulge consists of two domal uplifts bounded and separated by two major north-south-trending fault zones. Deformed sediments overlie these zones; a prominent slump flanks the area of the bulge. Five major acoustic units were identified in the seismic reflection profiles: an acoustic basement and four sedimentary units consisting of irregularly layered, cross-layered, contorted, and well-layered sequences. The acoustic basement is probably composed of crystalline volcanic rocks, and the layered acoustic units are probably sediments, primarily ash deposited in different environments. The cross-layered, irregularly layered, and contorted units appear to have been deposited in a dynamic environment subjected to strong currents, seismicity, and/or mass wasting, while the well-layered units were deposited in a low-energy environment. Locally, well-layered sequences interfinger with the other sedimentary units, indicating a transitional environment that alternated between high-energy and low-energy depositional processes. A submarine channel cuts most of the acoustic units and appears to be the conduit for sediment transport out of the caldera; it occupies an older buried channel north of the caldera that is presently being exhumed. In the south, active erosion of well-layered sediments is taking place. What are believed to be several young volcanic cones also disrupt the depositional layers. We conclude that the bulge in the seafloor and the associated fault zones are a result of emplacement of magma at a shallow depth. Contorted sediment and slumps adjacent to the bulge are probably the result of uplift and seismic activity. The pattern of seismicity appears to reflect increased magma pressure at depth beneath the caldera floor. This activity may eventually lead to an eruption. ?? 1986.

Acoustic-Emergent Phonology in the Amplitude Envelope of Child-Directed Speech

PubMed Central

Leong, Victoria; Goswami, Usha

2015-01-01

When acquiring language, young children may use acoustic spectro-temporal patterns in speech to derive phonological units in spoken language (e.g., prosodic stress patterns, syllables, phonemes). Children appear to learn acoustic-phonological mappings rapidly, without direct instruction, yet the underlying developmental mechanisms remain unclear. Across different languages, a relationship between amplitude envelope sensitivity and phonological development has been found, suggesting that children may make use of amplitude modulation (AM) patterns within the envelope to develop a phonological system. Here we present the Spectral Amplitude Modulation Phase Hierarchy (S-AMPH) model, a set of algorithms for deriving the dominant AM patterns in child-directed speech (CDS). Using Principal Components Analysis, we show that rhythmic CDS contains an AM hierarchy comprising 3 core modulation timescales. These timescales correspond to key phonological units: prosodic stress (Stress AM, ~2 Hz), syllables (Syllable AM, ~5 Hz) and onset-rime units (Phoneme AM, ~20 Hz). We argue that these AM patterns could in principle be used by naïve listeners to compute acoustic-phonological mappings without lexical knowledge. We then demonstrate that the modulation statistics within this AM hierarchy indeed parse the speech signal into a primitive hierarchically-organised phonological system comprising stress feet (proto-words), syllables and onset-rime units. We apply the S-AMPH model to two other CDS corpora, one spontaneous and one deliberately-timed. The model accurately identified 72–82% (freely-read CDS) and 90–98% (rhythmically-regular CDS) stress patterns, syllables and onset-rime units. This in-principle demonstration that primitive phonology can be extracted from speech AMs is termed Acoustic-Emergent Phonology (AEP) theory. AEP theory provides a set of methods for examining how early phonological development is shaped by the temporal modulation structure of speech across languages. The S-AMPH model reveals a crucial developmental role for stress feet (AMs ~2 Hz). Stress feet underpin different linguistic rhythm typologies, and speech rhythm underpins language acquisition by infants in all languages. PMID:26641472

Acoustic-Emergent Phonology in the Amplitude Envelope of Child-Directed Speech.

PubMed

Leong, Victoria; Goswami, Usha

2015-01-01

When acquiring language, young children may use acoustic spectro-temporal patterns in speech to derive phonological units in spoken language (e.g., prosodic stress patterns, syllables, phonemes). Children appear to learn acoustic-phonological mappings rapidly, without direct instruction, yet the underlying developmental mechanisms remain unclear. Across different languages, a relationship between amplitude envelope sensitivity and phonological development has been found, suggesting that children may make use of amplitude modulation (AM) patterns within the envelope to develop a phonological system. Here we present the Spectral Amplitude Modulation Phase Hierarchy (S-AMPH) model, a set of algorithms for deriving the dominant AM patterns in child-directed speech (CDS). Using Principal Components Analysis, we show that rhythmic CDS contains an AM hierarchy comprising 3 core modulation timescales. These timescales correspond to key phonological units: prosodic stress (Stress AM, ~2 Hz), syllables (Syllable AM, ~5 Hz) and onset-rime units (Phoneme AM, ~20 Hz). We argue that these AM patterns could in principle be used by naïve listeners to compute acoustic-phonological mappings without lexical knowledge. We then demonstrate that the modulation statistics within this AM hierarchy indeed parse the speech signal into a primitive hierarchically-organised phonological system comprising stress feet (proto-words), syllables and onset-rime units. We apply the S-AMPH model to two other CDS corpora, one spontaneous and one deliberately-timed. The model accurately identified 72-82% (freely-read CDS) and 90-98% (rhythmically-regular CDS) stress patterns, syllables and onset-rime units. This in-principle demonstration that primitive phonology can be extracted from speech AMs is termed Acoustic-Emergent Phonology (AEP) theory. AEP theory provides a set of methods for examining how early phonological development is shaped by the temporal modulation structure of speech across languages. The S-AMPH model reveals a crucial developmental role for stress feet (AMs ~2 Hz). Stress feet underpin different linguistic rhythm typologies, and speech rhythm underpins language acquisition by infants in all languages.

Flight and Walking in Locusts–Cholinergic Co-Activation, Temporal Coupling and Its Modulation by Biogenic Amines

PubMed Central

Rillich, Jan; Stevenson, Paul A.; Pflueger, Hans-Joachim

2013-01-01

Walking and flying in locusts are exemplary rhythmical behaviors generated by central pattern generators (CPG) that are tuned in intact animals by phasic sensory inputs. Although these two behaviors are mutually exclusive and controlled by independent CPGs, leg movements during flight can be coupled to the flight rhythm. To investigate potential central coupling between the underlying CPGs, we used the muscarinic agonist pilocarpine and the amines octopamine and tyramine to initiate fictive flight and walking in deafferented locust preparations. Our data illustrate that fictive walking is readily evoked by comparatively lower concentrations of pilocarpine, whereas higher concentrations are required to elicit fictive flight. Interestingly, fictive flight did not suppress fictive walking so that the two patterns were produced simultaneously. Frequently, leg motor units were temporally coupled to the flight rhythm, so that each spike in a step cycle volley occurred synchronously with wing motor units firing at flight rhythm frequency. Similarly, tyramine also induced fictive walking and flight, but mostly without any coupling between the two rhythms. Octopamine in contrast readily evoked fictive flight but generally failed to elicit fictive walking. Despite this, numerous leg motor units were recruited, whereby each was temporarily coupled to the flight rhythm. Our results support the notion that the CPGs for walking and flight are largely independent, but that coupling can be entrained by aminergic modulation. We speculate that octopamine biases the whole motor machinery of a locust to flight whereas tyramine primarily promotes walking. PMID:23671643

Functional coordination of muscles underlying changes in behavioural dynamics.

PubMed

Vernooij, Carlijn A; Rao, Guillaume; Perdikis, Dionysios; Huys, Raoul; Jirsa, Viktor K; Temprado, Jean-Jacques

2016-06-10

The dynamical systems approach addresses Bernstein's degrees of freedom problem by assuming that the neuro-musculo-skeletal system transiently assembles and dismantles its components into functional units (or synergies) to meet task demands. Strikingly, little is known from a dynamical point of view about the functioning of the muscular sub-system in this process. To investigate the interaction between the dynamical organisation at muscular and behavioural levels, we searched for specific signatures of a phase transition in muscular coordination when a transition is displayed at the behavioural level. Our results provide evidence that, during Fitts' task when behaviour switches to a different dynamical regime, muscular activation displays typical signatures of a phase transition; a reorganisation in muscular coordination patterns accompanied by a peak in the variability of muscle activation. This suggests that consistent changes occur in coordination processes across the different levels of description (i.e., behaviour and muscles). Specifically, in Fitts' task, target size acts as a control parameter that induces a destabilisation and a reorganisation of coordination patterns at different levels of the neuro-musculo-skeletal system.

Study of the mode of action of a polygalacturonase from the phytopathogen Burkholderia cepacia

PubMed Central

Massa, Claudia; Clausen, Mads H.; Stojan, Jure; Lamba, Doriano; Campa, Cristiana

2007-01-01

We have recently isolated and heterologously expressed BcPeh28A, an endopolygalacturonase from the phytopathogenic Gram-negative bacterium Burkholderia cepacia. Endopolygalacturonases belong to glycoside hydrolase family 28 and are responsible for the hydrolysis of the non-esterified regions of pectins. The mode of action of BcPeh28A on different substrates has been investigated and its enzymatic mechanism elucidated. The hydrolysis of polygalacturonate indicates that BcPeh28A is a non-processive enzyme that releases oligomers with chain lengths ranging from two to eight. By inspection of product progression curves, a kinetic model has been generated and extensively tested. It has been used to derive the kinetic parameters that describe the time course of the formation of six predominant products. Moreover, an investigation of the enzymatic activity on shorter substrates that differ in their overall length and methylation patterns sheds light on the architecture of the BcPeh28A active site. Specifically the tolerance of individual sites towards methylated saccharide units was rationalized on the basis of the hydrolysis of hexagalacturonides with different methylation patterns. PMID:17627609

Visual pattern recognition based on spatio-temporal patterns of retinal ganglion cells’ activities

PubMed Central

Jing, Wei; Liu, Wen-Zhong; Gong, Xin-Wei; Gong, Hai-Qing

2010-01-01

Neural information is processed based on integrated activities of relevant neurons. Concerted population activity is one of the important ways for retinal ganglion cells to efficiently organize and process visual information. In the present study, the spike activities of bullfrog retinal ganglion cells in response to three different visual patterns (checker-board, vertical gratings and horizontal gratings) were recorded using multi-electrode arrays. A measurement of subsequence distribution discrepancy (MSDD) was applied to identify the spatio-temporal patterns of retinal ganglion cells’ activities in response to different stimulation patterns. The results show that the population activity patterns were different in response to different stimulation patterns, such difference in activity pattern was consistently detectable even when visual adaptation occurred during repeated experimental trials. Therefore, the stimulus pattern can be reliably discriminated according to the spatio-temporal pattern of the neuronal activities calculated using the MSDD algorithm. PMID:21886670

Motor Activity and Intra-Individual Variability According to Sleep-wake States in Preschool-aged Children with Iron-Deficiency Anemia in Infancy

PubMed Central

Angulo-Barroso, R.M.; Peirano, P.; Algarin, C.; Kaciroti, N.; Lozoff, B.

2013-01-01

Background A chronic or acute insult may affect the regulatory processes that guide motor and behavioral performance, leading to increased intra-individual variability (IIV). Increased variability is often interpreted as an indication of regulatory dysfunction. Iron plays an important role in the regulatory processes of the nervous system and affects motor activity. To our knowledge, no study has examined the long-lasting patterns and IIV of motor activity following iron-deficiency anemia in human infants. Aims This study compared 48-hour motor activity and variability in preschool-aged children with or without iron-deficiency anemia (IDA) in infancy. Methods Motor activity was recorded through actigraphs during two week-days in 47 4-year-old Chilean children (23 former IDA and 24 non-anemic in infancy). All were given oral iron as infants. Sleep-wake states were identified by means of automated software. The frequency of movement units per minute was determined for each waking/sleep state during the individual day and night periods; data were examined in blocks of 15 minutes. Analyses of mean frequency and duration and intra-individual variability were conducted using multivariate mixed models. Results For daytime sleep, former IDA children were more active without a difference in the total duration. They also spent less time awake throughout the individual day period. Motor activity intra-individual variability was higher in former IDA children. Conclusions The findings suggest that IDA in infancy sets the stage for long lasting dysfunction in the neural processes regulating sleep-wake states and spontaneous motor activity patterns. PMID:24041817

Motor activity and intra-individual variability according to sleep-wake states in preschool-aged children with iron-deficiency anemia in infancy.

PubMed

Angulo-Barroso, R M; Peirano, P; Algarin, C; Kaciroti, N; Lozoff, B

2013-12-01

A chronic or acute insult may affect the regulatory processes that guide motor and behavioral performance, leading to increased intra-individual variability (IIV). Increased variability is often interpreted as an indication of regulatory dysfunction. Iron plays an important role in the regulatory processes of the nervous system and affects motor activity. To our knowledge, no study has examined the long-lasting patterns and IIV of motor activity following iron-deficiency anemia in human infants. This study compared 48-h motor activity and variability in preschool-aged children with or without iron-deficiency anemia (IDA) in infancy. Motor activity was recorded through actigraphs during two week-days in 47 4-year-old Chilean children (23 former IDA and 24 non-anemic in infancy). All were given oral iron as infants. Sleep-wake states were identified by means of automated software. The frequency of movement units per minute was determined for each waking/sleep state during the individual day and night periods; data were examined in blocks of 15 min. Analyses of mean frequency and duration and intra-individual variability were conducted using multivariate mixed models. For daytime sleep, former IDA children were more active without a difference in the total duration. They also spent less time awake throughout the individual day period. Motor activity intra-individual variability was higher in former IDA children. The findings suggest that IDA in infancy sets the stage for long lasting dysfunction in the neural processes regulating sleep-wake states and spontaneous motor activity patterns. © 2013.

Harnessing the power of theta: natural manipulations of cognitive performance during hippocampal theta-contingent eyeblink conditioning

PubMed Central

Hoffmann, Loren C.; Cicchese, Joseph J.; Berry, Stephen D.

2015-01-01

Neurobiological oscillations are regarded as essential to normal information processing, including coordination and timing of cells and assemblies within structures as well as in long feedback loops of distributed neural systems. The hippocampal theta rhythm is a 3–12 Hz oscillatory potential observed during cognitive processes ranging from spatial navigation to associative learning. The lower range, 3–7 Hz, can occur during immobility and depends upon the integrity of cholinergic forebrain systems. Several studies have shown that the amount of pre-training theta in the rabbit strongly predicts the acquisition rate of classical eyeblink conditioning and that impairment of this system substantially slows the rate of learning. Our lab has used a brain-computer interface (BCI) that delivers eyeblink conditioning trials contingent upon the explicit presence or absence of hippocampal theta. A behavioral benefit of theta-contingent training has been demonstrated in both delay and trace forms of the paradigm with a two- to four-fold increase in learning speed. This behavioral effect is accompanied by enhanced amplitude and synchrony of hippocampal local field potential (LFP)s, multi-unit excitation, and single-unit response patterns that depend on theta state. Additionally, training in the presence of hippocampal theta has led to increases in the salience of tone-induced unit firing patterns in the medial prefrontal cortex, followed by persistent multi-unit activity during the trace interval. In cerebellum, rhythmicity and precise synchrony of stimulus time-locked LFPs with those of hippocampus occur preferentially under the theta condition. Here we review these findings, integrate them into current models of hippocampal-dependent learning and suggest how improvement in our understanding of neurobiological oscillations is critical for theories of medial temporal lobe processes underlying intact and pathological learning. PMID:25918501

Harnessing the power of theta: natural manipulations of cognitive performance during hippocampal theta-contingent eyeblink conditioning.

PubMed

Hoffmann, Loren C; Cicchese, Joseph J; Berry, Stephen D

2015-01-01

Neurobiological oscillations are regarded as essential to normal information processing, including coordination and timing of cells and assemblies within structures as well as in long feedback loops of distributed neural systems. The hippocampal theta rhythm is a 3-12 Hz oscillatory potential observed during cognitive processes ranging from spatial navigation to associative learning. The lower range, 3-7 Hz, can occur during immobility and depends upon the integrity of cholinergic forebrain systems. Several studies have shown that the amount of pre-training theta in the rabbit strongly predicts the acquisition rate of classical eyeblink conditioning and that impairment of this system substantially slows the rate of learning. Our lab has used a brain-computer interface (BCI) that delivers eyeblink conditioning trials contingent upon the explicit presence or absence of hippocampal theta. A behavioral benefit of theta-contingent training has been demonstrated in both delay and trace forms of the paradigm with a two- to four-fold increase in learning speed. This behavioral effect is accompanied by enhanced amplitude and synchrony of hippocampal local field potential (LFP)s, multi-unit excitation, and single-unit response patterns that depend on theta state. Additionally, training in the presence of hippocampal theta has led to increases in the salience of tone-induced unit firing patterns in the medial prefrontal cortex, followed by persistent multi-unit activity during the trace interval. In cerebellum, rhythmicity and precise synchrony of stimulus time-locked LFPs with those of hippocampus occur preferentially under the theta condition. Here we review these findings, integrate them into current models of hippocampal-dependent learning and suggest how improvement in our understanding of neurobiological oscillations is critical for theories of medial temporal lobe processes underlying intact and pathological learning.

Dermoscopy of subungual haemorrhage: its usefulness in differential diagnosis from nail-unit melanoma.

PubMed

Mun, J-H; Kim, G-W; Jwa, S-W; Song, M; Kim, H-S; Ko, H-C; Kim, B-S; Kim, M-B

2013-06-01

Subungual haemorrhages are characterized by well-circumscribed dots or blotches with a red to red-black pigmentation, but some cases can be difficult to distinguish from subungual melanoma by the naked eye alone. Dermoscopy has proven to be a useful, noninvasive tool in the diagnosis of pigmented lesions in the nail; however, few dermoscopic studies of subungual haemorrhages have been reported. To investigate characteristic dermoscopic patterns of subungual haemorrhages, and to find distinctive features that can differentiate them from nail-unit melanomas. Patients with a confirmed diagnosis of either subungual haemorrhage or nail-unit melanoma at a tertiary university hospital were included in the study. Clinical features and dermoscopic patterns were evaluated. Sixty-four patients with a total of 90 lesions of subungual haemorrhage were enrolled in the study. The majority of cases (84%) showed combinations of more than one colour, while 16% had only one colour. The most common colour of the subungual haemorrhages was purple-black, in 37% of cases. A homogeneous pattern was observed in 92% of cases, globular patterns in 42% and streaks in 39%. Peripheral fading and periungual haemorrhages were found in 54% and 22% of cases, respectively. Destruction or dystrophy of the nail plate was observed in 16% of cases. In the 16 cases of nail-unit melanomas, Hutchinson sign, longitudinal irregular bands or lines, triangular shape of bands, vascular pattern, and ulcerations were found in 100%, 81%, 25%, 6% and 81% of cases, respectively. In contrast, these features were not found in subungual haemorrhages. Dermoscopy provides valuable information for the diagnosis of subungual haemorrhage and aids in the differential diagnosis from nail-unit melanoma. © 2013 The Authors. BJD © 2013 British Association of Dermatologists.

It Isn’t All Just Fun and Games: Collegiate Participation in Extracurricular Activities and Risk for Generalized and Sexual Harassment, Psychological Distress, and Alcohol Use

PubMed Central

McGinley, Meredith; Rospenda, Kathleen M.; Liu, Li; Richman, Judith A.

2016-01-01

Collegiate extracurricular activities, despite their benefits, may place students at an increased risk for experiencing harassment. This study utilizes multiple waves of data from an online longitudinal survey to examine how participation in college activities (intramural sports, fraternities/sororities, school clubs) relates to experiences of sexual and generalized harassment and outcomes (psychological distress, heavy alcohol use) among undergraduates (N = 1852, 58.6% female, 57.4% White) in the Midwestern United States. Activity participation was related to harassment, but the pattern depended on the activity, harassment type, and sex. Fraternity/sorority involvement was associated with generalized harassment, whereas school club involvement was linked to both generalized and sexual harassment. Female intramural athletes were at an increased risk to experience both harassment types. In addition to direct relations, activity participation was indirectly linked to future psychological distress (depression, anxiety) and heavy alcohol use via harassment. Implications for intervention with this college student population are discussed. PMID:27771523

Thinking in Patterns to Solve Multiplication, Division, and Fraction Problems in Second Grade

ERIC Educational Resources Information Center

Stokes, Patricia D.

2016-01-01

Experts think in patterns and structures using the specific "language" of their domains. For mathematicians, these patterns and structures are represented by numbers, symbols and their relationships (Stokes, 2014a). To determine whether elementary students in the United States could learn to think in mathematical patterns to solve…

Using a Network Model to Assess Risk of Forest Pest Spread via Recreational Travel

PubMed Central

Koch, Frank H.; Yemshanov, Denys; Haack, Robert A.; Magarey, Roger D.

2014-01-01

Long-distance dispersal pathways, which frequently relate to human activities, facilitate the spread of alien species. One pathway of concern in North America is the possible spread of forest pests in firewood carried by visitors to campgrounds or recreational facilities. We present a network model depicting the movement of campers and, by extension, potentially infested firewood. We constructed the model from US National Recreation Reservation Service data documenting more than seven million visitor reservations (including visitors from Canada) at campgrounds nationwide. This bi-directional model can be used to identify likely origin and destination locations for a camper-transported pest. To support broad-scale decision making, we used the model to generate summary maps for 48 US states and seven Canadian provinces that depict the most likely origins of campers traveling from outside the target state or province. The maps generally showed one of two basic spatial patterns of out-of-state (or out-of-province) origin risk. In the eastern United States, the riskiest out-of-state origin locations were usually found in a localized region restricted to portions of adjacent states. In the western United States, the riskiest out-of-state origin locations were typically associated with major urban areas located far from the state of interest. A few states and the Canadian provinces showed characteristics of both patterns. These model outputs can guide deployment of resources for surveillance, firewood inspections, or other activities. Significantly, the contrasting map patterns indicate that no single response strategy is appropriate for all states and provinces. If most out-of-state campers are traveling from distant areas, it may be effective to deploy resources at key points along major roads (e.g., interstate highways), since these locations could effectively represent bottlenecks of camper movement. If most campers are from nearby areas, they may have many feasible travel routes, so a more widely distributed deployment may be necessary. PMID:25007186

Using a network model to assess risk of forest pest spread via recreational travel.

PubMed

Koch, Frank H; Yemshanov, Denys; Haack, Robert A; Magarey, Roger D

2014-01-01

Long-distance dispersal pathways, which frequently relate to human activities, facilitate the spread of alien species. One pathway of concern in North America is the possible spread of forest pests in firewood carried by visitors to campgrounds or recreational facilities. We present a network model depicting the movement of campers and, by extension, potentially infested firewood. We constructed the model from US National Recreation Reservation Service data documenting more than seven million visitor reservations (including visitors from Canada) at campgrounds nationwide. This bi-directional model can be used to identify likely origin and destination locations for a camper-transported pest. To support broad-scale decision making, we used the model to generate summary maps for 48 US states and seven Canadian provinces that depict the most likely origins of campers traveling from outside the target state or province. The maps generally showed one of two basic spatial patterns of out-of-state (or out-of-province) origin risk. In the eastern United States, the riskiest out-of-state origin locations were usually found in a localized region restricted to portions of adjacent states. In the western United States, the riskiest out-of-state origin locations were typically associated with major urban areas located far from the state of interest. A few states and the Canadian provinces showed characteristics of both patterns. These model outputs can guide deployment of resources for surveillance, firewood inspections, or other activities. Significantly, the contrasting map patterns indicate that no single response strategy is appropriate for all states and provinces. If most out-of-state campers are traveling from distant areas, it may be effective to deploy resources at key points along major roads (e.g., interstate highways), since these locations could effectively represent bottlenecks of camper movement. If most campers are from nearby areas, they may have many feasible travel routes, so a more widely distributed deployment may be necessary.

Identification of autism spectrum disorder using deep learning and the ABIDE dataset.

PubMed

Heinsfeld, Anibal Sólon; Franco, Alexandre Rosa; Craddock, R Cameron; Buchweitz, Augusto; Meneguzzi, Felipe

2018-01-01

The goal of the present study was to apply deep learning algorithms to identify autism spectrum disorder (ASD) patients from large brain imaging dataset, based solely on the patients brain activation patterns. We investigated ASD patients brain imaging data from a world-wide multi-site database known as ABIDE (Autism Brain Imaging Data Exchange). ASD is a brain-based disorder characterized by social deficits and repetitive behaviors. According to recent Centers for Disease Control data, ASD affects one in 68 children in the United States. We investigated patterns of functional connectivity that objectively identify ASD participants from functional brain imaging data, and attempted to unveil the neural patterns that emerged from the classification. The results improved the state-of-the-art by achieving 70% accuracy in identification of ASD versus control patients in the dataset. The patterns that emerged from the classification show an anticorrelation of brain function between anterior and posterior areas of the brain; the anticorrelation corroborates current empirical evidence of anterior-posterior disruption in brain connectivity in ASD. We present the results and identify the areas of the brain that contributed most to differentiating ASD from typically developing controls as per our deep learning model.

Trends and characteristics of animal-vehicle collisions in the United States.

PubMed

Sullivan, John M

2011-02-01

Since 1990, fatal animal-vehicle collisions (AVCs) in the United States have more than doubled. This paper examines annual AVC trends in the United States over a 19-year period, seasonal and diurnal patterns of AVC risk, the geographic distribution of crash risk by state, and the association between posted speed limit and AVC crash risk in darkness. AVCs were compiled from the Fatality Analysis Reporting System (FARS) and the General Estimates System (GES) for the years 1990-2008 to examine annual crash trends for fatal and nonfatal crashes. Seasonal trends for fatal AVCs were examined with the aggregated FARS dataset; seasonal trends for fatal and nonfatal AVCs were also examined by aggregating four years of Michigan crash data. State-by-state distributions of fatal AVCs were also described with the aggregated FARS dataset. Finally, the relationship between posted speed limit and the odds that a fatal or nonfatal AVC occurred in darkness were examined with logistic regressions using the aggregated FARS and Michigan datasets. Between 1990 and 2008, fatal AVCs increased by 104% and by 1.3 crashes per trillion vehicle miles travelled per year. Although not all AVCs involve deer, daily and seasonal AVC crash trends follow the general activity pattern of deer populations, consistent with prior reports. The odds that a fatal AVC occurred in darkness were also found to increase by 2.3% for each mile-per-hour increase in speed; a similar, albeit smaller, effect was also observed in the aggregated Michigan dataset, among nonfatal crashes. AVCs represent a small but increasing share of crashes in the United States. Seasonal and daily variation in the pattern of AVCs seem to follow variation in deer exposure and ambient light level. Finally, the relative risk that a fatal and nonfatal AVC occurred in darkness is influenced by posted speed limit, suggesting that a driver's limited forward vision at night plays a role in AVCs, as it does in pedestrian collisions. The association between speed limit and crash risk in darkness suggests that AVC risk might be reduced with countermeasures that improve a driver's forward view of the road. Copyright © 2010 Elsevier Ltd. All rights reserved.

Selectionist and Evolutionary Approaches to Brain Function: A Critical Appraisal

PubMed Central

Fernando, Chrisantha; Szathmáry, Eörs; Husbands, Phil

2012-01-01

We consider approaches to brain dynamics and function that have been claimed to be Darwinian. These include Edelman’s theory of neuronal group selection, Changeux’s theory of synaptic selection and selective stabilization of pre-representations, Seung’s Darwinian synapse, Loewenstein’s synaptic melioration, Adam’s selfish synapse, and Calvin’s replicating activity patterns. Except for the last two, the proposed mechanisms are selectionist but not truly Darwinian, because no replicators with information transfer to copies and hereditary variation can be identified in them. All of them fit, however, a generalized selectionist framework conforming to the picture of Price’s covariance formulation, which deliberately was not specific even to selection in biology, and therefore does not imply an algorithmic picture of biological evolution. Bayesian models and reinforcement learning are formally in agreement with selection dynamics. A classification of search algorithms is shown to include Darwinian replicators (evolutionary units with multiplication, heredity, and variability) as the most powerful mechanism for search in a sparsely occupied search space. Examples are given of cases where parallel competitive search with information transfer among the units is more efficient than search without information transfer between units. Finally, we review our recent attempts to construct and analyze simple models of true Darwinian evolutionary units in the brain in terms of connectivity and activity copying of neuronal groups. Although none of the proposed neuronal replicators include miraculous mechanisms, their identification remains a challenge but also a great promise. PMID:22557963

Tracking search engine queries for suicide in the United Kingdom, 2004-2013.

PubMed

Arora, V S; Stuckler, D; McKee, M

2016-08-01

First, to determine if a cyclical trend is observed for search activity of suicide and three common suicide risk factors in the United Kingdom: depression, unemployment, and marital strain. Second, to test the validity of suicide search data as a potential marker of suicide risk by evaluating whether web searches for suicide associate with suicide rates among those of different ages and genders in the United Kingdom. Cross-sectional. Search engine data was obtained from Google Trends, a publicly available repository of information of trends and patterns of user searches on Google. The following phrases were entered into Google Trends to analyse relative search volume for suicide, depression, job loss, and divorce, respectively: 'suicide'; 'depression + depressed + hopeless'; 'unemployed + lost job'; 'divorce'. Spearman's rank correlation coefficient was employed to test bivariate associations between suicide search activity and official suicide rates from the Office of National Statistics (ONS). Cyclical trends were observed in search activity for suicide and depression-related search activity, with peaks in autumn and winter months, and a trough in summer months. A positive, non-significant association was found between suicide-related search activity and suicide rates in the general working-age population (15-64 years) (ρ = 0.164; P = 0.652). This association is stronger in younger age groups, particularly for those 25-34 years of age (ρ = 0.848; P = 0.002). We give credence to a link between search activity for suicide and suicide rates in the United Kingdom from 2004 to 2013 for high risk sub-populations (i.e. male youth and young professionals). There remains a need for further research on how Google Trends can be used in other areas of disease surveillance and for work to provide greater geographical precision, as well as research on ways of mitigating the risk of internet use leading to suicide ideation in youth. Copyright © 2015 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

Patterns of Inequality. Unit 3, The Philosophy of Equality and Inequality. Unit 4, Personal Inequality as an Ideological Concept.

ERIC Educational Resources Information Center

Hookham, Maurice; Holloway, Clive

Open University course units are presented on the philosophy of equality and inequality (Unit 3) and on personal inequality as an ideological concept (Unit 4). The substance of Unit 3 consists of extracts from the writings of eight philosophers. The role of the philosopher in forming legitimatizing ideologies is also illustrated. The eight…

Backscattered EM-wave manipulation using low cost 1-bit reflective surface at W-band

NASA Astrophysics Data System (ADS)

Taher Al-Nuaimi, Mustafa K.; Hong, Wei; He, Yejun

2018-04-01

The design of low cost 1-bit reflective (non-absorptive) surfaces for manipulation of backscattered EM-waves and radar cross section (RCS) reduction at W-band is presented in this article. The presented surface is designed based on the reflection phase cancellation principle. The unit cell used to compose the proposed surface has an obelus (division symbol of short wire and two disks above and below) like shape printed on a grounded dielectric material. Using this unit cell, surfaces that can efficiently manipulate the backscattered RCS pattern by using the proposed obelus-shaped unit cell (as ‘0’ element) and its mirrored unit cell (as ‘1’ element) in one surface with a 180°  ±  35° reflection phase difference between their reflection phases are designed. The proposed surfaces can generate various kinds of backscattered RCS patterns, such as single, three, or four lobes or even a low-level (reduced RCS) diffused reflection pattern when those two unit cells are distributed randomly across the surface aperture. For experimental characterization purposes, a 50  ×  50 mm2 surface is fabricated and measured.

The environment of the last hunters-gatherers and first agro-pastoralists in the western Mediterranean region, between the Rhone and the Northern Apennines (7th - 6th millennium cal. BCE): Attractiveness of the landscape units and settlement patterns

NASA Astrophysics Data System (ADS)

Battentier, Janet; Binder, Didier; Guillon, Sebastien; Maggi, Roberto; Negrino, Fabio; Sénépart, Ingrid; Tozzi, Carlo; Théry-Parisot, Isabelle; Delhon, Claire

2018-03-01

In the north western Mediterranean, in the area between the Rhone River and the Northern Apennines, the last Mesolithic societies (Castelnovian) and the first Neolithic societies (Impressed Ware or Impressa) coexisted during the first half of the 6th millennium cal. BCE (Before Common Era). Linking the two settlement distribution patterns (mainly high lands and low lands for the Castelnovian versus Mediterranean coastal areas for the Impressa) to their specific environmental backgrounds during that period of coexistence enables us to document the attractiveness of the various available landscape units as a function of the subsistence practices (hunting, fishing and gathering versus agro-pastoralism). Pollen and charcoal data from 41 archaeological sites along with contemporaneous natural (off archaeological sites) sequences (hereafter referred to as "off-site sequences") from three windows (Provence/Western Liguria, the middle Rhone valley/Prealps and Southern Alps, Eastern Liguria/Northern Apennines) were examined in order to reconstruct the vegetal landscape in the surroundings of the Mesolithic and Neolithic settlements between 6500 and 5400 cal. BCE. The importance of environmental versus cultural factors in the settlement preferences of both groups is discussed in order to document our reflection concerning non-consensual issues, such as the existence of interaction or avoidance behaviours or the sharing (or not) of parts or all of the territory and of its natural resources. The results notably highlight the expansion of fir forests that, based on ecological and accessibility criteria, could be considered as rather inauspicious for settlement and hunting as well as for pastoral activities. This expansion may have influenced the settlement patterns of both cultural complexes, leading populations to locate their settlements principally within landscape units that remained clear of extensive fir forests. It appears that, despite being motivated by the prevailing subsistence activities, the choice of an area of land for settlement is deeply guided by various other cultural factors which are less directly dependent upon natural resources. Thus, in an area providing a large range of possibilities, the landscape in which the groups establish themselves could be considered as just one of many cultural characteristics.

Fault activation by hydraulic fracturing in western Canada.

PubMed

Bao, Xuewei; Eaton, David W

2016-12-16

Hydraulic fracturing has been inferred to trigger the majority of injection-induced earthquakes in western Canada, in contrast to the Midwestern United States, where massive saltwater disposal is the dominant triggering mechanism. A template-based earthquake catalog from a seismically active Canadian shale play, combined with comprehensive injection data during a 4-month interval, shows that earthquakes are tightly clustered in space and time near hydraulic fracturing sites. The largest event [moment magnitude (M W ) 3.9] occurred several weeks after injection along a fault that appears to extend from the injection zone into crystalline basement. Patterns of seismicity indicate that stress changes during operations can activate fault slip to an offset distance of >1 km, whereas pressurization by hydraulic fracturing into a fault yields episodic seismicity that can persist for months. Copyright © 2016, American Association for the Advancement of Science.

Alterations in muscle mass and contractile phenotype in response to unloading models: role of transcriptional/pretranslational mechanisms

PubMed Central

Baldwin, Kenneth M.; Haddad, Fadia; Pandorf, Clay E.; Roy, Roland R.; Edgerton, V. Reggie

2013-01-01

Skeletal muscle is the largest organ system in mammalian organisms providing postural control and movement patterns of varying intensity. Through evolution, skeletal muscle fibers have evolved into three phenotype clusters defined as a motor unit which consists of all muscle fibers innervated by a single motoneuron linking varying numbers of fibers of similar phenotype. This fundamental organization of the motor unit reflects the fact that there is a remarkable interdependence of gene regulation between the motoneurons and the muscle mainly via activity-dependent mechanisms. These fiber types can be classified via the primary type of myosin heavy chain (MHC) gene expressed in the motor unit. Four MHC gene encoded proteins have been identified in striated muscle: slow type I MHC and three fast MHC types, IIa, IIx, and IIb. These MHCs dictate the intrinsic contraction speed of the myofiber with the type I generating the slowest and IIb the fastest contractile speed. Over the last ~35 years, a large body of knowledge suggests that altered loading state cause both fiber atrophy/wasting and a slow to fast shift in the contractile phenotype in the target muscle(s). Hence, this review will examine findings from three different animal models of unloading: (1) space flight (SF), i.e., microgravity; (2) hindlimb suspension (HS), a procedure that chronically eliminates weight bearing of the lower limbs; and (3) spinal cord isolation (SI), a surgical procedure that eliminates neural activation of the motoneurons and associated muscles while maintaining neurotrophic motoneuron-muscle connectivity. The collective findings demonstrate: (1) all three models show a similar pattern of fiber atrophy with differences mainly in the magnitude and kinetics of alteration; (2) transcriptional/pretranslational processes play a major role in both the atrophy process and phenotype shifts; and (3) signaling pathways impacting these alterations appear to be similar in each of the models investigated. PMID:24130531

Basic emotions and adaptation. A computational and evolutionary model.

PubMed

Pacella, Daniela; Ponticorvo, Michela; Gigliotta, Onofrio; Miglino, Orazio

2017-01-01

The core principles of the evolutionary theories of emotions declare that affective states represent crucial drives for action selection in the environment and regulated the behavior and adaptation of natural agents in ancestrally recurrent situations. While many different studies used autonomous artificial agents to simulate emotional responses and the way these patterns can affect decision-making, few are the approaches that tried to analyze the evolutionary emergence of affective behaviors directly from the specific adaptive problems posed by the ancestral environment. A model of the evolution of affective behaviors is presented using simulated artificial agents equipped with neural networks and physically inspired on the architecture of the iCub humanoid robot. We use genetic algorithms to train populations of virtual robots across generations, and investigate the spontaneous emergence of basic emotional behaviors in different experimental conditions. In particular, we focus on studying the emotion of fear, therefore the environment explored by the artificial agents can contain stimuli that are safe or dangerous to pick. The simulated task is based on classical conditioning and the agents are asked to learn a strategy to recognize whether the environment is safe or represents a threat to their lives and select the correct action to perform in absence of any visual cues. The simulated agents have special input units in their neural structure whose activation keep track of their actual "sensations" based on the outcome of past behavior. We train five different neural network architectures and then test the best ranked individuals comparing their performances and analyzing the unit activations in each individual's life cycle. We show that the agents, regardless of the presence of recurrent connections, spontaneously evolved the ability to cope with potentially dangerous environment by collecting information about the environment and then switching their behavior to a genetically selected pattern in order to maximize the possible reward. We also prove the determinant presence of an internal time perception unit for the robots to achieve the highest performance and survivability across all conditions.

Evidence for Mojave-Sonora megashear-Systematic left-lateral offset of Neoproterozoic to Lower Jurassic strata and facies, western United States and northwestern Mexico

USGS Publications Warehouse

Stewart, John H.

2005-01-01

Major successions as well as individual units of Neoproterozoic to Lower Jurassic strata and facies appear to be systematically offset left laterally from eastern California and western Nevada in the western United States to Sonora, Mexico. This pattern is most evident in units such as the "Johnnie oolite," a 1- to 2-m-thick oolite of the Neoproterozoic Rainstorm Member of the Johnnie Formation in the western United States and of the Clemente Formation in Sonora. The pattern is also evident in the Lower Cambrian Zabriskie Quartzite of the western United States and the correlative Proveedora Quartzite in Sonora. Matching of isopach lines of the Zabriskie Quartzite and Proveedora Quartzite suggests ???700-800 km of left-lateral offset. The offset pattern is also apparent in the distribution of distinctive lithologic types, unconformities, and fossil assemblages in other rocks ranging in age from Neoproterozoic to Early Jurassic. In the western United States, the distribution of facies in Neoproterozoic and Paleozoic strata indicates that the Cordilleran miogeocline trends north-south. A north-south trend is also suggested in Sonora, and if so is compatible with offset of the miogeocline but not with the ideas that the miogeocline wrapped around the continental margin and trends east-west in Sonora. An imperfect stratigraphic match of supposed offset segments along the megashear is apparent. Some units, such as the "Johnnie oolite" and Zabriskie-Proveedora, show almost perfect correspondence, but other units are significantly different. The differences seem to indicate that the indigenous succession of the western United States and offset segments in Mexico were not precisely side by side before offset but were separated by an area-now buried, eroded, or destroyed-that contained strata of intermediate facies. ?? 2005 Geological Society of America.

Changes in Work Patterns: A Synthesis of Five National Reports on the Service Sector. France, Germany, Japan, Sweden, the United States.

ERIC Educational Resources Information Center

Organisation for Economic Cooperation and Development, Paris (France). Centre for Educational Research and Innovation.

An analysis of the service sector in five countries (France, Germany, Japan, Sweden, and the United States) was made through synthesis of earlier research on work patterns in the countries. Some of the findings and issues discovered concerned the following: (1) the heterogeneity of the service sector; (2) the progress of part-time work; (3)…

Mechanisms Mediating the Perception of Complex Acoustic Patterns

DTIC Science & Technology

1990-11-09

units stimulated by the louder sound include the units stimulated by the fainter sound. Thus, auditory induction corresponds to a rather sophisticated...FIELD GRU - auditory perception, complex sounds I. I 19. ABSTRACT (Continue on reverse if necessary and identify by block number) Five studies were...show how auditory mechanisms employed for the processing of complex nonverbal patterns have been modified for the perception of speech. 2 Richard M

Fates of live trees retained in forest cutting units, western Cascade Range, Oregon.

Treesearch

P.E. Busby; P. Adler; T.L. Warren; F.J. Swanson

2006-01-01

To assess the fate of live trees retained in dispersed patterns across cutting units in the western Cascade Range of Oregon, we conducted repeat surveys (1993 and 2001) of sites cut as early as 1983. Our objectives in this study are to (1) survey survival and mortality of trees retained at the time of harvest, (2) describe temporal patterns of windthrow and other...

Indian Health Service Training Center, Training Course TC-70-4 (April 13-May 1, 1970): A Descriptive Analysis of the Utilization of Health Resources in the Zuni, New Mexico Service Unit.

ERIC Educational Resources Information Center

Public Health Service (DHEW), Washington, DC. Div. of Indian Health.

A descriptive study of health services utilization patterns, and possible factors contributing to such patterns, was conducted in April 1970 at the Zuni, New Mexico, Indian Health Service Unit. Health service utilization was explored by selected disease categories, preventative services (maternal and child health), and general population attitudes…

EVALUATING ECOREGIONS FOR SAMPLING AND MAPPING LAND-COVER PATTERNS

EPA Science Inventory

Ecoregional stratification has been proposed for sampling and mapping land- cover composition and pattern over time. Using a wall-to-wall land-cover map of the United States, we evaluated geographic scales of variance for 17 landscape pattern indices, and compared stratification ...

Implementing a Virtual Exchange Project for student nurses in Queensland and Nottingham.

PubMed

Todhunter, Fern; Hallawell, Bob; Pittaway, Debbie

2013-09-01

This paper discusses the design and initial progress made with a virtual learning environment to help student nurses develop an understanding of cultural awareness and globalization. Using a Web-based application the Virtual Exchange Project was designed to facilitate study-elsewhere experiences located in the student's own setting. Promotion of the United Nations' Millennium Development goals provided an opportunity for student nurses to explore changes in global health and disease patterns, nursing education and systems of nurse regulation in the United Kingdom and Australia. A pedagogical framework created for this activity acknowledges the social and academic identities that learners often use, when working together in a virtual environment. The architecture of the Virtual Exchange supports local conversations about nurse education and health and social issues across hemispheres. Copyright © 2012 Elsevier Ltd. All rights reserved.

Nosocomial bloodstream infections in a Turkish university hospital: study of Gram-negative bacilli and their sensitivity patterns.

PubMed

Köseoğlu , O; Kocagöz, S; Gür, D; Akova, M

2001-06-01

Treatment of nosocomial bacteraemia is usually governed by the surveillance results of the particular unit. Such results are especially important when antimicrobial resistance rates are high. Multiresistant isolates including Gram-negatives producing extended-spectrum beta-lactamases have been frequently reported in tertiary care units in Turkey. In this study, antimicrobial susceptibilities of Gram-negative blood isolates (n=348) were determined by microbroth dilution tests. The results showed carbapenems (meropenem and imipenem) to be uniformly more potent in vitro than any other drug against the Enterobacteriaceae. Quinolone antibiotics were more active in vitro than aminoglycosides against a range of bacteria. Gram-negative bloodstream isolates were highly resistant to many antimicrobial agents in the hospital. In order to prevent hospital infection and antimicrobial resistance, surveillance of aetiological agents must be performed regularly.

Annual and seasonal tornado activity in the United States and the global wind oscillation

NASA Astrophysics Data System (ADS)

Moore, Todd W.

2018-06-01

Previous studies have searched for relationships between tornado activity and atmospheric teleconnections to provide insight on the relationship between tornadoes, their environments, and larger scale patterns in the climate system. Knowledge of these relationships is practical because it can improve seasonal and sub-seasonal predictions of tornado probability and, therefore, help mitigate tornado-related losses. This study explores the relationships between the annual and seasonal tornado activity in the United States and the Global Wind Oscillation. Time series herein show that phases of the Global Wind Oscillation, and atmospheric angular momentum anomalies, vary over a period of roughly 20-25 years. Rank correlations indicate that tornado activity is weakly correlated with phases 2, 3, and 4 (positive) and 6, 7, and 8 (negative) of the Global Wind Oscillation in winter, spring, and fall. The correlation is not as clear in summer or at the annual scale. Non-parametric Mann-Whitney U tests indicate that winters and springs with more phase 2, 3, and 4 and fewer phase 6, 7, and 8 days tend to have more tornadoes. Lastly, logistic regression models indicate that winters and springs with more phase 2, 3, and 4 days have greater likelihoods of having more than normal tornado activity. Combined, these analyses suggest that seasons with more low atmospheric angular momentum days, or phase 2, 3, and 4 days, tend to have greater tornado activity than those with fewer days, and that this relationship is most evident in winter and spring.

Annual and seasonal tornado activity in the United States and the global wind oscillation

NASA Astrophysics Data System (ADS)

Moore, Todd W.

2017-08-01

Previous studies have searched for relationships between tornado activity and atmospheric teleconnections to provide insight on the relationship between tornadoes, their environments, and larger scale patterns in the climate system. Knowledge of these relationships is practical because it can improve seasonal and sub-seasonal predictions of tornado probability and, therefore, help mitigate tornado-related losses. This study explores the relationships between the annual and seasonal tornado activity in the United States and the Global Wind Oscillation. Time series herein show that phases of the Global Wind Oscillation, and atmospheric angular momentum anomalies, vary over a period of roughly 20-25 years. Rank correlations indicate that tornado activity is weakly correlated with phases 2, 3, and 4 (positive) and 6, 7, and 8 (negative) of the Global Wind Oscillation in winter, spring, and fall. The correlation is not as clear in summer or at the annual scale. Non-parametric Mann-Whitney U tests indicate that winters and springs with more phase 2, 3, and 4 and fewer phase 6, 7, and 8 days tend to have more tornadoes. Lastly, logistic regression models indicate that winters and springs with more phase 2, 3, and 4 days have greater likelihoods of having more than normal tornado activity. Combined, these analyses suggest that seasons with more low atmospheric angular momentum days, or phase 2, 3, and 4 days, tend to have greater tornado activity than those with fewer days, and that this relationship is most evident in winter and spring.

The Pattern Across the Continental United States of Evapotranspiration Variability Associated with Water Availability

NASA Technical Reports Server (NTRS)

Koster, Randal D.; Salvucci, Guido D.; Rigden, Angela J.; Jung, Martin; Collatz, G. James; Schubert, Siegfried D.

2015-01-01

The spatial pattern across the continental United States of the interannual variance of warm season water-dependent evapotranspiration, a pattern of relevance to land-atmosphere feedback, cannot be measured directly. Alternative and indirect approaches to estimating the pattern, however, do exist, and given the uncertainty of each, we use several such approaches here. We first quantify the water dependent evapotranspiration variance pattern inherent in two derived evapotranspiration datasets available from the literature. We then search for the pattern in proxy geophysical variables (air temperature, stream flow, and NDVI) known to have strong ties to evapotranspiration. The variances inherent in all of the different (and mostly independent) data sources show some differences but are generally strongly consistent they all show a large variance signal down the center of the U.S., with lower variances toward the east and (for the most part) toward the west. The robustness of the pattern across the datasets suggests that it indeed represents the pattern operating in nature. Using Budykos hydroclimatic framework, we show that the pattern can largely be explained by the relative strength of water and energy controls on evapotranspiration across the continent.

Estimated United States Residential Energy Use in 2005

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

Smith, C A; Johnson, D M; Simon, A J

2011-12-12

A flow chart depicting energy flow in the residential sector of the United States economy in 2005 has been constructed from publicly available data and estimates of national energy use patterns. Approximately 11,000 trillion British Thermal Units (trBTUs) of electricity and fuels were used throughout the United States residential sector in lighting, electronics, air conditioning, space heating, water heating, washing appliances, cooking appliances, refrigerators, and other appliances. The residential sector is powered mainly by electricity and natural gas. Other fuels used include petroleum products (fuel oil, liquefied petroleum gas and kerosene), biomass (wood), and on-premises solar, wind, and geothermal energy.more » The flow patterns represent a comprehensive systems view of energy used within the residential sector.« less

Understanding human activity patterns based on space-time-semantics

NASA Astrophysics Data System (ADS)

Huang, Wei; Li, Songnian

2016-11-01

Understanding human activity patterns plays a key role in various applications in an urban environment, such as transportation planning and traffic forecasting, urban planning, public health and safety, and emergency response. Most existing studies in modeling human activity patterns mainly focus on spatiotemporal dimensions, which lacks consideration of underlying semantic context. In fact, what people do and discuss at some places, inferring what is happening at the places, cannot be simple neglected because it is the root of human mobility patterns. We believe that the geo-tagged semantic context, representing what individuals do and discuss at a place and a specific time, drives a formation of specific human activity pattern. In this paper, we aim to model human activity patterns not only based on space and time but also with consideration of associated semantics, and attempt to prove a hypothesis that similar mobility patterns may have different motivations. We develop a spatiotemporal-semantic model to quantitatively express human activity patterns based on topic models, leading to an analysis of space, time and semantics. A case study is conducted using Twitter data in Toronto based on our model. Through computing the similarities between users in terms of spatiotemporal pattern, semantic pattern and spatiotemporal-semantic pattern, we find that only a small number of users (2.72%) have very similar activity patterns, while the majority (87.14%) show different activity patterns (i.e., similar spatiotemporal patterns and different semantic patterns, similar semantic patterns and different spatiotemporal patterns, or different in both). The population of users that has very similar activity patterns is decreased by 56.41% after incorporating semantic information in the corresponding spatiotemporal patterns, which can quantitatively prove the hypothesis.

Improved discriminability of spatiotemporal neural patterns in rat motor cortical areas as directional choice learning progresses

PubMed Central

Mao, Hongwei; Yuan, Yuan; Si, Jennie

2015-01-01

Animals learn to choose a proper action among alternatives to improve their odds of success in food foraging and other activities critical for survival. Through trial-and-error, they learn correct associations between their choices and external stimuli. While a neural network that underlies such learning process has been identified at a high level, it is still unclear how individual neurons and a neural ensemble adapt as learning progresses. In this study, we monitored the activity of single units in the rat medial and lateral agranular (AGm and AGl, respectively) areas as rats learned to make a left or right side lever press in response to a left or right side light cue. We noticed that rat movement parameters during the performance of the directional choice task quickly became stereotyped during the first 2–3 days or sessions. But learning the directional choice problem took weeks to occur. Accompanying rats' behavioral performance adaptation, we observed neural modulation by directional choice in recorded single units. Our analysis shows that ensemble mean firing rates in the cue-on period did not change significantly as learning progressed, and the ensemble mean rate difference between left and right side choices did not show a clear trend of change either. However, the spatiotemporal firing patterns of the neural ensemble exhibited improved discriminability between the two directional choices through learning. These results suggest a spatiotemporal neural coding scheme in a motor cortical neural ensemble that may be responsible for and contributing to learning the directional choice task. PMID:25798093

The gendered nature of filial piety--a study among Chinese Canadians.

PubMed

Chappell, Neena L; Kusch, Karen

2007-03-01

This paper examines the modern face of filial piety enactment among Chinese families living away from their homeland. It empirically assesses filial piety practices among a random sample of diasporic Chinese Canadians, by studying the role of sons, daughters and spouses in providing assistance with basic activities of daily living, instrumental activities of daily living and perceptions of support; the relative contribution of the traditional Chinese caring unit (son plus daughter-in-law) with assistance provided; whether source of assistance changes when amount of care is taken into account, when the gendered nature of tasks is taken into account and when controlling for other factors in multivariate analyses. N = 2,272 Chinese seniors (age 55+) living in seven cities across Canada. The findings reveal that, among these diasporic Chinese, patterns found in other Chinese societies are evident in their tendency to live with children, even when the spouse is still living, and the involvement of sons and the son/daughter-in-law unit in providing care. However, similar to recent findings for China, daughters and spouses are involved in all 3 areas of support examined and importantly, their involvement increases as more assistance is provided while that from sons decreases, notably in terms of IADL. The participation of daughters-in-law tends to be lower than that of either sons or daughters. The involvement of spouses increases for perceived or emotional support. The findings suggest a blending of Chinese and Canadian patterns of care and are discussed in terms of the changing but still gendered nature of care.

Shortage of cardiothoracic surgeons is likely by 2020.

PubMed

Grover, Atul; Gorman, Karyn; Dall, Timothy M; Jonas, Richard; Lytle, Bruce; Shemin, Richard; Wood, Douglas; Kron, Irving

2009-08-11

Even as the burden of cardiovascular disease in the United States is increasing as the population grows and ages, the number of active cardiothoracic surgeons has fallen for the first time in 20 years. Meanwhile, the treatment of patients with coronary artery disease continues to evolve amid uncertain changes in technology. This study evaluates current and future requirements for cardiothoracic surgeons in light of decreasing rates of coronary artery bypass grafting procedures. Projections of supply and demand for cardiothoracic surgeons are based on analysis of population, physician office, hospital, and physician data sets to estimate current patterns of healthcare use and delivery. Using a simulation model, we project the future supply of cardiothoracic surgeons under alternative assumptions about the number of new fellows trained each year. Future demand is modeled, taking into account patient demographics, under current and alternative use rates that include the elimination of open revascularization. By 2025, the demand for cardiothoracic surgeons could increase by 46% on the basis of population growth and aging if current healthcare use and service delivery patterns continue. Even with complete elimination of coronary artery bypass grafting, there is a projected shortfall of cardiothoracic surgeons because the active supply is projected to decrease 21% over the same time period as a result of retirement and declining entrants. The United States is facing a shortage of cardiothoracic surgeons within the next 10 years, which could diminish quality of care if non-board-certified physicians expand their role in cardiothoracic surgery or if patients must delay appropriate care because of a shortage of well-trained surgeons.

Trends in Physical Activity, Sedentary Behavior, Diet, and BMI Among US Adolescents, 2001–2009

PubMed Central

Wang, Jing

2013-01-01

OBJECTIVE: The high prevalence of adolescent obesity in the United States has been attributed to population changes in physical activity (PA), sedentary behaviors, and dietary behaviors. This study examines 8-year trends in these behaviors in US adolescents ages 11 to 16. METHODS: Nationally representative samples of US students in grades 6 to 10 were recruited during the 2001–2002 (N = 14 607), 2005–2006 (N = 9150), and 2009–2010 (N = 10 848) school years by using multistage stratified designs, with census regions and grades as strata, and school districts as the primary sampling units. African-American and Hispanic students were oversampled to obtain better estimates for those groups. Using the Health Behavior in School-aged Children quadrennial surveys, identical questions assessed BMI, PA, and sedentary and dietary behaviors at each school year. Logistic and linear regression analyses were conducted taking into account the sampling design and controlling for age, gender, race/ethnicity, and family affluence. RESULTS: Across the quadrennial surveys, significant increases were identified in number of days with at least 60 minutes of PA, daily consumption of fruits and vegetables, eating breakfast on weekdays and weekends, and BMI. Television viewing and consumption of sweets and sweetened beverages decreased across this same period. These same patterns were seen in all racial/ethnic groups. CONCLUSIONS: These patterns suggest that public health efforts to improve the obesity-related behaviors of US adolescents may be having some success. However, alternative explanations for the increase in BMI over the same period need to be considered. PMID:24043281

Exogenic and endogenic albedo and color patterns on Europa

NASA Technical Reports Server (NTRS)

Mcewen, A. S.

1986-01-01

New global and high-resolution multispectral mosaics of Europa have been produced from the Voyager imaging data. Photometric normalizations are based on multiple-image techniques that explicitly account for intrinsic albedo variations through pixel-by-pixel solutions. The exogenic color and albedo pattern on Europa is described by a second-order function of the cosine of the angular distance from the apex of orbital motion. On the basis of this second-order function and of color trends that are different on the leading and trailing hemispheres, the exogenic pattern is interpreted as being due to equilibrium between two dominant processes: (1) impact gardening and (2) magnetospheric interactions, including sulfur-ion implantation and sputtering redistribution. Removal of the model exogenic pattern in the mosaics reveals the endogenic variations, consisting of only two major units: darker (redder) and bright materials. Therefore Europa's visual spectral reflectivity is simple, having one continuous exogenic pattern and two discrete endogenic units.

Choreographing Patterns and Functions

ERIC Educational Resources Information Center

Hawes, Zachary; Moss, Joan; Finch, Heather; Katz, Jacques

2012-01-01

In this article, the authors begin with a description of an algebraic dance--the translation of composite linear growing patterns into choreographed movement--which was the last component of a research-based instructional unit that focused on fostering an understanding of linear functional rules through geometric growing patterns and…

Search Query Data to Monitor Interest in Behavior Change: Application for Public Health

PubMed Central

Carr, Lucas J.; Dunsiger, Shira I.

2012-01-01

There is a need for effective interventions and policies that target the leading preventable causes of death in the U.S. (e.g., smoking, overweight/obesity, physical inactivity). Such efforts could be aided by the use of publicly available, real-time search query data that illustrate times and locations of high and low public interest in behaviors related to preventable causes of death. Objectives This study explored patterns of search query activity for the terms ‘weight’, ‘diet’, ‘fitness’, and ‘smoking’ using Google Insights for Search. Methods Search activity for ‘weight’, ‘diet’, ‘fitness’, and ‘smoking’ conducted within the United States via Google between January 4th, 2004 (first date data was available) and November 28th, 2011 (date of data download and analysis) were analyzed. Using a generalized linear model, we explored the effects of time (month) on mean relative search volume for all four terms. Results Models suggest a significant effect of month on mean search volume for all four terms. Search activity for all four terms was highest in January with observable declines throughout the remainder of the year. Conclusions These findings demonstrate discernable temporal patterns of search activity for four areas of behavior change. These findings could be used to inform the timing, location and messaging of interventions, campaigns and policies targeting these behaviors. PMID:23110198

Comparing methods of measuring geographic patterns in temporal trends: an application to county-level heart disease mortality in the United States, 1973 to 2010.

PubMed

Vaughan, Adam S; Kramer, Michael R; Waller, Lance A; Schieb, Linda J; Greer, Sophia; Casper, Michele

2015-05-01

To demonstrate the implications of choosing analytical methods for quantifying spatiotemporal trends, we compare the assumptions, implementation, and outcomes of popular methods using county-level heart disease mortality in the United States between 1973 and 2010. We applied four regression-based approaches (joinpoint regression, both aspatial and spatial generalized linear mixed models, and Bayesian space-time model) and compared resulting inferences for geographic patterns of local estimates of annual percent change and associated uncertainty. The average local percent change in heart disease mortality from each method was -4.5%, with the Bayesian model having the smallest range of values. The associated uncertainty in percent change differed markedly across the methods, with the Bayesian space-time model producing the narrowest range of variance (0.0-0.8). The geographic pattern of percent change was consistent across methods with smaller declines in the South Central United States and larger declines in the Northeast and Midwest. However, the geographic patterns of uncertainty differed markedly between methods. The similarity of results, including geographic patterns, for magnitude of percent change across these methods validates the underlying spatial pattern of declines in heart disease mortality. However, marked differences in degree of uncertainty indicate that Bayesian modeling offers substantially more precise estimates. Copyright © 2015 Elsevier Inc. All rights reserved.

The Longer You Stay, the Worse Your Health? A Critical Review of the Negative Acculturation Theory among Asian Immigrants

PubMed Central

Ro, Annie

2014-01-01

Researchers have become increasingly interested in the health patterns of immigrants with longer residence in the United States, as this reveals the health consequences of integration processes. The negative acculturation effect has been the dominant interpretation of duration patterns, despite empirical and theoretical uncertainties about this assumption. This theory assumes that immigrant health declines with longer residence in the United States because of poorer health behaviors and health risks that reflect Americanized lifestyles. This paper reviews the empirical support for the negative acculturation theory among Asian immigrants to determine if and when it is an appropriate interpretation for duration patterns. I conclude that empirical inconsistencies and methodological issues limit the negative acculturation theory as the primary interpretation for duration patterns. First, there is no consistent evidence that health behaviors decline with time. There is also substantial group heterogeneity in duration patterns as well as heterogeneity across health outcomes. The literature has not adequately addressed methodological shortcomings, such as confounding by cohort effects or non-linear duration patterns. Length of residence in the United States is still an important aspect of Asian immigrant health, but the mechanisms of this relationship are still understudied. I propose alternative frameworks between duration and health that consider environmental influences and end with future research directions to explore research gaps. PMID:25111874

Renal cortical involvement in children with first UTI: does it differ in the presence of primary VUR?

PubMed

Aktaş, Gül Ege; Inanir, Sabahat; Turoğlu, Halil Turgut

2008-12-01

The aim of this study was to investigate the influence of vesicoureteral reflux (VUR) on dimercaptosuccinic acid (DMSA) scintigraphic patterns in children with first symptomatic urinary tract infection (UTI). A total of 45 children with the diagnosis of first symptomatic UTI (28 girls, 17 boys, mean age 18 months, range 1 month-11 years) were reviewed. All DMSA scans were obtained within 2 months of bacteriologically proven UTI (median 21 days, mean 26 +/- 21, 14). After the exclusion of the patients with bilateral cortical lesions, 82 renal units were analyzed. The scintigraphic patterns included regional and global description of renal cortical abnormality (normal or decreased differential renal function, regional renal function (RRF), and the number and severity of cortical lesions). Vesicoureteral reflux was detected in 26 (32%) renal units (15 with grade 1-2, 11 with grade 3-4). Renal cortical abnormality was observed in 10 renal units without VUR (10/56, 17%) and 13 renal units with VUR (13/26: 50%). Of the 15 renal units, 5 with grade 1-2 VUR (5/15) and 8 of the 11 renal units with grade 3-4 VUR (8/11) had renal cortical involvement. The most common scintigraphic pattern in the patients without VUR was the preserved RRF (>or=45%) and two or fewer photon-deficient areas. On the other hand, a decreased RRF (<45) associated with cortical lesions was the most frequent finding in patients with refluxing kidneys (8/26, 30%), especially in those with grade 3-4 disease. This investigation showed that the presence of VUR affects DMSA patterns in children with first symptomatic UTI.

Lifestyle Patterns and Weight Status in Spanish Adults: The ANIBES Study.

PubMed

Pérez-Rodrigo, Carmen; Gianzo-Citores, Marta; Gil, Ángel; González-Gross, Marcela; Ortega, Rosa M; Serra-Majem, Lluis; Varela-Moreiras, Gregorio; Aranceta-Bartrina, Javier

2017-06-14

Limited knowledge is available on lifestyle patterns in Spanish adults. We investigated dietary patterns and possible meaningful clustering of physical activity, sedentary behavior, sleep time, and smoking in Spanish adults aged 18-64 years and their association with obesity. Analysis was based on a subsample ( n = 1617) of the cross-sectional ANIBES study in Spain. We performed exploratory factor analysis and subsequent cluster analysis of dietary patterns, physical activity, sedentary behaviors, sleep time, and smoking. Logistic regression analysis was used to explore the association between the cluster solutions and obesity. Factor analysis identified four dietary patterns, " Traditional DP ", " Mediterranean DP ", " Snack DP " and " Dairy-sweet DP ". Dietary patterns, physical activity behaviors, sedentary behaviors, sleep time, and smoking in Spanish adults aggregated into three different clusters of lifestyle patterns: " Mixed diet-physically active-low sedentary lifestyle pattern ", " Not poor diet-low physical activity-low sedentary lifestyle pattern " and " Poor diet-low physical activity-sedentary lifestyle pattern ". A higher proportion of people aged 18-30 years was classified into the " Poor diet-low physical activity-sedentary lifestyle pattern ". The prevalence odds ratio for obesity in men in the " Mixed diet-physically active-low sedentary lifestyle pattern " was significantly lower compared to those in the " Poor diet-low physical activity-sedentary lifestyle pattern ". Those behavior patterns are helpful to identify specific issues in population subgroups and inform intervention strategies. The findings in this study underline the importance of designing and implementing interventions that address multiple health risk practices, considering lifestyle patterns and associated determinants.

Some implications of changing patterns of mineral consumption

USGS Publications Warehouse

Menzie, W. David; DeYoung,, John H.; Steblez, Walter G.

2003-01-01

DeYoung and Menzie (1999) examined the relations among population, Gross Domestic Product, and mineral consumption (aluminum, cement, copper, and salt) for Japan, Korea, and the United States between 1965 and 1995. They noted the extremely rapid growth of consumption in Korea between 1975 and 1995. Concomitantly, Korea's population growth rate declined. This paper extends that earlier work by examining patterns of consumption of these same commodities in the twenty most populous countries for the period 1970 through 1995. Developed countries, such as France, Germany, Japan, the United Kingdom, and the United States, show patterns of consumption that are stable (cement, copper, and salt) or grow slowly (aluminum). Some developing countries, including China, Thailand, and Turkey, show more rapid growth of consumption, especially of cement, copper, and aluminum. These changing patterns of mineral consumption in developing countries have important implications -- if they continue, there could be major increases in world mineral consumption and major increases in environmental residuals from mineral production and use. If China reaches the level of consumption of copper of developed countries, world consumption could reach levels more than twice that of 1995 (10.5 million tons).

Pattern Formation in Active Nematics

NASA Astrophysics Data System (ADS)

Mishra, Prashant

This thesis presents analytical and numerical studies of the nonequilibrium dynamics of active nematic liquid crystals. Active nematics are a new class of liquid crystals consisting of elongated rod-like units that convert energy into motion and spontaneously organize in large-scale structures with orientational order and self-sustained flows. Examples include suspensions of cytoskeletal filaments and associated motor proteins, monolayers of epithelial cells plated on a substrate, and bacteria swimming in a nematic liquid crystal. In these systems activity drives the continuous generation and annihilation of topological defects and streaming flows, resulting in spatio-temporal chaotic dynamics akin to fluid turbulence, but that occurs in a regime of flow of vanishing Reynolds number, where inertia is negligible. Quantifying the origin of this nonequilibrium dynamics has implications for understanding phenomena ranging from bacterial swarming to cytoplasmic flows in living cells. After a brief review (Chapter 2) of the properties of equilibrium or passive nematic liquid crystals, in Chapter 3 we discuss how the hydrodynamic equations of nematic liquid crystals can be modified to account for the effect of activity. We then use these equations of active nemato-hydrodynamics to characterize analytically the nonequilibrium steady states of the system and their stability. We supplement the analytical work with numerical solution of the full nonlinear equations for the active suspension and construct a phase diagram that identifies the various emergent patterns as a function of activity and nematic stiffness. In Chapter 4 we compare results obtained with two distinct hydrodynamic models that have been employed in previous studies. In both models we find that the chaotic spatio-temporal dynamics in the regime of fully developed active turbulence is controlled by a single active scale determined by the balance of active and elastic stresses. This work provides a unified understanding of apparent discrepancies in the previous literature and demonstrate that the essential physics is robust to the choice of model. Finally, in Chapter 5 we examine the dynamics of a compressible active nematic on a substrate. When frictional damping dominates over viscous dissipation, we eliminate flow in favor of active stresses to obtain a minimal model with renormalized elastic constants driven negative by activity. We show that spatially inhomogeneous patterns are selected via a mechanism analogous to that responsible for modulated phases at an equilibrium Lifshitz point.

Discovery of Aminopiperidine Indoles That Activate the Guanine Nucleotide Exchange Factor SOS1 and Modulate RAS Signaling.

PubMed

Abbott, Jason R; Hodges, Timothy R; Daniels, R Nathan; Patel, Pratiq A; Kennedy, Jack Phillip; Howes, Jennifer E; Akan, Denis T; Burns, Michael C; Sai, Jiqing; Sobolik, Tammy; Beesetty, Yugandhar; Lee, Taekyu; Rossanese, Olivia W; Phan, Jason; Waterson, Alex G; Fesik, Stephen W

2018-06-01

Deregulated RAS activity, often the result of mutation, is implicated in approximately 30% of all human cancers. Despite this statistic, no clinically successful treatment for RAS-driven tumors has yet been developed. One approach for modulating RAS activity is to target and affect the activity of proteins that interact with RAS, such as the guanine nucleotide exchange factor (GEF) son of sevenless homologue 1 (SOS1). Here, we report on structure-activity relationships (SAR) in an indole series of compounds. Using structure-based design, we systematically explored substitution patterns on the indole nucleus, the pendant amino acid moiety, and the linker unit that connects these two fragments. Best-in-class compounds activate the nucleotide exchange process at sub-micromolar concentrations in vitro, increase levels of active RAS-GTP in HeLa cells, and elicit signaling changes in the mitogen-activated protein kinase/extracellular regulated kinase (MAPK/ERK) pathway, resulting in a decrease in pERK1/2 T202/Y204 protein levels at higher compound concentrations.

Associations between physical activity patterns and dietary patterns in a representative sample of Polish girls aged 13-21 years: a cross-sectional study (GEBaHealth Project).

PubMed

Wadolowska, Lidia; Kowalkowska, Joanna; Lonnie, Marta; Czarnocinska, Jolanta; Jezewska-Zychowicz, Marzena; Babicz-Zielinska, Ewa

2016-08-02

Similar to other countries, trends of decreasing levels of physical activity (PA) and an increasing prevalence of unhealthy dietary patterns are observed among girls in Poland. Better understanding of potentially inter-related behaviours within this population can help to design tailored interventions. The purpose of this study was to determine associations between PA patterns and dietary patterns in a representative sample of Polish girls. Girls aged 13-21 years (n = 1107) were randomly selected for the study. PA was assessed using International Physical Activity Questionnaire - Long (IPAQ-L). Dietary data were collected with food frequency questionnaires. PA patterns and dietary patterns were drawn separately by Principal Component Analysis (PCA). Logistic regression was used to find the associations between PA patterns and dietary patterns. Four major PA patterns ('School/work activity', 'Active recreation', 'Yard activity' and 'Walking and domestic activity') and four dietary patterns ('Traditional Polish', 'Fruit & vegetables', 'Fast food & sweets' and 'Dairy & fats') were identified. Level of PA was the highest in the upper tertile of 'School/work activity' pattern (mean 1372.2 MET-minutes/week, 95 % Confidence Intervals [CI]: 1285.9-1458.5). Girls in upper tertiles of 'Yard activity', 'Active recreation' and 'School/work activity' patterns had significantly higher chances of being in the upper tertile of the 'Fruit and vegetables' dietary pattern (odds ratio [OR] 2.17, 95 % CI: 1.50-3.14, p < 0.0001; OR 2.02, 95 % CI: 1.41-2.91; p < 0.001 and OR 1.76, 95 % CI: 1.24-2.51, p < 0.01 respectively; all adjusted for confounders) in comparison to bottom tertiles. Weak, but significant inverse associations were found between upper tertiles of 'Active recreation' and 'Yard activity' patterns and unhealthy dietary patterns. We found associations between PA patterns and dietary patterns in the population of Polish girls. Girls with the highest adherence to the 'School/work activity' pattern had the highest levels of PA and presented pro-healthy dietary behaviours. School should be recognised as potentially efficient and important setting to maximise girls' PA potential. The after-school time is the area that should also be targeted to increase daily PA or to at least sustain the level of PA after completing education.

Forced phase-locked states and information retrieval in a two-layer network of oscillatory neurons with directional connectivity

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

Kazantsev, Victor; Pimashkin, Alexey; Department of Neurodynamics and Neurobiology, Nizhny Novgorod State University, 23 Gagarin Ave., 603950 Nizhny Novgorod

We propose two-layer architecture of associative memory oscillatory network with directional interlayer connectivity. The network is capable to store information in the form of phase-locked (in-phase and antiphase) oscillatory patterns. The first (input) layer takes an input pattern to be recognized and their units are unidirectionally connected with all units of the second (control) layer. The connection strengths are weighted using the Hebbian rule. The output (retrieved) patterns appear as forced-phase locked states of the control layer. The conditions are found and analytically expressed for pattern retrieval in response on incoming stimulus. It is shown that the system is capablemore » to recover patterns with a certain level of distortions or noises in their profiles. The architecture is implemented with the Kuramoto phase model and using synaptically coupled neural oscillators with spikes. It is found that the spiking model is capable to retrieve patterns using the spiking phase that translates memorized patterns into the spiking phase shifts at different time scales.« less

Dehydration-induced modulation of κ-opioid inhibition of vasopressin neurone activity

PubMed Central

Scott, Victoria; Bishop, Valerie R; Leng, Gareth; Brown, Colin H

2009-01-01

Dehydration increases vasopressin (antidiuretic hormone) secretion from the posterior pituitary gland to reduce water loss in the urine. Vasopressin secretion is determined by action potential firing in vasopressin neurones, which can exhibit continuous, phasic (alternating periods of activity and silence), or irregular activity. Autocrine κ-opioid inhibition contributes to the generation of activity patterning of vasopressin neurones under basal conditions and so we used in vivo extracellular single unit recording to test the hypothesis that changes in autocrine κ-opioid inhibition drive changes in activity patterning of vasopressin neurones during dehydration. Dehydration increased the firing rate of rat vasopressin neurones displaying continuous activity (from 7.1 ± 0.5 to 9.0 ± 0.6 spikes s−1) and phasic activity (from 4.2 ± 0.7 to 7.8 ± 0.9 spikes s−1), but not those displaying irregular activity. The dehydration-induced increase in phasic activity was via an increase in intraburst firing rate. The selective κ-opioid receptor antagonist nor-binaltorphimine increased the firing rate of phasic neurones in non-dehydrated rats (from 3.4 ± 0.8 to 5.3 ± 0.6 spikes s−1) and dehydrated rats (from 6.4 ± 0.5 to 9.1 ± 1.2 spikes s−1), indicating that κ-opioid feedback inhibition of phasic bursts is maintained during dehydration. In a separate series of experiments, prodynorphin mRNA expression was increased in vasopressin neurones of hyperosmotic rats, compared to hypo-osmotic rats. Hence, it appears that dynorphin expression in vasopressin neurones undergoes dynamic changes in proportion to the required secretion of vasopressin so that, even under stimulated conditions, autocrine feedback inhibition of vasopressin neurones prevents over-excitation. PMID:19822541

Neural correlates of virtual route recognition in congenital blindness.

PubMed

Kupers, Ron; Chebat, Daniel R; Madsen, Kristoffer H; Paulson, Olaf B; Ptito, Maurice

2010-07-13

Despite the importance of vision for spatial navigation, blind subjects retain the ability to represent spatial information and to move independently in space to localize and reach targets. However, the neural correlates of navigation in subjects lacking vision remain elusive. We therefore used functional MRI (fMRI) to explore the cortical network underlying successful navigation in blind subjects. We first trained congenitally blind and blindfolded sighted control subjects to perform a virtual navigation task with the tongue display unit (TDU), a tactile-to-vision sensory substitution device that translates a visual image into electrotactile stimulation applied to the tongue. After training, participants repeated the navigation task during fMRI. Although both groups successfully learned to use the TDU in the virtual navigation task, the brain activation patterns showed substantial differences. Blind but not blindfolded sighted control subjects activated the parahippocampus and visual cortex during navigation, areas that are recruited during topographical learning and spatial representation in sighted subjects. When the navigation task was performed under full vision in a second group of sighted participants, the activation pattern strongly resembled the one obtained in the blind when using the TDU. This suggests that in the absence of vision, cross-modal plasticity permits the recruitment of the same cortical network used for spatial navigation tasks in sighted subjects.

Different nucleosomal architectures at early and late replicating origins in Saccharomyces cerevisiae.

PubMed

Soriano, Ignacio; Morafraile, Esther C; Vázquez, Enrique; Antequera, Francisco; Segurado, Mónica

2014-09-13

Eukaryotic genomes are replicated during S phase according to a temporal program. Several determinants control the timing of origin firing, including the chromatin environment and epigenetic modifications. However, how chromatin structure influences the timing of the activation of specific origins is still poorly understood. By performing high-resolution analysis of genome-wide nucleosome positioning we have identified different chromatin architectures at early and late replication origins. These different patterns are already established in G1 and are tightly correlated with the organization of adjacent transcription units. Moreover, specific early and late nucleosomal patterns are fixed robustly, even in rpd3 mutants in which histone acetylation and origin timing have been significantly altered. Nevertheless, higher histone acetylation levels correlate with the local modulation of chromatin structure, leading to increased origin accessibility. In addition, we conducted parallel analyses of replication and nucleosome dynamics that revealed that chromatin structure at origins is modulated during origin activation. Our results show that early and late replication origins present distinctive nucleosomal configurations, which are preferentially associated to different genomic regions. Our data also reveal that origin structure is dynamic and can be locally modulated by histone deacetylation, as well as by origin activation. These data offer novel insight into the contribution of chromatin structure to origin selection and firing in budding yeast.

An Effective Quality Control of Pharmacologically Active Volatiles of Houttuynia cordata Thunb by Fast Gas Chromatography-Surface Acoustic Wave Sensor.

PubMed

Oh, Se Yeon

2015-06-03

Fast gas chromatography-surface acoustic wave sensor (GC/SAW) has been applied for the detection of the pharmacological volatiles emanated from Houttuynia cordata Thunb which is from South Korea. H. cordata Thunb with unpleasant and fishy odors shows a variety of pharmacological activities such as anti-microbial, anti-inflammatory, anti-cancer, and insect repellent. The aim of this study is to show a novel quality control by GC/SAW methodology for the discrimination of the three different parts of the plant such as leaves, aerial stems, and underground stems for H. cordata Thunb. Sixteen compounds were identified. β-Myrcene, cis-ocimene and decanal are the dominant volatiles for leaves (71.0%) and aerial stems (50.1%). While, monoterpenes (74.6%) are the dominant volatiles for underground stems. 2-Undecanone (1.3%) and lauraldehyde (3.5%) were found to be the characteristic components for leaves. Each part of the plant has its own characteristic fragrance pattern owing to its individual chemical compositions. Moreover, its individual characteristic fragrance patterns are conducive to discrimination of the three different parts of the plant. Consequently, fast GC/SAW can be a useful analytical method for quality control of the different parts of the plant with pharmacological volatiles as it provides second unit analysis, a simple and fragrant pattern recognition.

Relationships between hippocampal sharp waves, ripples and fast gamma oscillation: influence of dentate and entorhinal cortical activity

PubMed Central

Sullivan, David; Csicsvari, Jozsef; Mizuseki, Kenji; Montgomery, Sean; Diba, Kamran; Buzsáki, György

2011-01-01

Summary Hippocampal sharp waves (SPW) and associated fast (‘ripple’) oscillations in the CA1 region are among the most synchronous physiological patterns in the mammalian brain. Using two-dimensional arrays of electrodes for recording local field potentials and unit discharges in freely moving rats, we studied the emergence of ripple oscillations (140–220 Hz) and compared their origin and cellular-synaptic mechanisms with fast gamma oscillations (90–140 Hz). We show that (a) hippocampal SPW-Rs and fast gamma oscillations are quantitatively distinct patterns but involve the same networks and share similar mechanisms, (b) both the frequency and magnitude of fast oscillations is positively correlated with the magnitude of SPWs, (c) during both ripples and fast gamma oscillations the frequency of network oscillation is higher in CA1 than in CA3, (d) SPWs and associated firing of neurons are synchronous in the dorsal hippocampus and dorso-medial entorhinal cortex but ripples are confined to the CA1 pyramidal layer and its downstream targets and (e) the emergence of CA3 population bursts, a prerequisite for SPW-ripples, is biased by activity patterns in the dentate gyrus and entorhinal cortex, with highest probability of ripples associated with an ‘optimum’ level of dentate gamma power. We hypothesize that each hippocampal subnetwork possesses distinct resonant properties, tuned by the magnitude of the excitatory drive. PMID:21653864

Soft active matter: a contemporary example of Edwardsian statistical mechanics

NASA Astrophysics Data System (ADS)

Liverpool, Tanniemola

Colonies of swimming bacteria, algae or spermatozoa are examples of active systems composed of interacting units that consume energy and collectively generate motion and mechanical stresses. Due to the anisotropy of their interactions, these active particles can exhibit orientational order at high concentrations and have been called ``living liquid crystals''. Biology at the cellular and multicellular scale provides numerous examples of these active systems. They provide a novel class of experimentally accessible system far from equilibrium. Their rich collective behaviour includes non-equilibrium phase transitions and pattern formation on mesoscopic scales. Interestingly however, some of the theoretical insights gained from field theories applied to equilibrium soft matter systems can be used to explain aspects of their behaviour, but with a number of surprising new twists. I will describe and summarise recent theoretical results characterising the behaviour of such soft active systems highlighting in particular the effects of their internal dynamics on their macroscopic behaviour. With support of the EPSRC Grant No. EP/G026440/1.

Calculation of x-ray scattering patterns from nanocrystals at high x-ray intensity

PubMed Central

Abdullah, Malik Muhammad; Jurek, Zoltan; Son, Sang-Kil; Santra, Robin

2016-01-01

We present a generalized method to describe the x-ray scattering intensity of the Bragg spots in a diffraction pattern from nanocrystals exposed to intense x-ray pulses. Our method involves the subdivision of a crystal into smaller units. In order to calculate the dynamics within every unit, we employ a Monte-Carlo-molecular dynamics-ab-initio hybrid framework using real space periodic boundary conditions. By combining all the units, we simulate the diffraction pattern of a crystal larger than the transverse x-ray beam profile, a situation commonly encountered in femtosecond nanocrystallography experiments with focused x-ray free-electron laser radiation. Radiation damage is not spatially uniform and depends on the fluence associated with each specific region inside the crystal. To investigate the effects of uniform and non-uniform fluence distribution, we have used two different spatial beam profiles, Gaussian and flattop. PMID:27478859

Structure, form, and meaning in the mental lexicon: evidence from Arabic

PubMed Central

Boudelaa, Sami; Marslen-Wilson, William D.

2015-01-01

Does the organization of the mental lexicon reflect the combination of abstract underlying morphemic units or the concatenation of word-level phonological units? We address these fundamental issues in Arabic, a Semitic language where every surface form is potentially analyzable into abstract morphemic units – the word pattern and the root – and where this view contrasts with stem-based approaches, chiefly driven by linguistic considerations, in which neither roots nor word patterns play independent roles in word formation and lexical representation. Five cross-modal priming experiments examine the processing of morphologically complex forms in the three major subdivisions of the Arabic lexicon – deverbal nouns, verbs, and primitive nouns. The results demonstrate that root and word pattern morphemes function as abstract cognitive entities, operating independently of semantic factors and dissociable from possible phonological confounds, while stem-based approaches consistently fail to accommodate the basic psycholinguistic properties of the Arabic mental lexicon. PMID:26682237

Emergence of structural patterns out of synchronization in networks with competitive interactions

NASA Astrophysics Data System (ADS)

Assenza, Salvatore; Gutiérrez, Ricardo; Gómez-Gardeñes, Jesús; Latora, Vito; Boccaletti, Stefano

2011-09-01

Synchronization is a collective phenomenon occurring in systems of interacting units, and is ubiquitous in nature, society and technology. Recent studies have enlightened the important role played by the interaction topology on the emergence of synchronized states. However, most of these studies neglect that real world systems change their interaction patterns in time. Here, we analyze synchronization features in networks in which structural and dynamical features co-evolve. The feedback of the node dynamics on the interaction pattern is ruled by the competition of two mechanisms: homophily (reinforcing those interactions with other correlated units in the graph) and homeostasis (preserving the value of the input strength received by each unit). The competition between these two adaptive principles leads to the emergence of key structural properties observed in real world networks, such as modular and scale-free structures, together with a striking enhancement of local synchronization in systems with no global order.

Cortical activity is more stable when sensory stimuli are consciously perceived

PubMed Central

Schurger, Aaron; Sarigiannidis, Ioannis; Naccache, Lionel; Sitt, Jacobo D.; Dehaene, Stanislas

2015-01-01

According to recent evidence, stimulus-tuned neurons in the cerebral cortex exhibit reduced variability in firing rate across trials, after the onset of a stimulus. However, in order for a reduction in variability to be directly relevant to perception and behavior, it must be realized within trial—the pattern of activity must be relatively stable. Stability is characteristic of decision states in recurrent attractor networks, and its possible relevance to conscious perception has been suggested by theorists. However, it is difficult to measure on the within-trial time scales and broadly distributed spatial scales relevant to perception. We recorded simultaneous magneto- and electroencephalography (MEG and EEG) data while subjects observed threshold-level visual stimuli. Pattern-similarity analyses applied to the data from MEG gradiometers uncovered a pronounced decrease in variability across trials after stimulus onset, consistent with previous single-unit data. This was followed by a significant divergence in variability depending upon subjective report (seen/unseen), with seen trials exhibiting less variability. Applying the same analysis across time, within trial, we found that the latter effect coincided in time with a difference in the stability of the pattern of activity. Stability alone could be used to classify data from individual trials as “seen” or “unseen.” The same metric applied to EEG data from patients with disorders of consciousness exposed to auditory stimuli diverged parametrically according to clinically diagnosed level of consciousness. Differences in signal strength could not account for these results. Conscious perception may involve the transient stabilization of distributed cortical networks, corresponding to a global brain-scale decision. PMID:25847997

Human spinal cord injury: motor unit properties and behaviour.

PubMed

Thomas, C K; Bakels, R; Klein, C S; Zijdewind, I

2014-01-01

Spinal cord injury (SCI) results in widespread variation in muscle function. Review of motor unit data shows that changes in the amount and balance of excitatory and inhibitory inputs after SCI alter management of motoneurons. Not only are units recruited up to higher than usual relative forces when SCI leaves few units under voluntary control, the force contribution from recruitment increases due to elevation of twitch/tetanic force ratios. Force gradation and precision are also coarser with reduced unit numbers. Maximal unit firing rates are low in hand muscles, limiting voluntary strength, but are low, normal or high in limb muscles. Unit firing rates during spasms can exceed voluntary rates, emphasizing that deficits in descending drive limit force production. SCI also changes muscle properties. Motor unit weakness and fatigability seem universal across muscles and species, increasing the muscle weakness that arises from paralysis of units, motoneuron death and sensory impairment. Motor axon conduction velocity decreases after human SCI. Muscle contractile speed is also reduced, which lowers the stimulation frequencies needed to grade force when paralysed muscles are activated with patterned electrical stimulation. This slowing does not necessarily occur in hind limb muscles after cord transection in cats and rats. The nature, duration and level of SCI underlie some of these species differences, as do variations in muscle function, daily usage, tract control and fibre-type composition. Exploring this diversity is important to promote recovery of the hand, bowel, bladder and locomotor function most wanted by people with SCI. © 2013 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.

Motor unit recruitment patterns 2: the influence of myoelectric intensity and muscle fascicle strain rate.

PubMed

Hodson-Tole, Emma F; Wakeling, James M

2008-06-01

To effectively meet the force requirements of a given movement an appropriate number and combination of motor units must be recruited between and within muscles. Orderly recruitment of motor units has been shown to occur in a wide range of skeletal muscles, however, alternative strategies do occur. Faster motor units are better suited to developing force rapidly, and produce higher mechanical power with greater efficiency at faster shortening strain rates than slower motor units. As the frequency content of the myoelectric signal is related to the fibre type of the active motor units, we hypothesised that, in addition to an association between myoelectric frequency and intensity, there would be a significant association between muscle fascicle shortening strain rate and myoelectric frequency content. Myoelectric and sonomicrometric data were collected from the three ankle extensor muscles of the rat hind limb during walking and running. Myoelectric signals were analysed using wavelet transformation and principal component analysis to give a measure of the signal frequency content. Sonomicrometric signals were analysed to give measures of muscle fascicle strain and strain rate. The relationship between myoelectric frequency and both intensity and muscle fascicle strain rate was found to change across the time course of a stride, with differences also occurring in the strength of the associations between and within muscles. In addition to the orderly recruitment of motor units, a mechanical strategy of motor unit recruitment was therefore identified. Motor unit recruitment is therefore a multifactorial phenomenon, which is more complex than typically thought.

Recruitment order of motor units in human vastus lateralis muscle is maintained during fatiguing contractions.

PubMed

Adam, Alexander; De Luca, Carlo J

2003-11-01

Motor-unit firing patterns were studied in the vastus lateralis muscle of five healthy young men [21.4 +/- 0.9 (SD) yr] during a series of isometric knee extensions performed to exhaustion. Each contraction was held at a constant torque level, set to 20% of the maximal voluntary contraction at the beginning of the experiment. Electromyographic signals, recorded via a quadrifilar fine wire electrode, were processed with the precision decomposition technique to identify the firing times of individual motor units. In repeat experiments, whole-muscle mechanical properties were measured during the fatigue protocol using electrical stimulation. The main findings were a monotonic decrease in the recruitment threshold of all motor units and the progressive recruitment of new units, all without a change of the recruitment order. Motor units from the same subject showed a similar time course of threshold decline, but this decline varied among subjects (mean threshold decrease ranged from 23 to 73%). The mean threshold decline was linearly correlated (R2 >or= 0.96) with a decline in the elicited peak tetanic torque. In summary, the maintenance of recruitment order during fatigue strongly supports the notion that the observed common recruitment adaptations were a direct consequence of an increased excitatory drive to the motor unit pool. It is suggested that the increased central drive was necessary to compensate for the loss in force output from motor units whose muscle fibers were actively contracting. We therefore conclude that the control scheme of motor-unit recruitment remains invariant during fatigue at least in relatively large muscles performing submaximal isometric contractions.

Contrasting patterns of genetic diversity and population structure of Armillaria mellea sensu stricto in the eastern and western United States.

PubMed

Baumgartner, Kendra; Travadon, Renaud; Bruhn, Johann; Bergemann, Sarah E

2010-07-01

ABSTRACT Armillaria mellea infects hundreds of plant species in natural and managed ecosystems throughout the Northern hemisphere. Previously reported nuclear genetic divergence between eastern and western U.S. isolates is consistent with the disjunct range of A. mellea in North America, which is restricted mainly to both coasts of the United States. We investigated patterns of population structure and genetic diversity of the eastern (northern and southern Appalachians, Ozarks, and western Great Lakes) and western (Berkeley, Los Angeles, St. Helena, and San Jose, CA) regions of the United States. In total, 156 diploid isolates were genotyped using 12 microsatellite loci. Absence of genetic differentiation within either eastern subpopulations (theta(ST) = -0.002, P = 0.5 ) or western subpopulations (theta(ST) = 0.004, P = 0.3 ) suggests that spore dispersal within each region is sufficient to prevent geographic differentiation. In contrast to the western United States, our finding of more than one genetic cluster of isolates within the eastern United States (K = 3), revealed by Bayesian assignment of multilocus genotypes in STRUCTURE and confirmed by genetic multivariate analyses, suggests that eastern subpopulations are derived from multiple founder sources. The existence of amplifiable and nonamplifiable loci and contrasting patterns of genetic diversity between the two regions demonstrate that there are two geographically isolated, divergent genetic pools of A. mellea in the United States.

Learning Midlevel Auditory Codes from Natural Sound Statistics.

PubMed

Młynarski, Wiktor; McDermott, Josh H

2018-03-01

Interaction with the world requires an organism to transform sensory signals into representations in which behaviorally meaningful properties of the environment are made explicit. These representations are derived through cascades of neuronal processing stages in which neurons at each stage recode the output of preceding stages. Explanations of sensory coding may thus involve understanding how low-level patterns are combined into more complex structures. To gain insight into such midlevel representations for sound, we designed a hierarchical generative model of natural sounds that learns combinations of spectrotemporal features from natural stimulus statistics. In the first layer, the model forms a sparse convolutional code of spectrograms using a dictionary of learned spectrotemporal kernels. To generalize from specific kernel activation patterns, the second layer encodes patterns of time-varying magnitude of multiple first-layer coefficients. When trained on corpora of speech and environmental sounds, some second-layer units learned to group similar spectrotemporal features. Others instantiate opponency between distinct sets of features. Such groupings might be instantiated by neurons in the auditory cortex, providing a hypothesis for midlevel neuronal computation.

Reconstruction of the vegetation distribution of different topographic units of the Chinese Loess Plateau during the Holocene

NASA Astrophysics Data System (ADS)

Sun, Aizhi; Guo, Zhengtang; Wu, Haibin; Li, Qin; Yu, Yanyan; Luo, Yunli; Jiang, Wenying; Li, Xiaoqiang

2017-10-01

Soil erosion and related ecological restoration present a tremendous challenge to the socioeconomic development of the Chinese Loess Plateau (CLP). Although the Chinese government has addressed the problem of soil erosion via an afforestation programme, there have been several negative outcomes. One of the reasons for this is our incomplete understanding of the past natural vegetation distribution in the various topographic units of the CLP under different climate scenarios. Consequently, we used fossil pollen data from 41 sites from different topographic units, together with the biomization method, to reconstruct the Holocene vegetation distribution of the CLP. The results demonstrate significant differences in vegetation types between different topographic units: forest was distributed in mountainous areas, steppe was dominant in Yuan areas, and desert vegetation was distributed in the transition zone between loess and desert. The vegetation in the gully areas exhibited significant spatial differences during the mid-Holocene. In addition, the vegetation on the various topographic units was well-developed during the interval from 9 to 4 ka B.P., when regional moisture levels reached a maximum. This suggests that the East Asian Summer Monsoon was one of the main factors controlling the evolution of vegetation patterns during the Holocene. In addition, our results confirm that both topography and human activity were fundamental factors determining the vegetation distribution of the region. Against a background of ongoing global warming, we advocate a program of vegetation restoration including planting trees and shrubs in the mountainous areas, and promoting the growth of grasses in the Yuan areas and in the transitional zone between loess and desert. In the gully areas, the planting of trees and shrubs is appropriate for reducing soil erosion caused by human activities.

Stochastic nonlinear dynamics pattern formation and growth models

PubMed Central

Yaroslavsky, Leonid P

2007-01-01

Stochastic evolutionary growth and pattern formation models are treated in a unified way in terms of algorithmic models of nonlinear dynamic systems with feedback built of a standard set of signal processing units. A number of concrete models is described and illustrated by numerous examples of artificially generated patterns that closely imitate wide variety of patterns found in the nature. PMID:17908341

Crystallization and preliminary X-ray diffraction analysis of a novel Arg49 phospholipase A{sub 2} homologue from Zhaoermia mangshanensis venom

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

Murakami, Mário T.; Center for Applied Toxinology, CAT-CEPID, São Paulo, SP; Advanced Center for Genomics and Proteomics, UNESP-State University of São Paulo, São José do Rio Preto 15054-000

2007-07-01

A single crystal of zhaoermiatoxin with maximum dimensions of 0.2 × 0.2 × 0.5 mm was used for X-ray diffraction data collection to a resolution of 2.05 Å using synchrotron radiation and the diffraction pattern was indexed in the hexagonal space group P6{sub 4}, with unit-cell parameters a = 72.9, b = 72.9, c = 93.9 Å. Zhaoermiatoxin, an Arg49 phospholipase A{sub 2} homologue from Zhaoermia mangshanensis (formerly Trimeresurus mangshanensis, Ermia mangshanensis) venom is a novel member of the PLA{sub 2}-homologue family that possesses an arginine residue at position 49, probably arising from a secondary Lys49→Arg substitution that does notmore » alter the catalytic inactivity towards phospholipids. Like other Lys49 PLA{sub 2} homologues, zhaoermiatoxin induces oedema and strong myonecrosis without detectable PLA{sub 2} catalytic activity. A single crystal with maximum dimensions of 0.2 × 0.2 × 0.5 mm was used for X-ray diffraction data collection to a resolution of 2.05 Å using synchrotron radiation and the diffraction pattern was indexed in the hexagonal space group P6{sub 4}, with unit-cell parameters a = 72.9, b = 72.9, c = 93.9 Å.« less

Self-powered vision electronic-skin basing on piezo-photodetecting Ppy/PVDF pixel-patterned matrix for mimicking vision.

PubMed

Han, Wuxiao; Zhang, Linlin; He, Haoxuan; Liu, Hongmin; Xing, Lili; Xue, Xinyu

2018-06-22

The development of multifunctional electronic-skin that establishes human-machine interfaces, enhances perception abilities or has other distinct biomedical applications is the key to the realization of artificial intelligence. In this paper, a new self-powered (battery-free) flexible vision electronic-skin has been realized from pixel-patterned matrix of piezo-photodetecting PVDF/Ppy film. The electronic-skin under applied deformation can actively output piezoelectric voltage, and the outputting signal can be significantly influenced by UV illumination. The piezoelectric output can act as both the photodetecting signal and electricity power. The reliability is demonstrated over 200 light on-off cycles. The sensing unit matrix of 6 × 6 pixels on the electronic-skin can realize image recognition through mapping multi-point UV stimuli. This self-powered vision electronic-skin that simply mimics human retina may have potential application in vision substitution.

Irregularity of rest and activity: studies on circadian rhythmicity in man.

PubMed Central

Minors, D S; Nicholson, A N; Spencer, M B; Stone, B M; Waterhouse, J M

1986-01-01

1. Rectal temperature, electrolyte excretion and performance were studied in young adults who followed an irregular pattern of work and rest for 9 days in an isolation unit. 2. In the analysis, effects evoked by the pattern of work and rest were separated from the oscillatory component, and rhythms for individual days were examined by the cosinor method. 3. During the schedule, rhythms no longer showed a period of exactly 24 h, and this effect was confirmed by studies using a repeated cycle of irregular work and rest and by studies using constant routines. 4. Temperature and urinary constituents differed in the strength and phase of their rhythms when corrected for evoked effects, as well as in the strength of the evoked effects themselves. 5. There was evidence of deterioration in performance during work periods which exceeded 9 h, but there was no evidence of progressive deterioration in performance over the 9 day schedule. PMID:3625535

Self-powered vision electronic-skin basing on piezo-photodetecting Ppy/PVDF pixel-patterned matrix for mimicking vision

NASA Astrophysics Data System (ADS)

Han, Wuxiao; Zhang, Linlin; He, Haoxuan; Liu, Hongmin; Xing, Lili; Xue, Xinyu

2018-06-01

The development of multifunctional electronic-skin that establishes human-machine interfaces, enhances perception abilities or has other distinct biomedical applications is the key to the realization of artificial intelligence. In this paper, a new self-powered (battery-free) flexible vision electronic-skin has been realized from pixel-patterned matrix of piezo-photodetecting PVDF/Ppy film. The electronic-skin under applied deformation can actively output piezoelectric voltage, and the outputting signal can be significantly influenced by UV illumination. The piezoelectric output can act as both the photodetecting signal and electricity power. The reliability is demonstrated over 200 light on–off cycles. The sensing unit matrix of 6 × 6 pixels on the electronic-skin can realize image recognition through mapping multi-point UV stimuli. This self-powered vision electronic-skin that simply mimics human retina may have potential application in vision substitution.

Population rate dynamics and multineuron firing patterns in sensory cortex

PubMed Central

Okun, Michael; Yger, Pierre; Marguet, Stephan; Gerard-Mercier, Florian; Benucci, Andrea; Katzner, Steffen; Busse, Laura; Carandini, Matteo; Harris, Kenneth D.

2012-01-01

Cortical circuits encode sensory stimuli through the firing of neuronal ensembles, and also produce spontaneous population patterns in the absence of sensory drive. This population activity is often characterized experimentally by the distribution of multineuron “words” (binary firing vectors), and a match between spontaneous and evoked word distributions has been suggested to reflect learning of a probabilistic model of the sensory world. We analyzed multineuron word distributions in sensory cortex of anesthetized rats and cats, and found that they are dominated by fluctuations in population firing rate rather than precise interactions between individual units. Furthermore, cortical word distributions change when brain state shifts, and similar behavior is seen in simulated networks with fixed, random connectivity. Our results suggest that similarity or dissimilarity in multineuron word distributions could primarily reflect similarity or dissimilarity in population firing rate dynamics, and not necessarily the precise interactions between neurons that would indicate learning of sensory features. PMID:23197704

Personal exposure to ultrafine particles: the influence of time-activity patterns.

PubMed

Buonanno, G; Stabile, L; Morawska, L

2014-01-15

Exposure to ultrafine particles (UFPs) is deemed to be a major risk affecting human health. Therefore, airborne particle studies were performed in the recent years to evaluate the most critical micro-environments, as well as identifying the main UFP sources. Nonetheless, in order to properly evaluate the UFP exposure, personal monitoring is required as the only way to relate particle exposure levels to the activities performed and micro-environments visited. To this purpose, in the present work, the results of experimental analysis aimed at showing the effect of the time-activity patterns on UFP personal exposure are reported. In particular, 24 non-smoking couples (12 during winter and summer time, respectively), comprised of a man who worked full-time and a woman who was a homemaker, were analyzed using personal particle counter and GPS monitors. Each couple was investigated for a 48-h period, during which they also filled out a diary reporting the daily activities performed. Time activity patterns, particle number concentration exposure and the related dose received by the participants, in terms of particle alveolar-deposited surface area, were measured. The average exposure to particle number concentration was higher for women during both summer and winter (Summer: women 1.8 × 10(4) part. cm(-3); men 9.2 × 10(3) part. cm(-3); Winter: women 2.9 × 10(4) part. cm(-3); men 1.3 × 10(4) part. cm(-3)), which was likely due to the time spent undertaking cooking activities. Staying indoors after cooking also led to higher alveolar-deposited surface area dose for both women and men during the winter time (9.12 × 10(2) and 6.33 × 10(2) mm(2), respectively), when indoor ventilation was greatly reduced. The effect of cooking activities was also detected in terms of women's dose intensity (dose per unit time), being 8.6 and 6.6 in winter and summer, respectively. On the contrary, the highest dose intensity activity for men was time spent using transportation (2.8 in both winter and summer). © 2013.

Element concentrations in soils and other surficial materials of the conterminous United States

USGS Publications Warehouse

Shacklette, Hansford T.; Boerngen, Josephine G.

1984-01-01

Samples of soils or other regoliths, taken at a depth of approximately 20 cm form locations about 80 km apart, throughout the conterminous United States, were analyzed for their content of elements. In this manner, 1,318 sampling sites were chosen, and the results of the sample analyses for 50 elements were plotted on maps. The arithmetic and geometric mean, the geometric deviation, and a histogram showing frequencies of analytical values are given for 47 elements. The lower concentrations of some elements (notable, aluminum, barium, calcium, magnesium, potassium, sodium, and strontium) in most samples of surficial materials from the Eastern United States, and the greater abundance of heavy metals in the same materials of the Western United States, indicates a regional geochemical pattern of the largest scale. The low concentrations of many elements in soils characterize the Atlantic Coastal Plain. Souls of the Pacific Northwest generally have high concentrations of aluminum, cobalt, iron, scandium, and vanadium, but are low in boron. Soils of the Rocky Mountain region tend to have high concentrations of copper, lead, and zinc. High mercury concentrations in surficial materials are characteristic of Gulf Coast sampling sites and the Atlantic coast sites of Connecticut, Massachusetts, and Maine. At the State level, Florida has the most striking geochemical pattern by having soils that are low in concentrations of most elements considered in this study. Some smaller patterns of element abundance can be noted, but the degree of confidence in the validity of these patterns decreases as the patterns become less extensive.

LEDGF/p75 interacts with mRNA splicing factors and targets HIV-1 integration to highly spliced genes

PubMed Central

Singh, Parmit Kumar; Plumb, Matthew R.; Ferris, Andrea L.; Iben, James R.; Wu, Xiaolin; Fadel, Hind J.; Luke, Brian T.; Esnault, Caroline; Poeschla, Eric M.; Hughes, Stephen H.; Kvaratskhelia, Mamuka; Levin, Henry L.

2015-01-01

The host chromatin-binding factor LEDGF/p75 interacts with HIV-1 integrase and directs integration to active transcription units. To understand how LEDGF/p75 recognizes transcription units, we sequenced 1 million HIV-1 integration sites isolated from cultured HEK293T cells. Analysis of integration sites showed that cancer genes were preferentially targeted, raising concerns about using lentivirus vectors for gene therapy. Additional analysis led to the discovery that introns and alternative splicing contributed significantly to integration site selection. These correlations were independent of transcription levels, size of transcription units, and length of the introns. Multivariate analysis with five parameters previously found to predict integration sites showed that intron density is the strongest predictor of integration density in transcription units. Analysis of previously published HIV-1 integration site data showed that integration density in transcription units in mouse embryonic fibroblasts also correlated strongly with intron number, and this correlation was absent in cells lacking LEDGF. Affinity purification showed that LEDGF/p75 is associated with a number of splicing factors, and RNA sequencing (RNA-seq) analysis of HEK293T cells lacking LEDGF/p75 or the LEDGF/p75 integrase-binding domain (IBD) showed that LEDGF/p75 contributes to splicing patterns in half of the transcription units that have alternative isoforms. Thus, LEDGF/p75 interacts with splicing factors, contributes to exon choice, and directs HIV-1 integration to transcription units that are highly spliced. PMID:26545813

Change in waist circumference with longer time in the United States among Hispanic and Chinese immigrants: the modifying role of the neighborhood built environment.

PubMed

Albrecht, Sandra S; Osypuk, Theresa L; Kandula, Namratha R; Gallo, Linda C; Lê-Scherban, Félice; Shrager, Sandi; Diez Roux, Ana V

2015-10-01

We examined whether living in neighborhoods supportive of healthier diets and more active lifestyles may buffer immigrants against the unhealthy weight gain that is purported to occur with longer length of US residence. Neighborhood data referring to a 1-mile buffer around participants' baseline home addresses were linked to longitudinal data from 877 Hispanic and 684 Chinese immigrants aged 45 to 84 years in the Multi-Ethnic Study of Atherosclerosis. We used ethnicity-stratified linear mixed models to examine whether food and activity-based neighborhood measures (healthy food stores, walkability, and recreational facilities) were associated with change in waist circumference (WC) over a 9-year follow-up. Among Hispanics, living in neighborhoods with more resources for healthy food and recreational activity was related to lower baseline WC. However, there was no association with change in WC over time. Among Chinese, living in more walkable neighborhoods was associated with lower baseline WC and with slower increases in WC over time, especially among the most recent immigrant arrivals. Where immigrants reside may have implications for health patterns that emerge with longer time in the United States. Copyright © 2015 Elsevier Inc. All rights reserved.

Alcohol Use Patterns and DSM-5 Alcohol Use Disorder on Both Sides of the U.S.-Mexico Border.

PubMed

Greenfield, Thomas K; Ye, Yu; Lown, E Anne; Cherpitel, Cheryl J; Zemore, Sarah; Borges, Guilherme

2017-04-01

Alcohol consumption patterns on the U.S.-Mexico border and their relationships with DSM-5 alcohol use disorders (AUD) have been understudied. Yet, the effects of drinking by Mexican-origin individuals may differ between cities on versus off the border both in the United States and in Mexico. We characterize prior 12-month drinking patterns and examine their relationships with AUD, in border and off-border cities of Texas and adjacent Mexican states. Data come from the U.S.-Mexico Study of Alcohol and Related Conditions involving 2,336 Mexican Americans in Texas and 2,460 Mexicans in bordering states of Nuevo Leon and Tamaulipas in Mexico. Drinking pattern was defined as an interaction between volume and maximum amount, or intensity (never vs. ever 5+/4+ [men/women], 8+, and 12+ drinks in a day). DSM-5 AUD was assessed using an adaptation of the Alcohol Section of the World Health Organization Composite International Diagnostic Interview core. Separately by gender, 5 logistic regressions models controlling for age were estimated predicting symptoms in 2 or more AUD criteria domains from volume, heavy pattern and, successively, effects of country, and (by country) residing on vs. off the border, or in each of 3 cities/country. A segmentation analysis for Texas males based on rate of experiencing AUD generated several distinct volume groups, each partitioned by an empirically selected maximum, and helped identify a drinking-pattern typology. In gender-stratified models of AUD rates using this typology, adjusting for age, significant volume and intensity effects were seen, more strongly in the United States. Border versus interior differences implied more AUD for given patterns at the border in the United States and the reverse in Mexico, with some city differences also evident. Drinking-pattern analyses confirm that border proximity may affect drinking problems but in opposite directions in the United States and Mexico, possibly related to economic and psychological stresses specific to respective communities. Copyright © 2017 by the Research Society on Alcoholism.

Predicting assemblages and species richness of endemic fish in the upper Yangtze River.

PubMed

He, Yongfeng; Wang, Jianwei; Lek-Ang, Sithan; Lek, Sovan

2010-09-01

The present work describes the ability of two modeling methods, Classification and Regression Tree (CART) and Random Forest (RF), to predict endemic fish assemblages and species richness in the upper Yangtze River, and then to identify the determinant environmental factors contributing to the models. The models included 24 predictor variables and 2 response variables (fish assemblage and species richness) for a total of 46 site units. The predictive quality of the modeling approaches was judged with a leave-one-out validation procedure. There was an average success of 60.9% and 71.7% to assign each site unit to the correct assemblage of fish, and 73% and 84% to explain the variance in species richness, by using CART and RF models, respectively. RF proved to be better than CART in terms of accuracy and efficiency in ecological applications. In any case, the mixed models including both land cover and river characteristic variables were more powerful than either individual one in explaining the endemic fish distribution pattern in the upper Yangtze River. For instance, altitude, slope, length, discharge, runoff, farmland and alpine and sub-alpine meadow played important roles in driving the observed endemic fish assemblage structure, while farmland, slope grassland, discharge, runoff, altitude and drainage area in explaining the observed patterns of endemic species richness. Therefore, the various effects of human activity on natural aquatic ecosystems, in particular, the flow modification of the river and the land use changes may have a considerable effect on the endemic fish distribution patterns on a regional scale. Copyright 2010 Elsevier B.V. All rights reserved.

Sleep of 1- and 2-year-old children in intensive care.

PubMed

Corser, N C

1996-01-01

Physiologic and psychologic changes associated with sleep disturbance decrease the ability of a critically ill child to adapt to hospitalization and thus hamper recovery. Research demonstrates that intensive care settings interfere with sleep of adults, but little is known about the impact of these settings on children's sleep. An exploratory field study was conducted to describe the sleep-wake patterns of 1- and 2-year-old children in intensive care, identify intensive care environmental stimuli associated with sleep and waking states, compare the intensive care sleep-wake pattern to the pre-illness sleep-wake pattern, and determine the time required for children to return to their pre-illness sleep-wake pattern. Twelve children aged 13 to 35 months composed the sample for the study. Pre-illness and postdischarge sleep patterns, sleep patterns during a 12-hour night in the pediatric intensive care unit (PICU), and external and internal environmental stimuli were measured. Prior to hospitalization, subjects demonstrated sleep similar to that documented in healthy children. Children in the PICU experienced a significant loss of sleep, frequent awakenings, and a virtual rapid eye movement (REM) sleep deprivation. External environmental stimuli of light, noise, and caregiver activity were negatively correlated with sleep state. Pain and treatment with benzodiazepines were associated with sleep acquisition. Sleep changes persisted after discharge from the PICU and the hospital. Total sleep time recovered more rapidly than nighttime awakening. Parents perceived that their child's sleep remained different longer than total sleep time and night awakening values demonstrated.

A two-step patterning process increases the robustness of periodic patterning in the fly eye.

PubMed

Gavish, Avishai; Barkai, Naama

2016-06-01

Complex periodic patterns can self-organize through dynamic interactions between diffusible activators and inhibitors. In the biological context, self-organized patterning is challenged by spatial heterogeneities ('noise') inherent to biological systems. How spatial variability impacts the periodic patterning mechanism and how it can be buffered to ensure precise patterning is not well understood. We examine the effect of spatial heterogeneity on the periodic patterning of the fruit fly eye, an organ composed of ∼800 miniature eye units (ommatidia) whose periodic arrangement along a hexagonal lattice self-organizes during early stages of fly development. The patterning follows a two-step process, with an initial formation of evenly spaced clusters of ∼10 cells followed by a subsequent refinement of each cluster into a single selected cell. Using a probabilistic approach, we calculate the rate of patterning errors resulting from spatial heterogeneities in cell size, position and biosynthetic capacity. Notably, error rates were largely independent of the desired cluster size but followed the distributions of signaling speeds. Pre-formation of large clusters therefore greatly increases the reproducibility of the overall periodic arrangement, suggesting that the two-stage patterning process functions to guard the pattern against errors caused by spatial heterogeneities. Our results emphasize the constraints imposed on self-organized patterning mechanisms by the need to buffer stochastic effects. Author summary Complex periodic patterns are common in nature and are observed in physical, chemical and biological systems. Understanding how these patterns are generated in a precise manner is a key challenge. Biological patterns are especially intriguing, as they are generated in a noisy environment; cell position and cell size, for example, are subject to stochastic variations, as are the strengths of the chemical signals mediating cell-to-cell communication. The need to generate a precise and robust pattern in this 'noisy' environment restricts the space of patterning mechanisms that can function in the biological setting. Mathematical modeling is useful in comparing the sensitivity of different mechanisms to such variations, thereby highlighting key aspects of their design.We use mathematical modeling to study the periodic patterning of the fruit fly eye. In this system, a highly ordered lattice of differentiated cells is generated in a two-dimensional cell epithelium. The pattern is first observed by the appearance of evenly spaced clusters of ∼10 cells that express specific genes. Each cluster is subsequently refined into a single cell, which initiates the formation and differentiation of a miniature eye unit, the ommatidium. We formulate a mathematical model based on the known molecular properties of the patterning mechanism, and use a probabilistic approach to calculate the errors in cluster formation and refinement resulting from stochastic cell-to-cell variations ('noise') in different quantitative parameters. This enables us to define the parameters most influencing noise sensitivity. Notably, we find that this error is roughly independent of the desired cluster size, suggesting that large clusters are beneficial for ensuring the overall reproducibility of the periodic cluster arrangement. For the stage of cluster refinement, we find that rapid communication between cells is critical for reducing error. Our work provides new insights into the constraints imposed on mechanisms generating periodic patterning in a realistic, noisy environment, and in particular, discusses the different considerations in achieving optimal design of the patterning network.

A difference in the pattern of repair in a large genomic region in UV-irradiated normal human and Cockayne syndrome cells.

PubMed

Shanower, G A; Kantor, G J

1997-11-01

Xeroderma pigmentosum group C cells repair DNA damaged by ultraviolet radiation in an unusual pattern throughout the genome. They remove cyclobutane pyrimidine dimers only from the DNA of transcriptionally active chromatin regions and only from the strand that contains the transcribed strand. The repair proceeds in a manner that creates damage-free islands which are in some cases much larger than the active gene associated with them. For example, the small transcriptionally active beta-actin gene (3.5 kb) is repaired as part of a 50 kb single-stranded region. The repair responsible for creating these islands requires active transcription, suggesting that the two activities are coupled. A preferential repair pathway in normal human cells promotes repair of actively transcribed DNA strands and is coupled to transcription. It is not known if similar large islands, referred to as repair domains, are preferentially created as a result of the coupling. Data are presented showing that in normal cells, preferential repair in the beta-actin region is associated with the creation of a large, completely repaired region in the partially repaired genome. Repair at other genomic locations which contain inactive genes (insulin, 754) does not create similar large regions as quickly. In contrast, repair in Cockayne syndrome cells, which are defective in the preferential repair pathway but not in genome-overall repair, proceeds in the beta-actin region by a mechanism which does not create preferentially a large repaired region. Thus a correlation between the activity required to preferentially repair active genes and that required to create repaired domains is detected. We propose an involvement of the transcription-repair coupling factor in a coordinated repair pathway for removing DNA damage from entire transcription units.

Downstream effects of hippocampal sharp wave ripple oscillations on medial entorhinal cortex layer V neurons in vitro.

PubMed

Roth, Fabian C; Beyer, Katinka M; Both, Martin; Draguhn, Andreas; Egorov, Alexei V

2016-12-01

The entorhinal cortex (EC) is a critical component of the medial temporal lobe (MTL) memory system. Local networks within the MTL express a variety of state-dependent network oscillations that are believed to organize neuronal activity during memory formation. The peculiar pattern of sharp wave-ripple complexes (SPW-R) entrains neurons by a very fast oscillation at ∼200 Hz in the hippocampal areas CA3 and CA1 and then propagates through the "output loop" into the EC. The precise mechanisms of SPW-R propagation and the resulting cellular input patterns in the mEC are, however, largely unknown. We therefore investigated the activity of layer V (LV) principal neurons of the medial EC (mEC) during SPW-R oscillations in horizontal mouse brain slices. Intracellular recordings in the mEC were combined with extracellular monitoring of propagating network activity. SPW-R in CA1 were regularly followed by negative field potential deflections in the mEC. Propagation of SPW-R activity from CA1 to the mEC was mostly monosynaptic and excitatory, such that synaptic input to mEC LV neurons directly reflected unit activity in CA1. Comparison with propagating network activity from CA3 to CA1 revealed a similar role of excitatory long-range connections for both regions. However, SPW-R-induced activity in CA1 involved strong recruitment of rhythmic synaptic inhibition and corresponding fast field oscillations, in contrast to the mEC. These differences between features of propagating SPW-R emphasize the differential processing of network activity by each local network of the hippocampal output loop. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Three-dimensional metamaterials

DOEpatents

Burckel, David Bruce [Albuquerque, NM

2012-06-12

A fabrication method is capable of creating canonical metamaterial structures arrayed in a three-dimensional geometry. The method uses a membrane suspended over a cavity with predefined pattern as a directional evaporation mask. Metallic and/or dielectric material can be evaporated at high vacuum through the patterned membrane to deposit resonator structures on the interior walls of the cavity, thereby providing a unit cell of micron-scale dimension. The method can produce volumetric metamaterial structures comprising layers of such unit cells of resonator structures.

Constraints on somatosensory map development: mutants lead the way.

PubMed

Gaspar, Patricia; Renier, Nicolas

2018-05-09

In the rodent somatosensory system, the disproportionally large whisker representation and their specialization into barrel-shaped units in the different sensory relays has offered experimentalists with an ideal tool to identify mechanisms involved in brain map formation. These combine three intertwined constraints: Firstly, fasciculation of the incoming axons; secondly, early neural activity; finally, molecular patterning. Sophisticated genetic manipulations in mice have now allowed dissecting these mechanisms with greater accuracy. Here we discuss some recent papers that provided novel insights into how these different mapping rules and constraints interact to shape the barrel map. Copyright © 2018 Elsevier Ltd. All rights reserved.

Evaluation of Geographic Indices Describing Health Care Utilization.

PubMed

Kim, Agnus M; Park, Jong Heon; Kang, Sungchan; Kim, Yoon

2017-01-01

The accurate measurement of geographic patterns of health care utilization is a prerequisite for the study of geographic variations in health care utilization. While several measures have been developed to measure how accurately geographic units reflect the health care utilization patterns of residents, they have been only applied to hospitalization and need further evaluation. This study aimed to evaluate geographic indices describing health care utilization. We measured the utilization rate and four health care utilization indices (localization index, outflow index, inflow index, and net patient flow) for eight major procedures (coronary artery bypass graft surgery, percutaneous transluminal coronary angioplasty, surgery after hip fracture, knee replacement surgery, caesarean sections, hysterectomy, computed tomography scans, and magnetic resonance imaging scans) according to three levels of geographic units in Korea. Data were obtained from the National Health Insurance database in Korea. We evaluated the associations among the health care utilization indices and the utilization rates. In higher-level geographic units, the localization index tended to be high, while the inflow index and outflow index were lower. The indices showed different patterns depending on the procedure. A strong negative correlation between the localization index and the outflow index was observed for all procedures. Net patient flow showed a moderate positive correlation with the localization index and the inflow index. Health care utilization indices can be used as a proxy to describe the utilization pattern of a procedure in a geographic unit.

Spontaneous and electrically modulated spatiotemporal dynamics of the neocortical slow oscillation and associated local fast activity.

PubMed

Greenberg, Anastasia; Dickson, Clayton T

2013-12-01

The neocortical slow oscillation (SO; ~1Hz) of non-REM sleep and anesthesia reflects synchronized network activity composed of alternating active and silent (ON/OFF) phases at the local network and cellular level. The SO itself shows self-organized spatiotemporal dynamics as it appears to originate at unique foci on each cycle and then propagates across the cortical surface. During sleep, this rhythm is relevant for neuroplastic processes mediating memory consolidation especially since its enhancement by slow, rhythmic electrical fields improves subsequent recall. However, the neurobiological mechanism by which spontaneous or enhanced SO activity might operate on memory traces is unknown. Here we show a series of original results, using cycle to cycle tracking across multiple neocortical sites in urethane anesthetized rats: The spontaneous spatiotemporal dynamics of the SO are complex, showing interfering propagation patterns in the anterior-to-posterior plane. These patterns compete for expression and tend to alternate following phase resets that take place during the silent OFF phase of the SO. Applying sinusoidal electrical field stimulation to the anterior pole of the cerebral cortex progressively entrained local field, gamma, and multi-unit activity at all sites, while disrupting the coordination of endogenous SO activity. Field stimulation also biased propagation in the anterior-to-posterior direction and more notably, enhanced the long-range gamma synchrony between cortical regions. These results are the first to show that changes to slow wave dynamics cause enhancements in high frequency cortico-cortical communication and provide mechanistic clues into how the SO is relevant for sleep-dependent memory consolidation. © 2013.

Palaeomagnetic evidence for post-thrusting tectonic rotation in the Southeast Pyrenees, Spain

NASA Astrophysics Data System (ADS)

Keller, P.; Lowrie, W.; Gehring, A. U.

1994-12-01

The structural framework of the Southeast Pyrenees led to two conflicting interpretations—thrust tectonics vs. wrench tectonics—to explain the geometry of this mountain range. In the present study palaeomagnetic data are presented in an attempt to resolve this conflict. The data reveal different magnetisation directions that indicate tectonic rotations about vertical axes. By means of a regionally homogeneous pattern of rotation, three tectonic units could be distinguished in the Southeast Pyrenees. The Internal Unit in the north reveals no rotation since the Permian. The External Unit to the south shows anticlockwise rotation of 25°, younger than the Early Oligocene. The Pedraforca Unit, placed on the External Unit, shows 57° clockwise rotation which can be assigned to the Neogene. The anticlockwise rotation of the External Unit can be explained by differential compression during the last phase of Pyrenean thrusting, whereas the clockwise rotation of the Pedraforca Unit can be interpreted by post-thrusting tectonics. The rotation pattern of the Southeast Pyrenees provides evidence for both Cretaceous to Paleogene N-S compression and Neogene right-lateral wrench tectonics.

"Units of Comparison" across Languages, across Time

ERIC Educational Resources Information Center

Thomas, Margaret

2009-01-01

Lardiere's keynote article adverts to a succession of "units of comparison" that have been employed in the study of cross-linguistic differences, including mid-twentieth-century structural patterns, generative grammar's parameters, and (within contemporary Minimalism) features. This commentary expands on the idea of units of cross-linguistic…

Role of support afferentation in control of the tonic muscle activity

NASA Astrophysics Data System (ADS)

Kozlovskaya, I. B.; Sayenko, I. V.; Sayenko, D. G.; Miller, T. F.; Khusnutdinova, D. R.; Melnik, K. A.

2007-02-01

The paper summarizes the results of experimental studies advocating for the leading role of support afferentation in control of the functional organization of the tonic muscle system. It is shown that transition to supportless conditions is followed by a significant decline of transverse stiffness and maximal voluntary force of postural (extensor) muscles limiting their participation in locomotion and increasing involvement of phasic muscles. Mechanical stimulation of the support zones of the soles under the supportless conditions eliminates all the above-mentioned effects, including changes in transverse stiffness and maximal voluntary forces of postural muscles, and consequent loss of influence of postural muscles in the locomotor activity. It is suggested that support afferentation, facilitating (support is present) or suppressing (support is absent) the tonic motor units (MUs) activities, defines the coordination patterns of postural synergies, and ensures the optimal strategy of corrective postural responses.

Process evaluation of a multifaceted health program aiming to improve physical activity levels and dietary patterns among construction workers.

PubMed

Viester, Laura; Verhagen, Evert A L M; Bongers, Paulien M; van der Beek, Allard J

2014-11-01

To evaluate the process of a health promotion program, aiming to improve physical activity levels and diet among construction workers. The process evaluation was conducted after the RE-AIM framework for the evaluation of the public health impact of health promotion interventions. Effectiveness was assessed on motivational stage-of-change, self-efficacy, and decisional balance for physical activity and dietary behavior. The external validity of the trial was satisfactory with representative reach of workers and adoption of workplace units in the participating construction company. The extent to which the program was implemented as intended was modest. The intervention was effective on participants' progress through stages of behavior change. Based on the RE-AIM dimensions, it is concluded that for construction workers, the program is feasible and potentially effective, but adjustments are required before widespread implementation.

A Recovery Process of Active Cathode Paste from Spent Li-Ion Batteries

NASA Astrophysics Data System (ADS)

Toma, C. M.; Ghica, G. V.; Buzatu, M.; Petrescu, M. I.; Vasile, E.; Iacob, G.

2017-06-01

In this work, the depleted active paste from spent lithium-ion batteries was separated from cathode by means of ultrasonic vibration. First the unit cells were discharged in brine at room temperature, for safety reasons. Then anode, separator, electrolyte and cathode were separated. Spent Li-Ion batteries were introduced into a washing container to separate electrode materials from their support substrate: active paste (lithium cobalt oxide - LiCoO2) from cathode (Al foil) and graphite from anode (Cu foil). The Al foil and Cu foil were also recovered. A cleaning efficiency of 91% was achieved using a solution of 1.5 M acetic acid after a 6 minute time of exposure into an ultrasonic washing container with a frequency and electric power of 50 kHz and 50 W, respectively. The XRD patterns and the morphology of LiCoO2 powder were presented.